Vasopressin combined with epinephrine during cardiac resuscitation: a solution for the future?

Epinephrine has been employed for cardiac resuscitation for approximately 100 years [1], although it is known that this drug increases myocardial oxygen consumption during cardiopulmonary resuscitation (CPR) and increases the likelihood of cardiac failure after restoration of spontaneous circulation [2]. In contrast, vasopressin proved to be beneficial over epinephrine as regards improving coronary perfusion pressure during CPR and as regards improving neurological recovery in the CPR laboratory [3,4]. It was then hoped that vasopressin may also be better than epinephrine in large prospective clinical CPR trials [5], but these assumptions could not be proven in an inhospital CPR trial in Canada [6] and in an out-of-hospital CPR trial in Europe [7]. A large subgroup (n = 732) in the European vasopressin trial [7] and a retrospective analysis of CPR patients from Pittsburgh, PA, USA [8], however, suggested possible beneficial effects of a combination of vasopressin and epinephrine when given during CPR. This strategy is currently being studied in an ongoing, very large (> 2,000 patients), out-of-hospital prospective CPR trial in France.The exciting retrospective study of Grmec and Mally from Slovenia adds further support to the hypothesis that a combination of vasopressin and epinephrine given during CPR may be more effective than epinephrine alone [9]. While the authors acknowledge limitations of their investigation, such as a lack of randomizing and subgroup analysis of myocardial infarction patients, it is very impressive that 530 patients were studied in a very difficult setting without any funding. This investigation is in full agreement with studies showing that adding vasopressin in catecholamine-refractory shock states was beneficial during CPR [10], vasodilatory shock [11], and hemorrhagic shock [12]. Similar to balanced anaesthesia, it may be valuable to combine two drugs during CPR instead of increasing the dose of one drug. Accordingly, the Slovenian data