title: Use of continuous positive airway pressure (CPAP) in acute viral bronchiolitis: a systematic review.
abstract: BACKGROUND
  Continuous positive airway pressure (CPAP), used either alone or associated with heliox (CPAP-He), has become a popular therapeutic option for bronchiolitis. This systematic review assesses the impact of CPAP on endotracheal intubation, carbon dioxide pressure (PCO(2) ) and respiratory distress in patients with bronchiolitis.
  
  
  METHODS
  Systematic search including studies that used CPAP or CPAP-He in infants with bronchiolitis admitted to a PICU. Data analysis included descriptive statistics and the GRADE system.
  
  
  RESULTS
  Five CPAP (one crossover randomized controlled trial [RCT] and four before-after studies) and three CPAP-He (one quasi-RCT and two before-after) studies were included. CPAP was reported to reduce PCO(2) (-6.9 to -11.7 mmHg, respectively, P < 0.015), respiratory rate (-12 to -16 breaths/min after 2 hr, P < 0.01) and the modified Wood clinical asthma score (mWCAS, -2.2 points after 1 hr, P < 0.01). CPAP-He studies observed decreases in PCO(2) (-9.7 mmHg, P < 0.05), mWCAS (-2.12 points, P < 0.001), and respiratory rate (-8 to -13.7 breaths/min, P < 0.05) after 1 hr of treatment. Endotracheal intubation rates ranged from 0-12.5% (CPAP-He) to 17-27% (CPAP). After applying the GRADE system, the quality of evidence for a beneficial effect of CPAP and CPAP-He was classified as low.
  
  
  CONCLUSIONS
  The evidence supporting the use of CPAP to reduce PCO(2) and respiratory distress in bronchiolitis is of low methodological quality, and there is no conclusive evidence that CPAP reduces the need for intubation. No definitive conclusions could be drawn about the CPAP-He effect. Further research using higher quality methodology is needed to clarify the beneficial role of these interventions.
authors: Division of Pediatric Critical Care, Department of Pediatrics, McGill University, Montreal, QC, Canada.
authors: Matthew
authors: M
authors: Donlan
authors: Patricia S
authors: PS
authors: Fontela
authors: Pramod S
authors: PS
authors: Puligandla