BISAP Score

Bedside Index for Severity in Acute Pancreatitis

A simple 5-point score assessed within the first 24 hours of admission that predicts in-hospital mortality in acute pancreatitis. Compares favourably with Ranson and APACHE II for early severity stratification.

PancreatitisGeneral SurgeryGastroenterology
BISAP Score (within 24 h of admission)
SIRS criteria (≥2 of 4): Temperature <36°C or >38°C • HR >90 bpm • RR >20/min or PaCO₂ <32 mmHg • WBC <4,000 or >12,000 ×10⁹/L (or >10% bands)
Tick criteria above

Interpretation

BISAP ScoreIn-Hospital MortalityOrgan Failure RateManagement
0< 1%< 2%General ward — monitor; early oral feeding
1~1%~5%General ward with close monitoring
2~2–7%~10%Consider step-down/high-dependency unit
3~5–20%~20%HDU/ICU; early aggressive fluid resuscitation; CT at 72 h
4~22%~35%ICU; monitor for organ failure; consider early ERCP if gallstone aetiology
5~22–27%>50%ICU; multidisciplinary care; early identification of necrosis

Clinical Application

All five BISAP criteria can be assessed at the bedside within 24 hours of admission, without requiring CT imaging. This makes it particularly useful for early triage in emergency departments and general surgical wards.

  • Low-risk patients (0–1): Can be managed on a general ward. Early oral feeding (even with abdominal pain) is supported by evidence and should not be withheld.
  • Intermediate risk (2): Reassess at 48 hours; consider CT if clinical deterioration or persistent organ dysfunction.
  • High risk (≥3): Early aggressive IV hydration with lactated Ringer's or normal saline (goal 250–500 mL/h for first 24–48 h). CT pancreas at 72–96 hours to assess necrosis (CT delayed to avoid overestimating necrosis in first 48 h).
  • Gallstone pancreatitis: ERCP within 24 h only if cholangitis; otherwise cholecystectomy during index admission (mild) or after recovery (severe).

Evidence

Derived by Wu et al. (2008) from a database of 17,992 acute pancreatitis admissions. The c-statistic for in-hospital mortality was 0.82 vs 0.83 for Ranson (48 h) and 0.74 for APACHE II — demonstrating that BISAP at 24 h performs comparably to more complex scores assessed over a longer period.

Validated in multiple independent cohorts including Indian (Singh et al. 2009, n=212, AUC 0.77) and Chinese populations (Gao et al. 2015, meta-analysis: AUC 0.819 for mortality).

Limitations

  • Does not incorporate imaging findings (necrosis extent, fluid collections)
  • SIRS assessment can be subjective if not all criteria are formally recorded
  • Less granular than APACHE II for discriminating very high risk from extreme risk
  • Does not predict severity of necrosis — CT severity index required for this

References

  1. Wu BU, et al. The early prediction of mortality in acute pancreatitis: a large population-based study. Gut. 2008;57(12):1698–1703.
  2. Singh VK, et al. A prospective evaluation of the BISAP score and Ranson score in assessing severity of acute pancreatitis. Pancreas. 2009;38(7):e190–196.
  3. Banks PA, et al. Classification of acute pancreatitis — 2012: revision of the Atlanta classification. Gut. 2013;62(1):102–111.
  4. Tenner S, et al. American College of Gastroenterology Guideline: Management of Acute Pancreatitis. Am J Gastroenterol. 2013;108(9):1400–1415.

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