BISAP Score Calculator
BISAP Score Calculator
Score the Bedside Index for Severity in Acute Pancreatitis within the first 24 hours, with Wu’s published in-hospital mortality beside the total.
BISAP score
5 items → points + mortalityBUN 32 mg/dL, mental status normal, SIRS present, age 64, no pleural effusion
Scoring
All five assessed within the first 24 hours
- B
- blood urea nitrogen > 25 mg/dL
- I
- impaired mental status — Glasgow Coma Scale below 15
- S
- SIRS — any two of the four criteria
- A
- age > 60 years
- P
- pleural effusion on imaging
Worked example
BUN 32 mg/dL, mental status normal, SIRS present, age 64, no pleural effusion
BUN 32 > 25 → 1
Mental status normal → 0; SIRS present → 1; age 64 > 60 → 1; no effusion → 0
1 + 0 + 1 + 1 + 0 = 3 points → published in-hospital mortality 5.3 to 8.3%
Mortality by score
| BISAP | In-hospital mortality |
|---|---|
| 0–1 | 0.1–0.7% |
| 2 | 1.9–2.1% |
| 3 | 5.3–8.3% |
| 4 | 12.7–19.3% |
| 5 | 22.5–26.7% |
BISAP against the 48-hour scores
| Score | Complete at | Items | Discrimination for mortality |
|---|---|---|---|
| BISAP | 24 hours | 5 | AUC 0.82 (validation), against APACHE II 0.83 |
| Ranson's | 48 hours | 11 | Sensitivity 87–90%, specificity 67–87% above 2 points |
| Glasgow-Imrie | 48 hours | 8 | Derived against severe disease, not mortality |
Five items, one day, one outcome
BISAP was derived by classification and regression tree analysis on 17,992 episodes of acute pancreatitis from 212 hospitals and validated on a further 18,256 from 177 hospitals — a scale of derivation that no earlier pancreatitis score came close to. Five variables survived: blood urea nitrogen above 25 mg/dL, impaired mental status, SIRS, age above 60, and a pleural effusion. One point each, all assessed inside the first 24 hours.
The 24-hour window is the whole argument for the score. Ranson's criteria and Glasgow-Imrie are not complete until 48 hours have passed, by which time the escalation decisions have been taken on clinical grounds. BISAP reports on day one and, in the validation cohort, discriminated in-hospital mortality with an area under the curve of 0.82 against APACHE II's 0.83 — from five items rather than a full physiological dataset. That is the trade the score makes and it is a good one.
One of the five items is not really one item. SIRS is itself a four-part criterion set, so a BISAP of 1 driven by SIRS alone rests on a rule that Sepsis-3 retired from the sepsis definition in 2016 and that is met by a large fraction of patients with any acute inflammatory illness. This page does not restate those four criteria — score them on the SIRS criteria calculator and bring the answer back. What matters here is knowing that one fifth of the score is a composite with its own literature and its own well-documented lack of specificity.
The score's ceiling is what it was derived against. Wu's outcome was in-hospital mortality and nothing else. It was not derived against pancreatic necrosis, infected collections, walled-off necrosis, pseudocyst, splenic vein thrombosis or any other local complication, and the subsequent meta-analysis and validation series that report on BISAP are silent on those outcomes too. A patient with a BISAP of 1 can still develop extensive necrosis; the score has not been shown to say otherwise. Local complications are an imaging question, and under the revised Atlanta classification they are part of the definition of moderately severe disease rather than something a bedside index predicts.
Even for mortality, the working threshold is blunt. A BISAP of 3 or more carries a pooled sensitivity of 56% and a specificity of 91% for death, and 51% and 91% for severe acute pancreatitis. Used as a rule-in test for a high-risk group it performs well. Used as a rule-out it does not: nearly half of the patients who die score below 3.
Frequently asked questions
What BISAP score is high risk?
3 or more. Published in-hospital mortality is 0.1 to 0.7% at 0 to 1 points, 1.9 to 2.1% at 2, 5.3 to 8.3% at 3, 12.7 to 19.3% at 4 and 22.5 to 26.7% at 5, across Wu's two cohorts. At the 3-point cut-off, pooled sensitivity for death is 56% and specificity 91%.
When should BISAP be scored?
Within the first 24 hours of admission — that is how it was derived and it is the score's main advantage over Ranson's criteria and Glasgow-Imrie, both of which need 48 hours. Recount it as the urea and the SIRS criteria change through the first day.
Does BISAP predict pancreatic necrosis?
It has not been shown to. The score was derived against in-hospital mortality only, and neither the derivation nor the later meta-analyses report performance for necrosis or other local complications. A low BISAP is not evidence against necrosis; that is an imaging question.
What counts as SIRS for the BISAP score?
Any two of the four standard criteria — temperature above 38 °C or below 36 °C, heart rate above 90, respiratory rate above 20 or PaCO₂ below 32 mmHg, and white cells above 12 or below 4 ×10⁹/L or more than 10% band forms. Score them on the dedicated SIRS calculator and enter the answer here.
Related calculators
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):1698–703.
- Gao W, Yang HX, Ma CE. The value of BISAP score for predicting mortality and severity in acute pancreatitis: a systematic review and meta-analysis. PLOS ONE. 2015;10(6):e0130412.
- 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):102–11.
Medical Disclaimer: The tools and content provided here are for educational and reference purposes only. They are not intended to substitute for professional medical advice, diagnosis, or treatment. Clinical decisions should always be based on the comprehensive assessment of a qualified healthcare professional.