Related Experiment Video
Updated: Feb 14, 2026

OP-IVM: Combining In vitro Maturation after Oocyte Retrieval with Gynecological Surgery
Published on: May 9, 2021
Ultrasound-guided bilateral rectus sheath block reduces early postoperative pain after laparoscopic gynecologic
Sooyoung Cho1, Youn Jin Kim2, Kyungah Jeong3
1Department of Anesthesia and Pain Medicine, College of Medicine, Ewha Womans University, Seoul, Republic of Korea.
Purpose:
Rectus sheath block (RSB) is an anterior abdominal wall block that reduces postoperative pain associated with midline incisions. This study aims to investigate the effect of ultrasound-guided bilateral RSB (US-BRSB) on postoperative pain and analgesic consumption in patients undergoing laparoscopic gynecologic surgery.
Methods:
Sixty patients who underwent laparoscopic gynecologic surgery were allocated to RSB (n = 30) or control (n = 30) group. A bilateral US-BRSB procedure (30 ml of 0.25% ropivacaine) was performed after induction of general anesthesia in the RSB group. The control group proceeded the surgery without sham block. All patients received fentanyl-based intravenous patient-controlled analgesia and rescue analgesics upon demand. Pain was scored by a blinded observer using a verbal numerical rating scale (VNRS) at rest while coughing at 0, 1, 6, 12, 24, and 48 h after postanesthesia care unit (PACU) admission. The primary outcome was the total number of rescue analgesics used in the 48-h postoperative period.
Results:
At 0 h, VNRS were lower in the RSB group than in the control, both at rest (median VNRS 4.5 vs. 5, p = 0.02) and while coughing (median VNRS 6 vs. 7, p = 0.004). At 6 h, VNRS scores were lower in the RSB group than in the control while coughing (median VNRS 3 vs. 5, p = 0.01). Fentanyl use as rescue analgesics in the PACU was significantly lower in the RSB group than in the control (27.7 ± 32.1 vs. 53.3 ± 33.7 µg, respectively; p = 0.004). At 48 h postoperatively, the total number of rescue analgesics administered were significantly fewer in the RSB group than in the control (2.5 ± 2.5 vs. 3.9 ± 2.6, respectively; p = 0.04).
Conclusion:
US-BRSB reduces the immediate postoperative pain and opioid consumption during the early postoperative period. CLINICALTRIALS.
Gov Identifier:
NCT02476799, https://clinicaltrials.gov/ct2/show/NCT02476799 .
Related Concept Videos
Bioequivalence Experimental Study Designs: Completely Randomized and Randomized Block Designs
Random Error
Random Variables
Uppercase letters such as X or Y denote a random variable. Lowercase letters like x or y denote the value of a random variable. If X is a random variable, then X is written in words, and x is given as a number.
For example, let X = the...
Randomized Experiments
Simple randomization
Simple...
Pain
Random and Systematic Errors

