Effect of Mild Therapeutic Hypothermia in Comatose Survivors after Asphyxial Cardiac Arrest

ABSTRACT

PURPOSE: Therapeutic hypothermia (TH) has been a standard treatment for ventricular fibrillation (VF) cardiac arrest survivors to improve neurological outcomes. However, there is a lack of evidence that TH has a neuroprotective effect to asphyxial cardiac arrest, which is one of the most prevalent causes of sudden death besides VF cardiac arrest. We studied whether TH improves the neurological outcomes after resuscitation from asphyxial cardiac arrest. METHODS: We included asphyxial cardiac arrest survivors from January 2002 to December 2010. Clinical and neurological outcome data of 24 consecutive patients undergoing TH were compared with 18 patients who did not undergo TH (11 historical controls and seven refusal of TH by patient's next-of-kin). Neurological outcome was assessed at discharge according to the Cerebral Performance Category scale. The incidence of complications after asphyxial cardiac arrest was compared between the two groups. RESULTS: Baseline characteristics except arterial pH after recovery of spontaneous circulation were not different between the TH group and the non-hypothermic group. Good neurological outcome was similar between the TH group and the non-hypothermic group (8.3% vs 0.0%, p=0.498). The TH group included 18 hypokalemic patients, while non-hypothermic group included eight hypokalemic patients (p=0.044). The rate of other complication did not differ significantly between the two groups. CONCLUSION: Therapeutic hypothermia was not associated with good neurological outcome in asphyxial cardiac arrest survivors and was not associated significantly with the incidence of complications after asphyxial cardiac arrest. However, the findings are not conclusive because of a lack of patients, lack of randomization, and uncertainty of appropriateness of therapeutic hypothermia method to asphyxial cardiac arrest.