Hemodynamic effects of flunitrazepam in cardiac patients during anesthetic induction

The hemodynamic effects of flunitrazepam were studied in eight coronary patients (group I) and in six patients with compensated cardiac failure (group II) during the induction of anesthesia with droperidol 5 mg and fentanyl 4 micrograms . kg-1. A right sided cardiac catheterization was performed to measure cardiac output by thermodilution. In coronary patients, the hemodynamic parameters were only slightly modified (NS). Cardiac output (-12.7%) and oxygen consumption (-20.4%) decreased; Pvo2 increased from 6.4 +/- 0.1 to 7.3 +/- 0.3 kPa. In patients with cardiac failure, significant cardiovascular changes were not observed. Arterial pressure (-13%), cardiac output (-2.6%), oxygen consumption (-6%) and systemic vascular resistance (-13.4%) decreased; Pvo2 increased from 6.4 +/- 0.5 to 6.8 +/- 0.7 kPa. In both groups, heart rate and pulmonary capillary wedge pressure were unchanged. There was only a significant difference (p less than 0.05) between the decrease in systemic resistance in group II and in the absence of change in systemic resistance in group I. Decrease in oxygen consumption be decrease in oxygen demand could explain the slight decrease in cardiac output. Flunitrazepam was a good hypnotic for the induction of anesthesia in normovolaemic coronary patients and in patients with compensated cardiac failure.