Three studies (n=1,226 patients) were included. Sample size ranged from 169 to 732 patients. All three studies were of high quality according to the Jadad score. However, two studies had adequate allocation concealment and one study had inadequate allocation concealment.
Survival to hospital discharge (two studies): One study showed that survival to hospital discharge was significantly improved for a combination of vasopressin and epinephrine versus repeated doses of epinephrine alone (RR 3.69, 95% CI 1.52 to 8.95). The other study showed no statistically significant difference (RR 0.88, 95% CI 0.26 to 2.92).
Rates of return of spontaneous circulation (three studies): One study showed a statistically significant improved rate of ROSC with a combination of vasopressin and epinephrine versus epinephrine alone (RR 1.42, 95% CI 1.14 to 1.77). Two studies showed no statistically significant difference (RR 1.10, 95% CI 0.82 to 1.46 and RR 1.02, 95% CI 0.74 to 1.42).
Survival to hospital admission (two studies): One study found that survival to hospital admission was significantly improved for the combination of vasopressin and epinephrine versus repeated doses of epinephrine (RR 1.57, 95% CI 1.17 to 2.09). The other study found no statistically significant difference (RR 0.79, 95% CI 0.52 to 1.21).