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Anestesia local intraoperatoria para la reducción del dolor posoperatorio después de la anestesia general para el tratamiento odontológico de niños y adolescentes

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Resumen

Antecedentes

Mientras se realizan procedimientos odontológicos bajo anestesia general (AG), los profesionales administran anestésicos locales (AL) sistemáticamente de forma intraoperatoria a los niños. Los anestésicos locales se utilizan para ayudar a controlar el dolor posoperatorio y reducir la hemorragia y la respuesta fisiológica a los procedimientos. Los estudios de la efectividad de la AL intraoperatoria hasta la fecha ha presentado resultados contradictorios.

Objetivos

Evaluar los efectos de la anestesia local intraoperatoria para reducir el dolor posoperatorio luego de la anestesia general para el tratamiento odontológico en niños y jóvenes de hasta 17 años de edad.

Métodos de búsqueda

Se hicieron búsquedas en las siguientes bases de datos electrónicas: el registro de ensayos del Grupo Cochrane de Salud Oral (Cochrane Oral Health Group); el Registro Cochrane Central de Ensayos Controlados (Cochrane Central Register of Controlled Trials) (CENTRAL) (The Cochrane Library, 2013, número 12), MEDLINE vía OVID (1946 hasta el 2 de enero de 2014), EMBASE vía OVID (1980 hasta el 2 de enero de 2014) y Web of Science Conference Proceedings (1990 hasta el 2 de enero de 2014). Se buscaron ensayos en curso en el US National Institutes of Health Register, el metaRegister of Controlled Trials (mRCT) y en el International Federation of Pharmaceutical Manufacturers & Associations (IFPMA) Clinical Trials Portal. No se aplicó ninguna restricción de idioma o fecha de publicación al búscar en las bases de datos electrónicas.

Criterios de selección

Ensayos controlados aleatorizados en los que el anestésico local se administró de forma intraoperatoria bajo anestesia general para el tratamiento odontológico de niños y jóvenes de hasta 17 años de edad.

Obtención y análisis de los datos

Se utilizaron los procedimientos metodológicos estándar previstos por la Colaboración Cochrane. Se realizó la extracción de datos y la evaluación del riesgo de sesgo de forma independiente y por duplicado. Se estableció contacto con los autores para aclarar las omisiones en los informes de los ensayos. En las tablas de “Resumen de los hallazgos” se eligió informar los resultados del dolor, el malestar, la hemorragia posoperatoria y los parámetros fisiológicos relacionados con el anestésico general, debido a que los mismos se consideran los resultados de mayor importancia para los lectores de la revisión.

Resultados principales

Se incluyeron 14 ensayos en esta revisión, con 1152 participantes asignados al azar. Los estudios se publicaron entre 1990 y 2009 y se realizaron en el Reino Unido, Egipto, Arabia Saudita y los Estados Unidos. La edad de los participantes varió de dos a 40 años. Tres estudios tuvieron un riesgo general alto de sesgo; siete tuvieron un riesgo incierto de sesgo; y se consideró que cuatro estaban en riesgo bajo de sesgo.

La heterogeneidad clínica de los estudios incluidos impidió el agrupamiento de los estudios en cuanto al método de administración de la AL (p.ej., inyección intraligamental, inyección de infiltración o administración tópica) y la variación en el uso de analgésicos suplementarios y el tiempo de seguimiento.

De los siete estudios en los que la administración de la AL se realizó mediante una inyección de infiltración, seis estudios (cuerpo de evidencia de muy baja calidad, 542 participantes analizados, un estudio en riesgo general alto de sesgo, cuatro estudios en riesgo general incierto de sesgo, un estudio en riesgo general bajo de sesgo) midieron el dolor posoperatorio. Los resultados eran dudosos. Hubo una disminución en la hemorragia y un aumento del daño a los tejidos blandos en los grupos de AL, aunque los mismos no se consideraron clínicamente significativos.

En los dos estudios en los que la administración de AL se realizó mediante inyección intraligamentaria, no hubo diferencias en las puntuaciones medias del dolor, y no se informaron daños en los tejidos blandos (cuerpo de evidencia de muy baja calidad, 115 participantes analizados, un estudio en riesgo general alto de sesgo, un estudio en riesgo general incierto de sesgo).

Un estudio de tres brazos (cuerpo de evidencia de muy baja calidad, 54 participantes analizados, riesgo general alto de sesgo) comparó los efectos de la inyección de AL intraligamentaria y de infiltración con ningún tratamiento. No hubo evidencia de una diferencia media en el dolor, el malestar o la ansiedad posoperatoria entre los tres grupos.

Cuatro estudios (cuerpo de evidencia de muy baja calidad, 343 participantes analizados, dos estudios en riesgo general bajo de sesgo, dos estudios en riesgo general incierto de sesgo) evaluaron los efectos del AL tópico en comparación con ningún tratamiento o placebo. Un estudio (riesgo general de sesgo incierto) con un comparador sin tratamiento informó una media de dolor inferior en el grupo de AL; todos los otros estudios no informaron diferencias en las puntuaciones medias de dolor. Dos estudios informaron sobre la hemorragia (riesgo general incierto de sesgo): Un estudio informó un aumento clínicamente insignificante de la hemorragia sin tratamiento; el otro no informó ninguna diferencia.

Ninguno de los estudios informó sobre la satisfacción del participante o del niño.

Conclusiones de los autores

En esta revisión, fue difícil establecer conclusiones firmes en cuanto al beneficio del uso de un anestésico local para el tratamiento odontológico bajo anestesia general. La información presentada en los estudios incluidos fue integral y aplicable a la pregunta de la revisión, aunque finalmente no fue suficiente para considerar el objetivo de la revisión. No fue posible agrupar los estudios incluidos en un metanálisis debido a la variación apreciable en las medidas de resultado, las intervenciones y los tipos de tratamiento. La administración de analgesia complementaria oscureció aún más el efecto de los anestésicos locales.

Sobre la base de la revisión bibliográfica y los resultados de esta revisión, se recomienda la realización de ensayos controlados aleatorizados adicionales que reduzcan al mínimo el sesgo mediante la ocultación adecuada de la asignación y el cegamiento de los participantes y los asesores y que también evalúen el efecto del anestésico local intraoperatorio en el volumen y el tipo de anestésico utilizado y en el sistema cardiovascular en los participantes que reciben analgésicos complementarios. Los investigadores deben considerar el impacto de cualquier cambio en la salud y el bienestar del participante e informar las medidas iniciales del dolor o el malestar, o ambas, y la ansiedad preoperatoria.

PICOs

Population
Intervention
Comparison
Outcome

The PICO model is widely used and taught in evidence-based health care as a strategy for formulating questions and search strategies and for characterizing clinical studies or meta-analyses. PICO stands for four different potential components of a clinical question: Patient, Population or Problem; Intervention; Comparison; Outcome.

See more on using PICO in the Cochrane Handbook.

Resumen en términos sencillos

¿Una inyección de anestésico local en los niños y los jóvenes que reciben tratamiento odontológico bajo anestesia general alivia el dolor después del tratamiento?

Pregunta de la revisión

¿Las inyecciones de anestésico local administradas mientras los niños y los jóvenes (de hasta 17 años de edad) están recibiendo tratamiento odontológico bajo anestesia general reducen el dolor que sienten luego del procedimiento?

Antecedentes

Cuando se administra tratamiento odontológico a los niños y los jóvenes puede ser difícil hacerlo sencillamente utilizando una inyección de anestésico local (AL). El problema a menudo es que están demasiado ansiosos o que necesitan muchos procedimientos a la vez: Por ejemplo, pueden necesitar la extracción de muchos dientes al mismo tiempo. En estas circunstancias, el odontólogo comúnmente utiliza un anestésico general (AG) y administra el tratamiento en un hospital. En Inglaterra, hay más de 30 000 ingresos al hospital por año para los niños que necesitan la extracción de dientes bajo un AG.

Los problemas a menudo surgen después de este tratamiento y el más común es el dolor, cuya experiencia puede causar una respuesta emocional así como física. La experiencia puede dar lugar a una mayor dificultad para que el odontólogo administre el tratamiento necesario, y también puede causar que el niño o el joven evite el tratamiento odontológico. Se cree que la administración de inyecciones de AL durante el tratamiento odontológico bajo AG da lugar al adormecimiento y por lo tanto a la posibilidad de no sentir dolor durante un par de horas; después de este periodo los analgésicos pueden controlar el dolor. Sin embargo, no está claro cuáles son los beneficios del uso de AL en esta forma. Se han informado algunos efectos secundarios no deseados, como incomodidad, goteo y mordedura accidental de labios. Además, debido a que a menudo también se utilizan analgésicos, el efecto del AL no está definido claramente. También es importante aclarar las mejores dosis y clases de inyecciones que deben utilizarse para lograr el máximo beneficio.

Características de los estudios.

El Grupo Cochrane de Salud Oral realizó esta revisión y la evidencia en que se basa fue actualizada el 2 de enero de 2014. Se incluyeron 14 estudios, que se realizaron desde 1990 hasta 2009 en el Reino Unido, Egipto, Arabia Saudita y los EE.UU. Éstos incluyeron 1152 participantes de edades comprendidas entre dos y 40 años.

Resultados clave

Aunque los 14 estudios incluidos consideraron la pregunta de investigación, difirieron en la manera en que administraron la intervención y en los resultados que midieron. Lo anterior hizo que no se pudieran combinar los datos en los análisis. Los resultados de los estudios individuales en cuanto al dolor, la hemorragia y otros efectos adversos fueron inciertos. La administración de diferentes analgésicos adicionales puede haber ocultado el efecto del AL.

Se necesitan ensayos de alta calidad adicionales para evaluar los efectos beneficiosos o perjudiciales del AL administrada a los niños y los jóvenes mientras están recibiendo tratamiento odontológico bajo AG. Los temas que estos ensayos deben abordar incluyen los efectos secundarios locales (p.ej., goteo excesivo y mordedura de labios accidental), los efectos secundarios en otras partes del cuerpo (p.ej., el corazón), la satisfacción de los participantes y los padres, la dosis, el tipo de anestesia y los efectos de los analgésicos adicionales (p.ej., paracetamol).

Calidad de la evidencia

La calidad de los 14 estudios incluidos fue variable. Tres estudios se evaluaron como en riesgo general alto de sesgo, siete en riesgo incierto de sesgo y cuatro en riesgo bajo de sesgo.

Authors' conclusions

Implications for practice

In this review, it was difficult to reach firm conclusions as to the benefit of using local anaesthetic for dental treatment under general anaesthesia. The information reported in the included studies was comprehensive and applicable to the review question but ultimately not sufficient to address the objective of the review. We were unable to pool the included studies in a meta‐analysis because of substantial variation in outcome measures, interventions, and treatment types. The use of supplementary analgesia further obscured the effect of local anaesthetics.

Implications for research

Based on the literature review and the results of this review, we suggest the following research recommendations.

  • Further randomised controlled clinical trials (RCTs) need to be conducted to assess the effect of intraoperative local anaesthetic on the volume and type of anaesthetic used and on the cardiovascular system in patients receiving supplementary analgesics as well. Consideration should be given to the impact of any changes on the health and well‐being of the patient. These trials should report baseline measures of pain, distress, or both, and preoperative anxiety.

  • RCTs should be reported in line with the Consolidated Standards of Reporting Trials (CONSORT) statement for reporting of randomised controlled trials.

  • Trial protocols should be made available to facilitate assessment of selective reporting.

