Procainamide and survival in ventricular fibrillation out-of-hospital cardiac arrest.
OBJECTIVE
Procainamide is an antiarrhythmic drug of unproven efficacy in cardiac arrest. The association between procainamide and survival from out-of-hospital cardiac arrest was investigated to better determine the drug's potential role in resuscitation.


METHODS
The authors conducted a 10-year study of all witnessed, out-of-hospital, ventricular fibrillation (VF) or pulseless ventricular tachycardia (VT) cardiac arrests treated by emergency medical services (EMS) in King County, Washington. Patients were considered eligible for procainamide if they received more than three defibrillation shocks and intravenous (IV) bolus lidocaine. Four logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (CI) describing the relationship between procainamide and survival.


RESULTS
Of the 665 eligible patients, 176 received procainamide, and 489 did not. On average, procainamide recipients received more shocks and pharmacologic interventions and had lengthier resuscitations. Adjusted for their clinical and resuscitation characteristics, procainamide recipients had a lower likelihood of survival to hospital discharge (OR = 0.52; 95% CI = 0.36 to 0.75). Further adjustment for receipt of other cardiac medications during resuscitation negated this apparent adverse association (OR = 1.02; 95% CI = 0.66 to 1.57).


CONCLUSIONS
In this observational study of out-of-hospital VF and pulseless VT arrest, procainamide as second-line antiarrhythmic treatment was not associated with survival in models attempting to best account for confounding. The results suggest that procainamide, as administered in this investigation, does not have a large impact on outcome, but cannot eliminate the possibility of a smaller, clinically relevant effect on survival.
Markel
David T
DT
University of Washington School of Medicine, Seattle, WA, USA.
Gold
Laura S
LS
Allen
Judith
J
Fahrenbruch
Carol E
CE
Rea
Thomas D
TD
Eisenberg
Mickey S
MS
Kudenchuk
Peter J
PJ
D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D015986:Confounding Factors, Epidemiologic; D005260:Female; D006323:Heart Arrest / Q000401:mortality*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D011342:Procainamide / Q000627:therapeutic use*; D012189:Retrospective Studies; D017180:Tachycardia, Ventricular / Q000188:drug therapy* / Q000209:etiology / Q000401:mortality; D014693:Ventricular Fibrillation / Q000188:drug therapy* / Q000209:etiology / Q000401:mortality
D000889:Anti-Arrhythmia Agents; D011342:Procainamide