對於重症患者而言，加強咳嗽技術是否有助於拔管或脫離呼吸器？
Referencias
References to studies included in this review
References to studies excluded from this review
Additional references
References to other published versions of this review
Characteristics of studies
Characteristics of included studies [ordered by study ID]
Ir a:
| Methods | Single‐centre (Canada; mixed medical‐surgical‐trauma ICU) randomized controlled trial; 22‐month period from January 2001 | |
| Participants | 20 (10 intervention and 10 control) intubated adults (18 years and over) with at least unilateral lobar atelectasis or bilateral areas of significant atelectasis as determined by chest radiography Atelectasis was present for 72 hours or less Excluded patients with: bullous emphysema; recent pneumothorax; cardiac or neurologic instability; acute respiratory distress syndrome or acute lung injury; abdominal trauma or recent abdominal surgery; pericardial tubes; unstable spinal or pelvic fractures; inferior vena cava filters; PEEP ≥ 7.5 cm H2O; and patients likely to be extubated within less than 12 hours | |
| Interventions | Intervention: Breath stacking using a resuscitation bag equipped with a one‐way valve to manually inflate the lung, in a step‐like manner in 3 increments, to maximal insufflation capacity with the objective of re‐inflating atelectatic lung tissue. The breath‐stacking protocol immediately followed conventional physiotherapy, with the participant in a side‐lying position and the affected lung uppermost. Participants were oxygenated for 3 minutes on 100% FiO2 via the ventilator. 3 stacked breaths were given with bag squeezes without air escape (using one‐way valve) to maximal pressure of 40 cm H2O with a 10‐second hold at maximal pressure, followed by an abdominal thrust or chest squeeze The procedure was repeated twice more (for a total of 3 cycles). Participants were suctioned as required. The participant was allowed to rest on the ventilator for 3 ‐ 5 minutes to allow vital signs to return to baseline. The procedure (3 stacked breaths, assisted cough, suctioning and rest on ventilator) was repeated 3 times (for a total of 4 cycles or 12 stacked breaths). Twice‐daily treatment was continued until the participant was extubated, to a maximum of 72 hours or 6 treatment sessions Control: conventional physiotherapy (manual percussions and vibrations) twice daily for periods of 15 to 20 minutes with the most affected side uppermost. Chest physiotherapy was followed by 30 seconds of oxygenation and secretion removal via suctioning, without saline installation | |
| Outcomes | Atelectasis quantified on routine daily chest radiograph by a blinded radiologist using an adapted version of an atelectasis score used in a previous study by Joyce 1995 Oxygenation measured continuously, using a pulse oximeter, and recorded prior to treatment, immediately following treatment, and 30 minutes after the procedure Sputum volume collected in a 40 cc container with the volume visually estimated and recorded at the end of the procedure | |
| Notes | Unable to locate in Pubmed for PMID Funded by a grant from the Canadian Physiotherapy Cardio‐respiratory Society, a branch of the Canadian Lung Association No declarations of conflicts of interest | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Participants were randomly assigned using a computer‐generated random number table |
| Allocation concealment (selection bias) | Low risk | Used a system of opaque sealed envelopes |
| Blinding of participants and personnel (performance bias) | Unclear risk | Participants and physiotherapist providing the study treatments and researchers could not be blinded, but it is unclear whether this produced performance bias |
| Blinding of outcome assessment (detection bias) | Low risk | Primary outcome assessment (atelectasis) was done by a blinded radiologist. There is no evidence that the other study outcomes were assessed in a blinded manner. Outcomes not likely to be influenced by lack of blinding |
| Incomplete outcome data (attrition bias) | Low risk | No apparent incomplete outcome data |
| Selective reporting (reporting bias) | Low risk | No protocol available, but no evidence of selective outcome reporting |
| Other bias | Unclear risk | The study was forced to stop early, reaching only half of the target sample size due to failure to recruit participants |
| Methods | Single‐centre (Portugal, mixed medical‐surgical‐trauma ICU) randomized controlled trial; between 2007 and 2009 | |
| Participants | 75 (35 intervention; 40 control) adults (18 years and older) receiving mechanical ventilation for more than 48 hours for acute hypoxaemic and/or hypercapnic respiratory failure. To be eligible for the study, participants had to demonstrate readiness for discontinuation of mechanical ventilation by successfully tolerating a spontaneous breathing trial. People were excluded if demonstrating persistent weaning failure (failed 3+ spontaneous breathing trials in 1 week), required a tracheostomy, were haemodynamically or neurologically unstable (unable to respond to direct simple orders), lack of co‐operation, experienced facial or cranial trauma, or active upper gastrointestinal bleeding or had a confirmed diagnosis of neuromuscular disease | |
