Cardiovascular Effects of Water-soluble Benzodiazepine as an Anesthesia Induction Agent

Abstract

The new benzodiazepine, midazolam, that is water-soluble, shorter-acting, more potent, and less irritating to veins than diazepam, has been suggested use for induction of anesthesia. The induction tme (from the end of injection to spontaneous closing of eyes and to the disappearance of eyelash reflex), cardiovascular effects (mean arterial pressure; MAP, heart rate; HR, cardiac output; CO), and the effect on arterial oxygen saturation (Sa02) of an induction-sized dose (0.2 mg/kg) of midazolam in ASA class I or II surgical patients (N = 10) premedicated with glycoppyrolate were compared with those in the similar group of patients (N = 10) receiving thiopental (5 mg/kg). The induction time in midazolam group was significantly slower than in thiopental group. In both groups MAP decreased during induction but increased after intubation significantly. HR significantly increased at early induction period in thiopental group, and significantly increased after intubation in both groups. CO significantly decreased in thiopental group but did not change in midazolam group. In both groups Sa O2 did not change during induction but significantly increased after intubation. Although induction time was slow, midazolam, from the cardiovascular point of view, appears to offer some advantages over thiopental and, clinically, is at least as good as thiopental as an anesthesia induction agent in healthy surgical patients.