Abstract 12024: Changes in Respiratory System Static Compliance After Resuscitation in a Porcine Model of Prolonged Cardiac Arrest

Abstract

Introduction: Acute lung injury happens commonly after resuscitation due to ischemia reperfusion injury and complications of cardiopulmonary resuscitation (CPR). The static compliance of the respiratory system (Csrs) is a reliable indicator of lung injury, together with chest-wall compliance (Cscw) and lung compliance (Csl). In the present study, we investigated the changes in Csrs, Cscw and Csl after resuscitationin a porcine mode of prolonged cardiac arrest (CA). Hypothesis: Both Csrs and Csl are decreased after prolonged CA and CPR without significant changes in Cscw. Methods: Ventricular fibrillation was electrically induced and left untreated for 10 mins in six male domestic pigs weighing 39±3 kg. Defibrillation was then attempted by a single 150 J shock after 4 min of CPR. All the animals were resuscitated successfully. Succinylcholine chloride (1.0mg/kg) was given intravenously to relax the respiratory muscles and static pressure-volume (P-V) curves were obtained by constant low-flow method at baseline, 1, 2 and 8h after resuscitation. Airway opening pressure, esophageal pressure, transpulmonary pressure and tidal volume were assessed. Csrs, Cscw and Csl were calculated as the slope rates of the liner portion of the corresponding P-V curves. Results: Significant decreases in both Csrs and Csl were observed after resuscitation when compared with baseline (Figure). However, Cscw increased slightly at 1 h after resuscitation and returned to baseline 2 h post-resuscitation. Conclusion: Both Csrs and Csl were reduced significantly following resuscitation without significant changes of Cscw in a porcine model of prolonged CA and CPR.