Non-invasive Neurally Adjusted Ventilatory Assist (NAVA) in the pediatric ICU: assessing optimal Edi compliance.

Background: Bronchiolitis patients are supported with non-invasive conventional modalities (HFNC, CPAP and BiPAP). Neurally Adjusted Ventilatory Assist (NAVA) is a newer mode which supports based on electrical activity of the diaphragm (Edi). It is unclear if non-invasive NAVA is used within optimal operational parameters. The study aim was to evaluate Edi compliance.
Methods: A retrospective chart review of bronchiolitis patients admitted to the PICU from January 2015 to January 2018 was undertaken. NAVA compliance within optimal parameters (defined as Edi peak values between 5-15 μV and Edi min < 1μV) was assessed as the primary outcome. Secondary outcomes included PICU length of stay (LOS), duration to minimal respiratory support (defined as 4 L/min or less on HFNC) and intubation rate in the conventional (non-NAVA) and non-invasive NAVA.
Results: Sixty-three patients with a mean age of 6.89 months with 30 on NAVA and 33 on non-NAVA support were analyzed. Compliance with optimal Edi peak and Edi min was 50.4% (±37.5%) and 33.8% (±26.2%) respectively. Regression models for PICU LOS with minimal respiratory support and for 1L/kg of HFNC showed adjusted R2= 0.96 and 0.92, respectively. The mean PICU stay for NAVA was 146.00 hrs. (±66.26) versus 69.58 hrs. (±57.69) for the non-NAVA group (p<0.001). Duration to minimal respiratory support was 125.40 hrs. (±54.90) for NAVA versus 58.03 hrs. (±58.97) for non-NAVA group (p<0.001). A higher intubation rate was found in the NAVA group (13.33% versus 3.03%, p=0.296).
Conclusions: We found suboptimal compliance with operational parameters with non-invasive NAVA support. There was longer PICU LOS, time to minimal respiratory support in the NAVA compared to the non-NAVA support.