Effect of Opioid Versus Non-Opioid Analgesia on Surgical Pleth Index and Biomarkers of Surgical Stress During Neurosurgery for Brain Tumors: Preliminary Findings.

BACKGROUND: Stress response to surgery is mediated by the sympathetic nervous system and manifests as changes in hemodynamic and neuroendocrine parameters. Recently, the surgical pleth index (SPI) is employed for objective and continuous monitoring of nociceptive response during surgery. Opioids are the mainstay of managing stress response to nociception during the perioperative period. However, due to the well-known adverse effects of opioids, …