Summary of findings

Open in table viewer
Summary of findings for the main comparison. Infiltration injection LA versus placebo or no treatment

Infiltration injection LA compared with placebo or no treatment for reduction of postoperative pain

Participant or population: children undergoing dental extractions under general anaesthetic

Settings: secondary care

Intervention: infiltration injection LA

Comparison: placebo or no treatment

Outcomes

Number of participants
(studies)

Quality of the evidence
(GRADE)

Comments

Pain or distress

(self‐ or investigator‐reported pain measured postoperatively typically up to discharge)1

542 (6 studies)

Very low

⊕⊝⊝⊝2

Because of substantial clinical and methodological heterogeneity in the studies, we were unable to determine an estimate of effect

Bleeding

174 (2 studies)

Very low

⊕⊝⊝⊝2

Because of substantial clinical and methodological heterogeneity in the studies, we were unable to determine an estimate of effect

Physiological parameters

148 (2 studies)

Very low

⊕⊝⊝⊝2

Because of substantial clinical and methodological heterogeneity in the studies, we were unable to determine an estimate of effect

*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: confidence interval; LA: = local anaesthetic; RR: risk ratio.

GRADE Working Group grades of evidence
High quality: further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: we are very uncertain about the estimate.

12 studies reported on postoperative pain up to 24 hours after discharge.
2Quality of evidence assessment was downgraded for study limitations, inconsistency of effect, and imprecision. Pooling of studies was precluded by the clinical heterogeneity of the included studies in terms of analgesia (lignocaine plus adrenaline, lignocaine alone, or prilocaine plus felypressin), use of supplementary analgesics, and follow‐up time (see Table 3).

Open in table viewer
Summary of findings 2. Intraligamental injection LA versus no treatment

Intraligamental injection LA compared with no treatment for reduction of postoperative pain

Participant or population: children undergoing dental extractions under general anaesthetic

Settings: secondary care

Intervention: intraligamental injection LA

Comparison: no treatment

Outcomes

Number of participants
(studies)

Quality of the evidence
(GRADE)

Comments

Pain

(self‐ or investigator‐reported pain measured postoperatively on regaining consciousness and up to first hour following extraction)1

115 (2 studies)

Very low

⊕⊝⊝⊝2

Because of substantial clinical and methodological heterogeneity in the studies, we were unable to determine an estimate of effect

Bleeding

None of the studies reported on this outcome

Physiological parameters

None of the studies reported on this outcome

*The basis for the assumed risk (e.g., the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: confidence interval; LA: local anaesthetic; RR: risk ratio.

GRADE Working Group grades of evidence
High quality: further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: we are very uncertain about the estimate.

11 study also reported on postoperative pain up to 48 hours after discharge.
2Quality of evidence assessment was downgraded for study limitations, inconsistency of effect, and imprecision. Pooling of studies was precluded by the clinical heterogeneity of the included studies in terms of analgesia (bupivacaine plus adrenaline or lignocaine plus adrenaline), use of supplementary analgesics, and follow‐up time (see Table 4).

Open in table viewer
Summary of findings 3. Infiltration injection LA versus intraligamental injection LA versus no treatment

Infiltration injection LA compared with intraligamental injection LA with no treatment for reduction of postoperative pain

Participant or population: children undergoing dental extractions under general anaesthetic

Settings: secondary care

Intervention: infiltration injection LA, intraligamental LA

Comparison: no treatment

Outcomes

Number of participants
(studies)

Quality of the evidence
(GRADE)

Comments

Pain or distress

(Investigator‐reported pain measured postoperatively typically up to 30 minutes postoperatively)1

54 (1 study)

Very low

⊕⊝⊝⊝2

Because of substantial clinical and methodological heterogeneity in the studies, we were unable to determine an estimate of effect

Bleeding

None of the studies reported on this outcome

Physiological parameters

None of the studies reported on this outcome

*The basis for the assumed risk (e.g., the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: confidence interval; LA: local anaesthetic; RR: risk ratio.

GRADE Working Group grades of evidence
High quality: further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: we are very uncertain about the estimate.

11 study reported on postoperative pain on the first evening after discharge.
2Quality of evidence assessment was downgraded for study limitations, inconsistency of effect, and imprecision. Single study of lignocaine plus adrenaline LA (see Table 5).

Open in table viewer
Summary of findings 4. Topical LA versus no treatment or placebo

Topical LA compared with placebo or no treatment for reduction of postoperative pain

Participant or population: children undergoing dental extractions under general anaesthetic

Settings: secondary care

Intervention: topical LA

Comparison: placebo or no treatment

Outcomes

Number of participants
(studies)

Quality of the evidence
(GRADE)

Comments

Pain or distress

(self‐ or investigator‐reported pain measured postoperatively typically up to discharge)1

343 (4 studies)

Very low

⊕⊝⊝⊝1

Because of substantial clinical and methodological heterogeneity in the studies, we were unable to determine an estimate of effect

Bleeding

160 (2 studies)

Very low

⊕⊝⊝⊝1

Physiological parameters

None of the studies reported on this outcome

*The basis for the assumed risk (e.g., the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: confidence interval; LA: local anaesthetic; RR: risk ratio.

GRADE Working Group grades of evidence
High quality: further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: we are very uncertain about the estimate.

1Quality of evidence assessment was downgraded for study limitations, inconsistency of effect, and imprecision. Pooling of studies was precluded by the clinical heterogeneity of the included studies in terms of analgesia (lignocaine alone (delivered as spray), bupivacaine plus adrenaline (delivered on a dental swab)), use of supplementary analgesics, and follow‐up time (see Table 6).

Background

Description of the condition

The majority of dental treatment should be carried out in the dental chair using local anaesthesia (LA), but this can be difficult in children, either because the child is too anxious or because they require a significant amount of treatment. General anaesthesia (GA) is commonly used in these circumstances to manage behaviour. In England, there are over 30,000 hospital admissions for dental extractions in children per year (Moles 2009). This procedure is associated with significant postoperative morbidity; one of the most common complaints is postoperative pain (Atan 2004).

Pain is a multidimensional sensory experience that is unpleasant and has strong cognitive and emotional components (Pozos‐Guillen 2007). It may vary in intensity (mild, moderate, or severe), quality (sharp, burning, or dull), duration (transient, intermittent, or persistent), and referral (superficial or deep, localised or diffuse) (Pozos‐Guillen 2007). An experience of poorly managed pain related to dental treatment can cause patients to avoid seeking further treatment and make them more difficult to treat (Carr 1999). The management of pain is of particular importance in paediatric dentistry where patients are establishing perceptions of dental treatment.

Description of the intervention

A local anaesthetic is often injected into the soft tissues surrounding the surgical area before the extraction of teeth under GA. The commonest LA used is 2% lignocaine with adrenaline as vasoconstrictor, with infiltration injection the most common mode of administration.

How the intervention might work

Use of LA anaesthetises the soft tissues in the surgical area, by decreasing the permeability of the nerve cell membrane to sodium ions. This produces a reversible loss of function and sensation of nerve conduction impulses near to the site of injection (Sweetman 2006). This effect lasts for one to two hours, meaning that when the child recovers from the GA, their mouth will be numb. As this wears off, pain control can then be managed using oral analgesics. The use of LA might also have other benefits: Use of a vasoconstrictor reduces bleeding, which may help in controlling postoperative haemorrhage and also reduce the physiological response to the surgical procedures, e.g., rise in heart rate. Excessive changes in the physiological responses may necessitate additional administration of the anaesthetic agent, thus, potentially prolonging the GA.

Why it is important to do this review

Anecdotal observations and studies have suggested that the use of LA in young children could be distressing, uncomfortable, cause excessive dribbling, and maybe also inadvertent lip biting. Patients are often given other analgesics either rectally or intravenously, and it is unclear how much additional pain relief LA provides. Studies to date have reported contradictory results. It is unclear what doses should be given to provide appropriate levels of pain relief and what techniques should be used to administer the LA (e.g., infiltration versus intraligamental).

Objectives

To assess the effects of intraoperative local anaesthesia for reducing postoperative pain following general anaesthesia for dental treatment in children and young people aged 17 years or younger.

Methods

Criteria for considering studies for this review

Types of studies

All parallel group or split mouth randomised controlled trials evaluating intraoperative local anaesthesia for reduction of postoperative pain. Trials comparing active LA intervention with placebo or no treatment were eligible for inclusion, as were trials directly comparing one active LA intervention with another. We only included trials of a split mouth design when the outcomes could be directly attributed to the site of evaluation.

Quasi‐randomised trials and cross‐over trials were ineligible for inclusion because of the potential for carry over effects and uncertainty over an adequate washout period.

Types of participants

Participants aged 17 years or younger at the start of treatment having dental treatment including orthodontic treatment, fillings, removal of the nerve from a tooth, or extraction of a tooth under general anaesthesia.

Types of interventions

Active intervention: any local anaesthetic (including type/dose/method) given during dental treatment under general anaesthesia.

Comparator: placebo or no local anaesthetic or another local anaesthetic (including type/dose/method).

Types of outcome measures

Primary outcomes

  1. Postoperative pain or distress measures, or both (either expressed as intensity of pain or presence or absence of pain).

Secondary outcomes

  1. Intraoperative or postoperative bleeding.

  2. Cardiac arrhythmia, other cardiac or respiratory events, or both, and type and volume of general anaesthesia drug administered.

  3. Incidence of postoperative lip biting or cheek biting, prolonged numbness or allergy.

  4. Participant satisfaction.

  5. Parental satisfaction.

  6. Postoperative anxiety.

Search methods for identification of studies

Electronic searches

For the identification of studies for this review, we developed detailed search strategies for each database. We based these on the search strategy developed for MEDLINE (see Appendix 1) but revised appropriately for each database to take account of differences in controlled vocabulary and syntax rules.

We searched the following databases:

  • the Cochrane Oral Health Group Trials Register (to 2 January 2014) (see Appendix 2);

  • the Cochrane Central Register of Controlled Trials (CENTRAL; 2013, Issue 12) in The Cochrane Library (see Appendix 3);

  • MEDLINE via OVID (1946 to 2 January 2014) (see Appendix 1);

  • EMBASE via OVID (1980 to 2 January 2014) (see Appendix 4);

  • ISI Web of ScienceConference Proceedings (1990 to 2 January 2014) (see Appendix 5).

There were no restrictions on the language or date of publication. We checked the reference lists of all eligible trials for additional studies.

Searching other resources

We searched the following databases for ongoing trials up to 2 January 2014:

Handsearching

We handsearched the following journals:

  • International Journal of Paediatric Dentistry (2001 to 19 October 2012)

  • Pediatric Dentistry (2001 to 19 October 2012)

  • British Dental Journal (2001 19 October 2012)

  • Anesthesia Progress (2001 19 October 2012)

  • European Journal of Paediatric Dentistry (2001 to 19 October 2012)

  • European Archives of Paediatric Dentistry (2001 to 19 October 2012)

Unpublished studies

We contacted specialists in the field for any unpublished data.

Data collection and analysis

Selection of studies

Two review authors independently and in duplicate assessed titles and abstracts for inclusion in the review, resolving disagreements by discussion. We retrieved the full text of the potentially relevant reports and examined them for eligibility. There was no restriction by language on the studies for retrieval. Two review authors independently and in duplicate performed assessment of eligibility. We attempted correspondence with investigators to clarify study eligibility where primary studies did not report information or it was unclear. We made final decisions on study inclusion through discussion and consensus.

Data extraction and management

Two review authors independently and in duplicate extracted data into a specially designed 'Data extraction form' (see Appendix 9), resolving any disagreements by discussion.

We collected descriptive data where available in addition to that already outlined. We used these data to provide contextual information for the main outcomes, thus, aiding interpretation of results from this review. We give details in Appendix 9; these data include the following:

  • the year the study started if not the year it was available;

  • the country in which the study was carried out;

  • procedure and recovery time;

  • anxiety before and after treatment;

  • participant satisfaction, parent satisfaction, or both;

  • type and volume of general anaesthetic agent administered;

  • type and volume of any other analgesic administered immediately prior to or during the general anaesthetic; and

  • type of dental treatment.

We did not undertake any data transformations.

Assessment of risk of bias in included studies

We used the Cochrane 'Risk of bias' tool to assess the methodological quality of the studies as described in the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011). The review authors undertook this independently and in duplicate as part of the data extraction process. We assessed the included trials on the following domains.

