Preventing postoperative pain by local anesthetic instillation after laparoscopic gynecologic surgery: a placebo-controlled comparison of bupivacaine and ropivacaine

Abstract

We tested the hypothesis that local anesthetics instilled at the end of laparoscopic gynecologic procedures are able to prevent postoperative pain at wake-up and during the first 24 h. A total of 180 patients were randomly assigned into three groups to receive an intraperitoneal instillation of 20 mL of either bupivacaine 0.5% (Group B), ropivacaine 0.75% (Group R) or saline (Group S) at the end of surgery. All patients received analgesia with acetaminophen and ketoprofen IV infusions. Pain was assessed by using a 0-10 graded numerical scale (NS) every 5 min in the postanesthesia care unit and IV morphine was administered if NS was >4. Assessment of pain was continued every 4 h on the ward, and subcutaneous morphine was injected if needed to keep the NS score < 4. Postoperative nausea and vomiting (PONV) was rated on a 4-point scale. The morphine consumption at wake-up and over the first 24 h was significantly lower (P < 0.05) in Group B (mean, 0.92 mg at wake-up; 3.08 mg over 24 h) and in Group R (mean, 0.25 mg at wake-up; 0.69 mg over 24 h), than in Group S (mean, 4.18 mg at wake-up; 12.93 mg over 24 h). The morphine-sparing effect of ropivacaine was significantly greater than that of bupivacaine. Both local anesthetics were effective in the prevention of PONV. We concluded that local anesthetics should be instilled in all gynecologic patients at the end of all laparoscopic procedures.

Implications: Local anesthetic instillation (ropivacaine rather than bupivacaine) at the end of laparoscopy prevents postoperative pain and dramatically decreases the need for morphine. This technique, compared with placebo, is safe, improves patient comfort, shortens the stay in the postoperative care unit and decreases nursing care in the ward.