Abstract Body: Introduction: Current pediatric cardiopulmonary resuscitation (CPR) guidelines recommend that a rescuer performs manual ventilation at a rate of 20-30 breaths per minute (bpm) with an avoidance of excessive ventilation during CPR. Despite these recommendations, excessive ventilation is common during CPR, and performing manual ventilation can be difficult in settings with limited personnel. Using mechanical ventilation during CPR can provide relatively constant minute ventilation and offloads a rescuer to perform other tasks.

Research Question: Does mechanical ventilation produce similar gas exchange and intra-arrest hemodynamics compared to manual ventilation during CPR?

Aims: To compare gas exchange and intra-arrest hemodynamics when using manual ventilation versus three mechanical ventilation strategies: sustained inflation (SI), pressure-controlled mechanical ventilation (PCV), and volume-controlled mechanical ventilation (VCV).

Methods: This was a randomized, crossover study design. Twenty 4-5 kg swine were anesthetized and underwent up to 4 episodes of 1 minute of ventricular fibrillation-induced (VF) cardiac arrest and resuscitation. Each swine was assigned 4 different intra-arrest ventilatory strategies in random order including: 1) manual ventilation at a rate of 25 bpm, 2) SI at 15 cm H₂O, 3) PCV using pre-arrest peak inspiratory pressures, and 4) VCV using a pre-arrest tidal volume. Swine were resuscitated with chest compressions at 120 compressions per minute, epinephrine administration every 4 minutes, and defibrillation as clinically indicated starting 8 minutes into resuscitation. Arterial blood gases were obtained at baseline and at 4 and 8 min of resuscitation. Arterial diastolic blood pressure (DBP), myocardial perfusion pressure (MPP), and cerebral perfusion pressure (CPP) were measured at baseline and continuously during resuscitation.

Results: The twenty swine underwent a total of 32 VF cardiac arrests and resuscitation. At 4 and 8 minutes of CPR, SI, PCV, and VCV produced PaCO₂ and PaO₂ levels similar to that of manual ventilation (Figure 1). DBP, MPP, and CPP levels were also similar among the 4 groups at 4 and 8 minutes of resuscitation (Figure 2).

Conclusion: In this swine model of short VF pediatric cardiac arrest, sustained inflation, pressure-controlled and volume-controlled mechanical ventilation are feasible and provide adequate gas exchange and similar hemodynamics compared to manual ventilation.