Use of a Portable Mechanical Ventilator during Cardiopulmonary Resuscitation is Feasible, Improves Respiratory Parameters, and Prevents the Decrease of Dynamic Lung Compliance

Abstract

Background: For practical and protective ventilation during cardiopulmonary resuscitation (CPR), a 150-grams mechanical ventilator (VLP2000E) that limits peak inspiratory pressure (PIP) during simultaneous ventilation with chest compressions was developed. Objectives: To evaluate the feasibility of VLP2000E ventilation during CPR and to compare monitored parameters versus bag-valve ventilation. Methods: A randomized experimental study with 10 intubated pigs per group. After seven minutes of ventricular fibrillation, 2-minute CPR cycles were delivered. All animals were placed on VLP2000E after achieving return of spontaneous circulation (ROSC). Results: Bag-valve and VLP2000E groups had similar ROSC rate (60% vs. 50%, respectively) and arterial oxygen saturation in most CPR cycles, different baseline tidal volume [0.764 (0.068) vs. 0.591 (0.123) L, p = 0.0309, respectively] and, in 14 cycles, different PIP [52 (9) vs. 39 (5) cm H2 O, respectively], tidal volume [0.635 (0.172) vs. 0.306 (0.129) L], ETCO2 [14 (8) vs. 27 (9) mm Hg], and peak inspiratory flow [0.878 (0.234) vs. 0.533 (0.105) L/s], all p < 0.0001. Dynamic lung compliance (≥ 0.025 L/cm H2 O) decreased after ROSC in bag-valve group but was maintained in VLP2000E group [0.019 (0.006) vs. 0.024 (0.008) L/cm H2 O, p = 0.0003]. Conclusions: VLP2000E ventilation during CPR is feasible and equivalent to bag-valve ventilation in ROSC rate and arterial oxygen saturation. It produces better respiratory parameters, with lower airway pressure and tidal volume. VLP2000E ventilation also prevents the significant decrease of dynamic lung compliance observed after bag-valve ventilation. Further preclinical studies confirming these findings would be interesting.