Postoperative analgesic effect of epidural neostigmine and plasma cortisol and IL-6 responses

To examine whether epidural administration of neostigmine reduces the stress and inflammatory responses thereby improving postoperative pain status.

Randomized, double-blinded clinical study.

Operating rooms and wards of a university hospital.

40 ASA physical status I patients undergoing lower open abdominal surgery for benign gynecological disease.

Patients were randomly divided into four groups to receive different doses of epidural neostigmine (0, 0.05, 0.1, or 0.15 mg) with mepivacaine (100 mg) before general anesthesia induction.

The plasma levels of cortisol and interleukin-6 (IL-6) were determined perioperatively. The patients' pain rating was assessed by visual analog scale (VAS) in the postoperative period.

Epidural neostigmine at all doses significantly reduced the plasma levels of cortisol in the early surgical period; however, IL-6 levels were not affected by the neostigmine. The VAS scores were significantly decreased at 2 hours after the end of surgery by all doses of epidural neostigmine used in this study.

The preincisional epidural neostigmine transiently suppresses the stress responses during surgery and improves postoperative analgesia in patients undergoing lower open abdominal surgery.