Six studies (5,208 participants) were included. Five studies were on out-of-hospital arrest: four RCTs (4,478 participants) and one cohort study that used historical controls (530 participants). The sixth study was an RCT (200 participants) on in-hospital arrest. No results were reported for this study. Study size ranged from 40 to 2,894 participants.
There was no statistically significant difference in ROSC between vasopressin and epinephrine and epinephrine alone (five studies). Subgroup analyses showed no effect on ROSC in those people with asystole, ventricular fibrillation or pulseless electrical activity.
Survival at 24 hours was improved with vasopressin and epinephrine (OR 2.99, 95% CI 1.43 to 6.28, I2=6%; two studies). There was no statistically significant difference in survival to admission (three studies) and at discharge (four studies) between the two groups.
Funnel plot showed no evidence of publication bias.