Abstract 113: Ventilation is not Necessary During Cardiopulmonary Resuscitation in a Rat Model of Hemorrhagic Cardiac Arrest
Recent studies showed that arterial blood pressure during hemorrhagic shock is made worse with hyperventilation and improved with hypoventilation. However, there are few studies about the ventilation during cardiopulmonary resuscitation (CPR) in hemorrhagic cardiac arrest. To compare the effect of three ventilation strategies during CPR in an animal model of hemorrhagic cardiac arrest. Thirty-six male Sprague Dawley rats were anesthetized with pentobarbital ip. Hemorrhagic cardiac arrest was induced with removing of blood. After 3 minutes of cardiac arrest, animals were randomized to receive one of three ventilation strategies during CPR (n = 12 per group): normoventilation (20 breaths/min, FiO2 1.0), hypoventilation (10 breaths/min, FiO2 1.0), or no-ventilation. The rate of chest compressions (CC) was 240 −260/min and depth of CC was titrated to maintain diastolic arterial pressure between 25–30 mmHg in all groups. After 5 minutes of CPR, the all removing blood and epinephrine (0.02 mg/kg) were administered. There were no other therapies before, during or after CPR. The rates of return of spontaneous circulation (ROSC) were 92%, 83%, and 92% for normoventilation, hypoventilation, and no-ventilation groups, respectively. The survival rates at 2hrs after ROSC were 67%, 58%, and 67% for normoventilation, hypoventilation, and no-ventilation groups, respectively. The PCO2 levels immediately after ROSC were 70mmHg, 74 mmHg, and 80 mmHg for normoventilation, hypoventilation, and no-ventilation groups, respectively. The increases of plasma cytokine (TNF-alpha and IL-6) and lactate concentrations after ROSC were not significantly differences between all groups. Moreover, the elevations of coagulation parameters after ROSC were not significantly differences between all groups. The present study showed that there ware no significantly different on ROSC and the changes of cytokines and lactate and coagulation parameters between the three ventilation strategies during CPR in the hemorrhagic cardiac arrest model. These findings suggest that ventilation during CPR in hemorrhagic cardiac arrest may not be necessary.