GI & Liver

Bedside Index of Severity in Acute Pancreatitis (BISAP) Calculator

Five findings in the first 24 hours that estimate the risk of in-hospital death in acute pancreatitis.

Reviewed by Alex G, BSN, RN, CEN, CCRN, CMC, NREMT-P · From the Reference tab of the app

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Formula

One point each, from the first 24 hours:
BUN over 25 mg/dL
Impaired mental status
SIRS (2 or more criteria)
Age over 60
Pleural effusion
Total 0–5; 3 or more marks higher risk

How it is used

• Derived in 17,992 and validated in 18,256 US admissions; mortality ran from under 1% in the lowest-risk group to over 20% in the highest, and it predicted death as well as APACHE II (AUC 0.82 vs 0.83) (Wu 2008).
• In 397 prospective patients a score of 3 or more raised the odds of organ failure (7.4), persistent organ failure (12.7) and pancreatic necrosis (3.8) (Singh 2009).
• A score is a snapshot of the first day: in a later cohort one of seven deaths had a score of 1 and two had 2, so trends in vital signs, urine output and labs still drive care (Papachristou 2010).

Key points

• A BISAP item that appears after admission (new confusion, new SIRS, a rising BUN, a new effusion) is a change to report, not something to wait for a rescore on.

Same formula as the app. Open it in the web app.

Related one-pagers

• GI Bleeding, Liver Failure and PancreatitisBISAP gives a point each in the first 24 h for BUN above 25 mg/dL, impaired mentation, SIRS, age above 60 and pleural effusion; mortality runs from under 1% to over 20% (Wu 2008). ACG 2024 warns that no score predicts severity reliably and advises against CT on admission just to stage it.

Related calculators

• Child-Pugh Score (CTP)
• Glasgow-Blatchford Bleeding Score (GBS)
• Model for End-Stage Liver Disease (MELD 3.0)

For education and exam preparation only. Follow your institution’s protocols. For education and exam preparation only. Verify results independently and follow your institution’s protocols. Not a substitute for clinical judgment.