Noninvasive Neurally Adjusted Ventilatory Assist in Infants With Bronchiolitis: Respiratory Outcomes in a Single-Center, Retrospective Cohort, 2016–2018

Abstract

Objectives: To describe our experience of using noninvasive neurally adjusted ventilatory assist (NIV-NAVA) in infants with bronchiolitis, its association with the evolution of respiratory effort, and PICU outcomes. Design: Retrospective analysis of a prospectively curated, high-frequency electronic database. Setting: A PICU in a university-affiliated maternal-child health center in Canada. Patients: Patients younger than 2 years old who were admitted with a diagnosis of acute bronchiolitis and treated with NIV-NAVA from October 2016 to June 2018. Interventions: None. Measurements and Main Results: Patient characteristics, as well as respiratory and physiologic parameters, including electrical diaphragmatic activity (Edi), were extracted from the electronic database. Respiratory effort was estimated using the modified Wood Clinical Asthma Score (mWCAS) and the inspiratory Edi. A comparison in the respiratory effort data was made between the 2 hours before and 2 hours after starting NIV-NAVA. In the two seasons, 64 of 205 bronchiolitis patients were supported with NIV-NAVA. These 64 patients had a median (interquartile range [IQR]) age of 52 days (32–92 d), and there were 36 of 64 males. Treatment with NIV-NAVA was used after failure of first-tier noninvasive respiratory support; 25 of 64 patients (39%) had at least one medical comorbidity. NIV-NAVA initiation was associated with a moderate decrease in mWCAS from 3.0 (IQR, 2.5–3.5) to 2.5 (IQR, 2.0–3.0; p < 0.001). NIV-NAVA initiation was also associated with a statistically significant decrease in Edi (p < 0.01). However, this decrease was only clinically relevant in infants with a 2-hour baseline Edi greater than 20 μV; here, the before and after Edi was 44 μV (IQR, 33–54 μV) compared with 27 μV (IQR, 21–36 μV), respectively (p < 0.001). Overall, six of 64 patients (9%) required endotracheal intubation. Conclusions: In this single-center retrospective cohort, in infants with bronchiolitis who were considered to have failed first-tier noninvasive respiratory support, the use of NIV-NAVA was associated with a rapid decrease in respiratory effort and a 9% intubation rate.