Evaluating Lactate and CRP for Preoperative Risk Stratification in Acute Appendicitis: A Retrospective Study

Aim: Distinguishing complicated from uncomplicated appendicitis is important for patient management. Readily available biomarkers such as serum lactate and C-reactive protein (CRP) may contribute to this process, although their diagnostic accuracy remains debated.Material and Methods: This retrospective study included 156 patients who underwent appendectomy between 2018 and 2024. Patients were grouped as complicated or uncomplicated based on operative and histopathological findings. Preoperative serum lactate and CRP were analyzed using ROC curves, and multivariate logistic regression was performed to identify potential predictors.Results: Complicated appendicitis (n=60, 38.5%) was associated with higher lactate (median 2.5 vs 1.6 mmol/L, p<0.001) and CRP levels (median 85 vs 32 mg/L, p<0.001). ROC analysis suggested fair to good discriminative ability for lactate (AUC 0.82) and moderate performance for CRP (AUC 0.78). In multivariate analysis, lactate, CRP, and body temperature appeared as independent predictors, although effect sizes were modest.Conclusions: Preoperative lactate and CRP levels showed an association with complicated appendicitis and may provide supportive information in risk stratification. However, these biomarkers alone are not sufficient for diagnosis and should be interpreted cautiously in conjunction with clinical and imaging findings. Larger, prospective studies are required to validate their role.