Comparison of adrenaline and phenylephrine in out-of-hospital cardiopulmonary resuscitation. A double-blind study.
Phenylephrine, a strong alpha-adrenergic receptor-stimulating agent, was compared with adrenaline in 65 patients with out-of-hospital cardiac arrest, in a double-blind study. The resuscitation was performed by the physician-staffed Prehospital Emergency Care Unit of Helsinki University Central Hospital. The patients received either 1.0 mg of phenylephrine or 0.5 mg of adrenaline i.v. in the treatment of fine ventricular fibrillation, asystole or electromechanical dissociation. If two doses of either drug did not restore circulation, 0.5 mg of known 0.01% adrenaline was given i.v., maximally twice. In the adrenaline group, which consisted of 36 patients with a mean age of 61 years, 10 patients (28%) were successfully resuscitated. The phenylephrine group consisted of 29 patients with a mean age of 62 years. In this group nine patients (31%) were successfully resuscitated. The two groups were comparable regarding their apnoea-times, and there was no difference in the need for extra adrenaline between the groups. No adverse effects, such as hypertension or bradycardia, were noted in the patients treated with either adrenaline or phenylephrine, nor did the overall rate of successful resuscitation fall during the test period. It is concluded that phenylephrine seems as effective as adrenaline in the treatment of cardiac arrest, but further studies seem warranted.