Ropivacaine Use Intraincisionally Versus Intraperitoneally for Post-Laparoscopic Cholecystectomy Pain

Overview

Pain still remains a limiting factor in early discharge of patients undergoing laparoscopic cholecystectomy. Almost all earlier studies done to compare the efficacy of local anaesthetics used intraperitoneally as compared to intraincisionally used equal amounts of drugs at the two locations, usually 10-20 ml. Using this large amount of drug in the small space of intraincisional location as compared to similar amount of drug in large intraperitoneal space created an inadvertent bias in favor of patients receiving the drug intraincisionally so such patients naturally experienced less pain. The investigators decided to standardize the drug used at these two locations as 1ml/cm and conduct a new study comparing the effects of drugs in relieving pain when used at these two locations.

Aims \& Objectives: To conduct a randomized, triple-blind, placebo-controlled study by standardizing dose of local anesthetic, to compare the effectiveness of intraperitoneal against intraincisional use of ropivacaine 0.2% for post-laparoscopic cholecystectomy pain relief. Materials \& Methods: American Society of Anesthesiologists (ASA) physical status I or II patients underwent elective 4 port laparoscopic cholecystectomy by a single surgeon. Anesthetic and surgical techniques were standardized. Patients were randomized using envelope method into 3 groups according to location of drug use. Triple blinding was ensured and envelopes were opened only at the completion of study. All patients received \~23 ml of solution, of which 20 ml was given intraperitoneally \[1 ml/cm; 16 ml along right hemi-dome, approximately equal to length of right hemi-dome of diaphragm in an average adult and 4 ml in gall bladder fossa) and \~3 ml intraincisionally (1 ml/cm of length of incision). Controls (n=86) received \~23 ml normal saline (20 ml intraperitoneally and 1 ml/cm intraincisionally) while the intraperitoneal group (n=100) received 20 ml of intraperitoneal instillation of injection ropivacaine 0.2% and 1 ml/cm of normal saline intraincisionally at the end of procedure. Intraincisional group (n=108) received 20 ml normal saline intraperitoneally and 1 ml/cm of injection ropivacaine 0.2% infiltration at incisional site at the end of procedure. All patients received injection diclofenac sodium 75mg/1ml (aqueous) intravenously 12 hourly postoperatively. 5 different pain scales were used for assessment of overall pain. Pain scores were assessed at 5 points of time, that is, at 0.5, 4, 8, 12 and 24 hours postoperatively. Shoulder pain and extra dose of analgesic required (rescue analgesia) were also recorded.