Clinical predictors of survival in patients treated with therapeutic hypothermia following cardiac arrest

Introduction: Therapeutic hypothermia has been shown to provide neuroprotection and improved survival in patients suffering a cardiac arrest. We report outcomes of consecutive patients receiving therapeutic hypothermia for cardiac arrest and describe predictors of short and long-term survival.

Methods: Eighty patients receiving therapeutic hypothermia between January 2005 and December 2008 were identified and categorized as those who survived and died. Outcomes and predictors of survival were determined.

Results: Forty-five patients (56%) survived to hospital discharge and were alive at 30 days and among survivors 41 (91%) were alive 1 year after discharge. Survivors were younger, were more likely to present with VF, required less epinephrine during resuscitation, were more likely to have preserved renal function, and were less likely to be taking beta-blockers and ACE inhibitors. Predictors of survival included VF on presentation (OR 14.9, CI 2.7-83.2, p=0.002), pre-cardiac arrest aspirin use (OR 9.7, CI 1.6-61.1, p=0.02), return of spontaneous circulation <20 min (OR 9.4, CI 2.2-41.1, p=0.003), absence of coronary artery disease (OR 5.3, CI 1.1-24.7, p=0.002) and preserved renal function.

Conclusion: Therapeutic hypothermia is useful in the treatment of patients suffering a cardiac arrest. Several clinical factors may aid in predicting patients who are likely to survive after a cardiac arrest.