This study investigated the effect of type of surgery on consumption of propofol and remifentanil and recovery index.

Fifty female patients (ASA physical status 1, 2) scheduled for thyroidectomy (Group I) or mastectomy (Group II) received total intravenous anesthesia (TIVA) with propofol and remifentanil. The anesthesia was maintained with target-controlled infusion (TCI) of propofol and remifentanil under bispectral index (BIS) monitoring. The effect site concentration of propofol was controlled for maintaining BIS values within the range of 45-50. The effect site concentration of remifentanil was controlled for maintaining blood pressure and heart rate within 20% of baseline values. Blood pressure, heart rate, BIS, effect site concentration of propofol and remifentanil were measured before induction, during induction, at the beginning of operation, at the end of operation, and during recovery. The time from discontinuation of propofol to eye opening and regaining of orientation, total amount of propofol and remifentanil used, and the amount of drug per body weight kilogram per hour were investigated.

There were no significant differences between Group I and II on the amount of remifentanil used. Although the amount of propofol consumed per body weight kilogram per hour was larger in Group II, there were no significant differences of recovery index between Group I and II.

There were no significant differences in the amount of propofol and remifentanil consumed and recovery index in thyroidectomy and mastectomy under TIVA. The larger amount of propofol consumed per body weight per hour in Group II was thought as a result of shorter operation time than Group I.