Acute Pancreatitis Severity (BISAP, Ranson, Glasgow-Imrie and Revised Atlanta)
BISAP at the bedside, Ranson and Glasgow-Imrie at 48 hours, and the Revised Atlanta grade from organ failure · v1- Choose the stage first: within 24 hours of admission scores BISAP; at 48 hours the form adds what Ranson and Glasgow-Imrie need.
- Say whether organ function values are to hand. With a blood gas, creatinine and systolic pressure the tool grades the modified Marshall score and reads the Revised Atlanta class.
- Enter blood urea as your laboratory reports it, in mg/dL, mmol/L or as BUN. SIRS, the age criteria and the Ranson criteria set are ticked for you from what you enter.
- You get one verdict, each score against its published bands, the criteria behind every point, and the flags that change what to do next.
- Read a prediction as a prediction. Only organ failure and its duration grade severity, so reassess at 48 hours whatever the scores say.
- Children and adolescents under 18 years. Every score here was derived in adults, and the tool declines the age.
- Chronic pancreatitis, including an acute flare of established chronic disease. None of the scores here grades it.
- The diagnosis of acute pancreatitis. The tool assumes two of pain, enzymes above three times the upper limit, and typical imaging are already met.
- The choice of fluid, antibiotic, feeding or the timing of ERCP. The IV Fluid & Calorie Calculator handles volumes; the rest is for the treating team.
- A grade for local complications or infected necrosis. Collections and necrosis are entered as present or absent from the imaging report, and the tool does not score the CT.
1. Timing and Data Available
2. Age and Bedside Findings
3. SIRS in the First 24 Hours
4. Blood Urea
1. Timing of Each Score
Severity in acute pancreatitis is predicted early and graded late. The scores differ mainly in when they can be completed.
| When | What | What it tells you |
|---|---|---|
| Admission to 24 hours | BISAP; SIRS | Predicted in-hospital mortality; risk of organ failure |
| 48 hours | Ranson; Glasgow-Imrie; persistent SIRS | Predicted severe disease |
| 24 hours, 48 hours, 7 days | Modified Marshall and the Revised Atlanta class | The grade itself: mild, moderately severe or severe |
2. Severity Defined by Organ Failure
The Revised Atlanta classification of 2012 grades severity on organ failure and complications, not on any prediction score.
- Mild: no organ failure and no local or systemic complication.
- Moderately severe: organ failure that resolves within 48 hours, or a local complication, or an exacerbation of comorbid disease, without persistent organ failure.
- Severe: organ failure persisting beyond 48 hours. WSES 2019 puts the risk of death at about one in three.
- Organ failure within the first 24 hours means the patient does not have mild disease, and is treated as potentially severe until its duration is known.
3. The Modified Marshall Score at the Bedside
Three systems are graded 0 to 4, and 2 or more in any one is organ failure: PaO₂/FiO₂ of 300 or below, creatinine of 1.9 mg/dL or above, or a systolic pressure below 90 mmHg that does not respond to fluid.
- For a patient who is not ventilated, the classification estimates FiO₂ from flow: 2 L/min 25%, 4 L/min 30%, 6 to 8 L/min 40%, 9 to 10 L/min 50%.
- The creatinine row carries no formal correction for chronic kidney disease with a baseline of 1.4 mg/dL or more; what counts is the rise from baseline.
- Blood pressure is read off inotropic support. The table says nothing further, so this tool counts a patient on a vasopressor as not fluid responsive.
- The published mg/dL cells overlap at 3.6 and leave a gap between 1.8 and 1.9. Here 1.85 scores 1 and 3.6 scores 3.
4. Blood Urea and BUN
BISAP and Ranson were written in BUN, Glasgow-Imrie in urea mmol/L, and most Indian laboratories report blood urea in mg/dL. Blood urea is BUN multiplied by 2.14.
| Criterion | BUN, mg/dL | Blood urea, mg/dL | Blood urea, mmol/L |
|---|---|---|---|
| BISAP | above 25 | above 53.5 | above 8.92 |
| Glasgow-Imrie | above 44.8 | above 96.0 | above 16 |
| Ranson rise, non-gallstone | above 5 | above 10.7 | above 1.78 |
| Ranson rise, gallstone | above 2 | above 4.2 | above 0.71 |
The error runs one way. A blood urea of 50 mg/dL is a BUN of 23 and earns no BISAP point; typed into a BUN field it scores one.
