Comparative evaluation of opioid versus opioid free anaesthesia with ketamine and lidocaine on post-operative nausea and vomiting in patients undergoing laparoscopic cholecystectomy.

Opioids are commonly usedfor analgesia and supplementary sedation during general anaesthesia and are themost widely used agents for the treatment of acute pain in the immediatepostoperative period. Opioids provide effective analgesia and stableintraoperative hemodynamics, which are valuable during the perioperativeperiod. However, the use of opioids during the perioperative period is risky.Opioids have many potential adverse effects, including respiratory depression,postoperative nausea and vomiting (PONV), and opioid-induced hyperalgesia (OIH).These complications are associated with delayed patient recovery, prolongedstay in the post-anaesthetic care unit (PACU), delayed hospital discharge, andunexpected hospitalization, all contributing to an increased burden on patientsand resources.Perioperative opioidsare administered for postoperative analgesia, and intra-operatively to controlthe sympathetic response to surgical stimuli, frequently as a surrogate for presumedpain.Opioid free anaesthesia (OFA) is a technique where theintraoperative use of systemic, neuraxial or intracavitary opioid is completelyavoided. This new technique can provide intraoperativehemodynamic stability, immobility and postoperative analgesia withoutadministering opioid drugs, and therefore the absence of the numerous sideeffects caused by opioids.3Opioids are used in generalanaesthesia in various surgeries, though laparoscopic surgeries are consideredrelatively less painful and are associated with early recovery and lesserduration of hospital stay, they can cause severe pain, especially in four hoursof the immediate post-operative period. This may be attributed to theperitoneal irritation caused by the carbon dioxide insufflation pressures,bowel handling by the surgeons or irritation caused by the residual or retainedblood.4Post-operative nausea and vomiting (PONV) are some ofthe most common complications after anaesthesia, often reducing patientsatisfaction and prolonging the recovery and discharge from hospital. This isdefined as nausea or vomiting that occurs during first 24 hours to 48 hoursafter surgery. Opioids can cause nausea and vomiting by stimulating the areapostrema at floor of fourth ventricle.5The risk of PONV in thegeneral surgical population is approximately 30%. In high-risk patient groups,or high-risk surgical procedures, the risk of PONV can be as high as 80%. PONVis a distressing experience for the patient and can have a significant impacton patient satisfaction. PONV may prolong post-anaesthesia care unit (PACU)stay and increase the risk of postoperative complications.6Lidocaine is an amide localanaesthetic that has analgesic, antihyperalgesic and anti-inflammatoryproperties. These properties of lidocaine are mediated by channel blockade,inhibition of G protein coupled receptors and NMDA receptors.7In addition to improvinganalgesia, perioperative lidocaine infusion shortens the duration ofpostoperative ileus by an average of 8 hours, and decreases the incidence ofpostoperative nausea and vomiting. 8Ketamine, a phencyclidine derivative, anN-methyl-d-aspartate antagonist, blunts central pain sensitization at subanaesthetic doses (0.3mg/kg or less). Ketamine has been increasingly used as anadjunct in the management of acute postoperative pain.Ketamine caninhibit the spread of nociceptive impulses to the brain. It can be administeredby multiple routes, including intravenous, bolus injection, continuous IVinfusion, epidural route and even wound infiltration. Ketamine is now preferreddrug in many procedures like sedation for MRI, premedication in children,procedural sedation and acute and chronic pain management. Sub anaesthetic ketamineimproves pain scores and reduces perioperative opioid consumption in a broadrange of surgical procedures with a minimal risk of side effects. 9Lacunae in the existingknowledgeExtensive search of literature reveals that, ithas been found that no previous studies have        observed the effect of ketamine andlidocaine (OFA) on post-operative nausea and vomiting. Therefore, in this studywe will compare the effect of fentanyl (opioid)versus opioid free anaesthesia with ketamine and lidocaine on post-operativenausea and vomiting in patients undergoing laparoscopic cholecystectomy.