A Comparison of Leak Compensation During Pediatric Noninvasive Ventilation: A Lung Model Study

Abstract

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 H 2 O, and PEEP of 5 cm H 2 O. 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.

Simulation Studies for Device Evaluation

“…Therefore, we implemented the same experiment as that performed in an older study (10 y ago) 2 using the same parameters for the static portion; used the same dynamic experiments as used in many previous bench studies. [3][4][5][6][7][8] In addition, we showed that the most recent turbine transport ventilators are a breakthrough in the field of transport ventilators even if they have some limitations, and their performances are close to those of ICU ventilators.…”

“…5 Thus, the larger the tidal volume (V T ) and the higher the inspiratory flow of the "drive" ventilator, the higher the simulated inspiratory effort. A good way to quantify the inspiratory effort is by measuring the occlusion pressure (also called P 0.1 ) as described by Boussen et al 6 Many recent studies [7][8][9] have used a more sophisticated device: the ASL 5000 lung simulator (IngMar Medical, Pittsburgh, Pennsylvania). This is a computer-driven piston controlled by the equation of motion (Equation 1) to model any value of resistance and compliance for either a single-or double-compartment lung model.…”

“…The ASL 5000 lung simulator is probably very interesting to test in dynamic conditions. Studies using a TTL simulator are numerous, [3][4][5][6][7][8] and Mr Chatburn cites only three recent studies using the ASL 500 simulator. To allow better comparison with these more numerous studies carried out using all types of ventilators (transport, home, and ICU), we used the TTL simulator.…”

Seven Ventilators Challenged With Leaks During Neonatal Nasal CPAP: An Experimental Pilot Study

“…The large differences in performance among ventilators have also been investigated in other modes such as pediatric NIV. 9 There are several clinical studies that do not discuss the effect that uneven performance might have. For the neonatal population, this includes large pragmatic studies using nasal CPAP treatment in the control group.…”

“…8 Large differences between in vitro performance of ventilators have been reported for noninvasive ventilation (NIV) in pediatric settings. 9 If performance has an effect on outcome, investigations of respiratory support using modes such as nasal CPAP, NIV, and high frequency oscillatory ventilation may give conflicting results depending on the type of ventilator used. Hence, there is a need to investigate the capabilities of systems used for respiratory support.…”