Comparison of USG guided modified rectus sheath block with intraperitoneal instillation with Inj. Bupivacaine for postoperative pain relief in diagnostic laparoscopy

Background: Laparoscopic surgery is associated with considerable postoperative pain, though it is less compared to open surgery. Post laparoscopic pain results from phrenic nerve irritation caused by residual gas, stretching of the intraabdominal cavity and peritoneal inflammation. The Modified Rectus Sheath Block (MRSB) is fairly easy and reliable procedure when performed using ultrasound guidance so it is compared with the intraperitoneal instillation method by using Inj. Bupivacaine for postoperative analgesia in diagnostic laparoscopy. Aim of the study was to assess and compare the effect of the USG guided modified rectus sheath block (MRSB) with the intraperitoneal instillation using Inj. Bupivacaine in diagnostic laparoscopy. Material and methods: It was prospective randomized study. The Patients were randomly allocated in two groups. Group A were given USG guided rectus sheath block and Group B was given intraperitoneal 25 mg Bupivacaine. Patients with obesity, local anesthetic agent allergy and emergency surgeries were excluded. Pain was assessed 1, 6, 10 and 24 hours postoperatively by visual analogue pain score. Results: Postoperative pain was assessed by visual analogue pain score (VAS) at every hour for 24 hours postoperatively. The VAS was significantly lower in Group A at 6 and 10 hours postoperatively. After 6 hours the median pain score was 3 in group A while it was 7 in group B. After 8 hourrs the median pain score was 2 in group A compared with 5 in group B and after 10 hours the median score were 2 and 5 in group A, group B respectively (p.004 respectively). No significant difference noted in pain score at 1 hour and 24 hour post laparoscopy among the two groups. Conclusion: USG guided modified rectus sheath block (MRSB) provides prolonged post operative analgesia than intraperitoneal instillation in diagnostic laparoscopy.