  • sequence generation;

  • allocation concealment;

  • blinding of participants and personnel;

  • blinding of outcome assessor;

  • incomplete outcome data;

  • selective reporting; and

  • other sources of bias.

We tabulated a description of these domains for each included study, along with a judgement of low, high, or unclear risk of bias. We used the Cochrane 'Risk of bias' tool to assess the risk of bias for each study (Higgins 2011).

For the blinding of participants and personnel domain, we made a judgement based on the blinding of the participant only. As the included studies were likely to include no treatment as a comparator, we could not see how personnel could be blinded in such a trial. Furthermore, we judged the lack of blinding of personnel to have limited impact on performance bias.

We undertook a summary assessment of the risk of bias for the primary outcome (across domains) (Higgins 2011). Within a study, we gave a summary assessment of low risk of bias when there was a low risk of bias for all domains, unclear risk of bias when there was an unclear risk of bias for one or more domains, and high risk of bias when there was a high risk of bias for one or more domains.

Measures of treatment effect

For dichotomous outcomes, the intended measure of treatment effect was the risk ratio; for continuous outcomes, the intended measure of treatment effect was the mean difference for studies reporting an outcome on the same scale, and the standardised mean difference for studies reporting an outcome on different scales. We intended to calculate 95% confidence intervals alongside the treatment effect. However, the studies that reported pain either reported it as a continuous outcome, which was not normally distributed, or as an ordinal outcome with categories ranging from no pain through to severe pain. Where possible, we typically reported summary statistics as medians, range, or interquartile range (IQR). Where papers reported insufficient information to enable the calculation of effect measures, we reported summary measures as a narrative.

Unit of analysis issues

We planned to use the approaches described in the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011).

Dealing with missing data

We recorded missing data due to attrition as reported in the publication. For parallel group trials, we planned to use the approaches described by Follmann et al (Follmann 1992) to estimate the standard errors (SE) for those studies that did not explicitly report the SE.

Assessment of heterogeneity

We assessed clinical heterogeneity by examining the characteristics of participants and nature of interventions in each study. We intended to undertake meta‐analysis only when studies were of similar comparisons reporting comparable outcome measures. To assess statistical heterogeneity, we planned to use the Chi² test, to check whether heterogeneity was present, and the I² statistic, to describe the percentage of the variability in effect estimates due to heterogeneity rather than sampling error (Higgins 2011).

Assessment of reporting biases

We planned to assess reporting bias through funnel plots and formal testing (Egger 1997) when data from 10 or more studies were available.

Data synthesis

We undertook a meta‐analysis when there were studies of similar comparisons reporting the same outcomes at the same time points. We used risk ratios to combine dichotomous outcomes and (standardised) mean differences for continuous outcomes. For comparisons where we deemed meta‐analysis to be inappropriate due to clinical heterogeneity, we reported summary statistics and treatment effects in additional tables.

We based our primary analyses on all the included studies, irrespective of risk of bias.

We analysed and reported split mouth studies taking into account the paired nature of the data.

We reported studies with more than two groups separately.

Subgroup analysis and investigation of heterogeneity

We planned to assess the impact of the following factors on the effects of the intervention. We had proposed the following subgroup analyses:

  1. age (0 to 5, 6 to 9, 10 to 16 years);

  2. type of local anaesthetic (lignocaine, articaine, prilocaine, or others);

  3. method of administration of local anaesthetic (infiltration, block, or intraligamental); and

  4. extent of dental procedure (numbers of extractions or restorations).

Sensitivity analysis

We planned to undertake a sensitivity analysis, restricting comparisons to studies with low risk of bias and evaluating the robustness of the results to method of analysis (fixed‐effect and random‐effects model).

'Summary of findings' tables

We presented 'Summary of findings' tables following GRADE methods. We assessed the quality of the body of evidence by considering the overall risk of bias of the included studies, the directness of the evidence, the inconsistency of the results, the precision of the estimates, and the risk of publication bias. We categorised the quality of the body of evidence of the primary outcome and the secondary outcome of bleeding and physiological parameters under anaesthesia for each comparison as high, moderate, low, or very low. We elected to report these outcomes in the 'Summary of Findings' tables as we considered these to be the outcomes of greatest importance to readers of the review.

Results

Description of studies

Authors of the following papers provided further information on contact: Anand 2005 and Leong 2007.

Results of the search

We carried out the search in January 2014. After the removal of duplicates, a total of 569 records were identified through database searching. We assessed 18 full text records for eligibility, of which we excluded 4, leaving 14 included studies.

We did not identify any ongoing studies.

Figure 1, a flowchart, illustrates the flow of studies.


Study flow diagram

Study flow diagram

Included studies

Fourteen studies met the inclusion criteria, and we included them in this review (see the 'Characteristics of included studies' tables). All the studies except for Anand 2005 were of parallel design; the study by Anand 2005 used a split mouth design.

Characteristics of the participants

One study included participants over 17 year old at the start of the study (Rashad 1990), but as the mean age of participants was 11.4 years (standard deviation (SD) 8.1), we elected to include this study. The remaining studies involved children ranging in age from 2 to 12 years. The number of children randomised in the 14 studies ranged from 27 to 142, with 1152 children randomised in total. The range of dental care provided under general anaesthesia was diverse and ranged from oral surgery procedures (including multiple extractions, impactions, apicectomies, and pulpectomies (Rashad 1990)) to dental rehabilitation of primary teeth (Townsend 2009), and dental extractions of first permanent molars (Anand 2005). The majority of studies involved dental extractions of primary teeth.

Characteristics of the trial setting

Ten studies were carried out in the UK (Al‐Bahlani 2001; Anand 2005; Andrzejowski 2002; Coulthard 2006; Gazal 2004; Leong 2007; McWilliams 2007; Noble 1994; Quirke 2005; Sammons 2007), one was carried out in Egypt (Elhakim 1993), two in the USA (Townsend 2009; Watts 2009), and one in Saudi Arabia (Rashad 1990).

Characteristics of the interventions

Seven studies gave local anaesthetic (LA) as infiltration compared with either no treatment (Al‐Bahlani 2001; McWilliams 2007; Noble 1994; Townsend 2009; Watts 2009) or a placebo (Coulthard 2006; Rashad 1990). Two studies gave LA as intraligamental injection (Anand 2005; Sammons 2007); one study compared infiltration injection with intraligamental injection and no local treatment (Leong 2007). Four studies gave LA topically: Elhakim 1993 compared a lignocaine spray with a paracetamol suppository and no treatment. Andrzejowski 2002, Gazal 2004, and Quirke 2005 all compared bupivacaine, applied using a dental swab, with a saline placebo.

We summarise the composition of the local anaesthetics (LA) used in the studies in Table 1. Lignocaine was the most commonly used LA.

Open in table viewer
Table 1. Local anaesthetic used

Local anaesthetic

Study

2% lignocaine with 1:80000 adrenaline

Al‐Bahlani 2001; Leong 2007; Sammons 2007

2% lignocaine with 1:200000 adrenaline

Coulthard 2006

2% lignocaine with 1:100000 adrenaline

Townsend 2009; Watts 2009

2% lignocaine

Rashad 1990

4% lignocaine with 1:80000 adrenaline

McWilliams 2007

0.5% bupivacaine with 1:200000 adrenaline

Anand 2005

3% prilocaine 0.03 U/ml felypressin

Noble 1994

4 mg/kg lignocaine (delivered as spray)

Elhakim 1993

0.25% bupivacaine (topical) with 1:4000 adrenaline

Gazal 2004

0.25% bupivacaine (topical) with 1:200000 adrenaline

Andrzejowski 2002; Quirke 2005

Most of the studies gave additional analgesics alongside the LA either intraoperatively or immediately postoperatively (Andrzejowski 2002; Anand 2005; Coulthard 2006; Gazal 2004; Leong 2007; McWilliams 2007; Sammons 2007; Townsend 2009; Watts 2009). Doses were not always specified as they were given as part of the general anaesthetic (GA) protocol and not as part of the study.

Characteristics of the outcomes

All studies except one, Watts 2009, reported some measure of pain or distress, the primary outcome for this review. The included studies employed a variation of measures of pain intensity and distress, either singly or in combination, to measure postoperative pain. The investigators predominantly carried out outcome assessment, with only a small proportion of studies relying on self reporting or parental reporting. We summarise measures used in the included studies to assess pain and distress in Table 2. Where studies measured pain or distress, this was usually on waking, at regular intervals through to discharge, though two studies collected outcome measures for a longer period following the intervention (Leong 2007; Townsend 2009).

Open in table viewer
Table 2. Pain/distress scales

Pain/distress scale

Description

Recorded by

Study

5‐face scale of distress

5‐face scale ranging from no distress to very severe distress

Self‐reported

Gazal 2004

4‐category scale of distress

4‐point scale ranging from happy to distressed

Investigator

Noble 1994

5‐category scale of distress

5‐point scale ranging from asleep to distressed

Investigator

Coulthard 2006

Faces Legs Activity Crying Consolability (FLACC) assessment tool

Aggregate score based on observation of facial expression, leg movement, activity, crying, and consolability

Investigator

Townsend 2009

Modified pain/discomfort scale (MPDS)

Aggregate score based on observation of crying, movement, and agitation

Investigator

Leong 2007

Children's Hospital of Eastern Ontario Pain Scale (CHEOPS)

Aggregate score based on observation of crying, facial expression, verbal expression pain, torso movement, child touching the "wound", and leg movement

Investigator

McWilliams 2007

Presence/absence of pain

Investigator/self‐reported

Elhakim 1993; Rashad 1990

Simplified Toddler Preschooler‐Postoperative pain scale (STPPPS) or Toddler Preschooler‐Postoperative pain scale system (TPPPS)

Aggregate score based on observation of vocal pain expression, facial pain expression, and body pain expression

Investigator

Al‐Bahlani 2001; Leong 2007; Quirke 2005; Sammons 2007

Visual analogue scale (VAS)

Self‐reporting of pain based on a line ranging from no pain to worst pain

Self‐reported

Anand 2005; Noble 1994

Wong‐Baker FACES® Pain Rating Scale

6‐face scale for pain intensity assessment ranging from no hurt to hurts worst

Self‐reported/Parentp‐reported

Sammons 2007; Townsend 2009

5‐face pain scale

5‐face scale for pain intensity assessment ranging from no pain to very severe pain

Self‐reported

Coulthard 2006

4‐face pain scale

4‐face scale for pain intensity assessment ranging from 'I don't hurt at all' to 'I hurt the most'

Self‐reported

Andrzejowski 2002

CHEOPS = Children's Hospital of Eastern Ontario Pain Scale.FLACC = Faces Legs Activity Crying Consolability.
MPDS = modified pain/discomfort scale.
STPPPS = Simplified Toddler Preschooler‐Postoperative Pain Scale.
TPPPS = Toddler Preschooler‐Postoperative Pain Scale.
VAS = visual assessment scale.

Three studies assessed the degree of postoperative bleeding (Al‐Bahlani 2001; Andrzejowski 2002; McWilliams 2007), and four studies assessed the incidence of lip or cheek biting (Anand 2005; Coulthard 2006; Sammons 2007; Townsend 2009).

Two studies assessed physiological parameters related to the general anaesthetic (Rashad 1990; Watts 2009).

Two studies assessed postoperative anxiety using the Venham Picture Scale (Anand 2005; Leong 2007). None of the studies reported on participant or parental satisfaction.

Excluded studies

We excluded four studies that we considered to be potentially eligible from the review for the following reasons: One study was not a randomised controlled trial (Jürgens 2003); one study did not look at the use of local anaesthesia (Ogg 1983); one study added morphine to the positive control (Bhananker 2008); and one study only applied the local anaesthetic after the participant had woken up (Greengrass 1998).

