Cardiac arrest: VT/VF: hypothermia reduced death and improved neurological recovery following successful resuscitation

Clinical bottom line (level 1b)

  1. Patients successfully resuscitated from a VF-cardiac arrest who receive hypothermia treatment for 24 hours compared with normothermia were less likely to die (NNT = 6 at 6 months) and more likely to have a good neurological recovery (NNT = 6 at 6 months) .
The Hypothermia after Cardiac Arrest Study Group : N Engl J Med 2002; 346 : 549-556
Expires May 2004

The study

Single-blinded concealed randomised trial with intention-to-treat
Setting: 7 emergency departments, acute hospitals, Europe

275 patients (aged median 59, 76% male) with spontaneous circulation following a cardiac arrest

Excluded if
  • known pre-existing coagulopathy
  • occurrence of cardiac arrest after arrival of emergency medical personnel
  • response to verbal commands after return of spontaneous circulation
  • evidence of hypotension for > 30 minutes after return of spontaneous circulation
  • evidence of hypoxia for > 15 min after return of spontaneous circulation
  • terminal illness preceding cardiac arrest
  • follow-up unlikely
  • enrollment in another study
  • cardiac arrest not witnessed
  • initial arrhythmia not VT or VF
  • presumed non-cardiac origin for arrest
  • aged < 18, > 75
  • > 15 minutes from initial intervention, > 60 minutes from initiation of resuscitation to spontaneous circulation
  • temperature < 30 C on admission
  • comatosed before cardiac arrest due to drugs
  • pregnancy

Control Group: (n = 138, 138 analysed): normothermia
Experimental Group: (n = 137, 137 analysed): hypothermia: patients were cooled to 32-34 C using an external cooling device +/- ice packs for 24 hours and then allowed to rewarm passively
All patients were sedated using midazolam and fentanyl and paralysed using pancuronium.
100% followed for 6 months

The evidence

Outcome Time to outcome CER EER RRR
(95% CI)		 ARR
(95% CI)		 NNT
(95% CI)
good neurological recovery 6 months 54
(39.1%)		 75
(54.7%)		 40%
(8% to 81%)		 15.6%
(3.96% to 27.3%)		 6
(4 to 25)
death 6 months 76
(55.1%)		 56
(40.9%)		 26%
(5% to 42%)		 14.2%
(2.51% to 25.9%)		 7
(4 to 40)

Comments

  1. No difference in complications in the first 7 days was noted between the two groups.
  2. Patients were randomised in blocks of ten and stratified by centre.

Citation

  1. The Hypothermia after Cardiac Arrest Study Group , : mild therapeutic hypothermia to improve the neurologic outcome after cardiac arrest. N Engl J Med 2002; 346 : 549-556
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Contributor: Chris Ball, May 2002
Reviewer:

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