NEW YORK (Reuters Health) – Use of vasopressin provides no overall benefit in the resuscitation of cardiac arrest patients, but it may improve outcomes in a subset of asystolic patients – especially when administered promptly.
That’s the conclusion of a meta-analysis of randomized controlled trials reported in Resuscitation
“The novel finding of the current meta-analysis was that in the large asystole subgroup (n=3,210), vasopressin use was associated with an increased probability of long-term survival (absolute % increase ~1.0%, corresponding to 10 additional survivors for every 1,000 treated patients),” the authors report. “Furthermore, the vasopressin-related survival benefit was quadrupled in an asystole subgroup (n=642) with average time-to-drug < 20 min (absolute % increase = 4.0%, corresponding to 40 additional survivors for every 1,000 treated patients.”
Dr. Spyros D. Mentzelopoulos, with Evaggelismos General Hospital in Athens, Greece, and colleagues undertook the study because there have been favorable trial results reported since the last review in 2004, and the possibility of increased vasoconstricting efficacy of current vasopressin regimens during CPR.
The team identified six high-quality RCTs comparing vasopressin-containing regimens with adrenaline/epinephrine alone in 4,475 adults with cardiac arrest.
Overall, vasopressin compared with epinephrine alone did not increase rates of sustained return of spontaneous circulation (odds ratio 1.25; p=0.18), long-term survival (OR 1.13; p=0.61) or favorable neurologic outcome (OR 0.87; p=0.62), the report indicates.
However, when the initial cardiac rhythm was identified as asystole (as opposed to pulseless electrical activity or VF/VT), vasopressin use was associated with greater long-term survival (OR 1.80; p=0.04). Moreover, in asystolic patients treated within 20 minutes of collapse the odds ratio increased to 2.84 (p=0.02), Dr. Mentzelopoulos and colleagues found.
They conclude, “New RCTs specifically assessing vasopressin effects on subgroup neurological outcome are warranted.”
Vasopressin for cardiac arrest: Meta-analysis of randomized controlled trials