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Cochrane Database of Systematic Reviews

High initial concentration versus low initial concentration sevoflurane for inhalational induction of anaesthesia

Information

DOI:
https://doi.org/10.1002/14651858.CD006837.pub3Copy DOI
Database:
  1. Cochrane Database of Systematic Reviews
Version published:
  1. 29 June 2016see what's new
Type:
  1. Intervention
Stage:
  1. Review
Cochrane Editorial Group:

  1. Cochrane Anaesthesia Group

Copyright:
  1. Copyright © 2016 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.

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Authors

  • Polpun Boonmak

    Correspondence to: Department of Anaesthesiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand

    [email protected]

    [email protected]

  • Suhattaya Boonmak

    Department of Anaesthesiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand

  • Porjai Pattanittum

    Department of Biostatistics and Demography, Faculty of Public Health, Khon Kaen University, Khon Kaen, Thailand

Contributions of authors

Polpun Boonmak (PB), Suhattaya Boonmak (SB), Porjai Pattanittum (PP).

Conceiving of the review: PB.
Co‐ordinating the review: SB.
Undertaking manual searches: PB, SB.
Screening search results: PB, SB.
Organizing retrieval of papers: PB.
Screening retrieved papers against inclusion criteria: PB, SB.
Appraising the quality of papers: PB, SB.
Abstracting data from papers: PB, SB.
Writing to authors of papers to ask for additional information: PB.
Providing additional data related to papers: PB.
Obtaining and screening data on unpublished studies: PB.
Managing data for the review: PB, PP.
Entering data into Review Manager (RevMan 5.3): PB, SB.
Analysing RevMan statistical data: PB, PP.
Performing double entry of data: data entered by person one PB, data entered by person two SB.
Interpreting data: PB, PP.
Performing statistical analysis: PP.
Writing the review: PB, SB.
Writing the effects of interventions part: PP.
Creating 'Summary of findings' tables: PP, PB.
Commenting on the 'Summary of findings' tables: PB, SB.
Securing funding for the review: PB.
Performing previous work that was the foundation of the present study: PB.
Serving as guarantor for the review (one review author): PB.
Taking responsibility for reading and checking the review before submission: PB, SB, PP.

Sources of support

Internal sources

  • Systematic review grant, Faculty of Medicine, Khon Kaen University, Thailand.

  • Thai Cochrane Network, Thailand.

External sources

  • The Thailand Research Fund, Thailand.

Declarations of interest

Polpun Boonmak: none known.

Suhattaya Boonmak: none known.

Porjai Pattanittum: none known.

Acknowledgements

We would like to thank Jane Cracknell, Martha Delgado and Andrew Smith (Content Editors), Marialena Trivella (Statistical Editor), Thomas Ledowski and Mark Neuman (Peer Reviewers) and Janet Wale (representative of the Cochrane Consumer Network) for help and editorial advice provided during preparation of this systematic review (Boonmak 2012).

We would like to thank Martha Delgado, Marc Davison and Thomas Ledowski for help and editorial advice provided during preparation of the protocol for this systematic review (Boonmak 2007). We thank Karen Hovhannisyan for devising the search strategy and conducting the data search.

Version history

Published

Title

Stage

Authors

Version

2016 Jun 29

High initial concentration versus low initial concentration sevoflurane for inhalational induction of anaesthesia

Review

Polpun Boonmak, Suhattaya Boonmak, Porjai Pattanittum

https://doi.org/10.1002/14651858.CD006837.pub3

2012 Sep 12

High initial concentration versus low initial concentration sevoflurane for inhalational induction of anaesthesia

Review

Polpun Boonmak, Suhattaya Boonmak, Porjai Pattanittum

https://doi.org/10.1002/14651858.CD006837.pub2

2007 Oct 17

High concentration versus low concentration sevoflurane for anaesthesia induction

Protocol

Polpun Boonmak, Suhattaya Boonmak, Wimonrat Krisanaprakornkit, Porjai Pattanittum

https://doi.org/10.1002/14651858.CD006837

Differences between protocol and review

We changed the title to "High initial concentration versus low initial concentration sevoflurane for inhalational induction of anaesthesia".

We added two outcomes that we did not plan in the protocol (Boonmak 2007) ‐ time to endotracheal intubation and time to successful insertion of a laryngeal mask airway.

We did not use the risk ratio for dichotomous data, but we used the Peto odds ratio because events were rare.
We considered I2 > 35% as a sign of heterogeneity instead of I2 > 50%, as mentioned in the protocol.

If I2 was greater than 75%, we did not attempt to pool the results.

We conducted all analyses while using RevMan software version 5.3.5, not version 4.2.

Keywords

MeSH

Medical Subject Headings (MeSH) Keywords

Medical Subject Headings Check Words

Humans;

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.

Study flow diagram.
Figures and Tables -
Figure 1

Study flow diagram.

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Methodological quality summary: review authors' judgements about each methodological quality item for each included study.
Figures and Tables -
Figure 2

Methodological quality summary: review authors' judgements about each methodological quality item for each included study.

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Methodological quality graph: review authors' judgements about each methodological quality item presented as percentages across all included studies.
Figures and Tables -
Figure 3

Methodological quality graph: review authors' judgements about each methodological quality item presented as percentages across all included studies.

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Comparison 1 High initial concentration versus low initial concentration, Outcome 1 Time to loss of eyelash reflex (seconds).
Figures and Tables -
Analysis 1.1

Comparison 1 High initial concentration versus low initial concentration, Outcome 1 Time to loss of eyelash reflex (seconds).

