Systemic Anti-Inflammatory and Immunomodulatory Effects of Intravenous Lidocaine During Robotic-Assisted Radical Prostatectomy: A Prospective Observational Study.
: Surgical stress during robotic-assisted radical prostatectomy (RARP) elicits a measurable systemic inflammatory response despite the minimally invasive approach. Intravenous lidocaine has been increasingly investigated for its potential anti-inflammatory, analgesic, and immunomodulatory benefits, but evidence in robotic urologic oncology remains limited. This study aimed to evaluate whether intraoperative lidocaine infusion attenuates postoperative inflammation, improves analgesic outcomes, and accelerates early recovery following RARP. : This prospective non-randomized observational study included 80 patients undergoing elective RARP, divided into a Lidocaine Group ( = 40) receiving an intraoperative bolus and continuous infusion, and a Control Group ( = 40) receiving standard anesthesia without lidocaine. Serum IL-6, TNF-α, CRP, and fibrinogen were measured at baseline, end of surgery, and 24 h postoperatively. Postoperative pain scores, opioid consumption, gastrointestinal recovery, ambulation, and length of stay were recorded. Statistical analyses included repeated-measures ANOVA, correlation testing, and between-group comparisons. : Baseline characteristics were similar between groups. At 24 h postoperatively, lidocaine administration was associated with a significantly attenuated inflammatory response, with lower levels of IL-6 (45.7 ± 10.8 vs. 68.9 ± 12.6 pg/mL, < 0.01) and TNF-α (20.5 ± 5.1 vs. 27.2 ± 6.4 pg/mL, < 0.01) compared with controls. Patients receiving lidocaine reported lower postoperative pain scores and required significantly less opioid analgesia, with a total 24 h consumption of 8.9 ± 3.4 vs. 14.8 ± 5.2 mg morphine milligram equivalents ( < 0.001). Lidocaine was also associated with faster recovery, including earlier oral intake and a shorter length of hospital stay (2.9 ± 0.7 vs. 3.6 ± 0.9 days, = 0.003). No lidocaine-related adverse events were observed. : In this prospective observational study, intraoperative intravenous lidocaine was associated with attenuated early postoperative inflammation, improved analgesic outcomes, and enhanced early recovery following RARP. These findings support the potential role of intravenous lidocaine as a safe adjunct in multimodal perioperative management; however, given the non-randomized observational design, causal inferences should be interpreted with caution. Further randomized controlled trials are warranted to confirm causality and to validate long-term clinical and mechanistic effects. Potential residual confounding inherent to the observational design should be considered when interpreting these findings.