Diagnostic accuracy of routine hematological biomarkers for complications and prognosis in bowel obstruction: a systematic review and meta-analysis.

Abstract

BACKGROUND Bowel obstruction is a critical emergency. Although imaging like X-ray and computed tomography (CT) aids diagnosis, cost-effective hematological biomarkers are still needed. This study evaluates the diagnostic values of hematological biomarkers for detecting complications, determining the need for surgery, and predicting prognosis in patients with bowel obstruction. METHODS A systematic review and meta-analysis was conducted following PRISMA guidelines. We systematically searched Web of Science, PubMed, Scopus, Embase and Cochrane Library for studies published up to June 2025. Inclusion criteria encompassed observational or case-control studies reporting sensitivity/specificity of neutrophil-lymphocyte ratio (NLR), C-reactive protein (CRP), procalcitonin (PCT), D-dimer, or lactate in bowel obstruction outcomes. Data extraction included true/false, positives/negatives, cutoff values, and receiver operating characteristic (ROC) parameters. Bivariate models pooled sensitivity/specificity, while summary ROC curves and Youden index determined optimal thresholds. RESULTS This study included 34 articles comprising a total of 5871 patients. CRP at a cutoff of 26.91 mg/L (Youden index: 0.97) for diagnosing bowel ischemia showed pooled sensitivity and specificity of 0.80 and 0.92, respectively, with a summary receiver operating characteristic (SROC) curve and an area under the curve (AUC) of 0.91. PCT in determining the need for surgery achieved a cutoff of 0.12 ng/mL (Youden index: 0.8), with sensitivity and specificity of 0.75 and 0.74 (AUC: 0.79). NLR showed a cutoff of 7.2 (Youden index: 0.68), yielding sensitivity and specificity of 0.74 and 0.83 (AUC: 0.84) in the diagnosis of bowel ischemia. D-dimer (cutoff: 1.72 mg/L, Youden index: 0.91) and lactate (cutoff: 2.98 mmol/L, Youden index: 0.8) exhibited sensitivities of 0.83 and 0.77, specificities of 0.70 and 0.79, and AUCs of 0.85 for both, in the diagnosis of bowel ischemia. CONCLUSION NLR, CRP, PCT, D-dimer, and lactate may provide supplementary diagnostic value for bowel ischemia in patients with bowel obstruction. A PCT threshold > 0.12 ng/mL may assist in evaluating the need for surgery.