CARDIOPULMONARY BYPASS RESUSCITATION FOR ACCIDENTAL HYPOTHERMIA

Many victims of accidental hypothermia have been successfully resuscit ated with cardiopulmonary bypass, but questions remain regarding treat ment indications and efficacy. To assess the role of cardiopulmonary b ypass in resuscitation frog hypothermia a collective literature review was performed. Data on 68 hypothermic patients resuscitated with card iopulmonary bypass were analyzed. Impairment from alcohol, drug abuse, or mental illness was the most common predisposing factor for acciden tal hypothermia. Mean initial core temperature was 21 degrees C. Sixty -one patients (90%) were in cardiac arrest. Femoral-femoral bypass was used in 72% of patients. Overall survival was 60%. Eighty percent of survivors returned to their previous level of function. Sixty-seven pe rcent of nonsurvivors died because of inability to establish a cardiac rhythm or wean from bypass. Patient age, type of cardiopulmonary bypa ss (femoral-femoral or atrial-aortic), and initial core temperature we re not significant prognostic indicators. There were no survivors amon g the 6 patients with a core temperature less than 15 degrees C. Patie nts in cardiac arrest had a higher mortality than patients who were no t (p = 0.02). Climbing and avalanche victims had a higher mortality th an other hypothermic patients (p = 0.003). The possibility of publicat ion bias must be considered before firm conclusions can be drawn from this collective literature review. Controlled studies comparing the ef ficacy of cardiopulmonary bypass and alternative warming techniques ha ve not been done. Nevertheless, cardiopulmonary bypass has several adv antages over other warming methods for profoundly hypothermic patients . Tissue perfusion and oxygenation are maintained while rapid warming occurs. Cardiopulmonary bypass resuscitation is recommended for hypoth ermic patients in arrest and for patients with core temperatures lower than 25 degrees C, irrespective of rhythm. Patients in stable conditi on with temperatures between 25 degrees and 28 degrees C can be treate d with cardiopulmonary bypass or conventional warming methods.