BISAP Score: Purpose and Calculation

Clinical Purpose and Performance

The BISAP score is a simplified 5-point prognostic tool that can be calculated within the first 24 hours of presentation to identify patients at increased risk of mortality and severe disease, with a score ≥3 indicating significantly elevated risk and a score ≥2 serving as a clinically meaningful cutoff for severe acute pancreatitis and organ failure 1, 2, 3
BISAP identifies patients at increased risk of mortality BEFORE the onset of organ failure, unlike traditional scoring systems 1, 3
BISAP ≥2 is the statistically significant cutoff for severe acute pancreatitis, organ failure, and mortality 1, 3

BISAP can be calculated within the first 24 hours of admission, while Ranson and APACHE-II require 48 hours for full assessment 1, 3
BISAP outperforms Ranson criteria, CT severity index, CRP, hematocrit, and BMI for predicting severity and organ failure 1, 3

A BISAP score of 2 is the cutoff for severe acute pancreatitis and organ failure, and patients with this score should be considered for ICU-level monitoring or step-down unit 1, 3
A BISAP score ≥3 indicates significantly elevated mortality risk, and ICU admission is strongly recommended 1, 5

BISAP has suboptimal sensitivity (51-56%) for both mortality and severe disease, meaning it will miss some high-risk patients 1
The positive predictive value of BISAP varies by population and disease prevalence 1
BISAP score should not be used alone, but should be complemented with clinical judgment, CRP at 48-72 hours, and CT severity index 5
Prophylactic antibiotics should not be administered based on high BISAP score alone, but only for documented infected necrosis 1, 2, 5