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

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.