The charts of all adult patients with accidental hypothermia who were admitted to a single academic hospital during a 10 year period were retrospectively retrieved. The aim was to identify factors associated with survival of those with hypothermic cardiac arrest. Of 75 admitted patients, 44 were found to be haemodynamically stable and not to require invasive rewarming measures. Of the remaining 31 patients, 23 were in refractory cardiac arrest due to primary hypothermia and rewarmed using cardiopulmonary bypass (CPB). The aetiology of hypothermia was immersion in cold water in 48%, exposure to cold environment in 39% and submersion in 13% of these patients. Their median age was 50 years, and 83% were males. The patients received a total of 70 min of conventional CPR before institution of CPB. Fourteen of these patients (61%) survived to discharge from hospital. Factors associated with survival were age (P=0.015), arterial pH (P=0.011), PaCO 2 (P=0.003), and serum potassium (P=0.007). Logistic regression analysis showed that of the 23 patients, 22 could be correctly classified as survivor or nonsurvivor based on the level of serum potassium and arterial pCO 2 . It is concluded that patients with cardiac arrest due to primary hypothermia tolerate long periods of conventional CPR before institution of CPB. The possible predictive role of serum potassium and arterial pCO 2 needs further evaluation.
Reviram-se retrospectivamente os processos de todos os adultos admitidos com hipotermia acidental grave, num hospital universitario, nos ultimos dez anos. O estudo teve por objectivo identificar factores que influenciaram o resultado e a paragem cardiaca por hipotermia. Dos 75 doentes admitidos 44 estavam hemodinamicamente estaveis e nao necessitaram de aquecimento agressivo. Dos 31 restantes 23 estavam em paragem cardiaca refractaria por hipotermia primaria e forma reaquecidos com bypass cardio-pulmonar (CPB). A etiologia da hipotermia em 48% dos casos foi a imersao em agua fria, em 39% dos casos a exposicao a factores ambientais e 13% a submersao. A idade media era de 50 anos e 83% eram homens. Os doentes foram reanimados, com SBV convencional, durante 70 minutos antes de iniciarem a CPB. Destes, catorze (61%) tiveram alta hospitalar. Os factores relacionados com a sobrevida foram a idade (P=0.015), pH arterial (P=0.011), PaCO 2 (P=0.003) e o potassio serico (P=0.007). A analise por regressao logistica mostrou que dos 23 doentes, 22 poderiam ser correctamente classificados em sobreviventes ou nao sobreviventes, com base no valor do potassio serico e da PaCO 2 arterial. Concluimos que os doentes em paragem cardiaca prolongada por hipotermia primaria toleram longos periodos de SBV convencional, antes do inicio da CPB. O possivel valor predictivo do potassio e da PaCO 2 necessita de mais investigacao.
Se revisaron retrospectivamente los registros de todos los pacientes adultos con hipotermia accidental que fueron admitidos a un hospital academico durante un periodo de 10 anos. El objetivo fue identificar factores asociados con sobrevida y con paro cardiaco hipotermico. De 75 pacientes admitidos, 44 fueron encontrados hemodinamicamente estables y no requirieron medidas invasivas de recalentamiento. De lo 31 pacientes restantes, 23 estaban en paro cardiorrespiratorio refractario debido a hipotermia primaria y fueron recalentados usando bypass cardiopulmonar (CPB). La etiologia de la hipotermia fue inmersion en agua helada en 48%, exposicion a ambiente frio en 39% y sumergimiento en 13% de los casos. La mediana de edad fue 50 anos, y 83% fueron varones. Los pacientes recibieron un total de 70 minutos de reanimacion cardiopulmonar (CPR) convencional antes de la instalacion de CPB. Catorce de estos pacientes (61%) sobrevivieron al alta hospitalaria. Los factores asociados con la sobrevida fueron edad (P=0.015), pH arterial (P=0.011), PaCO 2 (P=0.003), y potasio serico (P=0.007). El analisis de regresion logistica mostro que de los 23 pacientes, 22 podrian ser correctamente clasificados en sobreviviente o no sobreviviente basado en el nivel de potasio serico y PaCO 2 . Se concluyo que los pacientes con paro cardiaco por hipotermia primaria toleran largos periodos de CPR convencional antes de la institucion de CPB. El posible rol de prediccion del potasio serico y la PaCO 2 arterial requiere ulterior evaluacion.