5. Ranson's Two Criteria Sets
Ranson's 1974 criteria are applied to pancreatitis not caused by gallstones. In 1982 he published separate thresholds for gallstone pancreatitis, with ten criteria instead of eleven.
| Criterion | Non-gallstone (1974) | Gallstone (1982) |
|---|---|---|
| Age | above 55 | above 70 |
| White cells | above 16,000/mm³ | above 18,000/mm³ |
| Glucose | above 200 mg/dL | above 220 mg/dL |
| LDH | above 350 U/L | above 400 U/L |
| AST | above 250 U/L | above 250 U/L |
| BUN rise in 48 hours | above 5 mg/dL | above 2 mg/dL |
| PaO₂ | below 60 mmHg | not a criterion |
| Base deficit | above 4 mmol/L | above 5 mmol/L |
| Fluid sequestration | above 6 L | above 4 L |
Both sets share a haematocrit fall of more than 10 points and a calcium below 8 mg/dL.
6. Markers That Do Not Grade Severity
- Amylase and lipase levels. They make the diagnosis and do not track severity; ACG 2024 advises against following them once the diagnosis is made.
- Early CT. Necrosis is usually not visible on admission. IAP 2025 places the first CT for severity at least 72 to 96 hours after the onset of symptoms; ACG 2024 reserves it for doubtful diagnosis or failure to improve within 48 to 72 hours.
- C-reactive protein on admission. It peaks only after 48 to 72 hours.
7. Predictive Performance of the Scores
No score predicts well enough to act on alone. ACG 2024 notes that Ranson and Glasgow-Imrie need 48 hours, by which time a severe course is usually obvious, and that BISAP may be no more accurate than watching the BUN and SIRS.
- BISAP had an area under the curve of 0.82 for mortality in its validation cohort of 18,256 admissions.
- A BISAP of 3 or more carried odds ratios of 7.4 for organ failure and 12.7 for persistent organ failure in a prospective cohort of 397.
- IAP 2025 recommends SIRS on admission and persistent SIRS at 48 hours to predict severe disease, and persistent organ failure to predict outcome.
8. Validation in Indian Patients
- Banaras Hindu University, 72 patients. Area under the curve for mortality: APACHE II 0.86, Ranson 0.84, Glasgow 0.83, BISAP 0.83. The best cut-offs were Ranson 3, Glasgow 3 and BISAP 2.
- Asian Institute of Gastroenterology, Hyderabad, 163 patients. The Revised Atlanta classes separated outcomes: mortality 38.9% in severe against 1.7% in moderately severe disease.
9. Disagreements Between Sources
| Point | One source | Another |
|---|---|---|
| Haematocrit | ACG 2024: 44 or more | WSES 2019: above 44% |
| BUN | ACG 2024: 20 mg/dL or more | WSES 2019: above 20 mg/dL |
| First CT | IAP 2025: at least 72 to 96 hours after onset | Revised Atlanta 2012: 5 to 7 days after admission is more reliable for necrosis |
| Early predictor | IAP 2025: SIRS and persistent SIRS | WSES 2019: BISAP, for its simplicity |
| Glasgow enzyme item | Modified Glasgow (Blamey 1984): LDH above 600 U/L | PANCREAS mnemonic: AST above 200 U/L or LDH above 600 U/L |
Abbreviations
ABG (Arterial Blood Gas) · ACG (American College of Gastroenterology) · AKI (Acute Kidney Injury) · APACHE (Acute Physiology and Chronic Health Evaluation) · AST (Aspartate Aminotransferase) · AUD (Alcohol Use Disorder) · BISAP (Bedside Index for Severity in Acute Pancreatitis) · BP (Blood Pressure) · BUN (Blood Urea Nitrogen) · CKD (Chronic Kidney Disease) · CT (Computed Tomography) · ERCP (Endoscopic Retrograde Cholangiopancreatography) · FiO₂ (Fraction of Inspired Oxygen) · GCS (Glasgow Coma Scale) · HDU (High Dependency Unit) · HFNO (High-Flow Nasal Oxygen) · IAP (International Association of Pancreatology) · ICU (Intensive Care Unit) · IV (Intravenous) · LDH (Lactate Dehydrogenase) · NIV (Non-Invasive Ventilation) · PaCO₂ (Arterial Partial Pressure of Carbon Dioxide) · PaO₂ (Arterial Partial Pressure of Oxygen) · PCV (Packed Cell Volume) · SGOT (Serum Glutamic Oxaloacetic Transaminase) · SIRS (Systemic Inflammatory Response Syndrome) · SpO₂ (Peripheral Oxygen Saturation) · TLC (Total Leucocyte Count) · WSES (World Society of Emergency Surgery)References
- Wu BU, Johannes RS, Sun X, Tabak Y, Conwell DL, Banks PA. The early prediction of mortality in acute pancreatitis: a large population-based study. Gut. 2008;57(12):1698-1703.
