Ranson Criteria Calculator — Acute Pancreatitis Severity & Mortality

How to Use This Calculator

1. Select each criterion present at admission (5 criteria).
2. At 48 hours, return and select each additional criterion present (6 criteria).
3. Ranson score and predicted mortality display instantly.
4. Use the Mortality Tiers tab for mortality estimates by score range.

Formula

Example

Frequently Asked Questions

• What are the Ranson criteria for pancreatitis? ▼
  The Ranson criteria are an 11-point scoring system used to predict the severity and mortality of acute pancreatitis, developed by John Ranson and colleagues at New York University and first published in Surgery, Gynecology and Obstetrics in 1974. The criteria are divided into two groups based on assessment timing. Five criteria are evaluated at admission: age greater than 55 years, white blood cell count greater than 16,000/mm³, serum glucose greater than 200 mg/dL (in non-diabetic patients), serum LDH greater than 350 IU/L, and AST greater than 250 IU/L. Six criteria are evaluated at 48 hours after admission: haematocrit drop greater than 10 percentage points, BUN rise greater than 5 mg/dL, serum calcium below 8 mg/dL, arterial PaO₂ below 60 mmHg, base deficit greater than 4 mEq/L, and estimated fluid sequestration greater than 6 litres. Each criterion scores 1 point when present, for a maximum of 11 points. Scores of 0–2 predict less than 1% mortality; scores 3–4 predict approximately 15%; scores 5–6 predict approximately 40%; and scores 7 or above predict approximately 100% mortality. It is important to note that the complete score cannot be calculated until 48 hours after admission.
• Why are Ranson criteria split into admission and 48-hour components? ▼
  The Ranson criteria are split between admission and 48-hour timepoints because acute pancreatitis severity evolves dynamically over the first two days. The five admission criteria capture the initial severity of the inflammatory insult — markers of inflammation (WBC, AST, LDH), metabolic derangement (glucose), and patient vulnerability (age). The six 48-hour criteria capture the systemic consequences of pancreatic inflammation, which reflect the magnitude of the systemic inflammatory response and evolving organ damage: respiratory failure (PaO₂ drop), haemoconcentration followed by haematocrit drop from capillary leakage, rising BUN from intravascular depletion and renal stress, hypocalcaemia from fat saponification and parathyroid suppression, metabolic acidosis (base deficit), and massive fluid third-spacing. This biological rationale — capturing both the initial severity and the 48-hour trajectory — makes Ranson more informative than a single-timepoint score, though also less convenient than alternatives like BISAP or Glasgow score, which can be fully assessed earlier. The 48-hour delay means that Ranson cannot guide very early triage decisions, which is one reason newer scores like BISAP (5 criteria, all assessed at 24 hours) have gained popularity in emergency settings.
• When are Ranson criteria most useful clinically? ▼
  Ranson criteria are most useful in several specific clinical contexts. In patients admitted with acute pancreatitis, Ranson scoring at admission plus 48 hours provides a validated, well-recognised prognostic framework that guides decisions about ICU admission (typically for Ranson ≥3), CT imaging timing (CT with contrast recommended for Ranson ≥3 to assess necrosis), and escalation of care. Ranson criteria are widely used in clinical research as an entry criterion and endpoint for pancreatitis trials, making them essential for interpreting the published literature. They are also embedded in many institutional pancreatitis protocols and electronic order sets. However, Ranson criteria are less useful for continuous monitoring (the score is fixed at 48 hours) or for distinguishing between mild and moderately severe pancreatitis (both have Ranson 0–2 but behave differently). Newer severity scores including BISAP, Glasgow-Imrie, and the revised Atlanta classification (which integrates clinical and CT findings) provide complementary information. In UK and European practice, Glasgow-Imrie is more commonly used than Ranson due to its single 48-hour assessment.
• How do Ranson criteria compare to APACHE II for pancreatitis? ▼
  Both Ranson criteria and APACHE II are commonly used to stratify acute pancreatitis severity, but they differ in their approach and practical applicability. APACHE II requires 12 physiological variables and is calculated at ICU admission and can be repeated daily — making it dynamic and useful for tracking trajectory, which Ranson cannot do after its fixed 48-hour assessment. Multiple head-to-head studies have shown that APACHE II and Ranson have broadly comparable predictive accuracy for severe pancreatitis, with AUROCs typically in the 0.7–0.8 range for both. However, the clinical context differs: Ranson is designed specifically for pancreatitis and is simple to memorise, while APACHE II is a generic ICU severity score that can be applied to any critically ill patient. Ranson's pancreatitis-specific thresholds (e.g., glucose >200, AST >250) have stronger pathophysiological rationale for this disease than the generic APACHE II physiology variables. A practical approach is to use BISAP or Glasgow-Imrie for rapid initial risk stratification in the emergency department or general ward, and APACHE II for patients requiring ICU care where dynamic daily monitoring adds value.
• What is the role of CT imaging alongside Ranson criteria? ▼
  CT imaging and Ranson criteria serve complementary roles in acute pancreatitis assessment and should not be seen as alternatives. Ranson criteria provide clinical and laboratory-based severity stratification and mortality prediction. Contrast-enhanced CT (CECT) of the abdomen provides morphological information: assessment of pancreatic necrosis extent (areas of non-enhancement after intravenous contrast), peripancreatic fluid collections, vascular complications, and extrapancreatic involvement. The CT Severity Index (CTSI, also called Balthazar score) grades CT findings on a 0–10 scale incorporating pancreatic inflammation (0–4 points) and percentage of pancreatic necrosis (0–6 points), with CTSI ≥6 predicting prolonged hospital stay, ICU requirement, and mortality with similar or better accuracy than Ranson in some studies. CECT is recommended for patients with Ranson ≥3, those not improving after 48–72 hours of conservative management, or when there is clinical suspicion of complications. Timing is important: CT performed within the first 24 hours may underestimate necrosis, which develops over 48–72 hours; optimal imaging is typically at 48–72 hours or later when clinical indication arises. MRI/MRCP offers an alternative without radiation, particularly for evaluating ductal anatomy and biliary obstruction.

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