Ranson Criteria for Pancreatitis
The Ranson criteria is a multifactor scoring system used to predict the severity of acute pancreatitis, with a score of ≥3 indicating severe disease with increased mortality risk. 1
Components of Ranson Criteria
The Ranson criteria consists of 11 parameters assessed at two time points:
At Admission:
- Age >55 years 1
- White blood cell count >16,000/mm³ 2
- Blood glucose >200 mg/dL 2
- Serum LDH >350 IU/L 2
- AST >250 IU/L 1
At 48 Hours After Admission:
- Hematocrit decrease >10% 1
- BUN increase >5 mg/dL 1
- Serum calcium <8 mg/dL 1
- Base deficit >4 mEq/L 1
- Fluid sequestration >6 L 1
- PaO₂ <60 mmHg 2
Clinical Significance and Interpretation
Three or more positive criteria indicate severe disease with increased risk of morbidity and mortality 3, 1
Mortality correlates with the number of positive criteria 1:
- 0-2 criteria: <5% mortality
- 3-4 criteria: 15-20% mortality
- 5-6 criteria: 40% mortality
- 7-8 criteria: >100% mortality
The 48-hour parameters (particularly BUN, calcium, base deficit, and fluid sequestration) are stronger predictors of mortality than admission parameters 1
Limitations and Considerations
- Requires 48 hours for complete assessment, delaying early intervention in severe cases 4
- Has approximately 70-80% accuracy in predicting severity 3
- Cannot be calculated at initial presentation since it requires 48-hour values 4
- Does not accurately predict the degree of pancreatic necrosis, which is best assessed by contrast-enhanced CT scanning 3
Comparison with Other Scoring Systems
- The Glasgow criteria have been validated in UK populations and use similar parameters to Ranson 3
- APACHE II score is equally accurate and can be calculated earlier (at admission) with ongoing daily assessment 3, 5
- BISAP score (Blood urea nitrogen >25 mg/dl, Impaired mental status, SIRS, Age >60 years, Pleural effusion) is simpler to calculate with comparable accuracy 5
- C-reactive protein (CRP) >210 mg/L within the first four days has similar prognostic value 3
- CT Severity Index (CTSI) may have stronger individual prognostic value for mortality than Ranson score 6
Practical Application
- Calculate Ranson score using parameters at admission and at 48 hours 3
- Consider complementary use of CRP measurement and APACHE II scoring for ongoing assessment 3
- Perform contrast-enhanced CT scan between days 3-10 in patients with predicted severe disease (Ranson ≥3) 3, 6
- Monitor for development of organ failure, which definitively indicates severe disease regardless of scoring 3