- Singh VK, Wu BU, Bollen TL, et al. A prospective evaluation of the bedside index for severity in acute pancreatitis score in assessing mortality and intermediate markers of severity in acute pancreatitis. Am J Gastroenterol. 2009;104(4):966-971.
- Ranson JH, Rifkind KM, Roses DF, Fink SD, Eng K, Spencer FC. Prognostic signs and the role of operative management in acute pancreatitis. Surg Gynecol Obstet. 1974;139(1):69-81.
- Ranson JH. Etiological and prognostic factors in human acute pancreatitis: a review. Am J Gastroenterol. 1982;77(9):633-638.
- Blamey SL, Imrie CW, O'Neill J, Gilmour WH, Carter DC. Prognostic factors in acute pancreatitis. Gut. 1984;25(12):1340-1346.
- Banks PA, Bollen TL, Dervenis C, et al. Classification of acute pancreatitis 2012: revision of the Atlanta classification and definitions by international consensus. Gut. 2013;62(1):102-111.
- Tenner S, Vege SS, Sheth SG, et al. American College of Gastroenterology Guidelines: Management of Acute Pancreatitis. Am J Gastroenterol. 2024;119(3):419-437.
- International Association of Pancreatology Revised Guidelines on Acute Pancreatitis 2025: supported and endorsed by the American Pancreatic Association, European Pancreatic Club, Indian Pancreas Club, and Japan Pancreas Society. Pancreatology. 2025;25(6):770-814.
- Leppäniemi A, Tolonen M, Tarasconi A, et al. 2019 WSES guidelines for the management of severe acute pancreatitis. World J Emerg Surg. 2019;14:27.
- Bone RC, Balk RA, Cerra FB, et al. Definitions for sepsis and organ failure and guidelines for the use of innovative therapies in sepsis. Chest. 1992;101(6):1644-1655.
- Khanna AK, Meher S, Prakash S, et al. Comparison of Ranson, Glasgow, MOSS, SIRS, BISAP, APACHE-II, CTSI scores, IL-6, CRP, and procalcitonin in predicting severity, organ failure, pancreatic necrosis, and mortality in acute pancreatitis. HPB Surg. 2013;2013:367581.
- Talukdar R, Bhattacharrya A, Rao B, Sharma M, Nageshwar Reddy D. Clinical utility of the revised Atlanta classification of acute pancreatitis in a prospective cohort: have all loose ends been tied? Pancreatology. 2014;14(4):257-262.
How to Cite This Tool
AMA Style:Umakanth S. Acute Pancreatitis Severity (BISAP, Ranson, Glasgow-Imrie and Revised Atlanta). Version 1. MEDiscuss Clinical Decision Support System. Published 2026. Accessed . https://mediscuss.org/cdss/pancreatitis-severity
Vancouver Style:Umakanth S. Acute Pancreatitis Severity (BISAP, Ranson, Glasgow-Imrie and Revised Atlanta) [Internet]. Version 1. MEDiscuss.org; 2026 [cited ]. Available from: https://mediscuss.org/cdss/pancreatitis-severity
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Category Risk Scores & Diagnostic PathwaysScore
Specialties Gastroenterology, Internal Medicine, General Surgery, Critical Care