Randomized controlled study of intraincisional infiltration versus intraperitoneal instillation of standardized dose of ropivacaine 0.2% in post-laparoscopic cholecystectomy pain: Do we really need high doses of local anesthetics-time to rethink!

Abstract

Earlier studies done to compare the efficacy of use of local anesthetics at intraperitoneal location versus intraincisional use had utilized equal amount of drugs at the two locations, usually 10-20ml. 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 these patients naturally experienced less pain. 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. 294 patients underwent elective 4-port laparoscopic cholecystectomy. Patients were triple blindly randomized. All patients received ~ 23ml of solution, of which 20ml was given intraperitoneally (1ml/cm; 16ml along right hemi-dome and 4ml in gall bladder fossa) and ~ 3ml intraincisionally (1ml/cm of length of incision). Solution was either normal saline or drug (0.2% ropivacaine) depending on the group [controls (n = 86), intraperitoneal group (n = 100), and intraincisional group (n = 108)]. 5 different pain scales were used for assessment of overall pain. Pain scores were assessed at 5 points of time. Patients in intraincisional group showed significantly less overall pain and rescue analgesia requirement (p < 0.05). Intraincisional group showed significantly less overall pain (p < 0.05) as compared to intraperitoneal group; however, use of rescue analgesia was comparable in the two groups (p > 0.05); and shoulder pain was significantly less in intraperitoneal group (p < 0.05). The intraincisional use of injection ropivacaine at its minimum concentration of 0.2% in minimal doses of 1ml/cm at the end of procedure provides significantly more post-operative analgesia as compared to intraperitoneal group and controls. However, for controlling shoulder pain, the use of intraperitoneal ropivacaine is desirable.