Risk of bias in included studies

We based 'Risk of bias' judgements on the information reported in the publication and, where contact with the authors could be made, our correspondence with authors where information was missing or unclear. Figure 2 and Figure 3 illustrate the results of the 'Risk of bias' assessment.


'Risk of bias' graph: review authors' judgements about each 'Risk of bias' item presented as percentages across all included studies

'Risk of bias' graph: review authors' judgements about each 'Risk of bias' item presented as percentages across all included studies


'Risk of bias' summary: review authors' judgements about each 'Risk of bias' item for each included study

'Risk of bias' summary: review authors' judgements about each 'Risk of bias' item for each included study

Allocation

Sequence generation

Eight studies described adequate methods of sequence generation, and we judged these to be at low risk of bias (Coulthard 2006; Gazal 2004; Leong 2007; McWilliams 2007; Noble 1994; Quirke 2005; Sammons 2007; Townsend 2009). The studies described a range of methods including the use of shuffled envelopes or computer randomisation. Six studies reported sequence generation as 'randomised' but did not report the method of sequence generation (Al‐Bahlani 2001; Anand 2005; Andrzejowski 2002; Elhakim 1993; Rashad 1990; Watts 2009). We judged these studies to be at unclear risk of bias for this domain.

Concealment of allocation

Generally, studies reported concealment of allocation poorly, with only six describing the method of allocation concealment, which typically was sealed envelopes (Andrzejowski 2002; Coulthard 2006; Gazal 2004; Leong 2007; Quirke 2005; Sammons 2007). We judged these studies to be at low risk of bias for this domain. We judged the remaining eight studies as unclear risk of bias for this domain because of insufficient information to enable a judgement to be made.

Blinding

Blinding of operators was difficult because of the nature of these studies; thus, we judged this domain on the blinding of the participant. Participants were unconscious in all cases so unaware of the LA used. Parents were not allowed in the operating theatre, so were also blinded. In only one study (Al‐Bahlani 2001) could the participants have been unblinded to the intervention. Participants were informed beforehand of the likely sensations they would feel postoperatively. This would be dependent on whether they were in the LA or non‐LA group. We assessed this study as high risk of performance bias. We judged all other studies to be at low risk of bias.

It would have been possible to perform a blinded outcome assessment of self‐reported pain, personnel‐reported distress, and clinical measures. Most studies blinded outcome assessors to the intervention, and we judged these studies to be at low risk of detection bias. One study, Al‐Bahlani 2001, did not report the blinding of the assessors; this, along with the fact that the participants were also not blinded, meant that we judged this study to be at high risk of detection bias. In another study (Watts 2009), which reported on physiological parameters observed intraoperatively, the researchers felt blinding of assessors to be unnecessary as the outcome measures were supposedly objective. We judged this study to be at high risk of bias as observers could potentially manipulate even these objective measurements to alter the readings.

Incomplete outcome data

We judged 11 studies to be at low risk of attrition bias as they either clearly described the number of dropouts (no differential dropout) (Coulthard 2006; Gazal 2004; McWilliams 2007; Sammons 2007) or the number of participants reported in the analyses was the same as the number randomised (Al‐Bahlani 2001; Anand 2005; Elhakim 1993; Noble 1994; Quirke 2005; Rashad 1990; Townsend 2009). We judged these studies to be at low risk of attrition bias. We judged two studies to be at high risk of attrition bias; in the first (Leong 2007), a significant number of the children did not provide outcome data (n = 29/87) as they were withdrawn from the study posthoc because they were given a different anaesthetic and analgesic regimen to the rest or had incomplete anaesthetic records. A further 4 children were withdrawn from the study or lost to follow up; the second study, Watts 2009, included all participants in the analysis, but the authors reported "only 46 percent of the study data being complete collections per patient". We judged one study, Andrzejowski 2002, to be at unclear risk of attrition bias where the overall number of dropouts was low (13/120) and the reasons were stated, but the attrition by group was unreported.

Selective reporting

We did not have access to trial protocols, so we used the information reported in the Methods and Results sections of the trial reports to make a judgement on selective reporting. All studies reported all outcome measures described in the Methods section, and we assessed these to be at low risk of reporting bias.

Other potential sources of bias

We judged one study, Noble 1994, to be at unclear risk of other potential sources of bias because of baseline imbalance in trial arms in gender and number of extractions. We judged one study, Al‐Bahlani 2001, to be at high risk of other potential sources of bias as the authors reduced the observation period for measure of pain (Toddler Preschooler‐Postoperative Pain Scale (TPPPS)) from the validated period of 30 minutes to 11 minutes as "no greater discrimination between groups could be determined after this period of observation". We judged all other studies to be at low risk of bias for this domain.

Overall risk of bias

We judged four studies to be at low risk of bias for all domains (Coulthard 2006; Gazal 2004; Quirke 2005; Sammons 2007), seven studies at unclear risk of bias for at least one domain (Anand 2005; Andrzejowski 2002; Elhakim 1993; McWilliams 2007; Noble 1994; Rashad 1990; Townsend 2009), and three studies at high risk of bias for at least one domain (Al‐Bahlani 2001; Leong 2007; Watts 2009).

Effects of interventions

See: Summary of findings for the main comparison Infiltration injection LA versus placebo or no treatment; Summary of findings 2 Intraligamental injection LA versus no treatment; Summary of findings 3 Infiltration injection LA versus intraligamental injection LA versus no treatment; Summary of findings 4 Topical LA versus no treatment or placebo

There was substantial clinical heterogeneity in the included studies as outlined below.

  • Local anaesthetic administration (e.g., intraligamental, infiltration, and topical) varied between studies as did LA composition (Table 1).

  • The included studies used 12 different types of outcome measures. These were either simple self‐reported or parent‐reported rating scales, such as the Wong‐Baker FACES® Pain Rating Scale, visual analogue scales (VAS), or more complex scales based on aggregating investigator scores of movement, crying, etc., such as the Children's Hospital of Eastern Ontario Pain Scale (CHEOPS) or TPPPS (Table 2).

  • There was variation in the use of supplementary analgesics. Nine out of 14 included studies gave additional analgesics alongside the LA either intraoperatively or immediately postoperatively (Anand 2005; Andrzejowski 2002; Coulthard 2006; Gazal 2004; Leong 2007; McWilliams 2007; Sammons 2007; Townsend 2009; Watts 2009). Doses were not always specified as they were given as part of the GA protocol and not as part of the study.

  • There was variation in time of follow up measurement.

We therefore elected to present the results of the studies as a narrative, with summary statistics presented in additional tables, based on the LA given, period of follow up, and the reported outcomes. We aggregated studies that were broadly similar into four groups in an attempt to make sense of the data:

  • infiltration injection LA versus either no treatment or placebo;

  • intraligamental injection LA versus no treatment;

  • infiltration injection LA versus intraligamental injection LA versus no treatment; and

  • topical LA versus placebo or no treatment.

Owing to a lack of comparable studies, we were unable to undertake sensitivity analyses. In future updates, should studies allow, we will carry out sensitivity analyses according to risk of bias and robustness of results to statistical model (fixed or random).

Comparison 1: infiltration injection LA versus no treatment or placebo

Seven studies compared infiltration injection LA with either no treatment (Al‐Bahlani 2001; McWilliams 2007; Noble 1994; Townsend 2009; Watts 2009) or a placebo (Coulthard 2006; Rashad 1990) (See summary of findings Table for the main comparison).

Lignocaine plus adrenaline

We included 5 studies, 1 at low risk of bias (Coulthard 2006), 2 at unclear risk of bias (McWilliams 2007; Townsend 2009), and 2 at high risk of bias (Al‐Bahlani 2001; Watts 2009), analysing 390 participants in the comparison of LA infiltration and no treatment (4 studies) or placebo (1 study). We present the results of the studies in Table 3. Four studies measure pain, distress, or both, the results of which were equivocal: Two studies that used self‐reported measures of pain (Coulthard 2006; Townsend 2009) and one study that used investigator‐reported measures of pain (McWilliams 2007) reported no statistically significant differences in pain irrelevant of the intervention. Two studies that used investigator‐reported measures of distress reported no statistically significant differences in distress irrelevant of the intervention (Coulthard 2006; Townsend 2009). One study that used investigator‐reported measures of pain (Al‐Bahlani 2001) reported a statistically significant difference in pain when given LA or no treatment, with greater pain reported for the LA group.

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Table 3. Infiltration injection LA versus placebo or no treatment (7 studies)

Lignocaine plus adrenaline

Study

Outcome

Treatment

Comparator

Results

LA

Saline placebo

Coulthard 2006*+

Pain (5‐face scale) waking

Mean 1.45 (1.38 sd) N = 70

Mean 1.37 (1.32 sd) N = 69

0.08 (95% CI ‐0.37 to 0.53) P = 0.72 (t‐test)

Pain (5‐face scale) 30 minutes postoperatively

Mean 1.74 (1.44 sd) N = 70

Mean 1.70 (1.32 sd) N = 69

0.04 (95% CI ‐0.42 to 0.50) P = 0.86 (t‐test)

Pain (5‐face scale) 24 hours postoperatively

Mean 0.69 (1.10 sd) N = 70

Mean 0.75 (1.23 sd) N = 69

‐0.06 (95% CI ‐0.45 to 0.33) P = 0.76 (t‐test)

Distress (5‐category) on waking

Mean 2.24 (0.87 sd) N = 70

Mean 2.20 (0.85 sd) N = 69

0.04 (95% CI ‐0.25 to 0.33) P = 0.78 (t‐test)

Distress (5‐category) 30 minutes postoperatively

Mean 2.57 (0.83 sd) N = 70

Mean 2.42 (0.74 sd) N = 69

0.15 (95% CI ‐0.11 to 0.41) P = 0.26 (t‐test)

Lip or cheek biting 24 hours postoperatively

3/70

1/69

P = 0.62 (Fisher's exact test)

Study

Outcome

Treatment

Comparator

Results

LA

No treatment

Watts 2009*+

Heart rate

Mean 119.53 bpm (16.50 sd) for LA. n = 24

Mean 124.38 bpm (16.45 sd) n = 24

‐4.85 (95% CI ‐14.42 to 4.72) P = 0.31 (t‐test)

End tidal CO2

Mean 50.2 mm Hg (3.55 sd) n = 24

Mean 47.46 mm Hg (4.16 sd) n = 24

2.74 (95% CI 0.49 to 4.99) P = 0.02 (t‐test)

Respiratory rate

Mean 30.33 brpm (5.08 sd) n = 24

Mean 32.08 brpm (5.50 sd) n = 24

‐1.75 (95% CI ‐4.83 to 1.33) P = 0.26 (t‐test)

Townsend 2009+

Pain (Wong‐Baker FACES® Pain Rating Scale, 6‐face scale) immediately postoperatively

N = 15

N = 12

Results not reported; authors 'did not use Wong‐Baker FACES immediately post‐operatively due to variable cooperation of subjects'

Pain (Wong‐Baker FACES® Pain Rating Scale, 6‐face scale) evening following surgery

Mean 0.30 (0.21) n = 10

Mean 0.60 (1.35) n = 10

P = 0.92 (Wilcoxon Rank Sum test)

Distress (FLACC) closest to discharge

Mean 2.47 (2.69) n = 15

Mean 2.58 (2.54) n = 12

P = 0.88 (Wilcoxon Rank Sum test)

Lip or cheek biting evening following surgery*

4/11

1/12

P = 0.16 (Fisher's exact test)

McWilliams 2007+

Pain (CHEOPS range 4 to 13) Assessment at 'period between when they awoke and when they were sufficiently recovered to leave for the discharge waiting area'. Exact time not specified

Median 6 (IQR 5 to 8) N = 38

Median 6 (IQR 5 to 8.75) n = 38

P = 0.99 (Mann Whitney U test)

Bleeding (suctioning for bleeding)*

0/38

5/38

P = 0.05 (Fisher's exact test)

