Comparing two different techniques of rectus sheath block after single port laparoscopic surgery in benign adnexal mass patients: Surgical versus ultrasonography guidance—A randomized, single-blind, case-controlled study

The purpose of this study was to compare the analgesic effect of surgical bilateral rectus sheath block (BRSB) and ultrasonography-guidance BRSB in patients undergoing single port laparoscopic surgery (SPLS) for ovarian cyst. Seventy-five patients were randomly allocated into three groups: the control and ultrasound (US)-guidance group (n=25, each) received BRSB with 10ml of normal saline or 0.5% ropivacaine bilaterally under US guidance at the end of surgery, respectively; the surgical group (n=25) received BRSB with10ml of 0.5% ropivacaine bilaterally just before suturing the surgical site. All patients received intravenous fentanyl 50μg for postoperative pain before emergence from anesthesia. Additional self-administered fentanyl and pain intensity were measured at postoperative 1, 6, 10 and 24h. Demographic characteristics showed no significant group-wise differences. The cumulative amount of fentanyl delivered was significantly lower in the US-guidance and surgical BRSB groups (189.20μg and 187.68μg, respectively) than the control group (286.40μg) on postoperative day 1 (P