BISAP Score Calculator
Bedside Index for Severity in Acute Pancreatitis. Early prediction of mortality risk within 24 hours of presentation using five simple clinical criteria.
BISAP Criteria (Within 24 Hours)
Mortality Risk by Score
| BISAP Score | In-Hospital Mortality | Risk Category | Recommendation |
|---|---|---|---|
| 0 | < 1% | Very Low | Standard ward care |
| 1 | ~2% | Low | Regular monitoring |
| 2 | ~7% | Moderate | Enhanced monitoring, ICU consult |
| 3 | ~15% | High | ICU admission recommended |
| 4 | 20-25% | Very High | Immediate ICU, aggressive care |
| 5 | 25-30% | Critical | Critical care, expect complications |
Low Risk (0-2): Mortality < 2%. Can typically be managed on general medical ward with standard supportive care.
High Risk (≥3): Mortality ≥15%. Strongly consider ICU admission and aggressive intervention. Higher likelihood of severe pancreatitis and organ failure.
About the BISAP Score
The BISAP (Bedside Index for Severity in Acute Pancreatitis) score is a simple, rapid clinical scoring system that can be completed within 24 hours of hospital presentation. It uses five readily available clinical and laboratory parameters to predict mortality in acute pancreatitis.
Advantages Over Other Scores
- Early assessment: Can be calculated within 24 hours (vs. 48 hours for Ranson)
- Simplicity: Only 5 variables (vs. 11 for Ranson, many more for APACHE-II)
- Bedside calculation: No complex formulas or extensive laboratory panels needed
- Well-validated: Multiple studies confirm accuracy across diverse populations
- Easy to remember: Mnemonic makes it simple to recall and apply
Clinical Applications
- Early risk stratification for triage decisions
- Identifying patients requiring ICU admission
- Predicting development of severe pancreatitis
- Guiding aggressiveness of supportive care
- Patient and family counseling regarding prognosis
- Clinical research and quality improvement initiatives
SIRS Criteria Details
SIRS (Systemic Inflammatory Response Syndrome) is present when ≥2 of these criteria are met:
- Temperature < 36°C (96.8°F) or > 38°C (100.4°F)
- Heart rate > 90 beats per minute
- Respiratory rate > 20 breaths/minute or PaCO₂ < 32 mmHg
- WBC < 4,000 cells/mm³ or > 12,000 cells/mm³ or > 10% immature bands
Validation Studies
The BISAP score has been validated in multiple large cohort studies with AUC values of 0.75-0.82 for predicting mortality, comparable to more complex scoring systems. Scores ≥3 have consistently been associated with significantly higher mortality and morbidity.
Frequently Asked Questions
When should the BISAP score be calculated?
BISAP should be calculated within 24 hours of hospital admission. All five criteria can be assessed at presentation or shortly thereafter, making it an excellent tool for early risk stratification.
How does BISAP compare to Ranson's criteria?
BISAP is simpler (5 vs. 11 variables) and faster (24 vs. 48 hours) than Ranson's criteria, with comparable accuracy for mortality prediction. BISAP is preferred for early assessment, while Ranson's may provide additional prognostic information once fully calculated.
What if I can't get imaging for pleural effusion right away?
You can still calculate a preliminary score without the pleural effusion criterion. However, all patients with acute pancreatitis should have chest imaging as part of their initial workup. If imaging is delayed, update the score once results are available.
Does the BISAP score predict specific complications?
Yes. Higher BISAP scores are associated with increased risk of organ failure, pancreatic necrosis, need for ICU admission, and longer hospital stays, in addition to mortality. A score ≥3 indicates high likelihood of severe pancreatitis.
Can BISAP be used for chronic pancreatitis?
No. BISAP is validated only for acute pancreatitis. It should not be used to assess exacerbations of chronic pancreatitis or other pancreatic conditions.
What defines impaired mental status?
Impaired mental status includes disorientation to person, place, or time; lethargy; somnolence; coma; or stupor. Essentially, any Glasgow Coma Scale score less than 15 or any altered mentation beyond baseline qualifies.
Should treatment differ based on BISAP score?
Yes. Higher BISAP scores warrant more aggressive fluid resuscitation, closer monitoring (ICU for scores ≥3), earlier nutritional support, and lower threshold for imaging and intervention. The score helps guide intensity of care.
How is BUN converted from mmol/L to mg/dL?
To convert BUN from mmol/L to mg/dL, multiply by 2.8. For example, 9 mmol/L = 25.2 mg/dL. The BISAP cutoff is BUN > 25 mg/dL (approximately 9 mmol/L).
Related Calculators
Ranson Criteria Calculator
48-hour pancreatitis severity assessment
Glasgow-Blatchford Score
Upper GI bleeding risk stratification
APACHE II Calculator
ICU mortality prediction
Child-Pugh Calculator
Liver disease severity scoring
SOFA Score Calculator
Sequential Organ Failure Assessment
SIRS Criteria Calculator
Systemic inflammatory response assessment