We read with interest the study by Lal, et al. [1] on the utility of nasal bubble continuous positive airway pressure (CPAP) in children with moderate to severe bronchiolitis. The authors noted a significant reduction in respiratory rate (cut-offs defined a priori) in the CPAP limb of the study. CPAP helps in bronchiolitis by splinting airways, thereby reducing airway collapse and atelectasis and improving oxygenation. Here, we comment on a few points in this study and present findings of two other original studies from resource-limited settings [2,3] not cited in this study.

Using only the first hour of therapy to judge improvement may be inadequate as pathology in bronchiolitis is likely to continue for at least 24-48 hours, necessitating longer support. Initial improvement in respiratory rate could have been related to non-respiratory factors like improved hydration, fever control and decreased anxiety. Sustained improvement in respiratory parameters, assessing need for additional/alternative respiratory support in either treatment arm, post-1 hour of therapy would have helped substantiate the initial improvement as respiratory. In a setting where bubble CPAP maybe the only means of non-invasive support available, it is important to know if children in standard care arm were offered a trial of CPAP in case of non-improvement?

We bring your attention to a prospective study from our center [2], where indigenous nasal bubble CPAP in children with hypoxemic clinical pneumonia (pneumonia n=240 and bronchiolitis n=90) aged 1 month to 12 years, was associated with good response and negligible failure rate and complications. Of the 330 enrolled children, 204 were initiated on nasal prongs oxygen, 110 with increased work of breathing and/or SpO2 <92% on bubble CPAP, and 16 were intubated at admission. The Respiratory Distress Assessment Instrument (RDAI) tool objectively assessed worsening respiratory distress or improvement. 53 children on nasal prongs were switched to bubble CPAP for worsening respiratory distress. Only 3 children from the bubble CPAP group required intubation.

Chisthi, et al. [3], in their study in Bangladesh, enrolled children <5 years of age with pneumonia/bronchiolitis to receive either bubble CPAP, low flow oxygen or high flow oxygen. They found that treatment failure and mortality were lower in the bubble CPAP arm as compared to the low flow oxygen therapy group; the trial was terminated early due to mortality difference (higher in low flow oxygen group).

1. Lal SN, Kaur J, Anthwal P, Bahl P, Puliyel JM. Continuous positive airway pressure in bronchiolitis: A randomized controlled trial. Indian Pediatr. 2018;55:27-30

2. Jayashree M, KiranBabu H, Singhi S, Nallasamy K. Use of nasal bubble CPAP in children with hypoxemic clinical pneumonia—Report from a resource limited set-up. J Trop Pediatr. 2016;62:69-74.