MILD THERAPEUTIC HYPOTHERMIA TO IMPROVE THE NEUROLOGIC OUTCOME AFTER CARDIAC ARREST
The Article: Hypothermia after Cardiac Arrest Study Group. “Mild therapeutic hypothermia to improve the neurologic outcome after cardiac arrest.” N Engl J Med2002.346 (2002): 549-556.
The Idea: Several animal studies prior to this randomized controlled trial had shown that moderate systemic hypothermia or mild hypothermia markedly mitigated brain damage after cardiac arrest in dogs. Prior to hypothermic therapy, there was no therapy with documented efficacy in preventing brain damage after cardiac arrest.
The Study: In this multicenter trial with blinded assessment of the outcome, patients who had been resuscitated after cardiac arrest due to ventricular fibrillation were randomly assigned to undergo therapeutic hypothermia (target temperature of 32°C to 34°C) over a period of 24 hours or to receive standard treatment with normothermia. The primary end point was a favorable neurologic outcome within six months after cardiac arrest; secondary end points were mortality within six months and the rate of complications within seven days.
The Findings: 75 of the 136 patients (55%) in the hypothermia group had a favorable neurologic outcome as compared with 54 of 137 (39%) in the normothermia. Mortality at six months was 41% in the hypothermia group (56 of 137 patients died), as compared with 55% in the normothermia group (76 of 138 patients).
The Takeaway: In patients who have been successfully resuscitated after cardiac arrest due to ventricular fibrillation, therapeutic mild hypothermia increased the rate of a favorable neurologic outcome and reduced mortality.