Sunday, June 24, 2012

NAVA vs. Pressure Support in Pediatric Patients

Pressure Support Ventilation can be  associated with 8 types of patient ventilator asynchronies. 


The researchers sought to determine if neurally adjusted ventilatory assist (NAVA) enhances asynchrony, ventilatory drive, breath-to-breath variability and COMFORT score when compared to pressure support (PS).  Twelve pediatric patients with asynchrony (auto-triggering, double triggering or non-triggered breaths) were enrolled in a non-randomized short-term cross-over trial.  Four sequential 10-min periods of data were recorded after 20 min of ventilatory stabilization (wash-out) at pre-determined settings.


The median asynchrony index was notably lower during NAVA than during 2-PS(opt) and 4-PS(opt). In NAVA mode, the NAVA trigger accounted for approximately 66% of triggered breaths. The median trigger delay with respect to neural inspiratory time was considerably lower during NAVA than during 2-PS(opt) and 4-PS(opt). The median electrical activity of the diaphragm (EAdi) change during trigger delay normalized to maximum inspiratory. EAdi difference was notably lower during NAVA than during 2-PS(opt) and 4-PS(opt).  Additionally, NAVA produced a significantly higher coefficient of variation of tidal volume than 2-PS(opt) and 4-PS(opt). The median comfort score during NAVA was lower than that during 2-PS(opt) and 4-PS(opt).


This research shows that NAVA results in improved synchrony, reduced ventilatory drive, increased breath-to-breath mechanical variability and improved patient comfort compared to optimized PS.


De le Olivia, P., Schuffelmann, C., Gomez-Zamora, A., & Kacmarek, R. M., (2012). Asynchrony, neural drive, ventilatory variability and COMFORT: NAVA versus pressure support in pediatric patients. A non-randomized cross-over trialIntensive Care Medicine, 38(5), 838-846.