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| Pressure Support Ventilation can be associated with 8 types of patient ventilator asynchronies. |
Overview
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.
Results
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).
Conclusion
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.
Reference
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 trial. Intensive Care Medicine, 38(5), 838-846.