Preoperative anxiety activates the hypothalamo-pituitary-adrenal axis and the sympathetic nervous system, and also affects immune responses. Therefore, there is a need to reduce the anxiety.

Forty-eight healthy patients scheduled for elective knee arthroscopic and reconstructive surgery under spinal anesthesia (SA) were randomly allocated into the control (CG, n = 24) and the alprazolam group (AG, n = 24). Oral 0.25 mg alprazolam in the evening before SA and 0.5 mg alprazolam 90 min before SA were administered to patients of the AG. Visual analogue scale (VAS) scores of anxiety were measured in the operating room before SA (ORSA) and operating room during operation and discharge day (DD). Serum ACTH and cortisol in the ORSA and DD, systolic and diastolic blood pressure and heart rate in the ward and ORSA, sleep time and number of night awakenings in the night before SA were measured.

Age (31.9 ± 10.8 yr), sex, height, weight, and sleep time were not significantly different between the two groups. The number of night awakenings in the AG were significantly lower than in the CG. VAS scores of anxiety in the ORSA were significantly higher in the CG than in the AG. ACTH and cortisol levels in the CG were significantly higher in the ORSA than in the DD. ACTH and cortisol levels in the AG were not significantly different between the ORSA and the DD. Cortisol level in the ORSA were significantly lower in the AG than in the CG. Diastolic blood pressure and heart rate in the ORSA were significantly lower in the AG than in the CG.

These indicate that oral alprazolam attenuates preoperative stress responses to regional anesthesia.