| Interventions | Intervention: After passing the spontaneous breathing trial and study randomization and before extubation, participants received an MI‐E treatment (3 sessions) using the Cough Assist (Philips Respironics, Carlsbad, CA, USA) through the endotracheal tube with pressures set at 40 cm H2O for insufflation and ‐40 cm H2O for exsufflation. An insufflation/exsufflation time ratio of 3:2 seconds and a pause of 3 seconds between each cycle were used. 8 cycles were applied in every session with an abdominal thrust timed to the exsufflation cycle.In addition to standard medical therapy, in the first 48 hours after extubation, each participant received 3 daily MI‐E treatments via a lightweight, elastic oronasal mask. Treatments (3 sessions each) were divided between morning, afternoon, and night. No MI‐E treatments were performed after the 48‐hour study period. All MI‐E treatments were administered by a trained respiratory therapist, ICU physician, or nurse. Other post‐extubation management was the same as that for the control group Control: Participants received postextubation standard medical therapy, including supplemental oxygen (as needed), respiratory chest physiotherapy, bronchodilators, antibiotics, and other therapies as directed by the attending physician. Criteria for NIV included: respiratory rate > 35 beats/min; SpO2 < 90%; 20% variation of heart rate or blood pressure; dyspnoea with respiratory distress; PaO2 < 60 mm Hg; PaCO2 > 45 mmHg; pH < 7.35. NIV failure was declared when the criteria for its application were not resolved or the person demonstrated NIV intolerance in the first 2 hours of use. Noninvasive ventilation was provided via an ICU ventilator with noninvasive mode or via a portable pressure‐cycled ventilator through an oronasal mask as the first choice. Other interfaces, such as nasal, total face, helmet, and mouthpieces were used if the participant did not tolerate the oronasal mask. The fraction of inspired oxygen and the positive end‐expiratory pressure were titrated to maintain the arterial oxygen saturation above 90% (or PaO2 > 60 mmHg). Ventilator settings were subsequently adjusted as needed for the person’s comfort. The decision to discontinue noninvasive ventilation was left to the attending physician The decision to reintubate was that of the attending physician, who recorded the single most relevant reason for reintubation | |
| Outcomes | Primary: reintubation rate defined as no need for reintubation within the first 48 hrs of extubation Secondary outcomes Total ICU length of stay from admission to discharge Postextubation ICU length of stay (time from extubation to ICU discharge) NIV failure rate (not defined) | |
| Notes | Unclear if or who funded the study Two authors received fees for lecturing and for attending professional meetings from Philips Respironics, Inc., who have an interest in the subject of the manuscript | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | A “computer‐generated table” was used for random allocation |
| Allocation concealment (selection bias) | Low risk | The randomization table and allocation sequence were concealed both from the primary investigator and from all medical, respiratory therapy, and nursing staff of the ICU |
| Blinding of participants and personnel (performance bias) | Unclear risk | No blinding of clinical staff, researcher staff. or participants possible due to the nature of the intervention, but it is unclear whether this produced performance bias, particularly as reintubation was at the discretion of the attending physician who was not blinded |
| Blinding of outcome assessment (detection bias) | Unclear risk | Not specified in the paper whether outcome assessors were blinded, but unlikely to bias assessment of objective outcomes such as reintubation |
| Incomplete outcome data (attrition bias) | Low risk | No evidence that there were missing data. No attrition noted |
| Selective reporting (reporting bias) | Unclear risk | Outcomes match the registered protocol, but this was registered after completion of trial recruitment |
| Other bias | Unclear risk | Two of the study authors declared receiving funds for lecturing and attending professional meetings from Philips Respironics, the manufacturer of the Cough Assist Device used in this study, although the manufacturer did not provide funding or support for this trial |
| Methods | Single‐centre (USA, paediatric ICU) case‐control study; study period unclear, although historical controls were taken from the preceding 10 years | |
| Participants | 17 children (10 cases and 7 controls) with neuromuscular disease admitted for respiratory distress None of the cases was unable to sustain > 2 minutes of ventilator‐free breathing Children were excluded if, whether intubated or not, they could survive without using ventilatory support An additional participant was excluded for hypotension with cardiac failure secondary to terminal cardiomyopathy Historical controls comprised children with neuromuscular disease admitted to the participating unit in the preceding 10 years who failed conventional management before the inception of the extubation protocol, and received invasive ventilation via a tracheostomy | |
