Comparative Study of Postoperative Pain Relief Using Preincisional Versus Postincisional Infiltration With 0.25% Bupivacaine in Abdominal Hysterectomy Under General Anesthesia

BACKGROUND AND AIMS: Hysterectomy, probably the most common non-pregnancy related surgery performed in gynaecology, is associated with moderate to severe post-operative pain. Wound infiltration with local anaesthetic agent reduces the transmission of pain from the wound, in addition, local inflammatory response to the injury is also suppressed. The infiltration of local anaesthesia can be done either pre- or post-operatively. The present study was designed to determine the efficacy of pre-incisional infiltration versus post-incisional infiltration with 0.25% Bupivacaine in providing post-operative pain relief in patients undergoing abdominal hysterectomy. METHODS: In Prospective Interventional Randomised study, 90 female patients posted for elective abdominal hysterectomy under general anaesthesia were randomly allocated into three equal groups of 30 patients each. GROUP I: Patients receiving subcutaneous infiltration with 40 mL of 0.25% Bupivacaine 5 mins before skin incision. GROUP II: Patients receiving subcutaneous infiltration of surgical area with 40 mL of 0.25% Bupivacaine at end of surgery (after peritoneal closure). GROUP III (CONTROL GROUP): Patients receiving no local anaesthetic infiltration. Observations were made for the duration of effective analgesia from end of the surgery until the first use of rescue analgesic along with the frequency and cumulative amount of rescue analgesics in 24 hours. RESULTS: We found that at baseline, pain score of patients in Group III (3.87±1.17) was maximum followed by that in Group I (2.57±0.90) and minimum in Group II (2.20±0.61). Requirement of first analgesia was earliest in Group III (79.50±23.90 minutes) followed by Group I (136.83±13.16 minutes) and last in Group II (146.17±12.78 minutes), in addition, cumulative dose of analgesia was required by patients in Group III (152.50±36.76 mg) followed by that in Group I (132.50±37.80 mg) and minimum by that in Group II (115.00±38.06 mg). CONCLUSION: Subcutaneous infiltration of Bupivacaine either pre-incisional or post-incisional, helped to reduce the immediate post-operative pain intensity, delayed the first rescue analgesic requirement, reduced the post-operative dose and frequency of rescue analgesia. However, post-incisional intervention had an edge over pre-incisional intervention.