Comparison of intraoperative relatively high-dose and low-dose remifentanil for postoperative epidural analgesia after gynecological abdomonal surgery

INTERVENTION: In the high‐dose remifentanil group, while an end‐tidal sevoflurane concentration was maintained at 1.2% throughout anaesthesia, a remifentanil infusion was started at a rate of 0.25 ug/kg/min and subsequently increased or decreased stepwise by 0.05 ug/kg/min increments to maintain systolic blood pressure within 20% of baseline values during surgery. In the low‐dose remifentanil group, while a remifentanil infusion was maintained at a rate of 0.1 ug/kg/min throughout anaesthesia, an end‐tidal sevoflurane concentration was started at 2.0% and subsequently increased or decreased stepwise by 0.5% increments to maintain systolic blood pressure within 20% of baseline values during surgery. CONDITION: gynecological abdominal surgery PRIMARY OUTCOME: cumulative amount of local anesthetics at 48 h after surgery SECONDARY OUTCOME: pain intensity assessed with the Prince Henry pain scale INCLUSION CRITERIA: patients undergo elective gynaecological abdominal surgery with lower abdominal incision below umbilicus