Postoperative C-reactive protein to albumin ratio as an early predictor of complications after major abdominal surgery

Background Postoperative complications after major abdominal surgery remain a significant cause of morbidity and prolonged hospitalization. The C-reactive protein to albumin ratio (CAR) has been proposed as an integrated marker reflecting systemic inflammation and nutritional status. This study aimed to evaluate the predictive value of postoperative CAR for early detection of complications following major abdominal surgery in a Nepalese tertiary care setting. Methods This prospective cohort study enrolled 83 patients aged 18–70 years undergoing elective or emergency major abdominal surgery at B.P. Koirala Institute of Health Sciences, Nepal. Preoperative and postoperative (day 3) serum C-reactive protein (CRP) and albumin levels were measured to calculate CAR. Postoperative complications were classified using the Clavien-Dindo system. Data were analyzed using descriptive statistics, Chi-square test, Student’s t-test, univariate and binary logistic regression, and ROC curve analysis. Results Postoperative major complications occurred in 54 patients (65%). Patients with complications had significantly lower preoperative albumin (3.9 ± 0.3 vs. 4.7 ± 0.4 g/dl; p < 0.001), lower postoperative albumin (3.1 ± 0.3 vs. 4.4 ± 0.6 g/dl; p < 0.001), higher postoperative CAR (1.16 ± 0.26 vs. 0.92 ± 0.16; p < 0.001), and longer hospital stays (13.1 ± 8.2 vs. 4.1 ± 1.9 days; p < 0.001). Binary logistic regression did not identify CAR, CRP, or albumin as independent predictors of complications. However, ROC analysis demonstrated excellent diagnostic accuracy for postoperative albumin (AUC = 0.947, sensitivity 100%, specificity 89.7%) compared to CAR (AUC = 0.786) and CRP (AUC = 0.689). Conclusion Although postoperative CAR was significantly higher in patients with complications, postoperative albumin demonstrated superior diagnostic accuracy for predicting adverse outcomes. Incorporating both albumin and CAR into routine postoperative assessment may enhance early detection of complications and guide clinical decision-making in resource-limited settings.