Nasal continuous positive airway pressure decreases respiratory muscles overload in young infants with severe acute viral bronchiolitis

Abstract

Objective: To determine the efficacy of nasal continuous positive airway pressure (nCPAP) on respiratory distress symptoms and respiratory effort in young infants with acute respiratory syncytial virus bronchiolitis.

Design: Prospective study.

Setting: The paediatric intensive care unit of a university hospital.

Patients: Twelve infants less than 3 months of age, with severe respiratory distress.

Interventions: Respiratory distress was quantified with a specific scoring system. Oesophageal pressure (Pes) was measured during spontaneous ventilation before and after nCPAP, delivered through an infant-adapted ventilator. Simultaneous recording of gastric pressure (Pgas) was performed in the five oldest patients.

Measurements and results: The respiratory distress score decreased after nCPAP, particularly accessory muscles' use and expiratory wheezing. The breathing pattern was modified, with shorter inspiratory and longer expiratory time. Pes swings and PTPes(insp), two indices of inspiratory effort, were reduced by 54 (+/-4)% and 59 (+/-5)%. PTPgas(exp), an indicator of expiratory muscles activity, was completely abolished. A significant correlation was observed between the respiratory distress score and Pes swings at baseline and after nCPAP.

Conclusions: In young infants with severe acute respiratory syncytial virus bronchiolitis, nCPAP rapidly unloads respiratory muscles and improves respiratory distress symptoms.