A comparison of postoperative analgesic efficacy of opioid-free anesthesia using intravenous paracetamol (15 mg/kg), lignocaine (2 mg/kg), and magnesium sulfate (20 mg/kg) versus standard opioid anesthesia using intravenous tramadol (2 mg/kg) for preemptive analgesia in abdominal surgeries under general anesthesia

INTRODUCTION: Pain is an unpleasant sensory and emotional experience and is considered the fifth vital sign. Opioid-free anesthesia (OFA) is a technique where no intraoperative systemic, neuraxial, or intracavitary opioids are administered during the anesthesia. The prescription misuse/overuse has generated an opioid crisis which has led to the need for OFA. In this study, we will investigate the 24-h postsurgical analgesia and analgesic consumption with the use of OFA versus opioid anesthesia (tramadol) in patients undergoing abdominal surgery under general anesthesia. METHODOLOGY: Sixty patients of the American Society of Anesthesiologists Grade I-II scheduled for various abdominal surgeries were randomly assigned into two groups, with 30 patients in each group. Group A (opioid-free group): received IV lignocaine (2 mg/kg), IV magnesium sulfate (20 mg/kg), and V paracetamol (15 mg/kg) in 100 ml NS. Group B (opioid group): received IV tramadol (2 mg/kg) in 100 ml NS. Hemodynamic parameters, postoperative analgesic consumption, duration of analgesia, and any adverse effects were recorded. RESULTS: A very significant difference was observed between the study groups for mean values of mean arterial pressure at the last stages of surgery, with hemodynamics more stable in the opioid-free group (P < 0.01). In terms of mean values of minimum alveolar concentration throughout the surgery, the opioid group showed more anesthetic-sparing effect (P < 0.05). In terms of postoperative pain scores between the groups, the opioid-free group experienced less pain (P < 0.01). There was no difference between the groups in postoperative analgesic consumption and duration of analgesia. More side effects were noted in the opioid group. CONCLUSION: This study concludes that avoiding opioid use by preemptive administration of intravenous paracetamol, lignocaine, and magnesium sulfate provides safe, effective, and satisfactory analgesia in patients undergoing various abdominal surgeries under general anesthesia.