Abstract P138: Early Selective Head Cooling during CPR Improves Success of Resuscitation in a Porcine Model of Pulseless Electrical Activity Cardiac Arrest
Introduction: We previously reported that early and selective head cooling during CPR improves outcomes after prolonged ventricular fibrillation (VF). In the present study, we investigated head cooling in settings of pulseless electrical activity (PEA).
Hypothesis: Early head cooling during CPR improves outcomes when cardiac arrest is associated with PEA.
Methods: VF was electrically induced in 16 domestic male pigs weighing 40±3 kg. After 14 min of untreated VF, PEA was induced following delivery of one or more electrical shocks. One minute after onset of PEA, CPR was started, including chest compression and ventilation with oxygen. CPR was continued for 5 minutes prior to attempted defibrillation if animals return to VF and resumption of CPR prior to return of spontaneous circulation (ROSC). Failing to achieve ROSC, resuscitation efforts were discontinued after 15 minutes. In 8 animals, selective head cooling was begun coincident with start of CPR and 8 randomized controls were identically treated except for head cooling. Aortic and right atrial pressures and nasal, body and right jugular vein temperatures were continuously measured. Coronary perfusion pressure (CPP) was computed from aortic compression diastolic and simultaneous right atrial pressures.
Results: Six of eight animals were resuscitated after early head cooling and only one untreated control (p=0.012). Nasal, body and jugular vein temperatures decreased after cooling (Table⇓). Head cooling was associated with greater CPP (p=0.001) as shown in the Table⇓.
Conclusion: When selective head cooling was initiated during CPR in settings of PEA, the likelihood of successful resuscitation was improved in relationship to significantly greater CPP.