Randomized control trial investigation as to the effect of Bupivacaine on postoperative analgesia following tubal ligation

Bilateral tubal ligation is a limited surgical procedure with minimal tissue injury, yet postoperative recovery time-span and analgesic requirements are not often proportional to this kind of surgery. Sixty ASA I-II females scheduled for TL minilaparatomy under general anesthesia were entered into this prospective, randomized, double blind, placebo-controlled clinical trial. Patients were randomly divided into two groups. Exclusion criteria were chronic abdominal pain, obesity, drug abuse, intubation and need for other surgical procedures in addition to TL. The patients received 10 mg Metocloprimede, 20 mg Hyoscine or equal volume of isotonic saline (control) as pre anesthetic agents. In experimental group (n=29) 10cc and 3cc Bupivacaine (0.25%) and in control group (n=31) 10cc and 3cc isotonic saline were injected bilaterally into incision site and mesosalpinx respectively. IV petidin (25 mg as needed) was given to relieve pain in postanesthesia care unit. Presence of pain, severity of pain and need for analgesics were assessed postoperatively in recovery unit, 6 and 24 hour and also 7 days after surgery. The collected data were analyzed by means of X², Mann-Whitney and T-tests. Pain score at recovery, and in the seventh postoperative day were significantly lower in the experimental than in the control group (p<0.05). But no difference between pain scores were noticed in Bupivacaine and control groups after 6 and 24 hours of operation. The total amount of analgesics required for pain relief was significantly more in control group than in bupivacaine group (p<0.05). This study suggests that a regimen of IV injection of Metoclopramide (10 mg) and Hyoscine (20 mg), accompanied with Bupivacaine infiltration into the periumblical skin incision site and into both medial and lateral segments of uterine tubes and mesosalpinx, bilaterally, can eliminate pain in both the immediate postoperative recovery period and 7 days after minilaparatomy for tubal ligation.