| Interventions | Intervention: Assisted coughing was initiated manually or mechanically if the SaO2 was < 95%. Participants were encouraged to first air‐stack to maximum lung volumes before receiving manual cough assistance. Manually‐assisted coughing was provided by an assistant compressing the upper abdomen in synchrony with the child's own cough. Mechanical insufflation‐exsufflation was provided via the endotracheal tube by the In‐exsufflator using inspiratory pressures of +35 to +45 cm H2O and expiratory pressures of ‐35 to ‐45 cm H2O. Cough flows were increased further by manually compressing the upper abdomen concomitantly with the forced exsufflation. Any episodic decreases in SaO2 < 95% were treated with assisted coughing until mucus was extruded and SaO2 levels returned to baseline Portable volume ventilators (PLV‐100, Respironics) with assist‐control mod and tidal volumes of 800 to 1500 mL and without positive end‐expiratory pressure (PEEP). Intubated children were managed conventionally with respect to ventilation, analgesia, sedation, and nutrition (nasogastric feeds). No weaning attempts were made. Extubation was attempted only when no supplemental oxygen was required to maintain an SaO2 of > 94% and when any chest radiograph abnormalities improved. All participants were extubated to continuous noninvasive intermittent positive pressure ventilation. After extubation, assisted peak cough flow was measured Control: The historical controls failed conventional management before the inception of our protocol and received a tracheostomy. | |
| Outcomes | Level of respiratory support at PICU discharge (nil; nighttime only; > 16 hours of support) Need for reintubation Upper respiratory infection after discharge (acute upper respiratory infections that necessitated reintroduction of the protocol) Hospital readmission Mortality after discharge Tracheostomy after discharge Length of stay | |
| Notes | Unclear if or who funded the study No mention of author conflicts of interest | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Non‐randomized study, therefore not assessed |
| Allocation concealment (selection bias) | Unclear risk | Non‐randomized study, therefore not assessed |
| Blinding of participants and personnel (performance bias) | Unclear risk | Non‐randomized study, therefore not assessed |
| Blinding of outcome assessment (detection bias) | Unclear risk | Non‐randomized study, therefore not assessed |
| Incomplete outcome data (attrition bias) | Unclear risk | Non‐randomized study, therefore not assessed |
| Selective reporting (reporting bias) | Unclear risk | Non‐randomized study, therefore not assessed |
| Other bias | Unclear risk | Non‐randomized study, therefore not assessed |
Cm H2O: centimetres of water; FiO2: Fraction of inspired oxygen; mm Hg: millimetres of mercury; ICU: intensive care unit; MI‐E: mechanical insufflation‐exsufflation; NIV: non‐invasive ventilation; PaO2: partial pressure (arterial) of oxygen; PEEP: positive end expiratory pressure; pH: acid‐base measured on logarithmic scale; PICU: paediatric intensive care unit; PMID: PubMed identification number; SpO2: oxygen saturation (peripheral)
Characteristics of excluded studies [ordered by study ID]
Ir a:
| Study | Reason for exclusion |
| Non‐randomized study without a control group | |
| Non‐randomized study without a control group | |
| Non‐randomized study without a control group | |
| Non‐randomized study without a control group | |
| Intervention did not comprise a cough augmentation technique | |
| Participants were not using invasive ventilatory support at study entry and therefore cough augmentation techniques were used to prevent intubation as opposed facilitating weaning and preventing reintubation | |
| Intervention did not comprise a cough augmentation technique | |
| Patients were excluded if requiring invasive ventilatory support | |
| Non‐randomized study without a control group | |
| Cross‐over randomized controlled trial. This design means it is impossible to determine which intervention impacts on fixed clinical outcomes such as extubation success | |
| Patients were excluded if requiring invasive ventilatory support | |
| Cross‐over randomized controlled trial. This design means it is impossible to determine which intervention impacts on fixed clinical outcomes such as extubation success | |
| Non‐randomized study without a control group | |
| Participants were not using invasive ventilatory support at study entry and therefore cough augmentation techniques were used to prevent intubation as opposed facilitating weaning and preventing reintubation | |
| Control arm also included a cough augmentation technique (manually‐assisted cough) |
Study flow diagram.
