[Comprehensive evaluation of the effect of triazolam on amnesia during the preoperative period].

BACKGROUND

Triazolam reportedly has greater amnesic potential than other benzodiazepines. The present study was designed to investigate whether this amnesic potential can be applied to surgical patients as premedication, thus relieving them from postoperatively remembering preoperative fears of anesthesia and surgery.

METHODS

We prospectively evaluated the effect on amnesia of triazolam administered during the preoperative period in 80 patients between 20-64 years of age (mean, 43.1 +/- 14.3 years) who underwent surgeries for non-malignant diseases under general anesthesia maintained with sevoflurane and nitrous oxide in oxygen throughout the operation, or general anesthesia maintained with the same anesthetics combined with epidural or spinal anesthesia. Patients with diseases or factors influencing the effect of triazolam, such as a history of mental diseases, recent sedative or antihistamine usage, or current sleep disturbances, were excluded from this study. Triazolam was administered to the 80 patients orally at a dose of 0.375 mg 60 minutes prior to entering the operating room. During structured interviews on postoperative day 1, the patients were asked to state what they remembered of the preoperative period. Amnesia was classified based on the patients' last memory before the anesthetic induction as follows: loss of memory from immediately after taking triazolam, loss of memory at departure from the ward, loss of memory at the entrance to the operating room, loss of memory at the operating table and some recall of events at the operating table.

RESULTS

Interviews revealed that 26.3% of the patients experienced loss of memory immediately after taking triazolam, this number increasing to 28.8% of the patients at departure from the ward, 35.0% at the entrance to the operating room and 67.5% on the operating table. The remaining patients (32.5%) had some memory of the operating room and table. Triazolam caused no respiratory depression at the operating table, although 2 of the patients experienced dizziness, 1 patient had nausea and 1 patient felt heavy-headed during the period between taking triazolam and the induction of anesthesia. Although 13 patients had delayed emergence from general anesthesia, these patients remaining anesthetized even 5 minutes after the concentration of sevoflurane in the expired gas decreased and remained below 0.1 percent, all these patients emerged immediately after intravenous administration of flumazenil.

CONCLUSIONS

The use of triazolam as premedication produced a high incidence of amnesia for preoperative events without causing respiratory depression. Triazolam appears to be a useful premedicant for surgical patients who wish to have no memory at the operating room.