Al‐Bahlani 2001

Pain (TPPPS) 11‐minute period of observation

Mean rank 63.96 n = 50

Mean rank 37.07 n = 50

P < 0.0001 (Mann Whitney U Test)

Bleeding (collection of 'all the aspirated fluids and used swabs')*

Mean total blood loss per root 0.79 (sd 0.06) n = 48

Mean total blood loss per root 1.19 (sd 0.1) n = 50

‐0.4 (95% CI ‐0.43 to ‐0.37) P < 0.0001 (t‐test) (2 outlying values removed 6.16 and 3.96)

Lignocaine alone

Study

Outcome

Treatment

Comparator

Results

LA

Placebo

Rashad 1990*+

Postoperative pain (presence or absence)

21/50

36/50

P = 0.004 (Fisher's exact test)

Maximum pulse rate during surgery

Mean 83.3 (9.6 sd) n = 50

Mean 99.6 (14.1 sd) n = 50

‐16.3 (95% CI ‐21.09 to ‐11.51) P < 0.001 (t‐test)

End tidal CO2 postoperative

Mean 39.8 nn Hg (3.8) n = 50

Mean 38.8 mmHg (4.2 sd) n = 50

1.0 (95% CI ‐0.59 to 2.59) P = 0.21

Volume of GA (halothane) delivered

Mean 0.86% (0.28 sd) n = 50

Mean 1.73% (0.03 sd) n = 50

‐0.87 (95% CI ‐0.95 to ‐0.79) P < 0.001 (t‐test)

Incidence of perioperative cardiac dysrhythmias

1/50

14/50

P < 0.001 (Fisher's exact test)

Prilocaine plus felypressin

Study

Outcome

Treatment

Comparator

Results

LA

No treatment

Noble 1994 *

Distress (4‐point scale: high score = high distress) on wakening

Median 2 (1 to 2 IQR) n = 57

Median 3 (2 to 4 IQR) n=43

P = 0.007 (Mann Whitney U test)

Distress (4‐point scale: high score = high distress) before discharge

Median 2 (1 to 3 IQR) n = 57

Median 2 (2 to 3 IQR) n = 43

P = 0.03 (Mann Whitney U test)

Pain (VAS)

N = 30 completed VAS (57 randomised)

N = 23 completed VAS (43 randomised)

Authors reported 'distressed children were significantly less likely to complete this method of assessment'

CHEOPS = Children's Hospital of Eastern Ontario Pain Scale.
CI = confidence interval.
CO2 = carbon dioxide.
FLACC = Faces Legs Activity Crying Consolability.
GA = general anaesthesia.
IQR = interquartile range
LA = local anaesthetic.
n = number.
P = P value.
*re‐analysis of reported data.
SD = standard deviation.
+studies where supplementary analgesics were given.
TPPPS = Toddler Preschooler‐Postoperative Pain Scale.
VAS = visual assessment scale.

Two studies (Al‐Bahlani 2001; McWilliams 2007) reported on postoperative bleeding; both studies reported more bleeding in the no‐treatment group compared with the infiltration LA group. Two studies (Coulthard 2006; Townsend 2009) reported on lip or cheek biting, with no statistically significant difference in prevalence. One study, Watts 2009, assessed perioperative physiological parameters 30 seconds after pulpotomy, crown, and extraction. For those children undergoing extraction, the study authors reported a statistically significant difference in mean end tidal CO2 in favour of infiltration LA. No statistically significant difference in mean heart rate or respiratory rate was observed.

None of the studies reported on patient satisfaction, child satisfaction, or postoperative anxiety.

Lignocaine alone

We included 1 study (Rashad 1990), at unclear risk of bias, analysing 100 participantsin the comparison of LA infiltration and placebo. The study authors reported a statistically significant difference in the prevalence of postoperative pain, with more participants reporting pain in the placebo group compared with the infiltration LA group. The study authors also reported that the perioperative maximum pulse rate, volume of GA delivered, and incidence of cardiac dysrhythmias was significantly lower in the infiltration LA group. Mean values of end tidal CO2 were also lower in the placebo group, though this result was not significant (see Table 3).

The study did not report on bleeding, lip biting, participant satisfaction, child satisfaction, or postoperative anxiety.

Prilocaine plus felypressin

We included 1 study (Noble 1994), at unclear risk of bias, analysing 100 participants in the comparison of LA infiltration and no treatment. The study authors reported statistically significantly higher investigator‐reported distress in the infiltration LA group compared with the no‐treatment group (see Table 3).

The study did not report bleeding, cardiac events, lip biting, patient satisfaction, child satisfaction, or postoperative anxiety.

Comparison 2: intraligamental injection LA versus no treatment

Two studies (Anand 2005; Sammons 2007) compared intraligamental injection LA with no treatment (See summary of findings Table 2).

Bupivacaine plus adrenaline

We included 1 split mouth study (Anand 2005), at unclear risk of bias, analysing 30 participants in the comparison of intraligamental LA and no treatment. The study authors reported no difference in the pain on regaining consciousness between the LA side of the mouth compared with the no‐treatment side of the mouth (see Table 4). Lip biting and numbness was reported for the intraligamental LA side of the mouth only. The study used the Venham Picture Scale to measure postoperative anxiety, but due to the split mouth study design, we were unable to compare postoperative anxiety between the intraligamental LA and no‐treatment sides of the mouth.

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Table 4. Intraligamental injection LA versus no treatment (2 studies)

Bupivacaine plus adrenaline

Study

Outcome

Treatment

Comparator

Results

LA

No treatment

Anand 2005+

Pain (VAS 0 to 100 mm) maxilla on regaining consciousness

Median 18 (10 to 39 IQR) n = 29

Median 29 (11 to 50 IQR) n = 29

P = 0.33 between test and control sides P = 0.33 (Wilcoxon matched pairs signed rank)

Pain (VAS 0 to 100 mm) mandible on regaining consciousness

Median 20 (5 to 45 IQR) n = 25

Median 30 (12 to 50 IQR) n = 25

P = 0.29 between test and control sides P = 0.29 (Wilcoxon matched pairs signed rank)

Lip biting, numbness

"None of the patients showed signs of post‐operative soft tissue trauma following ILA." 21 children reported numbness felt on experimental side. Numbness on no‐treatment side was not reported

Postoperative anxiety (Venham Picture Scale)

Not appropriate outcome in split mouth study

Lignocaine plus adrenaline

Study

Outcome

Treatment

Comparator

Results

LA

No treatment

Sammons 2007+

Pain (TPPS 0 to 7): total pain score over 4 time points in the first hour after tooth extraction

Median 3 (0 to 7.5 IQR) n = 41

Median 3 (0 to 10 IQR) n = 44

P = 0.42 (Mann Whitney U Test)

Pain (Wong‐Baker FACES Pain Rating Scale)

Summary statistics not reported

Summary statistics not reported

"There was no difference in the...pain scores in the first 4 h after returning home or on the 2 days following the extraction." n = 58

Lip or cheek biting, numbness, allergy

"There were no adverse events reported in this study"

CI = confidence interval.
IQR = interquartile range.
ILA = intraoperative local anaesthesia.
LA = local anaesthetic.
n = number.
P = P value,
*re‐analysis of reported data.
+studies where supplementary analgesics were given.
TPPPS = Toddler Preschooler‐Postoperative Pain Scale.
VAS = visual assessment scale.

The study did not report on bleeding, cardiac events, patient satisfaction, or child satisfaction.

Lignocaine plus adrenaline

We included 1study (Sammons 2007), at low risk of bias, analysing 85 participants in the comparison of intraligamental injection LA and no treatment. The authors reported no statistically significant difference in the self‐reported or investigator‐reported total pain score in the first hour postoperatively, and no participants reported lip or cheek biting (see Table 4).

The study did not report on bleeding, cardiac events, patient satisfaction, child satisfaction, or postoperative anxiety.

Comparison 3: infiltration injection LA versus intraligamental injection LA versus no treatment

Lignocaine plus adrenaline

We included 1 study (Leong 2007), at high risk of bias, analysing 54 participants in the comparison of infiltration injection LA, intraligamental injection LA, and no treatment (See summary of findings Table 3). The authors reported no statistically significant difference in investigator‐reported pain or distress up to 30 minutes postoperatively. There was however a statistically significant difference in parent‐reported pain on the first night; though, as the median scores for all three groups was zero, there is no indication of which groups differ (see Table 5).

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Table 5. Infiltration injection LA versus intraligamental injection LA versus no treatment (1 study)

Lignocaine plus adrenaline

LA infiltration

LA intraligamental

No treatment

Study

Outcome

Treatment

Treatment

Comparator

Results

Leong 2007+

Pain/discomfort (STPPPS) immediately on waking

Median 4 (2.5 to 4.0 IQR) n = 17

Median 4 (2.5 to 5.0 IQR) n = 19

Median 4 (3.8 to 5.0 IQR) n = 18

P = 0.32 (Kruskal‐Walis test)

Pain/discomfort (STPPPS) 30 minutes after waking

Median 2 (0 to 4.0 IQR) n = 17

Median 1 (0 to 3.0 IQR) n = 19

Median 2 (0 to 3.3 IQR) n = 18

P = 0.73 (Kruskal‐Walis test)

Pain/discomfort (STPPPS) first night

Median 0 (0 to 1.0 IQR) n = 17

Median 0 (0 to 0 IQR) n = 18

Median 0 (0 to 0 IQR) n = 17

P = 0.036 (Kruskal‐Walis test)

Pain/discomfort (MPDS) immediately on waking

Median 4 (1.0 to 4.0 IQR) n = 17

Median 4 (0 to 4.0 IQR) n = 19

Median 2.5 (1.8 to 4.5 IQR) n = 18

P = 0.96 (Kruskal‐Walis test)

Pain/discomfort (MPDS) 15 minutes after waking

Median 1 (0 to 1.0 IQR) n = 17

Median 0 (0 to 3.0 IQR) n = 19

Median 2 (0 to 4 IQR) n = 18

P = 0.15 (Kruskal‐Walis test)

Pain/discomfort (MPDS) 30 minutes after waking

Median 0 (0 to 1.0 IQR) n = 17

Median 0 (0 to 1 IQR) n = 19

Median 0.5 (0 to 1 IQR) n = 18

P = 0.49 (Kruskal‐Walis test)

Postoperative anxiety (Venham Picture Test)

Median 5.0 (1.5 to 9.0 IQR) n = 17

Median 9 (5.3 to 9.0 IQR) n = 18

Median 7 (4.0 to 9.0 IQR) n = 17

P = 0.23 (Kruskal‐Walis test) (The scale ranges from 0 to 8, but a score of 9 was given if the child refused to use the scale)

IQR = interquartile range.
LA = local anaesthetic.
MPDS = modified pain/discomfort scale.
n = number.
P = P value.
+studies where supplementary analgesics were given.
*re‐analysis of reported data.
STPPPS = Simplified Toddler Preschooler‐Postoperative Pain Scale.

The Venham Picture Scale was used to assess preoperative and postoperative anxiety in 52 children. Mean postoperative anxiety was not statistically significantly different for the three groups.

The study did not report on bleeding, cardiac events, lip or cheek biting, patient satisfaction, or child satisfaction.

Comparison 4: topical LA versus placebo or no treatment

Four studies delivered LA topically as a spray (Elhakim 1993) or as a dental swab (Andrzejowski 2002; Gazal 2004; Quirke 2005) (See summary of findings Table 4).

Lignocaine (delivered as spray)

We included 1 study (Elhakim 1993), at unclear risk of bias, analysing 40 participants in the comparison of topical LA by a metered spray and no treatment. The reported prevalence of pain up to 60 minutes postoperatively was significantly less in the spray group compared with the group with no intervention (see Table 6). The study authors also noted prolonged postoperative bleeding in the no‐treatment group.