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Comparison 1 High initial concentration versus low initial concentration, Outcome 2 Cough.
Figures and Tables -
Analysis 1.2

Comparison 1 High initial concentration versus low initial concentration, Outcome 2 Cough.

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Comparison 1 High initial concentration versus low initial concentration, Outcome 3 Laryngospasm.
Figures and Tables -
Analysis 1.3

Comparison 1 High initial concentration versus low initial concentration, Outcome 3 Laryngospasm.

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Comparison 1 High initial concentration versus low initial concentration, Outcome 4 Breath holding.
Figures and Tables -
Analysis 1.4

Comparison 1 High initial concentration versus low initial concentration, Outcome 4 Breath holding.

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Comparison 1 High initial concentration versus low initial concentration, Outcome 5 Apneoa.
Figures and Tables -
Analysis 1.5

Comparison 1 High initial concentration versus low initial concentration, Outcome 5 Apneoa.

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Comparison 1 High initial concentration versus low initial concentration, Outcome 6 Patient movement.
Figures and Tables -
Analysis 1.6

Comparison 1 High initial concentration versus low initial concentration, Outcome 6 Patient movement.

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Comparison 1 High initial concentration versus low initial concentration, Outcome 7 Salivation.
Figures and Tables -
Analysis 1.7

Comparison 1 High initial concentration versus low initial concentration, Outcome 7 Salivation.

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Comparison 1 High initial concentration versus low initial concentration, Outcome 8 Bradycardia.
Figures and Tables -
Analysis 1.8

Comparison 1 High initial concentration versus low initial concentration, Outcome 8 Bradycardia.

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Summary of findings for the main comparison. High initial concentration versus low initial concentration for inhalational induction of anaesthesia

High initial concentration versus low initial concentration for inhalational induction of anaesthesia

Patient or population: patients with inhalational induction of anaesthesia
Settings: patients undergoing various surgical procedures in operating rooms in Asia, Europe, North America
Intervention: high initial concentration versus low initial concentration

Outcomes

Illustrative comparative risks* (95% CI)

Relative effect
(95% CI)

Number of participants
(studies)

Quality of the evidence
(GRADE)

Comments

Assumed risk

Corresponding risk

Control

High initial concentration vs low initial concentration

Time to loss of eyelash reflex

Mean time to loss of eyelash reflex in control groups was
112.9 seconds

Mean time to loss of eyelash reflex in intervention groups was
41 lower
(31.37 to 50.62 lower)

443
(6 studies)

⊕⊕⊝⊝
lowa

Cough

38 per 1000

47 per 1000
(21 to 101)

OR 1.23
(0.53 to 2.81)

589
(8 studies)

⊕⊕⊝⊝
lowb

Laryngospasm

5 per 1000

7 per 1000
(1 to 68)

OR 1.59
(0.16 to 15.92)

588
(7 studies)

⊕⊕⊝⊝
lowc

Breath holding

56 per 1000

64 per 1000
(27 to 144)

OR 1.16
(0.47 to 2.83)

389
(5 studies)

⊕⊕⊝⊝
lowd

Apneoa

141 per 1000

442 per 1000
(242 to 802)

RR 3.14
(1.72 to 5.7)

160
(2 studies)

⊕⊕⊝⊝
lowe

Patient movement

163 per 1000

186 per 1000
(113 to 309)

RR 1.14
(0.69 to 1.89)

445
(5 studies)

⊕⊕⊝⊝
lowf

Bradycardia

66 per 1000

53 per 1000
(15 to 169)

OR 0.8
(0.22 to 2.88)

199
(3 studies)

⊕⊕⊝⊝
lowg

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

aDowngraded two levels because of serious concerns about selection bias, allocation concealment and blinding

bDowngraded two levels because of serious concerns about allocation concealment and blinding

cDowngraded two levels because of serious concerns about selection bias, allocation concealment and blinding

dDowngraded two levels because of serious concerns about selection bias, allocation concealment and blinding

eDowngraded two levels because of serious concerns about allocation concealment and blinding

fDowngraded two levels because of serious concerns about allocation concealment and blinding

gDowngraded two levels because of serious concerns about allocation concealment

Figures and Tables -
Summary of findings for the main comparison. High initial concentration versus low initial concentration for inhalational induction of anaesthesia
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Comparison 1. High initial concentration versus low initial concentration

Outcome or subgroup title

No. of studies

No. of participants

Statistical method

Effect size

1 Time to loss of eyelash reflex (seconds) Show forest plot

6

443

Mean Difference (IV, Random, 95% CI)

‐39.00 [‐50.62, ‐31.37]

2 Cough Show forest plot

8

589

Peto Odds Ratio (Peto, Fixed, 95% CI)

1.23 [0.53, 2.81]

3 Laryngospasm Show forest plot

7

588

Peto Odds Ratio (Peto, Fixed, 95% CI)

1.59 [0.16, 15.92]

4 Breath holding Show forest plot

5

389

Peto Odds Ratio (Peto, Fixed, 95% CI)

1.16 [0.47, 2.83]

5 Apneoa Show forest plot

2

160

Risk Ratio (M‐H, Fixed, 95% CI)

3.14 [1.72, 5.70]

6 Patient movement Show forest plot

5

445

Risk Ratio (M‐H, Random, 95% CI)

1.14 [0.69, 1.89]

7 Salivation Show forest plot

6

487

Peto Odds Ratio (Peto, Fixed, 95% CI)

1.23 [0.36, 4.21]

8 Bradycardia Show forest plot

3

199

Peto Odds Ratio (Peto, Fixed, 95% CI)

0.80 [0.22, 2.88]
Figures and Tables -
Comparison 1. High initial concentration versus low initial concentration
Navigate to table in Review