Hypothermia and neurological outcome after cardiac arrest

Abstract

Multi-centred studies in patients who remain comatose after cardiac arrest and also in newborn babies with perinatal asphyxia have clearly demonstrated that mild hypothermia (32-34 degrees C) can improve neurological outcome after post-anoxic injury. This represents a highly promising development in the field of neurocritical care. This review discusses the place of mild therapeutic hypothermia in the overall therapeutic strategy for cardiac arrest patients. Cooling should not be viewed in isolation but in the context of a 'treatment bundle,' which together can significantly improve outcome after cardiac arrest. Favourable outcomes of 50-60% are now routinely achieved in many centres in patients with witnessed arrest and an initial rhythm of ventricular fibrillation or ventricular tachycardia. These results have been achieved by combining a number of therapeutic strategies, including early and effective resuscitation with greater emphasis on continuing chest compressions throughout various procedures (including resumption of compressions immediately after defibrillation even if rhythm has been restored) as well as prevention of hypoxia and hypotension in all stages following restoration of spontaneous circulation. Regarding the use of hypothermia, early induction and proper management of side-effects are the key elements of successful implementation. Treatment should include the rapid infusion of 1500-3000 mL of cold fluids to induce hypothermia and prevent hypovolaemia and hypotension. Educational activities to increase awareness and acceptance of new therapeutic options and European Resuscitation Council guidelines are urgently required.