BISAP Score (Pancreatitis)

Acute pancreatitis ranges from a mild, self-limiting illness to a life-threatening emergency with multi-organ failure and 15–30% mortality. The challenge in early management is identifying which patients with acute pancreatitis will deteriorate — before they deteriorate. The BISAP (Bedside Index of Severity in Acute Pancreatitis) score answers this question using five parameters obtainable within the first 24 hours of presentation, without CT scanning. The BISAP calculator provides immediate severity stratification at the bedside. Note: all clinical scores should be interpreted by qualified healthcare professionals in conjunction with full clinical assessment.

BISAP Score Components and Scoring

One point each for:

• B — BUN above 25 mg/dL: elevated BUN reflects intravascular depletion, third-spacing, and decreased renal perfusion — early markers of systemic compromise in severe pancreatitis
• I — Impaired mental status: altered consciousness (Glasgow Coma Scale below 15) from any cause; represents CNS impact of severe systemic illness
• S — SIRS (≥2 criteria): temperature above 38°C or below 36°C; heart rate above 90; respiratory rate above 20 or PaCO₂ below 32 mmHg; WBC above 12,000 or below 4,000 or above 10% bands
• A — Age above 60 years: independent predictor of worse outcomes in acute pancreatitis; reduced physiologic reserve
• P — Pleural effusion on imaging: indicates third-space fluid accumulation and more extensive pancreatic/peripancreatic inflammation

Total score: 0–5. Use this online calculator for immediate BISAP scoring. The APACHE II score provides a more comprehensive but complex severity assessment.

BISAP Severity Thresholds and Clinical Decisions

Mortality risk by BISAP score (Wu et al., 2008 validation):

• Score 0: 0.1% mortality — appropriate for general ward admission; most can be managed with supportive care
• Score 1: 0.4% mortality — general ward admission; monitor closely for clinical deterioration
• Score 2: 1.6% mortality — step-down unit or close monitoring; higher risk of organ failure
• Score 3: 5.3% mortality — ICU admission consideration; significant risk of persistent organ failure
• Score 4: 12.7% mortality — ICU admission indicated; high risk of multi-organ failure
• Score 5: 22.5% mortality — critical care required; aggressive supportive management needed

The APACHE II calculator and gastroenterology calculators provide complementary severity assessment tools. All scores are clinical aids — management decisions require physician evaluation.

BISAP vs. Ranson's Criteria: Comparative Accuracy

BISAP was validated against Ranson's Criteria (the previous standard) and APACHE II. Key comparisons:

• BISAP AUC for predicting mortality: 0.82 (Wu 2008); similar to APACHE II (0.83) and superior to Ranson's (0.79) in independent validation
• BISAP requires only 5 parameters available at admission; Ranson's requires 11 parameters at admission plus 6 more at 48 hours
• BISAP AUC for organ failure prediction: 0.81 vs. Ranson's 0.74
• BISAP can be recalculated during admission to track evolving severity; Ranson's is a static 48-hour score

The practical advantage of BISAP is its bedside simplicity — all parameters are routinely available from initial blood work, vital signs, and basic imaging, making it an ideal triage tool for emergency department and ward physicians.

Early Management Guided by BISAP

ACG (American College of Gastroenterology) 2013 Guidelines recommend: aggressive intravenous hydration (Lactated Ringer's preferred over normal saline for non-hypercalcemic, non-hypernatremic patients) at 250–500 mL/hour in the first 12–24 hours; early enteral nutrition (within 24–72 hours if tolerated) for severe pancreatitis; ERCP within 24 hours for acute biliary pancreatitis with cholangitis; CT with contrast at 48–72 hours if clinical worsening or BISAP score suggests severe disease. BISAP score 3+ should trigger gastroenterology/surgery consultation and ICU triage evaluation in most clinical settings.