Effect of the addition of vasopressin or vasopressin plus nitroglycerin to epinephrine on arterial blood pressure during cardiopulmonary resuscitation in humans

Background: Infusion of a vasopressor during cardiopulmonary resuscitation (CPR) in humans increases end decompression (diastolic) arterial blood pressure, and consequently increases vital organ perfusion pressure and survival. Several vasoactive drugs have been tested alone or in combination, but their hemodynamic effects have not been investigated clinically in humans.

Study objective: We tested the hypothesis that epinephrine (1 mg) co-administered with vasopressin (40 IU) ± nitroglycerin (300 μg) results in higher diastolic blood pressure than epinephrine alone.

Study design: A prospective, randomized, double-blinded controlled trial in the prehospital setting. The study included 48 patients with witnessed cardiac arrest. Patients received either epinephrine alone (E alone) or epinephrine plus vasopressin (E+V) or epinephrine plus vasopressin plus nitroglycerin (E+V+N). A femoral arterial catheter was inserted for arterial pressure measurement.

Outcome measures: The primary end point was diastolic blood pressure during CPR, 15 min after the first drug administration (T = 15 min).

Results: After exclusions, a total of 44 patients were enrolled. Diastolic blood pressures (mm Hg) at T = 15 min were not statistically different between groups (median [interquartile range]: 20 [10], 15 [6], and 15 [13] for E alone, E+V, and E+V+N, respectively. The rate of return of spontaneous circulation was 63% (n = 10) in the epinephrine group, 43% (n = 6) in the epinephrine plus vasopressin group, and 36% (n = 5) in the triple therapy group (NS).

Conclusions: Addition of vasopressin or vasopressin plus nitroglycerin to epinephrine did not increase perfusion blood pressure compared to epinephrine alone in humans in cardiac arrest, suggesting the absence of benefit in using these drug combination(s).