Ranson Criteria Calculator (Acute Pancreatitis)
Ranson score for acute pancreatitis severity — five admission criteria and six 48-hour criteria for non-gallstone and gallstone pancreatitis — with predicted mortality.
How it works
Non-gallstone — admission: age > 55, WBC > 16, glucose > 11.1 mmol/L, LDH > 350, AST > 250; 48 h: Hct fall > 10%, urea rise > 1.8 mmol/L, Ca < 2.0 mmol/L, PaO₂ < 60 mmHg, base deficit > 4, fluid sequestration > 6 L. ≥ 3 = severe
Ranson’s 1974 criteria were the first systematic way to predict which patients with acute pancreatitis would develop the severe, necrotising form. Five values at admission reflect the inflammatory hit; six more at 48 hours reflect its systemic consequences — haemoconcentration, renal impairment, hypocalcaemia from fat saponification, hypoxia, acidosis and third-space fluid loss. Three or more criteria predict severe disease with mortality climbing steeply. The obvious drawback is the 48-hour wait, which is why BISAP (calculable at admission) and the revised Atlanta classification (organ failure and local complications) have largely superseded it for real-time decisions. Ranson remains widely taught and is still used as a reference standard.
Worked example
Non-gallstone, age 58, WBC 17, glucose 12.5, LDH 300, AST 180 → 3 admission criteria; at 48 h haematocrit fell 8 points, urea rose 1.5, calcium 1.9, PaO₂ 56, base deficit 5, 7 L of fluid → 4 more: Ranson 7, mortality around 40–100%.
Frequently asked questions
How do I measure fluid sequestration?
Total fluids given minus urine output (and other measured losses) over the first 48 hours — a positive balance above 6 litres scores.
Is Ranson still recommended?
Guidelines now favour BISAP, APACHE II or simply the presence of persistent organ failure at 48 hours. Ranson is acceptable but slower and less accurate.
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Clinical decision tool for education and for use by trained clinicians alongside judgement — not a diagnosis and not a substitute for medical assessment. Scores validated in specific populations may not apply to every patient.