Both vasopressin alone and vasopressin followed by adrenaline improve survival in patients with refractory asystolic cardiac arrest compared with adrenaline alone, results from a large, multicenter trial show.
Both vasopressin alone and vasopressin followed by adrenaline improve survival in patients with refractory asystolic cardiac arrest compared with adrenaline alone, results from a large, multicenter trial show. Cardiac arrest due to asystole causes a flat line on the ECG trace, and is a difficult cause of cardiac arrest to treat, since it does not respond to defibrillation. Current international guidelines only recommend adrenaline for the resuscitation of patients with cardiac arrest due to asystole. If confirmed, the findings could lead to changes in the international guidelines for advanced cardiac life support (ACLS). Adrenaline has been used during CPR for over 100 years, but its use has become controversial because it is linked with increased myocardial oxygen consumption, ventricular arrhythmias, and myocardial dysfunction after resuscitation. In contrast, laboratory and small clinical studies have shown that vasopressin increases blood flow and oxygen delivery to the heart and brain, increases the chances of successful resuscitation, and improves neurological outcome. Noting that data on the use of vasopressin therapy remains limited, Volker Wenzel (Leopold-Franzens University, Innsbruck, Austria) and colleagues evaluated the effects of vasopressin and adrenaline on survival after out-of-hospital cardiac arrest in adults with ventricular fibrillation, pulseless electrical activity, or asystole. The 1189 study participants were randomly assigned to receive either vasopressin (n=589) or adrenaline (n=597). The first dose of either drug was given intravenously, and if spontaneous circulation was not re-established within 3 minutes of the first dose, a second identical dose was injected. If spontaneous circulation still did not occur, doses of adrenaline could be administered at the discretion of the attending physician. Wenzel’s team reports in the New England Journal of Medicine that there were no significant differences between the two drugs in rate of survival to hospital admission among patients with ventricular fibrillation or pulseless electrical activity. However, in patients with asystole, vasopressin resulted in significantly greater survival to hospital admission than adrenaline (29.0% vs 20.3%, p=0.02), and also in survival to hospital discharge (4.7% vs 1.5%, p=0.04). Furthermore, among patients in whom the first two doses of either drug failed to achieve spontaneous circulation, survival to hospital admission after additional therapy with adrenline was significantly higher among patients initially treated with vasopressin than those initially given adrenaline (25.7% vs 16.4%, p=0.002). In an editorial accompanying the article, Kevin McIntyre (Brigham and Women’s Hospital, Boston, Massachusetts, USA) calls the findings “an important breakthrough in the science of resuscitation. He states: “These advances should be translated into a new standard of care without delay. Practitioners should perhaps be encouraged to incorporate the use of vasopressin into their resuscitation protocols immediately.”N Engl J Med 2004; 350: 105-113