Open in table viewer
Table 6. Topical LA versus placebo or no treatment (4 studies)

Lignocaine alone (delivered as spray)

Study

Outcome

Treatment

Comparator

Results

LA

No treatment

Elhakim 1993 *

Pain (presence or absence) 15 minutes

2/20

15/20

P < 0.001 (Fisher's exact test)

Pain (presence or absence) 30 minutes

1/20

11/20

P < 0.001 (Fisher's exact test)

Pain (presence or absence) 60 minutes

2/20

9/20

P = 0.03 (Fisher's exact test)

Bleeding

"There was no early postoperative adverse effects in all groups except for a greater incidence of prolonged postoperative blood oozing in the group C [no treatment] associated with crying." No summary statistics reported

Bupivacaine plus adrenaline (delivered on a dental swab)

Study

Outcome

Treatment

Comparator

Results

LA

Placebo

Andrzejowski 2002*+

Pain (4‐category scale) 15 minutes postoperatively

Median 1.5 (1 to 2 IQR) n = 58

Median 1 (1 to 3 IQR) n = 62

P = 0.66 (Mann Whitney U Test)

Pain (4‐category scale) 30 minutes postoperatively

Median 1 (0 to 2 IQR) n = 58

Median 1 (0 to 2 IQR) n = 62

P = 0.46 (Mann Whitney U Test)

Bleeding at 15 and 30 minutes

"There was no difference in degree of bleeding between the groups. The average of the nurse's subjective assessment of bleeding was 'mild' in both groups at 15 min and 'none' at 30 min"

Gazal 2004*+

Distress (5‐category faces scale) postoperatively

Mean 1.28 (1.31 sd) n = 68

Mean 1.56 (1.20 sd) n = 67

‐0.28 (95% CI ‐0.71 to 0.15) P = 0.19 (t‐Test)

Distress (5‐category faces scale) 15 minutes postoperatively

Mean 1.90 (1.49 sd) n = 68

Mean 1.96 (1.33 sd) n = 67

‐0.06 (95% CI ‐0.54 to 0.42) P = 0.81 (t‐Test)

Quirke 2005

Pain (TPPPS) 5 minutes postoperatively

Median 0 (0 to 7 Range) n = 24

Median 0 (0 to 7 Range) n = 24

"There was no significant difference in the individual maximum pain scores between the two groups (Mann Whitney U Test P > 0.05)"

Pain (TPPPS) 10 minutes postoperatively

Median 1 (0 to 8 Range) n = 24

Median 0 (0 to 7 Range) n = 24

Pain (TPPPS) 15minutes postoperatively

Median 0 (0 to 7 Range) n = 24

Median 0 (0 to 7 Range) n = 24

Pain (TPPPS) 30 minutes postoperatively

Median 1 (0 to 7 Range) n = 24

Median 0 (0 to 5 Range) n = 24

Pain (TPPPS) combined over all 4 time points

Median 1.5 (0 to 29 Range) n = 24

Median 1 (0 to 25 Range) n = 24

"…no significant difference between the two groups (P > 0.05)"

CI = confidence interval.
IQR = interquartile range.
LA = local anaesthetic.
n = number.
P = P value.
SD = standard deviation.
+studies where supplementary analgesics were given.
*re‐analysis of reported data.
TPPPS = Toddler Preschooler‐Postoperative Pain Scale.

The study did not report on cardiac events, lip or cheek biting, patient satisfaction, child satisfaction, or postoperative anxiety.

Bupivacaine plus adrenaline (delivered as dental swab)

We included 3 studies, 1 at unclear risk of bias (Andrzejowski 2002) and 2 at low risk of bias (Gazal 2004; Quirke 2005), analysing 303 participants in the comparison of topical LA by dental swab with LA and placebo swab. All three studies reported no statistically significant difference in self‐reported postoperative pain (Andrzejowski 2002), investigator‐reported pain (Quirke 2005), or self‐reported distress (Gazal 2004) (see Table 6).

Only one study, Andrzejowski 2002, reported on postoperative bleeding, with the nurse‐assessed degree of bleeding deemed 'mild' in both groups.

None of the studies reported on cardiac events, lip or cheek biting, patient satisfaction, child satisfaction, or postoperative anxiety.

Discussion

Summary of main results

In this review, it was difficult to reach firm conclusions as to the benefit of using local anaesthetic for dental treatment under general anaesthesia. We were unable to pool the included studies in a meta‐analysis because of substantial variation in outcome measures, interventions, and treatment types. The use of supplementary analgesics further obscured the effect of local anaesthetics (LA); differences between LA and no‐LA groups were only seen when supplementary analgesics were not given.

Overall completeness and applicability of evidence

The information reported in the included studies was comprehensive and applicable to the review question, but ultimately not sufficient to address the objective of the review. The age range of participants in the included studies was broad, and whilst the variability in age can be seen as an advantage in terms of applicability, it can complicate outcome assessment as recording pain or distress in younger children is particularly difficult. There was also variability in the dental procedures being carried out, with children having single or multiple extractions of primary teeth or permanent teeth. The interventions evaluated and treatment protocol, i.e., general anaesthetic (GA) used, supplementary analgesia, varied between studies and was not always fully reported. There was baseline imbalance in one study (Noble 1994), which included more males than females in the no‐LA group and more extractions in the LA group. This could potentially have distorted the results as extractions may elicit more pain, and there may be a difference in pain reporting between genders (Denning 2000).

Pain assessment

Pain assessment remains difficult in young children because of their limited ability to understand assessment instructions and to articulate descriptions of their pain. The approach taken by the majority of studies in this review was to look at other possible measures of pain such as participant movement or signs of distress. It is likely that this measure was less sensitive than self‐reported measures, which would have been used in older age groups. It is also important to note that very young children might be confused between the discomfort due to the feeling of numbness resulting from local anaesthetic (LA) administration and a feeling of pain.

The baseline anxiety of the child will influence the measurement of pain (Versloot 2008), yet only two of the studies recorded this (Anand 2005; Leong 2007). Ideally, this should always be recorded to either allow sampling of a high‐ or low‐anxiety group or to allow comparison of the effects of preoperative analgesics on postoperative pain in high‐ and low‐anxiety participants.

Studies measured pain at waking or shortly afterwards; follow‐up times then varied, with some studies reviewing participants up to several days postoperatively (Anand 2005; Leong 2007). Measuring pain immediately postoperatively may have posed difficulties as participants are likely to be very distressed on waking anyway. It is likely that this further reduced the sensitivity of the measurement. Given that most studies used short‐acting local anaesthetics, it is unclear why they assessed pain more than several hours after the procedure. It is interesting to note that one of the studies, Leong 2007, noted less pain in the intraligamental group on the first night. It is difficult to postulate a physiological reason for this.

One study, Watts 2009, did not record pain or distress as an outcome, but only looked at the physiologic effect of local anaesthetics. We included this study as it provided information on a secondary outcome of the review.

Analgesics used

The concomitant use of analgesics will have affected the assessment of the impact of use of local anaesthetic intraoperatively. Of the nine studies that gave preoperative or perioperative supplementary analgesics and assessed pain or distress (Anand 2005; Andrzejowski 2002; Coulthard 2006; Gazal 2004; Leong 2007; Townsend 2009; McWilliams 2007; Rashad 1990; Sammons 2007), it is interesting to note that only one of these studies reported a difference in pain scores between the LA and no‐LA or placebo groups (Rashad 1990). Of the four studies that did not give preoperative or perioperative supplementary analgesics and assessed pain or distress (Al‐Bahlani 2001; Elhakim 1993; Noble 1994; Quirke 2005), two studies reported significantly less prevalence of pain (Elhakim 1993) or levels of distress (Noble 1994), one study reported an increased level of pain in the LA group (Al‐Bahlani 2001), and one study reported no statistically significant difference between pain levels in the LA and placebo groups (Quirke 2005).

Use of analgesics during treatment under general anaesthetic would be considered the norm, as is recommended by the Association of Paediatric Anaesthetists (www.rcoa.ac.uk/node/2269). It is biologically plausible that their analgesic effect may obscure any additional effect from the local anaesthetic.

Local anaesthetic

Lignocaine was most commonly used, which is unsurprising as it is the standard drug for dental management of intraoperative pain. Given that the aim of these studies was to look at managing postoperative pain, consideration could be given in future to the use of longer‐lasting local anaesthetic agents. However, in young children, this might also increase the risk of lip biting postoperatively. The majority of studies delivered the LA as an infiltration injection, so it is difficult to draw any conclusions as to the comparative effectiveness of other modes of delivery, such as intraligamental injections or topical spray. Three of the studies used bupivacaine delivered topically (Andrzejowski 2002; Gazal 2004; Quirke 2005); none of these studies reported any analgesic effect.

Other effects of local anaesthetic

Secondary outcomes for this review included other possible effects of local anaesthetic, such as reduction in postoperative bleeding, type and volume of local anaesthesia, cardiac arrhythmias, and increased incidence of lip‐biting.

In two studies, use of LA led to a statistically significant reduction in bleeding; however, this was felt to be clinically insignificant (Al‐Bahlani 2001; McWilliams 2007). Andrzejowski 2002 reported no difference between groups (no statistical testing). In the two studies that looked at the effect on the general anaesthetic (Rashad 1990; Watts 2009), use of LA resulted in a reduction in the volume of anaesthetic gas given, lower mean pulse rates, lower respiratory rates, a reduction in cardiac arrhythmias, lower end tidal carbon dioxide, and a reduced requirement for the anaesthetist to intervene. Interestingly, in Rashad 1990, analgesics were not given before or during the general anaesthetic, and in Watts 2009, they were only given 30 minutes before the end of the case. This is an area that could be investigated further to firstly determine if these differences can be seen if analgesics are given at induction and secondly to better understand the clinical significance (if any) of these anaesthetic events.

Of the four studies reporting lip biting, two noted a greater incidence of lip biting in the LA group (Coulthard 2006; Townsend 2009). This was not judged to be clinically significant in either study.

Quality of the evidence

The overall quality of the body of evidence for the outcomes of pain or distress, bleeding, and physiological parameters was very low for all comparisons. We downgraded the quality of evidence because of inconsistency, imprecision, and risk of bias. We believe that the variation between the studies in terms of their protocols is sufficient to justify our decision not to combine any data. The small sample sizes in many of the studies available and the overall risk of bias for studies contributing information to many of the outcomes also impact on our confidence in the results. We are very uncertain about the effect of the intervention for all four comparisons, and the body of evidence does not allow any robust conclusions to be made.

Potential biases in the review process

When assessing selective reporting bias, we assumed that the studies reported all planned outcomes, based on concordance between the Methods and Results sections of the primary studies. Ideally, it is best to assess selective reporting bias against the study protocol; however, the protocols of the included studies were not publicly available at the time of writing.

We have assumed in McWilliams 2007 that an inconsistency in the CHEOPS score is a reporting error. This may be an incorrect assumption.

Agreements and disagreements with other studies or reviews

We were unable to source any other systematic reviews on this topic. Guidelines for the management of children referred for dental extractions under general anaesthesia produced by the Association of Paediatric Anaesthetists of Great Britain and Ireland recommend that "Infiltration of a local anaesthetic agent combined with a vasoconstrictor agent may have a role in achieving haemostasis, with possibly some benefit in terms of analgesia in the older child who is able to understand the sensation of numbness" (www.rcoa.ac.uk/node/2269). However, the evidence for this recommendation is grade B, as defined by the Scottish Intercollegiate Guidelines Network (SIGN).

