How it's calculated
One point each for five criteria present within 24 hours of admission — BUN >25 mg/dL, impaired mentation, SIRS, age over 60, and pleural effusion on imaging — for a total score of 0-5.
BISAP score and mortality
| Score | Approximate in-hospital mortality |
|---|---|
| 0-2 | < 2% |
| 3 | ~5-8% |
| 4-5 | ~15-20% |
Clinical use
- Calculated within the first 24 hours of admission for acute pancreatitis to identify patients at higher risk of mortality and organ failure.
- A score of 3 or more should prompt closer monitoring and consideration of a higher level of care.
- Complements — rather than replaces — clinical judgement, imaging findings, and other severity scores such as Ranson's criteria.
Frequently asked questions
What does BISAP stand for?
Bedside Index for Severity in Acute Pancreatitis — BUN, Impaired mental status, SIRS, Age, Pleural effusion.
How is BISAP different from Ranson's criteria?
BISAP uses only 5 simple bedside/lab criteria available within 24 hours and needs no 48-hour follow-up data, making it faster to calculate than Ranson's criteria, which needs values at both admission and 48 hours.
What SIRS criteria count toward the BISAP score?
Temperature below 36°C or above 38°C, heart rate above 90/min, respiratory rate above 20/min (or PaCO2 below 32 mmHg), and white cell count below 4 or above 12 ×10&sup9;/L — 2 or more of these four criteria qualifies as SIRS present.
References
- Wu BU, et al. The early prediction of mortality in acute pancreatitis: a large population-based study. Gut. 2008;57:1698-1703.
- Papachristou GI, et al. Comparison of BISAP, Ranson's, APACHE-II, and CTSI scores in predicting organ failure, complications, and mortality in acute pancreatitis. Am J Gastroenterol. 2010.