What scores are used to assess the severity of pancreatitis?

Severity Assessment Scores in Acute Pancreatitis

Use the BISAP score as your primary bedside tool for early severity assessment within 24 hours of admission, as it is simple, accurate, and comparable to more complex systems in predicting mortality and organ failure. 1

Primary Recommended Scoring System: BISAP

The BISAP score should be calculated within the first 24 hours and assigns one point for each of the following criteria 2, 1:

• Blood urea nitrogen >25 mg/dL (>8.9 mmol/L)
• Impaired mental status
• Systemic inflammatory response syndrome (SIRS) present
• Age >60 years
• Pleural effusion on radiography

A BISAP score ≥2 is the critical cutoff indicating severe acute pancreatitis, organ failure risk, and increased mortality 2, 3. The BISAP score demonstrated an area under the curve (AUC) of 0.80 for predicting severe pancreatitis and 0.93 for organ failure, performing as well as APACHE-II but with far greater simplicity 3.

Alternative Scoring Systems

APACHE-II Score

APACHE-II remains highly accurate but is more cumbersome for routine bedside use 2. Key performance characteristics include:

• Score ≥8 indicates severe acute pancreatitis 2, 1
• Score ≥6 has 95% sensitivity for detecting complications but only 50% positive predictive value 2, 1
• Can be used for daily ongoing assessment to monitor disease progression or recovery 2, 1
• Demonstrated the highest accuracy (AUC 0.88) for predicting severe acute pancreatitis in comparative studies 2

The main disadvantage is that APACHE-II evaluates 12 physiologic measurements plus chronic health status, making it cumbersome as not all parameters are routinely collected 2.

Traditional 48-Hour Scores

Ranson and Glasgow scores require 48 hours to complete, limiting their utility for early risk stratification 2:

• Ranson score ≥3 indicates severe disease (sensitivity 75-87%, specificity 68-77.5%, PPV 28.6-49%) 2
• Glasgow score ≥3 indicates severe disease (sensitivity 61-71%, specificity 88-89%, PPV 59-66%) 2
• Despite requiring 48 hours, these scores remain useful to confirm or exclude severe disease 2

Laboratory Markers

C-Reactive Protein (CRP)

CRP is a valuable independent prognostic marker that should be measured serially 2, 1:

• Peak CRP >210 mg/L in the first 4 days (or >120 mg/L at end of first week) indicates severe disease with ~80% accuracy 2, 1
• CRP ≥150 mg/L on day 3 can be used as a prognostic factor 1
• CRP combined with Glasgow criteria may further improve prognostication 2

Other Laboratory Predictors

• Hematocrit >44% is an independent risk factor for pancreatic necrosis 1
• Blood urea nitrogen >20 mg/dL independently predicts mortality 1
• Procalcitonin is highly sensitive for detecting pancreatic infection, with low values being strong negative predictors of infected necrosis 1

Radiological Assessment: CT Severity Index (CTSI)

Perform dynamic contrast-enhanced CT scan in all severe cases between days 3-10 after admission 2, 1. The timing allows for:

• Initial resuscitation to be completed 2
• Assessment of pancreatic necrosis extent and peripancreatic fluid collections 2
• CTSI ≥3 indicates severe disease 2
• Modified CTSI consistently shows the highest AUC (0.919-0.993) for predicting severe pancreatitis, pancreatic necrosis, organ failure, and ICU admission 4

The CTSI scores 0-10 based on pancreatic inflammation grade and extent of necrosis, with scores 7-10 correlating with 92% morbidity and 17% mortality 1.

Practical Clinical Algorithm

Within 24 hours of admission:

1. Calculate BISAP score immediately 1
2. Measure baseline CRP (repeat on day 3) 1
3. Monitor for organ failure development (pulmonary, circulatory, renal) 2, 1

At 48 hours:

• Consider calculating Ranson or Glasgow score if BISAP is equivocal 2
• Use APACHE-II for ongoing daily monitoring in severe cases 2, 1

Days 3-10:

• Perform contrast-enhanced CT with CTSI calculation in all patients with predicted severe disease 2, 1

Common Pitfalls

Avoid waiting 48 hours for risk stratification when BISAP can identify high-risk patients within 24 hours, potentially before organ failure develops 2. The key advantage of BISAP is its ability to identify patients at increased risk of mortality prior to the onset of organ failure 2.

Do not rely solely on admission scores – use APACHE-II for daily reassessment in severe cases to detect disease progression or sepsis 2. While different scoring systems show similar overall predictive accuracy, BISAP's simplicity makes it most practical for initial bedside assessment 2.