IMPLEMENTATION OF AN ONCO-ANESTHESIA PROTOCOL USING MULTIMODAL, OPIOID-SPARING TECHNIQUES FOR PATIENTS UNDERGOING MAJOR CANCER SURGERY

Abstract

Background: Cancer surgery represents a major physiological and psychological stressor, often necessitating complex anesthesia and perioperative pain management. Traditionally, opioids have been central to anesthetic practice in oncologic surgery. However, their adverse effects—including respiratory depression, nausea, ileus, immunosuppression, and potential influence on tumor recurrence—have led to growing interest in opioid-sparing or opioid-free anesthesia (OFA). Multimodal anesthesia integrates regional blocks, non-opioid systemic analgesics, and enhanced recovery protocols to improve outcomes and accelerate postoperative recovery in cancer patients.

Objectives: The present study aimed to develop, implement, and evaluate an institutional onco-anesthesia protocol incorporating multimodal, opioid-sparing techniques for patients undergoing major cancer surgery, assessing its feasibility, analgesic efficacy, hemodynamic stability, and impact on postoperative recovery.

Methods: A prospective interventional study was conducted over twelve months in the Department of Anesthesiology at a Shri Sathya Sai Medical college & Research Institute . Adult patients aged 18–70 years scheduled for major cancer surgeries (abdominal, thoracic, and head and neck) were included. The multimodal opioid-sparing protocol comprised preoperative gabapentinoids and acetaminophen, intraoperative dexmedetomidine infusion, intravenous lignocaine, ketamine, and paracetamol, combined with regional anesthesia techniques such as epidural, transversus abdominis plane (TAP), or paravertebral blocks, depending on the surgical site. Intraoperative hemodynamic parameters, anesthetic requirements, and postoperative pain scores were recorded and compared to a historical control group receiving conventional opioid-based anesthesia.

Results: A total of 120 patients were enrolled, with 60 in the multimodal protocol group and 60 in the control group. The multimodal group demonstrated significantly reduced intraoperative fentanyl use (mean 22.4 ± 8.7 µg vs. 178.6 ± 42.1 µg, p < 0.001) and lower postoperative morphine requirement in the first 24 hours (3.4 ± 1.2 mg vs. 9.6 ± 2.8 mg, p < 0.001). Mean pain scores on the Visual Analogue Scale (VAS)

were also significantly lower at 2, 6, and 12 hours postoperatively (p < 0.01 for all time points).  Hemodynamic stability was maintained throughout surgery with fewer fluctuations in mean arterial pressure. Additionally, early recovery milestones such as return of bowel function and ambulation were achieved faster in the multimodal group (p < 0.05). No increase in intraoperative awareness or inadequate analgesia was observed.

Conclusion: The implementation of an onco-anesthesia protocol using multimodal, opioid-sparing strategies proved to be safe, feasible, and clinically effective. It resulted in superior analgesia, greater hemodynamic stability, and faster postoperative recovery compared to conventional opioid-based anesthesia. These findings support a paradigm shift toward integrating multimodal, opioid-minimizing approaches in cancer surgery to enhance patient comfort, reduce opioid-related complications, and potentially improve long-term oncologic outcomes..