Prediction of Postoperative Pain and Opioid Consumption Using Intraoperative Surgical Pleth Index After Surgical Incision: An Observational Study

Abstract

Kangha Jung, Mi Hye Park, Duk Kyung Kim, Byung Jun Kim Department of Anesthesiology and Pain Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South KoreaCorrespondence: Mi Hye ParkDepartment of Anesthesiology and Pain Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 51 Ilwon-Ro, Gangnam-Gu, Seoul 06351, South KoreaTel [phone]Fax [phone]Email [email protected]: We evaluated whether the surgical pleth index (SPI) following surgical incision was related to postoperative pain and opioid consumption.Methods: This prospective observational study was performed in 50 patients undergoing laparotomy under sevoflurane-based general anesthesia. We recorded the highest SPI during surgical incision. The postoperative pain with a numerical rating scale (NRS) and opioid consumption during postoperative 24 h were compared in patients who showed SPI over 50 (Group H) or 20– 50 (Group L). The relationship between postoperative opioid consumption and SPI values (pre-incision, post-incision SPI value, change of SPI value, and post-incision SPI minus pre-incision SPI) was evaluated using receiver-operating characteristic analysis.Results: The mean of the highest SPI value during surgical incision was 56 (SD, 12; range, 26– 85). Twenty-nine (63%) patients were included in Group H and 17 (37%) patients in Group L. There was a significant difference in NRS during recovery room stay and on postoperative 24 h in two groups (5 [5, 6] vs 7 [6, 8], p=0.007 and 3.5 [3, 5] vs 5 [5,6], p=0.006, Group L vs Group H). Group H used higher fentanyl via patient control analgesia during postoperative 24 h (573 (253) μg vs 817 (305) μg, p=0.008). A change of pre-incision and post-incision SPI value of 23, which showed the highest sensitivity (67%) and specificity (68%), was defined post hoc as the cut-off for fentanyl consumption during postoperative 24 h ≥ 1000 μg.Conclusion: Our finding suggests that the SPI response to nociceptive stimuli during surgery is closely related to the degree of patient postoperative pain and opioid requirements. This information may be used to provide proper intraoperative analgesia and individual postoperative pain management.Keywords: opioid, postoperative pain, stress response, surgical incision, surgical pleth index

Keywords

• opioid
• postoperative pain
• stress response
• surgical incision
• surgical pleth index