Risk of bias summary: review authors' judgements about each risk of bias item for each included study.
| Cough augmentation techniques compared with no cough augmentation techniques for critically‐ill, mechanically‐ventilated adults and children | ||||||
| Patient or population: critically‐ill mechanically‐ventilated adults and children requiring extubation from mechanical ventilation Settings: High acuity setting including ICUs, weaning centres, respiratory intermediate care units, and high‐dependency units in Europe and North America Intervention: Cough augmentation techniques including lung volume recruitment, manually‐assisted cough and mechanical insufflation‐exsufflation Comparison: No cough augmentation | ||||||
| Outcomes | Illustrative comparative risks* (95% CI) | Relative effect | No of Participants | Quality of the evidence | Comments | |
| Assumed risk | Corresponding risk | |||||
| No cough augmentation | Cough augmentation | |||||
| Extubation successa | 87% | 83% | RR 1.58 (1.13 to 2.20) | 75 participants | ⊕⊝⊝⊝ | |
| Duration of mechanical ventilationb | 4 days | 11.7 days | Mean difference ‐6.1 days (‐8.4 to ‐3.8) | 75 participants | ⊕⊝⊝⊝ | |
| ICU mortalitya | 28% | 0% | Not calculable, as no event rates in the 1 trial reporting data on this outcome | 75 participants | ⊕⊝⊝⊝ | |
| Adverse events 1. Hypotensionc 2. Hypertensiond 3. Secretion encumbrance resulting in severe hypoxaemia requiring reintubationc | 12% 6.5% 9% | 3% 10% 6% | RR 3.4 (0.1 to 81.3) RR 3.0 (0.1 to 65.9) RR 0.25 (0.1 to 1.1) | 75 participants 20 participants 1 trial 75 participants | ⊕⊝⊝⊝ | |
| *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% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). aAssumed risk is derived from a large international cohort study of mechanical ventilation and weaning by Esteban 2013 and refers to the rate of reintubation reported in this study. bAssumed risk is derived from a large international cohort study of mechanical ventilation and weaning by Esteban 2008. cAssumed risk is derived from adverse events (hypotension and hypoxaemia) reported in a systematic review of recruitment manoeuvres in people with acute lung injury (Fan 2008). dAssumed risk is derived from rates of hypertension noted during 6691 episodes of endotracheal suctioning (Evans 2014). | ||||||
| GRADE Working Group grades of evidence | ||||||
| 1We based our downgrading decisions from high to very low on unclear risk of bias, inability to assess consistency or publication bias, and uncertainty about the estimate of effect due to the limited number of studies contributing outcome data. 2We based our downgrading decisions from high to very low on unclear risk of bias, inability to assess consistency or publication bias, imprecision due to wide confidence intervals, and uncertainty about the estimate of effect due to the limited number of studies contributing outcome data. We have not included reintubation or weaning success in the 'Summary of findings' table as no studies reported these outcomes. | ||||||
| Cough augmentation | No cough augmentation | |||||
| Study | N | mean (SD) | N | mean (SD) | mean difference | 95% CIs |
| Duration of mechanical ventilation (days) | ||||||
| 35 | 11.7 (3.5) | 40 | 17.8 (6.4) | ‐6.1 | ‐8.4 to ‐3.8 | |
| ICU length of stay (days)1 | ||||||
| 35 | 16.9 (11.1) | 40 | 19.3 (8.1) | ‐2.4 | ‐6.9 to 2.01 | |
| 10 | 47.6 (7.3) | 7 | 51.1 (7.8) | ‐3.5 | ‐10.8 to 3.8 | |
| 1The ICU length of stay for cases reported in Niranjan 1998 includes the four cases that were not intubated at the start of the study. | ||||||
| Cough augmentation | No cough augmentation | |||||
| Study | Events | Total | Events | Total | RR | 95% CIs |
| Haemodynamic compromise | ||||||
| 1 | 35 | 0 | 40 | 3.4 | 0.1 to 81.3 | |
| 1 | 10 | 0 | 10 | 3.0 | 0.1 to 65.9 | |
| Secretion encumbrance resulting in severe hypoxaemia requiring reintubation | ||||||
| 2 | 35 | 9 | 40 | 0.25 | 0.1 to 1.1 | |
