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 NIV. METHODS Using a lung simulator, we compared the Maquet Servo-i, Dräger V500, Dräger Carina, Covidien PB840, Respironics V60, Respironics Vision, GE Healthcare/Engström Carestation, CareFusion 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.