Is continuous positive airway pressure by helmet effective in the treatment of infants with bronchiolitis?

BEEM Bottom Line

Why is this study important?

Bronchiolitis caused by respiratory syncytial virus (RSV) is a common cause of emergency department (ED) visits among neonates and may result in acute respiratory failure. Continuous positive airway pressure (CPAP) is often used as first-line noninvasive respiratory support. However, it may not be well tolerated. This is the first study comparing helmet delivery of CPAP to the traditional face mask CPAP delivery in infants.

Which, if any, threats to validity are most likely to have an impact on the results and how?

Randomized controlled trials that are stopped early have been demonstrated to report implausibly large treatment effects favoring the intervention, particularly when the number of events is small.[1] This trial is no different except that the statistically significant difference (p = 0.009) reported could not be reproduced from the outcome data reported. 

How do the key results compare with the current evidence?

The current literature is quite limited but suggests that helmet delivery of CPAP is feasible and may be better tolerated than a traditional face mask.[2][3] This study agrees with these conclusions; however, due to the small number of events, it does not provide enough evidence to conclude that helmet CPAP is superior to other delivery methods of CPAP.

How should this study impact the care of ED patients?

This study supports the feasibility of helmet-delivered CPAP, however, until more methodologically robust research is done, the evidence is insufficient to warrant a practice change away from the standard approach of face mask CPAP currently used across most healthcare facilities.

Study Summary

Pubmed ID


Study Reference

Chidini G, Piastra M, Marchesi T, et al. Continuous positive airway pressure with helmet versus mask in infants with bronchiolitis: an RCT. Pediatrics 2015;135:e868–75.

Study Design

Multicenter, nonblinded, randomized controlled trial.


Included: Children (6–12 months old) with a diagnosis of RSV infection consistent with clinical features, positive nasopharyngeal swabs, and predefined acute respiratory failure admitted to 3 Italian pediatric intensive care units.

Excluded: Need for intubation; Glasgow Coma Scale score < 12; acidosis (pH < 7.25); cough or gag reflex impairment; upper airway obstruction; facial/gastric surgery; need for vasopressor or inotropes; enrollment in another study.


Helmet CPAP in increasing from 4–10 cm H2O (by 2 cm H2O) to obtain pulse oxygen saturation ≥ 94% with fraction of inspired oxygen ≤ 0.6 continuously for 24 hours until oxygenation and clinical status improved.


Face mask CPAP same as above.


Primary: Treatment failure defined as discontinuation of CPAP because of intolerance of or need for intubation. Intolerance was assessed using the Objective Pain Scale (OPS) and the COMFORT scale.

Secondary: CPAP application time; number of patients requiring sedation; and complications.

Key Results

N = 30 patients.

Sig. Outcome Outcome Helmet/Total vs. Outcome Face Mask/Total NNT (95% CI)
NSS Treatment failure 3/17 vs. 7/13 2.8 (1.5 to ∞)
SS Requiring sedation 6/17 vs. 13/13 1.7 (1.5 to 4.6)
NSS Complications 0/17 vs. 0/17 N/A

CI = confidence interval; N/A = not available; NNT = number needed to treat; NSS = not statistically significant; Sig. = significance; SS = statistically significant.

BEEM Critique

Risk of Bias Assessment

Appraisers (A)
A1 A2 A3
1 The patients were recruited consecutively. Yes Yes Yes
2 The patients were adequately randomized (allocation sequence adequately generated). Yes Yes Yes
3 The allocation sequence was adequately concealed. Yes Yes Yes
4 The patients in all groups were similar with respect to prognostic factors. Yes Yes Yes
5 All clinicians, patients, and outcome assessors were unaware of group allocation. No No No
6 All groups were treated equally except for the intervention. Yes Yes Yes
7 The follow-up was complete given the study duration (100% if in-hospital follow-up). Yes Yes Yes
8 The patients were analyzed in the groups to which they were randomized (ITT). Yes Yes Yes
9 All patient-important outcomes were considered. No No No
10 The effect size of the primary outcome is clinically significant. No No No

A = appraiser; ITT = intention to treat.

Funding & Conflicts of Interest


No external funding.

Conflicts of Interest


Potential Threats to Validity


Type I error due to small sample size secondary to early trial termination.

Selection Bias

None identified.

Measurement Bias

No time specification for outcomes. Tools to assess intolerance to CPAP may not be ideal. The OPS assesses crying as an item, but it is not clear how this was assessed during CPAP application or if the infant was sedated. Similarly, the OPS assesses complaints of pain, but the participants are preverbal. Behavioural measures of distress may have been more appropriate

Analysis Bias

Sample size requirement was 30 per group, but the study was stopped following an interim analysis because it was believed that the primary end point was achieved in favor of helmet treatment.


None identified.




Melissa Chan, MD, FRCPC
Division of Pediatric Emergency Medicine, Department of Pediatrics, University of Alberta, Edmonton, AB, Canada


Worster A; Poonai N; Chan M.

Competing Interest Disclosure

Dr. Chan - No conflicts of interest (ICMJE)


  1. Montori VM, Devereaux PJ, Adhikari NK, et al. Randomized trials stopped early for benefit: a systematic review. JAMA 2005;294:2203–9.
  2. Codazzi D, Nacoti M, Passoni M, et al. Continuous positive airway pressure with modified helmet for treatment of hypoxemic acute respiratory failure in infants and a preschool population: a feasibility study. Pediatr Crit Care Med 2006;7:455–60.
  3. Trevisanuto D, Grazzina N, Doglioni N, et al. A new device for administration of continuous positive airway pressure in preterm infants: comparison with a standard nasal CPAP continuous positive airway pressure system. Intensive Care Med 2005;31:859–64.