Abstract
Introduction: Systemic inflammation plays a pivotal role in postoperative pain and complications after total knee arthroplasty (TKA). Intrathecal adjuvants may modulate this response by influencing inflammatory markers such as C reactive protein (CRP) and systemic immune inflammation index (SII) to test analgesic efficacy and overall postoperative outcomes.
Objectives: This study aimed to compare the effects of adding intrathecal dexmedetomidine versus fentanyl to bupivacaine on postoperative inflammatory markers, perioperative and clinical outcomes in patients undergoing .
Patients and Methods: This randomized single blind clinical trial enrolled patients undergoing elective who received intrathecal bupivacaine (12.5 mg, 0.5% hyperbaric) supplemented with either dexmedetomidine (25 µg) or fentanyl (25 µg). Postoperative complications were recorded. Venous blood samples were collected preoperatively, 24 and 48 hours postoperatively to measure serum CRP and the SII.
Results: Postoperative inflammatory markers showed a significantly attenuated response in the dexmedetomidine group, with lower CRP levels and SII values at 24 and 48 hours compared with fentanyl (P < 0.001). Clinically, dexmedetomidine was associated with a lower incidence of postoperative nausea and vomiting (P=0.036), fewer episodes of intraoperative hypoxia (P=0.009), reduced postoperative pain scores (P=0.039) and a longer time to first opioid request (P=0.017), despite a modest prolongation of anesthesia duration (P=0.035).
Conclusion: Dexmedetomidine as an intrathecal adjuvant to bupivacaine in was associated with lower postoperative CRP and SII levels, reduced pain intensity, and fewer postoperative complications compared with fentanyl, indicating superior attenuation of the systemic inflammatory response, despite fentanyl demonstrating relatively greater perioperative blood pressure stability.
Trial Registration: The trial protocol was approved in the Iranian registry of clinical trial (identifier: IRCT20190325043107N58; https://irct.behdasht.gov.ir/trial/84871, Ethical code; IR.TBZMED.REC.1402.390).