Comparison between synchronized and non-synchronized ventilation and between guided and non-guided chest compressions during resuscitation in a pediatric animal model after asphyxial cardiac arrest

INTRODUCTION: There are no studies comparing synchronized and non-synchronized ventilation with bag-valve mask ventilation (BVMV) during cardiopulmonary resuscitation (CPR) in pediatric patients. The main aim is to compare between synchronized and non-synchronized BVMV with chest compressions (CC), and between guided and non-guided CC with a real-time feedback-device in a pediatric animal model of asphyxial cardiac arrest (CA). The secondary aim is to analyze the quality of CC during resuscitation. METHODS: 60 piglets were randomized for CPR into four groups: Group A: guided-CC and synchronized ventilation; Group B: guided-CC and non-synchronized ventilation; Group C: non-guided CC and synchronized ventilation; Group D: non-guided CC and non-synchronized ventilation. Return of spontaneous circulation (ROSC), hemodynamic and respiratory parameters, and quality of CC were compared between all groups. RESULTS: 60 piglets were included. Twenty-six (46.5%) achieved ROSC: A (46.7%), B (66.7%), C (26.7%) and D (33.3%). Survival rates were higher in group B than in groups A+C+D (66.7% vs 35.6%, p = 0.035). ROSC was higher with guided-CC (A+B 56.7% vs C+D 30%, p = 0.037). Piglets receiving non-synchronized ventilation did not show different rates of ROSC than synchronized ventilation (B+D 50% vs A+C 36.7%, p = 0.297). Non-synchronized groups showed lower arterial pCO(2) after 3 minutes of CPR than synchronized groups: 57 vs 71 mmHg, p = 0.019. No differences were found in arterial pH and pO(2), mean arterial pressure (MAP) or cerebral blood flow between groups. Chest compressions were shallower in surviving than in non-surviving piglets (4.7 vs 5.1 cm, p = 0.047). There was a negative correlation between time without CC and MAP (r = -0.35, p = 0.038). CONCLUSIONS: The group receiving non-synchronized ventilation and guided-CC obtained significantly higher ROSC rates than the other modalities of resuscitation. Guided-CC achieved higher ROSC rates than non-guided CC. Non-synchronized ventilation was associated with better ventilation parameters, with no differences in hemodynamics or cerebral flow.