In laparoscopic colectomy, opioid-free anesthesia attained an intraoperative pain threshold index that exhibited comparable efficacy as opioid anesthesia regimen.

In order to offer a pain threshold index-monitored effective analgesia-antinociception balance during laparoscopic radical colectomy, a placebo-controlled, double-blind, randomized trial sought to examine the efficacy of opioid-free anesthesia (OFA).

Randomly assigned into two groups, 102 patients undergoing colectomy under general anesthesia were given either opioid-free anesthesia (group OFA) using dexmedetomidine (10-minute loading dose of 0.6 μg/kg−1, followed by a 0.5 μg/kg−1/h−1 continuous infusion) and sevoflurane as well as a bilateral paravertebral blockade (15 ml of 0.5% ropivacaine and 0.2 μg/kg−1 dexmedetomidine each side) or opioid-based anesthesia (group OA) using bilateral paravertebral blockade (15 ml of 0.5% ropivacaine per side), sevoflurane, and remifentanil.

As measured by the pain threshold index using the multifunction combination monitor, the major endpoint variable was the degree of pain experienced throughout the procedure. The repeated measures analysis of variance and Student's t-test were used to assess results. Blood glucose concentration, lactic levels, and wavelet index throughout the procedure were the secondary endpoints ascertained. Further evaluations included the opioid side effects, usage of rescue analgesics, and visual analogue scale (VAS) following surgery.

Evaluation showed that there was no clinically meaningful difference between the groups in the intraoperative pain threshold index values from the beginning of the procedure to its conclusion. Furthermore, both the OA and OFA groups demonstrated comparable alterations in the brain wavelet index measurements. No clinically meaningful difference in VAS scores was witnessed between both groups. But, non-opioid anesthesia did lessen the need for rescue analgesics following surgery.

The levels of intra-operative blood glucose in the OFA group elevated by 20% from baseline and were substantially greater compared to those in the OA group. Opioid-related adverse reactions such as postoperative episodes of vomiting and nausea, pruritus, intestinal paralysis, and urinary incontinence did not differ substantially from those in the OA group.

In comparison with opioid anesthesia, OFA with a bilateral paravertebral block in patients having laparoscopic colectomy may offer appropriate analgesia and antinociception effects during surgery, with improved antinociception to intubation stimulation in people, guided by pain threshold index monitoring.