1. CPAP and High-Flow Nasal Cannula Oxygen in Bronchiolitis
Ian P. Sinha, PhD, Antonia K.S. McBride, MBChB, Rachel Smith, MBChB, Ricardo M. Fernandes, MD 
CHEST 
Volume 148, Issue 3, Pages (September 2015)
DOI: /chest
Copyright © 2015 The American College of Chest Physicians Terms and Conditions

2. Figure 1
Mechanisms of respiratoryfailure in bronchiolitis andpossible actions of CPAP and HFNC. Intraluminal mucus and debris cause airway obstruction (A) and increased resistance (B). Warmed, humidified oxygen can reduce intraluminal mucus (A1), and positive end-expiratory pressure (PEEP) from CPAP (and possibly HFNC) might help to overcome resistance (B1). Intraluminal obstruction causes atelectasis (C). Increased PEEP prevents atelectasis (C1). Increased interstitial edema limits oxygen transport to blood, contributing to hypoxemic respiratory failure (D). CPAP and HFNC are efficient methods of delivering high oxygen concentrations to the lower airways (D1), which may overcome this. All these mechanisms cause respiratory muscle fatigue (E). Overcoming airway resistance (A1 and B1), reducing atelectasis (C1), and increasing oxygen delivery to the blood (D1) can help to reduce this respiratory muscle fatigue (E1). Although primarily a small airways disease, increased respiratory efforts can cause upper airway collapse in infants (F), and PEEP may help to reduce this (F1). HFNC = high-flow nasal cannula.
CHEST  , DOI: ( /chest )
Copyright © 2015 The American College of Chest Physicians Terms and Conditions