BISAP Score (Pancreatitis)

Background

The Bedside Index for Severity in Acute Pancreatitis (BISAP) predicts in-hospital mortality using five variables available within the first 24 hours of presentation. One point is given for each of: Blood urea nitrogen >25 mg/dL (urea >8.9 mmol/L), Impaired mental status, the presence of a Systemic inflammatory response syndrome (SIRS), Age >60, and Pleural effusion on imaging — a maximum of 5. It was designed as a simpler alternative to older multi-parameter systems such as Ranson and APACHE II that require 48 hours or many variables. The acronym summarises its five components.

Interpreting the result

Mortality rises with the score. A score of 0–2 indicates lower mortality risk, while a score of 3–5 indicates higher mortality and should prompt consideration of high-dependency or intensive care. The score allows early identification of patients at risk of a severe course, supporting timely escalation, fluid resuscitation and senior review. As with other scores, it informs rather than dictates disposition and must be read alongside the clinical trajectory and evolving organ-failure assessment.

Worked example

A 68-year-old with acute pancreatitis has a urea of 11 mmol/L, meets SIRS criteria and has a pleural effusion on imaging, with normal mental status: Age >60 (1) + raised urea (1) + SIRS (1) + Pleural effusion (1) = 4. This high-risk score warrants consideration of high-dependency or intensive care.

Pearls / pitfalls

• BISAP is an early stratification tool, not a final severity classification; persistent organ failure beyond 48 hours remains the strongest determinant of a severe course.
• SIRS is dynamic, so the score can change over the first day — reassess rather than relying on a single time point.
• A low score does not guarantee a benign course; ongoing fluid resuscitation and close monitoring remain essential in all but the mildest cases.
• It predicts mortality but does not directly identify local complications such as necrosis, which require imaging and clinical follow-up.

Evidence & validation

Derived and validated by Wu and colleagues using large pancreatitis datasets, BISAP performs comparably to more complex scores for predicting mortality and is referenced in acute pancreatitis guidance as an early severity stratification tool, alongside markers such as persistent organ failure.

Frequently asked questions

References

1. Wu BU, Johannes RS, Sun X, et al. The early prediction of mortality in acute pancreatitis: a large population-based study (BISAP). Gut. 2008;57(12):1698–1703.
2. Working Group IAP/APA Acute Pancreatitis Guidelines. IAP/APA evidence-based guidelines for the management of acute pancreatitis. Pancreatology. 2013.

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