A comparison of leak compensation during pediatric noninvasive ventilation: a lung model study.

BACKGROUND: Ventilators used for noninvasive ventilation (NIV) must be able to synchronize in the presence of system leaks. We compared the ability of 7 ICU ventilators and 3 dedicated NIV ventilators to compensate for leaks during pediatric NW. METHODS: Using a lung simulator, we compared the Magnet Servo-i, Drager V500, Drager Carina, Covidien PB840, Respironics V60, Respironics Vision, GE Healthcare/Engstrom Carestation, Care Fusion Avea, Hamilton C3, and Hamilton G5 during increasing (n = 6) and decreasing leaks (n = 6). With a lung simulator we tested 4 leak levels (baseline [BL] 2-3 L/min, L1 5-6 L/min, L2 9-10 L/min, and L3 19-20 L/min); 3 patient weights (10, 20, and 30 kg); and 3 lung mechanics scenarios (normal, obstructive, and restrictive). The ventilator settings were NIV mode, pressure support of 10 cm H2O, and PEEP of 5 cm H2O. The synchronization rate (synchronized cycles/total simulated respirations) was recorded for each ventilator and each leak scenario. Synchronization was defined as triggering without auto-triggering, miss-triggering, delayed cycling, or premature cycling. RESULTS: The mean synchronization rate across all ventilators was 68 +/- 27% (range 23-96%) and marked differences existed between the ventilators (P < .001). Significant differences in synchronization rate were observed between the 10-kg model (mean 57 +/- 30%, range 17-93%), the 20-kg model (69 +/- 30%, 25-98%), and the 30-kg models (77 +/- 22%, 28-97%) (P < .001). The synchronization rate for the obstructive model (60 +/- 30%, 9-94%) was significantly different from the normal model (71 +/- 29%, 18-98%) and the restrictive model (72 +/- 28%, 23-98%) (P < .001). The PB840 and the C3 had synchronization rates over 90% overall across all body weights, all lung mechanic profiles, and all leak levels. CONCLUSIONS: Leak compensation in NIV for pediatric use can partially compensate for leaks, but varies widely among ventilators, patient weights, and lung mechanics.