EFFECTS OF PROPOFOL AND THIOPENTONE, AND BENZODIAZEPINE PREMEDICATIONON HEART-RATE-VARIABILITY MEASURED BY SPECTRAL-ANALYSIS

We studied the effects of temazepam premedication and induction of ana esthesia with thiopentone or propofol on the heart rate power spectrum in 47 patients undergoing elective minor surgery. Eighteen patients r eceived temazepam 20 mg orally as premedication. There was a significa nt reduction in high frequency power and total power, and an increase in the ratio of low to high frequency power after induction of anaesth esia with either propofol or thiopentone. Patients who had received te mazepam premedication had significantly greater low frequency, high fr equency and total power than those who were not premedicated. There wa s no significant difference between premedicated and unpremedicated pa tients in the ratio of low to ventilatory frequency power.