Amiodarone for resuscitation after out-of-hospital cardiac arrest due to ventricular fibrillation.
BACKGROUND
Whether antiarrhythmic drugs improve the rate of successful resuscitation after out-of-hospital cardiac arrest has not been determined in randomized clinical trials.


METHODS
We conducted a randomized, double-blind, placebo-controlled study of intravenous amiodarone in patients with out-of-hospital cardiac arrest. Patients who had cardiac arrest with ventricular fibrillation (or pulseless ventricular tachycardia) and who had not been resuscitated after receiving three or more precordial shocks were randomly assigned to receive 300 mg of intravenous amiodarone (246 patients) or placebo (258 patients).


RESULTS
The treatment groups had similar clinical profiles. There was no significant difference between the amiodarone and placebo groups in the duration of the resuscitation attempt (42+/-16.4 and 43+/-16.3 minutes, respectively), the number of shocks delivered (4+/-3 and 6+/-5), or the proportion of patients who required additional antiarrhythmic drugs after the administration of the study drug (66 percent and 73 percent). More patients in the amiodarone group than in the placebo group had hypotension (59 percent vs. 48 percent, P=0.04) or bradycardia (41 percent vs. 25 percent, P=0.004) after receiving the study drug. Recipients of amiodarone were more likely to survive to be admitted to the hospital (44 percent, vs. 34 percent of the placebo group; P=0.03). The benefit of amiodarone was consistent among all subgroups and at all times of drug administration. The adjusted odds ratio for survival to admission to the hospital in the amiodarone group as compared with the placebo group was 1.6 (95 percent confidence interval, 1.1 to 2.4; P=0.02). The trial did not have sufficient statistical power to detect differences in survival to hospital discharge, which differed only slightly between the two groups.


CONCLUSIONS
In patients with out-of-hospital cardiac arrest due to refractory ventricular arrhythmias, treatment with amiodarone resulted in a higher rate of survival to hospital admission. Whether this benefit extends to survival to discharge from the hospital merits further investigation.
Kudenchuk
P J
PJ
Department of Medicine, University of Washington, Seattle 98195-6422, USA.
Cobb
L A
LA
Copass
M K
MK
Cummins
R O
RO
Doherty
A M
AM
Fahrenbruch
C E
CE
Hallstrom
A P
AP
Murray
W A
WA
Olsufka
M
M
Walsh
T
T
D000368:Aged; D000638:Amiodarone / Q000009:adverse effects / Q000627:therapeutic use*; D000889:Anti-Arrhythmia Agents / Q000009:adverse effects / Q000627:therapeutic use*; D016887:Cardiopulmonary Resuscitation; D004311:Double-Blind Method; D004554:Electric Countershock; D004632:Emergency Medical Services; D005260:Female; D006323:Heart Arrest / Q000188:drug therapy* / Q000209:etiology / Q000401:mortality / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D015996:Survival Rate; D013610:Tachycardia / Q000150:complications / Q000628:therapy; D014693:Ventricular Fibrillation / Q000150:complications* / Q000628:therapy
D000889:Anti-Arrhythmia Agents; D000638:Amiodarone