The Predictive Role of Inflammatory Biochemical Markers in Post-Operative Delirium After Vascular Surgery Procedures

Background: Post-operative delirium (POD) is a common complication, especially in elderly patients who underwent vascular surgery procedures. The aim of this study was to evaluate the relation of inflammatory biochemical markers as neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and systemic inflammation index (SII) with POD occurrence. Methods: This was a single-center, retrospective, observational study. We analyzed the perioperative data of patients who had undergone elective vascular surgery procedures. The occurrence of delirium after procedure was used to divide the population in two groups: POD-pos and POD-neg group. ROC curves were performed to find the appropriate cut-off values of NLR, PLR and SII. Multivariate analysis was used to identify the independent predictors for POD. Results: A total of 646 patients were enrolled. Mean age was 76.2±9.8 years, 68.4% were male. Seventy-three patients (11.3%) developed POD. Mean hospital stay was significantly increased in the POD-pos group (6.1±5.4 vs 3.2±2.8 days, p=0.0001). In-hospital reinterventions were more frequent in the POD-pos group (8.2% vs 3.8%). Blood values analysis reported significant differences: Hb, NLR, PLR, SII, creatinine and RCP were strongly increased (p<0.05) in the POD-pos group. ROC curves identified cut-off values for NLR>3.57, PLR>139.2 and SII>676.4. Multivariate analysis revealed that age, Renal Failure, peripheral revascularization procedures, major amputation, general anesthesia, hospitalization in the previous month, NLR>3.57 and SII>676.4 were independent risk factors for POD. Conclusion: POD represents a common complication of vascular surgery patients. Our study demonstrated that NLR, PLR and SII are reliable and readily available laboratory predictors of POD in vascular surgery that could help in POD risk-stratification.