Background: Frailty is increasingly being recognized as a risk factor for adverse outcomes in older surgical patients undergoing surgery. We investigated the association between frailty and intraoperative complications using multiple frailty assessment tools in older patients undergoing elective intermediate- to high-risk non-cardiac surgery. Methods: This retrospective cohort study included 637 older patients scheduled for elective non-cardiac surgery. Frailty was assessed using the Clinical Frailty Scale (CFS), FRAIL scale, and modified Frailty Index-11 (mFI-11). The predictive ability of frailty tools was analyzed and compared using the area under the receiver operating characteristic curve (AUC). Results: Frailty was significantly associated with higher intraoperative complication rates (FRAIL scale: p = 0.01; mFI-11: p = 0.046). Patients considered frail using the mFI-11 were more likely to have unplanned intensive care unit admissions (p < 0.001). Those classified as frail by the FRAIL scale and mFI-11 had significantly higher rates of vasopressor/inotrope use (p = 0.001 and p = 0.005, respectively) and mechanical ventilation (p = 0.033 and p = 0.007, respectively). In the univariate analysis, frailty measured using the FRAIL scale was significantly associated with intraoperative complications (odds ratio [OR], 2.41; 95% confidence interval [CI]: 1.33–4.38; p = 0.004); this association was not significant in the multivariate analysis (adjusted OR, 1.69; 95% CI: 0.83–3.43; p = 0.148; AUC = 0.550). Atrial fibrillation, hemoglobin levels, anesthesia type, and surgical subspecialty were stronger predictors of intraoperative complications. Conclusions: Frailty assessments demonstrate the limited predictive ability for intraoperative complications. Specific comorbidities, surgical techniques, and anesthesia types play more critical roles. Comprehensive preoperative evaluations integrating frailty with broader risk stratification methods are necessary to enhance patient outcomes and ensure safety.

Background: Oxidative stress and systemic inflammation during cardiac surgery can lead to postoperative complications. Although vitamin C and thiamine (vitamin B1) have individually demonstrated protective effects, their combined effects remain underexplored. This study aimed to evaluate the efficacy of combined vitamin C and B1 therapy versus that of vitamin C alone in reducing inflammatory and cardiac biomarkers and improving postoperative outcomes in patients undergoing cardiac surgery. Methods: In this prospective, double-blind, randomized controlled trial, 64 patients scheduled for elective cardiac surgery at a tertiary care center were randomized to receive either 1000 mg vitamin C or a combination of 1000 mg vitamin C and 100 mg vitamin B1 at four perioperative time points. Primary outcomes included changes in inflammatory biomarkers [C-reactive protein, interleukin-6 (IL-6), and white blood cells], and cardiac biomarkers [creatine kinase-MB, Troponin-I, and lactate dehydrogenase]. Secondary outcomes included hemodynamic parameters and left ventricular function. Results: Compared with vitamin C alone, combined vitamin B1 and vitamin C significantly reduced postoperative cardiac biomarker levels. IL-6 levels were significantly lower immediately in the combined group; however, this effect was not sustained at 24 h post-surgery. Up to 24 h after surgery, no significant differences in hemodynamic stability or left ventricular ejection were observed between the groups. Notably, the combined therapy group demonstrated a lower incidence of postoperative arrhythmias and shorter dobutamine duration within 24 postoperatively. Conclusions: Combined vitamin C and B1 therapy significantly reduced markers of myocardial injury and early inflammatory responses (IL-6) in patients undergoing cardiac surgery, suggesting its potential as a protective agent.