Randomized clinical trial of magnesium, diazepam, or both after out-of-hospital cardiac arrest.
OBJECTIVE
To evaluate the feasibility, safety, and efficacy of interventions aimed at improving neurologic outcome after cardiac arrest.


METHODS
The authors conducted a double-blind, placebo-controlled, randomized clinical trial with factorial design to see if magnesium, diazepam, or both, when given immediately following resuscitation from out-of-hospital cardiac arrest, would increase the proportion of patients awakening, defined as following commands or having comprehensible speech. If the patient regained a systolic blood pressure of at least 90 mm Hg and had not awakened, paramedics injected IV two syringes stored in a sealed kit. The first always contained either 2 g magnesium sulfate (M) or placebo (P); the second contained either 10 mg diazepam (D) or P. Awakening at any time by 3 months was determined by record review, and independence at 3 months was determined by telephone calls. Over 30 months, 300 patients were randomized in balanced blocks of 4, 75 each to MD, MP, PD, or PP. The study was conducted under waiver of consent.


RESULTS
Despite the design, the four treatment groups differed on baseline variables collected before randomization. Percent awake by 3 months for each group were: MD, 29.3%; MP, 46.7%; PD, 30.7%; PP, 37.3%. Percent independent at 3 months were: MD, 17.3%; MP, 34.7%; PD, 17.3%; PP, 25.3%. Significant interactions were lacking. After adjusting for baseline imbalances, none of these differences was significant, and no adverse effects were identified.


CONCLUSIONS
Neither magnesium nor diazepam significantly improved neurologic outcome from cardiac arrest.
Department of Neurology, University of Washington, Seattle, USA. wl@u.washington.edu
W T
WT
Longstreth
C E
CE
Fahrenbruch
M
M
Olsufka
T R
TR
Walsh
M K
MK
Copass
L A
LA
Cobb
D000203:Activities of Daily Living; D000368:Aged; D000488:Allied Health Personnel; D015986:Confounding Factors, Epidemiologic; D003975:Diazepam / Q000008:administration & dosage*; D004311:Double-Blind Method; D004554:Electric Countershock; D004632:Emergency Medical Services; D005260:Female; D006323:Heart Arrest / Q000150:complications* / Q000628:therapy; D006801:Humans; D007275:Injections, Intravenous; D008278:Magnesium Sulfate / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D009422:Nervous System Diseases / Q000209:etiology / Q000517:prevention & control*; D012151:Resuscitation; D013995:Time; D016896:Treatment Outcome; D014851:Wakefulness / Q000187:drug effects*
D008278:Magnesium Sulfate; D003975:Diazepam