Analgesic efficacy of peritubal infiltration of ropivacaine versus ropivacaine and morphine in percutaneous nephrolithotomy under ultrasonic guidance

BACKGROUND AND PURPOSE: Percutaneous nephrolithotomy is a safe and effective endourologic procedure which is less morbid than open surgery. However, pain around a nephrostomy tube requires good post-operative analgesia. We hypothesize that infiltration of local anesthetic with opioid from the renal capsule to the skin around the nephrostomy tract under ultrasonic guidance would alleviate the postoperative pain for a long period. METHODS: A total of 60 ASA physical status I to II patients were selected for a prospective randomized double-blind controlled study in percutaneous nephrolithotomy surgeries. Patients were divided into group R (n=30) and group RM (n=30). Balanced general anesthesia was given. After completion of the surgical procedure, a 23-gauze spinal needle was inserted at 6 and 12 O’clock position under ultrasonic guidance up to renal capsule along the nephrostomy tube. A 10 ml drug solution was infiltrated in each tract while withdrawing from renal capsule to the skin. After extubation, the patient was shifted to the post-anesthesia care unit for 24 hours. Post-operative pain was assessed using the visual analog scale (VAS) and dynamic visual analog scale (DVAS) (during deep breathing and coughing) rating 0-10 for initial 24 hours. Rescue analgesia was given in the form of injection tramadol 1.0 mg/kg intravenously when VAS ≥4 and maximum up to 400 mg in 24 hours. Time to 1(st) rescue analgesic, number of doses of tramadol and total consumption of tramadol required in initial 24 hours were noted. Patients were observed for any side effect and treated accordingly. RESULTS: Time to 1(st) rescue analgesic, i.e., duration of analgesia in group RM is more prolonged than group R (P=0.0004). The number of doses of tramadol in 24 hours in group R were higher as compared to group RM (P=0.0003). The total amount of tramadol in 24 hours in group R was more than in group RM (P=0.0013). Side effects like nausea and vomiting and sedation were comparable in both the groups. CONCLUSION: Addition of morphine to ropivacaine for nephrostomy tract infiltration significantly prolonged the duration of post-operative analgesia and reduced the number of doses and total consumption of rescue analgesic in initial 24 hours in percutaneous nephrolithotomy surgery.