Subsequent ventricular fibrillation and survival in out-of-hospital cardiac arrests presenting with PEA or asystole.
BACKGROUND
The prognostic implications of conversion to ventricular fibrillation (VF) in out-of-hospital cardiac arrest (OHCA) patients with an initial non-shockable rhythm are unclear.


OBJECTIVE
Among OHCA patients with an initial non-shockable rhythm, survival is better in individuals who subsequently develop VF and are defibrillated.


METHODS



METHODS
Utstein style population-based cohort study.


METHODS
adults (age>or=18 years) with OHCA of presumed cardiac etiology and initial rhythm of pulseless electrical activity (PEA) or asystole treated by emergency medical services systems in Osaka, Japan from January 1, 2001 to December 31, 2005. Primary outcome measure was one-month neurologically favorable survival (CPC<or=2). Outcome of patients with subsequent VF (SHOCK group) was compared to that of patients with sustained non-shockable rhythm (NON-SHOCK group) using logistic regression to adjust for potential confounding variables.


RESULTS
Of 14,316 OHCA, 12,353 cases had PEA or asystole as the initial rhythm. Of these, 11,766 (95%) remained in a non-shockable rhythm throughout the resuscitation effort while 587 (5%) subsequently developed VF and were defibrillated. Neurologically favorable survival at one month was significantly better in the SHOCK group (6% versus 1%, p<0.001). Subsequent VF remained a significant predictor (OR, 4.3; 95% CI, 2.8-6.7) of neurologically favorable survival after adjustment for potential confounders.


CONCLUSIONS
Based on a large-scaled population-based cohort of OHCA, subsequent VF with defibrillation was associated with better outcomes among patients with an initial non-shockable rhythm.
Kajino
Kentaro
K
Department of Traumatology and Acute Critical Medicine, Osaka University, Graduate School of medicine, Suita, Japan. kajihanapu@yahoo.co.jp
Iwami
Taku
T
Daya
Mohamud
M
Nishiuchi
Tatsuya
T
Hayashi
Yasuyuki
Y
Ikeuchi
Hisashi
H
Tanaka
Hiroshi
H
Shimazu
Takeshi
T
Sugimoto
Hisashi
H
D000368:Aged; D000704:Analysis of Variance; D004554:Electric Countershock / Q000379:methods*; D004632:Emergency Medical Services; D005260:Female; D006323:Heart Arrest / Q000150:complications* / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010045:Outpatients; D011379:Prognosis; D011446:Prospective Studies; D011674:Pulse; D015996:Survival Rate; D016896:Treatment Outcome; D014693:Ventricular Fibrillation / Q000209:etiology* / Q000503:physiopathology / Q000628:therapy*