Perfusion index as a valuable tool to assess analgesia during laparoscopic surgeries under general anesthesia

Background & objective: Effective pain management during laparoscopic surgery under general anesthesia remains a challenge due to the lack of objective tools to assess nociception. The Perfusion Index (PI), derived from pulse oximetry, reflects peripheral perfusion and may serve as a non-invasive marker for analgesia adequacy by detecting sympathetic activation caused by nociceptive stimuli. We evaluated PI as a tool for assessing analgesia during laparoscopic surgeries by comparing its changes in response to painful stimuli and correlating it with hemodynamic parameters. Methodology: This prospective observational study was conducted in the Department of Anesthesiology at Dr. D. Y. Patil Medical College, Hospital and Research Centre, Pimpri, Pune, Maharashtra, India, after the approval by Institutional Ethics Committee. In this prospective observational study, 90 ASA I/II patients, aged 18–60 years, undergoing elective laparoscopic surgery, were enrolled. PI, heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) were recorded at baseline, after induction, during pneumoperitoneum creation (P0), and after port insertions (P1–P3), every 1 min for first 10 min followed by every 5 min for 30 min. Fentanyl 1 µg/kg was administered after P1, and changes in PI and hemodynamic were analysed. Results: PI decreased significantly during P1 (5.49 ± 0.05) compared to P0 (6.33 ± 0.06, P < 0.001), reflecting nociceptive response. After fentanyl administration, PI increased at P2 (5.72 ± 0.13) and P3 (6.01 ± 0.06, P < 0.001), indicating significant analgesia efficacy. HR spiked at P1 (88.18 ± 17.70 bpm) but stabilized post-fentanyl. No significant correlations were found between PI and SBP, DBP, or MAP. Conclusion: PI effectively tracks nociceptive stimuli and analgesia efficacy during laparoscopic surgery, offering a real-time, non-invasive monitoring tool. Its dynamic changes align with painful events, supporting its utility in optimizing intraoperative pain management. Abbreviations: DBP: diastolic blood pressure, HR: heart rate, MAP: mean arterial pressure, PI: Perfusion Index, SBP: systolic blood pressure, Keywords: Analgesia; Fentanyl; General Anesthesia; Hemodynamic; Laparoscopic Surgery; Nociception; Perfusion Index; Peripheral Perfusion Citation: Shah B, Badam B, Salim R, Pramanik P. Perfusion index as a valuable tool to assess analgesia during laparoscopic surgeries under general anesthesia. Anaesth. pain intensive care 2025;29(5):541-547. DOI: 10.35975/apic.v29i5.2925 Received: May 08, 2024; Revised: June 07, 2024; Accepted: June 09, 2025