The electrostabilizing effect of a combination of midazolam and fentanyl: an experimental study in the dog

Using a model of local myocardial ischaemia in the dog, the authors studied the electrostabilizing effect of a combination of the benzodiazepine midazolam (Dormicum Hoffman--La Roche) and the strong narcotic analgesic drug Fentanyl (Richter). The electrostabilizing effect was assessed using the method of ventricular fibrillation threshold (VFT) measurement. The same increase in the fibrillation threshold as that induced by the administration of midazolam or fentanyl alone was achieved by a combination of both drugs given, however, in reduced doses. The electrostabilizing effect of benzodiazepines and potent analgesics is enhanced by their simultaneous administration. At the same time, the adverse side effects observed on the administration of fentanyl alone (bradycardias, hypotension, cardiac blockade) due to the prevalence of parasympathetic drive, are reduced. Simultaneous administration of a benzodiazepine and an analgesic has become a modern technique, in anaesthesiology, so-called analgosedation. Experiments have shown the technique, in addition to the generally recognized analgesia, sedation and anxiolysis, exerts electrostabilizing effects on the myocardium damaged by ischaemia. The authors therefore recommend analgosedation in the drug treatment of acute myocardial infarction.