Predictors of poor neurologic outcome in patients undergoing therapeutic hypothermia after cardiac arrest.

BACKGROUND: Therapeutic hypothermia (TH) has been shown to reduce the degree of anoxic brain injury, decrease mortality, and improve neurologic recovery in patients surviving cardiac arrest. However, there is a paucity of data on potential markers of neurologic outcome that physicians can use in this setting. METHODS: A retrospective medical records review of 41 consecutive survivors of cardiac arrest treated with TH (2004-08) was examined. RESULTS: Mean patient age was 66 years old. Most subjects had an out-of-hospital, witnessed cardiac arrest, and two-thirds had received bystander cardiopulmonary resuscitation (CPR). About half of the patients had nonventricular tachycardia/fibrillation (VT/VF) arrests. Fifty-nine percent (24 of 41 subjects) died or experienced severe neurologic impairment. By bivariate analysis, factors associated with a poor neurologic prognosis included: 1) a first rhythm at cardiac arrest other than VT/VF (P = 0.01); 2) the presence of acute kidney injury (AKI) in the intensive care unit (ICU) (P < 0.001); 3) any treated cardiac arrhythmia after admission (P = 0.05); and 4) a Glasgow Coma Score <8 determined 12 hours after rewarming (P < 0.001). Using multiple regression analysis, non-VT/VF arrest, AKI, and cardiac arrhythmia remained significant risk factors for poor neurologic recovery. The cumulative risk of death or poor neurologic outcome increased with the presence of two or more risk factors. CONCLUSION: Several simple, reproducible clinical markers can help predict neurologic recovery, during and after treatment, in patients managed with TH for cardiac arrest.

Community-based application of mild therapeutic hypothermia for survivors of cardiac arrest.

OBJECTIVE: To demonstrate that the application of therapeutic hypothermia is technically feasible in a community-based setting. BACKGROUND: Implementation of therapeutic hypothermia for survivors of cardiac arrest in the United States has been slow, at least partially because of the perception that this therapy is technically difficult, especially at the community level. STUDY DESIGN: Retrospective cohort study with historical controls. METHODS: At our three community hospitals and after return of spontaneous circulation (ROSC), survivors of cardiac arrest were treated with therapeutic hypothermia using ice and cooling blankets or suits in order to cool patients to 32 degrees C-34 degrees C within 4 hours to achieve goal temperature within 8 hours and to maintain goal temperature for 24 hours. RESULTS: Beginning in 2004, 44 survivors of cardiac arrest were managed with therapeutic hypothermia. The mean time from ROSC to initiation of therapeutic hypothermia was 2.8 hours (range, 0.2-7.8 hours), the mean time from ROSC to goal temperature was 7.2 hours (range, 0.8-15.1 hours), and the mean time maintained at goal temperature was 24.5 hours (range, 9-28 hours). Once patients achieved goal temperature, 4.4% of the temperature readings were above 34 degrees C, reflecting undercooling, while 16.4% of the readings were below 32 degrees C, indicative of overcooling. Overall survival until hospital discharge with good neurologic outcome was 43%, compared to only 13% (P < 0.001) among selected controls. There were no major complications directly attributable to the induction of hypothermia or rewarming. CONCLUSION: A simple protocol of mild therapeutic hypothermia using locally available resources is technically feasible and safe in a community-based setting.