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

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 cmH ₂ O, 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 (PTP _ES /min). Other outcomes included improvement of the other components of the respiratory effort.
Results: NIPPV Clin and Phys were associated with a lower PTP _ES /min (164 [105; 202] and 106 [78; 161] cmH ₂ O s/min, respectively) than CPAP Clin (178 [145; 236] cmH ₂ O 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. PTP _ES /min with NIPPV (Clin or Phys) was not different from PTP _ES /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 cmH ₂ O in infants with severe acute bronchiolitis. CPAP Phys performs as well as NIPPV Clin.
(© 2023 The Authors. Pediatric Pulmonology published by Wiley Periodicals LLC.)