Complicated Acute Cholecystitis: The Role of C-Reactive Protein and Neutrophil-Lymphocyte Ratio as Predictive Markers of Severity

Objectives The clinical diagnosis of complicated acute cholecystitis (CAC) remains difficult with several pathological or ultrasonography criteria used to differentiate it from uncomplicated acute cholecystitis (UAC). This study aims to evaluate the use of combined inflammatory markers C-reactive protein (CRP) and neutrophil-to-lymphocyte ratio (NLR) as surrogate markers to differentiate between UAC and CAC. Methods We identified 600 consecutive patients admitted with biliary symptoms during an acute surgical take from our electronic prospectively maintained database over a period of 55 months. Only patients undergoing emergency cholecystectomy performed during the index admission were included. The primary outcome was the finding of CAC versus UAC. Results A total of 176 patients underwent emergency laparoscopic cholecystectomy (ELC) during the index admission, including 118 (67%) females with a median age of 51 years (range: 21-97 years). The proportion of UAC (130 [74%]) and CAC (46 [26%]) was determined along with demographic data. Multivariate regression analysis showed that patient’s age (OR=1.047; p=0.003), higher CRP (OR=1.005; p=0.012) and NLR (OR=1.094; p=0.047) were significant independent factors associated with severity of cholecystitis. Receiver operating characteristic (ROC) analysis for CRP showed an AUC (area under the curve) of 0.773 (95% CI: 0.698- 0.849). Using a cut-off value of 55 mg/L for CRP, the sensitivity of CAC was 73.9% and specificity was 73.1% in predicting CAC. The median post-operative length of stay was four days. The conversion rate from laparoscopic cholecystectomy to open surgery was 2% (4/176), and 5% (9/176) patients suffered post-operative complications with no mortality at 30 days. Conclusion CRP, NLR and age were independent factors associated with the severity of acute cholecystitis. NLR and CRP can be used as surrogate markers to predict patients at risk of CAC during emergency admission, which can inform future guidelines. Moreover, ELC for CAC can be safely performed under the supervision of dedicated upper GI surgeons.