Study flow diagram
Figures and Tables -
Figure 1

Study flow diagram

'Risk of bias' graph: review authors' judgements about each 'Risk of bias' item presented as percentages across all included studies
Figures and Tables -
Figure 2

'Risk of bias' graph: review authors' judgements about each 'Risk of bias' item presented as percentages across all included studies

'Risk of bias' summary: review authors' judgements about each 'Risk of bias' item for each included study
Figures and Tables -
Figure 3

'Risk of bias' summary: review authors' judgements about each 'Risk of bias' item for each included study

Summary of findings for the main comparison. Infiltration injection LA versus placebo or no treatment

Infiltration injection LA compared with placebo or no treatment for reduction of postoperative pain

Participant or population: children undergoing dental extractions under general anaesthetic

Settings: secondary care

Intervention: infiltration injection LA

Comparison: placebo or no treatment

Outcomes

Number of participants
(studies)

Quality of the evidence
(GRADE)

Comments

Pain or distress

(self‐ or investigator‐reported pain measured postoperatively typically up to discharge)1

542 (6 studies)

Very low

⊕⊝⊝⊝2

Because of substantial clinical and methodological heterogeneity in the studies, we were unable to determine an estimate of effect

Bleeding

174 (2 studies)

Very low

⊕⊝⊝⊝2

Because of substantial clinical and methodological heterogeneity in the studies, we were unable to determine an estimate of effect

Physiological parameters

148 (2 studies)

Very low

⊕⊝⊝⊝2

Because of substantial clinical and methodological heterogeneity in the studies, we were unable to determine an estimate of effect

*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: confidence interval; LA: = local anaesthetic; RR: risk ratio.

GRADE Working Group grades of evidence
High quality: further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: we are very uncertain about the estimate.

12 studies reported on postoperative pain up to 24 hours after discharge.
2Quality of evidence assessment was downgraded for study limitations, inconsistency of effect, and imprecision. Pooling of studies was precluded by the clinical heterogeneity of the included studies in terms of analgesia (lignocaine plus adrenaline, lignocaine alone, or prilocaine plus felypressin), use of supplementary analgesics, and follow‐up time (see Table 3).

Figures and Tables -
Summary of findings for the main comparison. Infiltration injection LA versus placebo or no treatment
Summary of findings 2. Intraligamental injection LA versus no treatment

Intraligamental injection LA compared with no treatment for reduction of postoperative pain

Participant or population: children undergoing dental extractions under general anaesthetic

Settings: secondary care

Intervention: intraligamental injection LA

Comparison: no treatment

Outcomes

Number of participants
(studies)

Quality of the evidence
(GRADE)

Comments

Pain

(self‐ or investigator‐reported pain measured postoperatively on regaining consciousness and up to first hour following extraction)1

115 (2 studies)

Very low

⊕⊝⊝⊝2

Because of substantial clinical and methodological heterogeneity in the studies, we were unable to determine an estimate of effect

Bleeding

None of the studies reported on this outcome

Physiological parameters

None of the studies reported on this outcome

*The basis for the assumed risk (e.g., the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: confidence interval; LA: local anaesthetic; RR: risk ratio.

GRADE Working Group grades of evidence
High quality: further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: we are very uncertain about the estimate.

11 study also reported on postoperative pain up to 48 hours after discharge.
2Quality of evidence assessment was downgraded for study limitations, inconsistency of effect, and imprecision. Pooling of studies was precluded by the clinical heterogeneity of the included studies in terms of analgesia (bupivacaine plus adrenaline or lignocaine plus adrenaline), use of supplementary analgesics, and follow‐up time (see Table 4).

Figures and Tables -
Summary of findings 2. Intraligamental injection LA versus no treatment
Summary of findings 3. Infiltration injection LA versus intraligamental injection LA versus no treatment

Infiltration injection LA compared with intraligamental injection LA with no treatment for reduction of postoperative pain

Participant or population: children undergoing dental extractions under general anaesthetic

Settings: secondary care

Intervention: infiltration injection LA, intraligamental LA

Comparison: no treatment

Outcomes

Number of participants
(studies)

Quality of the evidence
(GRADE)

Comments

Pain or distress

(Investigator‐reported pain measured postoperatively typically up to 30 minutes postoperatively)1

54 (1 study)

Very low

⊕⊝⊝⊝2

Because of substantial clinical and methodological heterogeneity in the studies, we were unable to determine an estimate of effect

Bleeding

None of the studies reported on this outcome

Physiological parameters

None of the studies reported on this outcome

*The basis for the assumed risk (e.g., the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: confidence interval; LA: local anaesthetic; RR: risk ratio.

GRADE Working Group grades of evidence
High quality: further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: we are very uncertain about the estimate.

11 study reported on postoperative pain on the first evening after discharge.
2Quality of evidence assessment was downgraded for study limitations, inconsistency of effect, and imprecision. Single study of lignocaine plus adrenaline LA (see Table 5).

Figures and Tables -
Summary of findings 3. Infiltration injection LA versus intraligamental injection LA versus no treatment
Summary of findings 4. Topical LA versus no treatment or placebo

Topical LA compared with placebo or no treatment for reduction of postoperative pain

Participant or population: children undergoing dental extractions under general anaesthetic

Settings: secondary care

Intervention: topical LA

Comparison: placebo or no treatment

Outcomes

Number of participants
(studies)

Quality of the evidence
(GRADE)

Comments

Pain or distress

(self‐ or investigator‐reported pain measured postoperatively typically up to discharge)1

343 (4 studies)

Very low

⊕⊝⊝⊝1

Because of substantial clinical and methodological heterogeneity in the studies, we were unable to determine an estimate of effect

Bleeding

160 (2 studies)

Very low

⊕⊝⊝⊝1

Physiological parameters

None of the studies reported on this outcome

*The basis for the assumed risk (e.g., the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: confidence interval; LA: local anaesthetic; RR: risk ratio.

GRADE Working Group grades of evidence
High quality: further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: we are very uncertain about the estimate.

1Quality of evidence assessment was downgraded for study limitations, inconsistency of effect, and imprecision. Pooling of studies was precluded by the clinical heterogeneity of the included studies in terms of analgesia (lignocaine alone (delivered as spray), bupivacaine plus adrenaline (delivered on a dental swab)), use of supplementary analgesics, and follow‐up time (see Table 6).

Figures and Tables -
Summary of findings 4. Topical LA versus no treatment or placebo
Table 1. Local anaesthetic used

Local anaesthetic

Study

2% lignocaine with 1:80000 adrenaline

Al‐Bahlani 2001; Leong 2007; Sammons 2007

2% lignocaine with 1:200000 adrenaline

Coulthard 2006

2% lignocaine with 1:100000 adrenaline

Townsend 2009; Watts 2009

2% lignocaine

Rashad 1990

4% lignocaine with 1:80000 adrenaline

McWilliams 2007

0.5% bupivacaine with 1:200000 adrenaline

Anand 2005

3% prilocaine 0.03 U/ml felypressin

Noble 1994

4 mg/kg lignocaine (delivered as spray)

Elhakim 1993

0.25% bupivacaine (topical) with 1:4000 adrenaline

Gazal 2004

0.25% bupivacaine (topical) with 1:200000 adrenaline

Andrzejowski 2002; Quirke 2005

Figures and Tables -
Table 1. Local anaesthetic used
Table 2. Pain/distress scales

Pain/distress scale

Description

Recorded by

Study

5‐face scale of distress

5‐face scale ranging from no distress to very severe distress

Self‐reported

Gazal 2004

4‐category scale of distress

4‐point scale ranging from happy to distressed

Investigator

Noble 1994

5‐category scale of distress

5‐point scale ranging from asleep to distressed

Investigator

Coulthard 2006

Faces Legs Activity Crying Consolability (FLACC) assessment tool

Aggregate score based on observation of facial expression, leg movement, activity, crying, and consolability

Investigator

Townsend 2009

Modified pain/discomfort scale (MPDS)

Aggregate score based on observation of crying, movement, and agitation

Investigator

Leong 2007

Children's Hospital of Eastern Ontario Pain Scale (CHEOPS)

Aggregate score based on observation of crying, facial expression, verbal expression pain, torso movement, child touching the "wound", and leg movement

Investigator

McWilliams 2007

Presence/absence of pain

Investigator/self‐reported

Elhakim 1993; Rashad 1990

Simplified Toddler Preschooler‐Postoperative pain scale (STPPPS) or Toddler Preschooler‐Postoperative pain scale system (TPPPS)

Aggregate score based on observation of vocal pain expression, facial pain expression, and body pain expression

Investigator

Al‐Bahlani 2001; Leong 2007; Quirke 2005; Sammons 2007

Visual analogue scale (VAS)

Self‐reporting of pain based on a line ranging from no pain to worst pain

Self‐reported

Anand 2005; Noble 1994

Wong‐Baker FACES® Pain Rating Scale

6‐face scale for pain intensity assessment ranging from no hurt to hurts worst

Self‐reported/Parentp‐reported

Sammons 2007; Townsend 2009

5‐face pain scale

5‐face scale for pain intensity assessment ranging from no pain to very severe pain

Self‐reported

Coulthard 2006

4‐face pain scale

4‐face scale for pain intensity assessment ranging from 'I don't hurt at all' to 'I hurt the most'

Self‐reported

Andrzejowski 2002

CHEOPS = Children's Hospital of Eastern Ontario Pain Scale.FLACC = Faces Legs Activity Crying Consolability.
MPDS = modified pain/discomfort scale.
STPPPS = Simplified Toddler Preschooler‐Postoperative Pain Scale.
TPPPS = Toddler Preschooler‐Postoperative Pain Scale.
VAS = visual assessment scale.

Figures and Tables -
Table 2. Pain/distress scales
Table 3. Infiltration injection LA versus placebo or no treatment (7 studies)

Lignocaine plus adrenaline

Study

Outcome

Treatment

Comparator

Results

LA

Saline placebo

Coulthard 2006*+

Pain (5‐face scale) waking

Mean 1.45 (1.38 sd) N = 70

Mean 1.37 (1.32 sd) N = 69

0.08 (95% CI ‐0.37 to 0.53) P = 0.72 (t‐test)

Pain (5‐face scale) 30 minutes postoperatively

Mean 1.74 (1.44 sd) N = 70

Mean 1.70 (1.32 sd) N = 69

0.04 (95% CI ‐0.42 to 0.50) P = 0.86 (t‐test)

Pain (5‐face scale) 24 hours postoperatively

Mean 0.69 (1.10 sd) N = 70

Mean 0.75 (1.23 sd) N = 69

‐0.06 (95% CI ‐0.45 to 0.33) P = 0.76 (t‐test)

Distress (5‐category) on waking

Mean 2.24 (0.87 sd) N = 70

Mean 2.20 (0.85 sd) N = 69

0.04 (95% CI ‐0.25 to 0.33) P = 0.78 (t‐test)

Distress (5‐category) 30 minutes postoperatively

Mean 2.57 (0.83 sd) N = 70

Mean 2.42 (0.74 sd) N = 69

0.15 (95% CI ‐0.11 to 0.41) P = 0.26 (t‐test)

Lip or cheek biting 24 hours postoperatively

3/70

1/69

P = 0.62 (Fisher's exact test)

Study

Outcome

Treatment

Comparator

Results

LA

No treatment

Watts 2009*+

Heart rate

Mean 119.53 bpm (16.50 sd) for LA. n = 24

Mean 124.38 bpm (16.45 sd) n = 24

‐4.85 (95% CI ‐14.42 to 4.72) P = 0.31 (t‐test)

End tidal CO2

Mean 50.2 mm Hg (3.55 sd) n = 24

Mean 47.46 mm Hg (4.16 sd) n = 24

2.74 (95% CI 0.49 to 4.99) P = 0.02 (t‐test)

Respiratory rate

Mean 30.33 brpm (5.08 sd) n = 24

Mean 32.08 brpm (5.50 sd) n = 24

‐1.75 (95% CI ‐4.83 to 1.33) P = 0.26 (t‐test)

Townsend 2009+

Pain (Wong‐Baker FACES® Pain Rating Scale, 6‐face scale) immediately postoperatively

N = 15

N = 12

Results not reported; authors 'did not use Wong‐Baker FACES immediately post‐operatively due to variable cooperation of subjects'

Pain (Wong‐Baker FACES® Pain Rating Scale, 6‐face scale) evening following surgery

