Remifentanil is an ultra-short-acting
opioid that sometimes causes
opioid-induced
hyperalgesia, which has led to controversy regarding the association between intraoperative
remifentanil administration and
postoperative pain. This study aimed to assess the effects of the intraoperative
remifentanil dose on
postoperative pain. Patients undergoing esophageal, gastric/hepatobiliary, or intestinal/colon surgery and using postoperative patient-controlled
epidural analgesia were analyzed. The patients were divided into two groups based on the average intraoperative
remifentanil dose (high-dose
remifentanil [HR] group: ≥0.1 μg/kg/min; low-dose
remifentanil [LR] group: <0.1 μg/kg/min). In all, 406 patients met the inclusion criteria. A significant difference in the average dose of
remifentanil was seen between the groups during the
anesthesia period (0.14±0.05 vs. 0.07±0.02 μg/kg/min). However, no significant difference was seen in pre- or intraoperative patient characteristics. Numerical rating scale (NRS) scores on postoperative day 1 were similar between the groups (HR: 1.7±2.0; LR: 1.7±2.0; p=0.74). The incidence of poor
pain control (NRS > 3/10) was also similar between the groups (HR: 14%;
LR: 16%; p=0.57). Older age (> 60 years) and type of surgery (esophageal surgery) were associated with worse postoperative NRS scores. No significant association was seen between the intraoperative
remifentanil dose and postoperative NRS scores following thoracoabdominal surgery with postoperative epidural
pain management.