STUDY ON THE IMPACT OF INTRAVENOUS KETAMINE IN COLORECTAL CANCER SURGERY

Abstract: A significant inflammatory response, excruciating postoperative pain, and postoperative ileus are all linked to colorectal resections. This study sought to assess the primary effects of ketamine and lidocaine as well as their interactions in patients with colorectal cancer (CRC) following open surgery. If the combined effects of two medications are equal to the total of their individual effects, the interaction may be additive; if they are more than the sum of their individual effects, it may be multiplicative. We postulated that ketamine and lidocaine may work in concert or additively to lessen the inflammatory response. 112 patients having elective open colorectal resection were randomly assigned to receive either lidocaine or a placebo and either ketamine or a placebo. All subjects received an intravenous bolus of lidocaine 1.5 mg/kg, ketamine 0.5 mg/kg, and/or a matched saline volume after general anaesthesia was induced. This was followed by a continuous infusion of lidocaine 2 mg/kg/h, ketamine 0.2 mg/kg/h, and/or a matched saline volume until the procedure was completed. Serum measurements of the white blood cell (WBC) count, interleukins (IL-6, IL-8), and C-reactive protein (CRP) were the main outcomes. These measurements were made 12 and 36 hours following surgery. We evaluated the principal effects of ketamine and lidocaine as well as their interactions. For primary analyses, Neither the lidocaine nor the ketamine intervention produced statistically significant changes in any of the inflammatory markers that were examined. At 12 or 36 hours following surgery, there was no evidence of a multiplicative interaction between the two treatments: WBC count, P =.89 and P =.84, IL-6, P =.06 and P =.05, IL-8, and CRP, P =.41 and P =.98, respectively. There was no indication of additive interactions with respect to inflammatory measures. With the exception of lidocaine alone, both lidocaine and ketamine dramatically decreased intraoperative opioid intake when compared to a placebo. They also improved pain levels. Gut motility was not significantly affected by any intervention. The findings of our study do not support the intraoperative administration of ketamine and lidocaine to patients having open surgery for colorectal cancer.