Mean 0.30 (0.21) n = 10

Mean 0.60 (1.35) n = 10

P = 0.92 (Wilcoxon Rank Sum test)

Distress (FLACC) closest to discharge

Mean 2.47 (2.69) n = 15

Mean 2.58 (2.54) n = 12

P = 0.88 (Wilcoxon Rank Sum test)

Lip or cheek biting evening following surgery*

4/11

1/12

P = 0.16 (Fisher's exact test)

McWilliams 2007+

Pain (CHEOPS range 4 to 13) Assessment at 'period between when they awoke and when they were sufficiently recovered to leave for the discharge waiting area'. Exact time not specified

Median 6 (IQR 5 to 8) N = 38

Median 6 (IQR 5 to 8.75) n = 38

P = 0.99 (Mann Whitney U test)

Bleeding (suctioning for bleeding)*

0/38

5/38

P = 0.05 (Fisher's exact test)

Al‐Bahlani 2001

Pain (TPPPS) 11‐minute period of observation

Mean rank 63.96 n = 50

Mean rank 37.07 n = 50

P < 0.0001 (Mann Whitney U Test)

Bleeding (collection of 'all the aspirated fluids and used swabs')*

Mean total blood loss per root 0.79 (sd 0.06) n = 48

Mean total blood loss per root 1.19 (sd 0.1) n = 50

‐0.4 (95% CI ‐0.43 to ‐0.37) P < 0.0001 (t‐test) (2 outlying values removed 6.16 and 3.96)

Lignocaine alone

Study

Outcome

Treatment

Comparator

Results

LA

Placebo

Rashad 1990*+

Postoperative pain (presence or absence)

21/50

36/50

P = 0.004 (Fisher's exact test)

Maximum pulse rate during surgery

Mean 83.3 (9.6 sd) n = 50

Mean 99.6 (14.1 sd) n = 50

‐16.3 (95% CI ‐21.09 to ‐11.51) P < 0.001 (t‐test)

End tidal CO2 postoperative

Mean 39.8 nn Hg (3.8) n = 50

Mean 38.8 mmHg (4.2 sd) n = 50

1.0 (95% CI ‐0.59 to 2.59) P = 0.21

Volume of GA (halothane) delivered

Mean 0.86% (0.28 sd) n = 50

Mean 1.73% (0.03 sd) n = 50

‐0.87 (95% CI ‐0.95 to ‐0.79) P < 0.001 (t‐test)

Incidence of perioperative cardiac dysrhythmias

1/50

14/50

P < 0.001 (Fisher's exact test)

Prilocaine plus felypressin

Study

Outcome

Treatment

Comparator

Results

LA

No treatment

Noble 1994 *

Distress (4‐point scale: high score = high distress) on wakening

Median 2 (1 to 2 IQR) n = 57

Median 3 (2 to 4 IQR) n=43

P = 0.007 (Mann Whitney U test)

Distress (4‐point scale: high score = high distress) before discharge

Median 2 (1 to 3 IQR) n = 57

Median 2 (2 to 3 IQR) n = 43

P = 0.03 (Mann Whitney U test)

Pain (VAS)

N = 30 completed VAS (57 randomised)

N = 23 completed VAS (43 randomised)

Authors reported 'distressed children were significantly less likely to complete this method of assessment'

CHEOPS = Children's Hospital of Eastern Ontario Pain Scale.
CI = confidence interval.
CO2 = carbon dioxide.
FLACC = Faces Legs Activity Crying Consolability.
GA = general anaesthesia.
IQR = interquartile range
LA = local anaesthetic.
n = number.
P = P value.
*re‐analysis of reported data.
SD = standard deviation.
+studies where supplementary analgesics were given.
TPPPS = Toddler Preschooler‐Postoperative Pain Scale.
VAS = visual assessment scale.

Figures and Tables -
Table 3. Infiltration injection LA versus placebo or no treatment (7 studies)
Table 4. Intraligamental injection LA versus no treatment (2 studies)

Bupivacaine plus adrenaline

Study

Outcome

Treatment

Comparator

Results

LA

No treatment

Anand 2005+

Pain (VAS 0 to 100 mm) maxilla on regaining consciousness

Median 18 (10 to 39 IQR) n = 29

Median 29 (11 to 50 IQR) n = 29

P = 0.33 between test and control sides P = 0.33 (Wilcoxon matched pairs signed rank)

Pain (VAS 0 to 100 mm) mandible on regaining consciousness

Median 20 (5 to 45 IQR) n = 25

Median 30 (12 to 50 IQR) n = 25

P = 0.29 between test and control sides P = 0.29 (Wilcoxon matched pairs signed rank)

Lip biting, numbness

"None of the patients showed signs of post‐operative soft tissue trauma following ILA." 21 children reported numbness felt on experimental side. Numbness on no‐treatment side was not reported

Postoperative anxiety (Venham Picture Scale)

Not appropriate outcome in split mouth study

Lignocaine plus adrenaline

Study

Outcome

Treatment

Comparator

Results

LA

No treatment

Sammons 2007+

Pain (TPPS 0 to 7): total pain score over 4 time points in the first hour after tooth extraction

Median 3 (0 to 7.5 IQR) n = 41

Median 3 (0 to 10 IQR) n = 44

P = 0.42 (Mann Whitney U Test)

Pain (Wong‐Baker FACES Pain Rating Scale)

Summary statistics not reported

Summary statistics not reported

"There was no difference in the...pain scores in the first 4 h after returning home or on the 2 days following the extraction." n = 58

Lip or cheek biting, numbness, allergy

"There were no adverse events reported in this study"

CI = confidence interval.
IQR = interquartile range.
ILA = intraoperative local anaesthesia.
LA = local anaesthetic.
n = number.
P = P value,
*re‐analysis of reported data.
+studies where supplementary analgesics were given.
TPPPS = Toddler Preschooler‐Postoperative Pain Scale.
VAS = visual assessment scale.

Figures and Tables -
Table 4. Intraligamental injection LA versus no treatment (2 studies)
Table 5. Infiltration injection LA versus intraligamental injection LA versus no treatment (1 study)

Lignocaine plus adrenaline

LA infiltration

LA intraligamental

No treatment

Study

Outcome

Treatment

Treatment

Comparator

Results

Leong 2007+

Pain/discomfort (STPPPS) immediately on waking

Median 4 (2.5 to 4.0 IQR) n = 17

Median 4 (2.5 to 5.0 IQR) n = 19

Median 4 (3.8 to 5.0 IQR) n = 18

P = 0.32 (Kruskal‐Walis test)

Pain/discomfort (STPPPS) 30 minutes after waking

Median 2 (0 to 4.0 IQR) n = 17

Median 1 (0 to 3.0 IQR) n = 19

Median 2 (0 to 3.3 IQR) n = 18

P = 0.73 (Kruskal‐Walis test)

Pain/discomfort (STPPPS) first night

Median 0 (0 to 1.0 IQR) n = 17

Median 0 (0 to 0 IQR) n = 18

Median 0 (0 to 0 IQR) n = 17

P = 0.036 (Kruskal‐Walis test)

Pain/discomfort (MPDS) immediately on waking

Median 4 (1.0 to 4.0 IQR) n = 17

Median 4 (0 to 4.0 IQR) n = 19

Median 2.5 (1.8 to 4.5 IQR) n = 18

P = 0.96 (Kruskal‐Walis test)

Pain/discomfort (MPDS) 15 minutes after waking

Median 1 (0 to 1.0 IQR) n = 17

Median 0 (0 to 3.0 IQR) n = 19

Median 2 (0 to 4 IQR) n = 18

P = 0.15 (Kruskal‐Walis test)

Pain/discomfort (MPDS) 30 minutes after waking

Median 0 (0 to 1.0 IQR) n = 17

Median 0 (0 to 1 IQR) n = 19

Median 0.5 (0 to 1 IQR) n = 18

P = 0.49 (Kruskal‐Walis test)

Postoperative anxiety (Venham Picture Test)

Median 5.0 (1.5 to 9.0 IQR) n = 17

Median 9 (5.3 to 9.0 IQR) n = 18

Median 7 (4.0 to 9.0 IQR) n = 17

P = 0.23 (Kruskal‐Walis test) (The scale ranges from 0 to 8, but a score of 9 was given if the child refused to use the scale)

IQR = interquartile range.
LA = local anaesthetic.
MPDS = modified pain/discomfort scale.
n = number.
P = P value.
+studies where supplementary analgesics were given.
*re‐analysis of reported data.
STPPPS = Simplified Toddler Preschooler‐Postoperative Pain Scale.

Figures and Tables -
Table 5. Infiltration injection LA versus intraligamental injection LA versus no treatment (1 study)
Table 6. Topical LA versus placebo or no treatment (4 studies)

Lignocaine alone (delivered as spray)

Study

Outcome

Treatment

Comparator

Results

LA

No treatment

Elhakim 1993 *

Pain (presence or absence) 15 minutes

2/20

15/20

P < 0.001 (Fisher's exact test)

Pain (presence or absence) 30 minutes

1/20

11/20

P < 0.001 (Fisher's exact test)

Pain (presence or absence) 60 minutes

2/20

9/20

P = 0.03 (Fisher's exact test)

Bleeding

"There was no early postoperative adverse effects in all groups except for a greater incidence of prolonged postoperative blood oozing in the group C [no treatment] associated with crying." No summary statistics reported

Bupivacaine plus adrenaline (delivered on a dental swab)

Study

Outcome

Treatment

Comparator

Results

LA

Placebo

Andrzejowski 2002*+

Pain (4‐category scale) 15 minutes postoperatively

Median 1.5 (1 to 2 IQR) n = 58

Median 1 (1 to 3 IQR) n = 62

P = 0.66 (Mann Whitney U Test)

Pain (4‐category scale) 30 minutes postoperatively

Median 1 (0 to 2 IQR) n = 58

Median 1 (0 to 2 IQR) n = 62

P = 0.46 (Mann Whitney U Test)

Bleeding at 15 and 30 minutes

"There was no difference in degree of bleeding between the groups. The average of the nurse's subjective assessment of bleeding was 'mild' in both groups at 15 min and 'none' at 30 min"

Gazal 2004*+

Distress (5‐category faces scale) postoperatively

Mean 1.28 (1.31 sd) n = 68

Mean 1.56 (1.20 sd) n = 67

‐0.28 (95% CI ‐0.71 to 0.15) P = 0.19 (t‐Test)

Distress (5‐category faces scale) 15 minutes postoperatively

Mean 1.90 (1.49 sd) n = 68

Mean 1.96 (1.33 sd) n = 67

‐0.06 (95% CI ‐0.54 to 0.42) P = 0.81 (t‐Test)

Quirke 2005

Pain (TPPPS) 5 minutes postoperatively

Median 0 (0 to 7 Range) n = 24

Median 0 (0 to 7 Range) n = 24

"There was no significant difference in the individual maximum pain scores between the two groups (Mann Whitney U Test P > 0.05)"

Pain (TPPPS) 10 minutes postoperatively

Median 1 (0 to 8 Range) n = 24

Median 0 (0 to 7 Range) n = 24

Pain (TPPPS) 15minutes postoperatively

Median 0 (0 to 7 Range) n = 24

Median 0 (0 to 7 Range) n = 24

Pain (TPPPS) 30 minutes postoperatively

Median 1 (0 to 7 Range) n = 24

Median 0 (0 to 5 Range) n = 24

Pain (TPPPS) combined over all 4 time points

Median 1.5 (0 to 29 Range) n = 24

Median 1 (0 to 25 Range) n = 24

"…no significant difference between the two groups (P > 0.05)"

CI = confidence interval.
IQR = interquartile range.
LA = local anaesthetic.
n = number.
P = P value.
SD = standard deviation.
+studies where supplementary analgesics were given.
*re‐analysis of reported data.
TPPPS = Toddler Preschooler‐Postoperative Pain Scale.

Figures and Tables -
Table 6. Topical LA versus placebo or no treatment (4 studies)