Respiratory effort during noninvasive positive pressure ventilation and continuous positive airway pressure in severe acute viral bronchiolitis

Abstract

Objectives: To assess if noninvasive positive pressure ventilation (NIPPV) is associated with a greater reduction in respiratory effort as compared to continuous positive airway pressure (CPAP) during severe acute bronchiolitis, with both supports set either clinically or physiologically. Methods: Twenty infants (median [IQR] age 1.2 [0.9; 3.2] months) treated <24 h with noninvasive respiratory support (CPAP Clin, set at 7 cmH2O, or NIPPV Clin) for bronchiolitis were included in a prospective single-center crossover study. Esogastric pressures were measured first with the baseline support, then with the other support. For each support, recordings were performed with the clinical setting and a physiological setting (CPAP Phys and NIPPV Phys), aiming at normalising respiratory effort. Patients were then treated with the optimal support. The primary outcome was the greatest reduction in esophageal pressure–time product (PTPES/min). Other outcomes included improvement of the other components of the respiratory effort. Results: NIPPV Clin and Phys were associated with a lower PTPES/min (164 [105; 202] and 106 [78; 161] cmH2O s/min, respectively) than CPAP Clin (178 [145; 236] cmH2O s/min; p = 0.01 and 2 × 10−4, respectively). NIPPV Clin and Phys were also associated with a significant reduction of all other markers of respiratory effort as compared to CPAP Clin. PTPES/min with NIPPV (Clin or Phys) was not different from PTPES/min with CPAP Phys. There was no significant difference between physiological and clinical settings. Conclusion: NIPPV is associated with a significant reduction in respiratory effort as compared to CPAP set at +7 cmH2O in infants with severe acute bronchiolitis. CPAP Phys performs as well as NIPPV Clin.