An investigation into the effect of depth of anesthesia on postoperative pain in laparoscopic cholecystectomy surgery: a double-blind clinical trial

Abstract

Backgrounds and objective

Some studies have shown that deeper anesthesia is more effective on postoperative analgesia and reduces the need for sedative drugs. This study sought to investigate the effect of depth of anesthesia on postoperative pain in laparoscopic cholecystectomy.

Materials and methods

In this double-blind clinical trial, 60 patients undergoing laparoscopic cholecystectomy were randomly divided into two groups: low bispectral index (L-BIS=35–44) and high bispectral index (H-BIS=45–55). Anesthesia protocol was the same for both groups (propofol and remifentanil). The pain intensity (at rest and during cough) was evaluated based on the visual analog scale scores in recovery and at 8, 16 and 24 hours after surgery.

Results

The mean pain score was significantly lower in patients in the L-BIS group at all examined times at rest and during cough than that in the H-BIS group. The number of patients in need of additional sedative drug in the H-BIS group in recovery was significantly more than that in the L-BIS group (27 vs 18 patients, P=0.007). The incidence of nausea in the recovery room 8 hours after the surgery was significantly less in the L-BIS group than that in the H-BIS group, while at 16 and 24 hours, no case of nausea was reported in the two groups.

Conclusion

Given the results of this study, it seems that general anesthesia with propofol and remifentanil with L-BIS causes less need for additional analgesic drug and less nausea and vomiting compared to anesthesia with H-BIS.

Keywords:

• BIS
• postoperative pain
• depth of anesthesia
• laparoscopic cholecystectomy

Author contributions

Poupak Rahimzadeh contributed to study concept and design, Seyed Hamid Reza Faiz to acquisition of data, Seyed Alireza Seyed Siamdoust to analysis and interpretation of data, Seyed Hamid Reza Faiz, Leila Houshmand, and Poupak Rahimzadeh to overview of the manuscript for important intellectual content, Poupak Rahimzadeh and Seyed Alireza Seyed Siamdust to administrative, technical, and material support, and Poupak Rahimzadeh to study supervision. All authors contributed toward data analysis, drafting and critically revising the paper, gave final approval of the version to be published, and agree to be accountable for all aspects of the work.

Disclosure

The authors report no conflicts of interest in this work.