Intravenous lidocaine reduces systemic inflammation but not myocardial injury following thoracic surgery for lung cancer: a randomized controlled trial.

BACKGROUND: Elevated high-sensitivity troponin T levels shortly after noncardiac surgery are closely linked to myocardial injury, a key factor in 30-day postoperative mortality. Intravenous lidocaine, known for its potent anti-inflammatory and membrane-stabilizing properties, has shown cardioprotective potential in other surgical settings, but its efficacy in noncardiac thoracic surgery remains unclear. OBJECTIVES: This study was a double-blind, placebo-controlled randomized trial. Participants were randomly allocated to the lidocaine or placebo group with a 1:1 ratio. DESIGN: Single-centre, double-blind, randomized controlled trial. SETTING: Academic tertiary care medical centre. PATIENTS: Patients scheduled for noncardiac thoracic surgery, predominantly via video-assisted thoracoscopic surgery (VATS), under general anesthesia from June 12, 2021 to June 12, 2022. INTERVENTIONS: Patients received intravenous lidocaine (1.5 mg kg− 1 bolus pre-induction followed by 1.5 mg kg− 1 h− 1 infusion until surgery end) or volume-matched saline. Dosing was adjusted to ideal body weight for BMI ≥ 25 kg m−². Study drugs were prepared by blinded staff and administered via standardized pumps. MAIN OUTCOME MEASURES: The primary outcome was high-sensitivity troponin T concentration at 24 h postoperatively. Secondary outcomes encompassed: (1) the absolute change from baseline to 24 h post-surgery for high-sensitivity troponin T (2) the occurrence of MINS, identified by high-sensitivity troponin T levels of 14 ng l− 1 or higher within 48 h after surgery; (3) levels of NT-proBNP, CK-MB, myoglobin, hs-CRP, and inflammatory markers on the first and second postoperative days; (4) overall opioid use during surgery; and (5) hemodynamic parameters during the operation. RESULTS: Between June 12, 2021, and June 12, 2022, we enrolled 119 patients who underwent thoracic surgery for lung cancer (mean age 59.41 years [SD 11.085], 58 [48.7%] male). The median [IQR] 24-hour high-sensitivity troponin T level did not differ between the lidocaine and control groups (8.00 [6.00–15.00] ng l− 1 vs. 8.00 [5.00–10.00] ng l− 1, P = 0.34). Additionally, the absolute change in hs-TnT from baseline showed no significant difference (3.21 ± 5.93 ng l⁻¹ vs. 3.00 ± 8.56 ng l⁻¹, P = 0.88).The incidence of MINS was similar between the groups (23.3% vs. 23.7%, P = 0.96). Lidocaine exhibited significant anti-inflammatory properties, resulting in an 84.8% reduction in 48-hour IL-6 levels (46.5 ± 33.6 pg ml− 1 vs. 307.0 ± 312.2 pg ml− 1, P = 0.04). In a post-hoc analysis, age was identified as a significant independent predictor of myocardial injury (OR 0.259 for age < 65 vs. ≥ 65 years; 95% CI 0.107 to 0.627; P = 0.003), but no evidence of an interaction with the treatment allocation was found. CONCLUSIONS: Perioperative lidocaine infusion significantly suppressed systemic inflammation, but did not reduce early myocardial biomarker release in the overall cohort. The finding that younger age was associated with a lower risk of myocardial injury, irrespective of treatment group, suggests that age is a key prognostic factor. Further studies are warranted to explore age-specific cardioprotective strategies and the underlying mechanisms of inflammatory-myocardial coupling. TRIAL REGISTRATION: ChiCTR2100047336. Registered on June 12, 2021.