Is continuous positive airway pressure (CPAP) better or worse than supportive treatment for children with acute bronchiolitis?
Bronchiolitis is inflammation of the small airways in the lungs, and a common cause for emergency department treatment amongst young children. Children with acute bronchiolitis usually receive supportive care that includes ensuring adequate hydration, with oxygen added as needed. Treatment with CPAP involves providing positive air pressure by blowing air from a pump to keep airways open, and may be effective for children with bronchiolitis. This is an update of a review first published in 2015 and updated in 2019.
15 August 2021
We included three small randomised controlled trials (studies in which participants are randomly assigned to one of two or more treatment groups) involving a total of 122 children aged up to 12 months who were diagnosed with bronchiolitis. We did not identify any new trials for inclusion in this update. The three studies were conducted at single centres in France, the UK, and India. All studies compared CPAP with standard therapy.
Study funding sources
One study was funded by a university hospital; one reported that no funding was received; and the third study did not mention the funding source.
The limited available evidence prevented any conclusions regarding the effect of CPAP on the need for mechanical ventilation in children with bronchiolitis. Limited, low certainty evidence indicated that breathing improved (respiratory rate decreased) in children who received CPAP. The length of time children spent in the hospital was similar between the CPAP and the standard therapy groups. No children in the studies were reported to have died. The studies did not report on time to recovery, change in partial oxygen pressure, how often children were admitted to hospital from the emergency department, how long children were in the emergency department, or the need for intensive care admission. There were no local nasal effects or shock as reported by one study. No children were reported to have had air in the cavity between the lungs and the chest wall, causing lung collapse (pneumothorax) as reported by one study. Two studies did not report on local nasal effects, shock, or pneumothorax. The study added in the previous update of the review in 2019 contributed data to the assessment of respiratory rate and the need for mechanical ventilation.
Certainty of the evidence
We found limited, low certainty evidence related to CPAP for children with bronchiolitis. The certainty of the evidence was reduced due to high risk of bias, losses to follow-up, selective reporting, and the wide range of values reported by the included studies.
The use of CPAP did not reduce the need for mechanical ventilation in children with bronchiolitis, although the evidence was of low certainty. Limited, low certainty evidence suggests that breathing improved (a decreased respiratory rate) in children with bronchiolitis who received CPAP; this finding is unchanged from the 2015 review and 2019 update. Due to the limited available evidence, the effect of CPAP in children with acute bronchiolitis is uncertain for our other outcomes. Larger, adequately powered trials are needed to evaluate the effect of CPAP for children with acute bronchiolitis.
Acute bronchiolitis is one of the most frequent causes of emergency department visits and hospitalisation in children up to three years of age. There is no specific treatment for bronchiolitis except for supportive treatment, which includes ensuring adequate hydration and oxygen supplementation. Continuous positive airway pressure (CPAP) aims to widen the lungs' peripheral airways, enabling deflation of overdistended lungs in bronchiolitis. Increased airway pressure also prevents the collapse of poorly supported peripheral small airways during expiration. Observational studies report that CPAP is beneficial for children with acute bronchiolitis. This is an update of a review first published in 2015 and updated in 2019.
To assess the efficacy and safety of CPAP compared to no CPAP or sham CPAP in infants and children up to three years of age with acute bronchiolitis.
We conducted searches of CENTRAL (2021, Issue 7), which includes the Cochrane Acute Respiratory Infections Group Specialised Register, MEDLINE (1946 to August 2021), Embase (1974 to August 2021), CINAHL (1981 to August 2021), and LILACS (1982 to August 2021) in August 2021. We also searched the US National Institutes of Health Ongoing Trials Register ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) for completed and ongoing trials on 26 October 2021.
We considered randomised controlled trials (RCTs), quasi-RCTs, cross-over RCTs, and cluster-RCTs evaluating the effect of CPAP in children with acute bronchiolitis.
Two review authors independently assessed study eligibility, extracted data using a structured pro forma, analysed data, and performed meta-analyses. We used the Cochrane risk of bias tool to assess risk of bias in the included studies. We created a summary of the findings table employing GRADEpro GDT software.
We included three studies with a total of 122 children (62/60 in intervention/control arms) aged up to 12 months investigating nasal CPAP compared with supportive (or 'standard') therapy. We included one new trial (72 children) in the 2019 update that contributed data to the assessment of respiratory rate and the need for mechanical ventilation for this update. We did not identify any new trials for inclusion in the current update. The included studies were single-centre trials conducted in France, the UK, and India. Two studies were parallel-group RCTs, and one study was a cross-over RCT. The evidence provided by the included studies was of low certainty; we made an assessment of high risk of bias for blinding, incomplete outcome data, and selective reporting, and confidence intervals were wide.
The effect of CPAP on the need for mechanical ventilation in children with acute bronchiolitis was uncertain due to risk of bias and imprecision around the effect estimate (risk difference −0.01, 95% confidence interval (CI) −0.09 to 0.08; 3 RCTs, 122 children; low certainty evidence). None of the trials measured time to recovery. Limited, low certainty evidence indicated that CPAP decreased respiratory rate (decreased respiratory rate is better) (mean difference (MD) −3.81, 95% CI −5.78 to −1.84; 2 RCTs, 91 children; low certainty evidence). Only one trial measured change in arterial oxygen saturation (increased oxygen saturation is better), and the results were imprecise (MD −1.70%, 95% CI −3.76 to 0.36; 1 RCT, 19 children; low certainty evidence). The effect of CPAP on change in arterial partial carbon dioxide pressure (pCO₂) (decrease in pCO₂ is better) was imprecise (MD −2.62 mmHg, 95% CI −5.29 to 0.05; 2 RCTs, 50 children; low certainty evidence). Duration of hospital stay was similar in both the CPAP and supportive care groups (MD 0.07 days, 95% CI −0.36 to 0.50; 2 RCTs, 50 children; low certainty evidence). Two studies did not report pneumothorax, but pneumothorax did not occur in one study. No studies reported occurrences of deaths. Several outcomes (change in partial oxygen pressure, hospital admission rate (from the emergency department to hospital), duration of emergency department stay, and need for intensive care unit admission) were not reported in the included studies.