D Dimer as a marker of severity and prognosis in acute pancreatitis

Abstract

Introduction: Acute Pancreatitis (AP) has a substantial burden on health System. AP scores needs battery of tests, applicable only after 48 hours. CT severity index (CTSI) is not helpful at an early stage. It would be of great help, with a simple single test that is widely available, cost effective which can predict Severe AP (SAP), clinical progression & outcome. Method: Prospective observational study. Diagnosis of AP and severity grading was made as per Revised Atlanta Criteria. Patients were categorised into Mild AP and Complicated AP (CAP) which includes Moderate and severe AP. D-dimer done within 3 days of disease onset. Chronic/Recurrent Pancreatitis, coagulopathy, Pregnancy, Trauma, Liver disease, on anticoagulants and organ failure excluded. Modified Marshal Scoring system used for organ failure. APACHE II score, RANSONS, CTSI used. D-Dimer, CRP, routine tests done. Mean, Median, Mann whitney U test, Chi square test, Receiver Operator Characteristic ROC curve analysis done. Result: 30 patients. 50% mild AP, 43.3% moderately severe AP, 6.7% SAP. 93.3% elevated D-Dimer. Median D-Dimer in Mild AP 567 ng/L, CAP 2732 ng/L (p<0.001). D-Dimer in normal CT 363 ng/L vs. positive CTSI 1916 ng/L (p=0.005), increases as CTSI increases (p=0.04). D-Dimer in organ failure 4776 ng/L vs 776.5ng/L in absent organ failure (p=0.001). D Dimer increases as severity of Organ failure increases (p=0.04). D-dimer in ICU patients 2732ng/L (p=0.021) D-dimer and APACHE II score correlates well with increase in predictive mortality rate (p=0.01). On ROC, D-dimer>933.5ng/L suggestive of CAP, D-Dimer > 827.5ng/L is highly associated with positive CTSI sensitivity 90.9%, specificity 83.3%, D-dimer > 1060.5ng/L suggestive of Organ failure sensitivity 85.7%, specificity 72.7%. Conclusion: Coagulopathy & microthrombi plays a significant role in early pathogenesis. D-Dimer test acts at the level of this core pathogenesis, even before the complications sets in, unlike scores/CTSI which are not helpful in the initial days of AP.