6 cmH2O continuous positive airway pressure versus conventional oxygen therapy in severe viral bronchiolitis: A randomized trial

Abstract

Objective To compare the effects of nasal continuous positive airway pressure (nCPAP) and conventional oxygen therapy on the clinical signs of respiratory distress and the respiratory muscle workload in acute viral bronchiolitis. Design Prospective, randomized, monocentric study carried out in the pediatric intensive care unit (PICU) of a university hospital. Patients Infants <6 months old, admitted to the PICU with severe respiratory syncytial virus bronchiolitis. Intervention The patients were randomized into two groups for 6 hr. The nCPAP group (n = 10) received 6 cmH2O pressure support delivered by a jet flow generator and the control group (n = 9) received an air/oxygen mixture from a heated humidifier. Respiratory distress was assessed by the modified Wood's clinical asthma score (m-WCAS), and inspiratory muscle work was evaluated by calculating the pressure-time product per breath (PTP insp/breath) and per minute (PTPinsp/min) from the esophageal pressure (Pes) recordings. Measurements and Main Results Compared with control condition, nCPAP decreased m-WCAS [-2.4 (1.05) vs. -0.5 (1.3), P = 0.03], PTPesinsp/breath [-9.7 (5.7) vs. -1.4 (8.2), P = 0.04], PTPesinsp/min [-666 (402) vs. -116 (352), P = 0.015], and FiO 2 [-7 (10) vs. +5 (15), P = 0.05]. Significant worsening of m-WCAS was only observed in the control group (4/9 vs. 0/10, P = 0.03). Conclusions nCPAP rapidly decreased inspiratory work in young infants with acute bronchiolitis. Improvement in the respiratory distress score at 6 hr was proportional to the initial clinical severity, suggesting the importance of rapid nCPAP initiation in the more severe forms of the disease. © 2012 Wiley Periodicals, Inc.