Risk Stratification and Management of Acute Pancreatitis

BISAP Scoring

A BISAP score ≥ 3 is a statistically significant cutoff for identifying patients at high risk of severe acute pancreatitis, organ failure, and mortality [1][2].
In validation studies, a BISAP score ≥ 3 demonstrated a sensitivity of ≈ 79.8 % and a specificity of ≈ 91.6 % for predicting severe disease, providing a negative predictive value of ≈ 95 % [1][2].
The score is derived from five readily available variables: age > 60 years, pleural effusion on imaging, presence of SIRS, blood urea nitrogen > 8.9 mmol/L, and altered mental status. Each positive criterion contributes one point [1][2]3.

The Ranson score requires 11 criteria (5 on admission, 6 at 48 h) and cannot be fully calculated until 48 hours after presentation, limiting its usefulness for early risk stratification [1][2].
A threshold of ≥ 3 points on the Ranson score is traditionally used to predict severe disease 2.

Mild acute pancreatitis – no organ failure and no local or systemic complications [4][5]6.
Moderately severe acute pancreatitis – transient organ failure (< 48 h) and/or local complications (e.g., pleural effusion, ascites) or exacerbation of comorbid disease [4][5].
Severe acute pancreatitis – persistent organ failure (> 48 h) [4][5].
Patients with local complications and SIRS but without documented persistent organ failure are classified as moderately severe, indicating a risk of progression to severe disease [4][3].
Persistent SIRS lasting > 48 h is associated with a mortality rate of ≈ 25 % versus ≈ 8 % for transient SIRS 3.
Development of persistent organ failure (> 48 h) raises mortality risk to > 50 % 3.

Patients with a BISAP score ≥ 3 and a moderately severe classification should receive intensive monitoring, often at the ICU level, due to the high risk of deterioration [1][2].
Contrast‑enhanced computed tomography is recommended after ≥ 72 h from symptom onset to evaluate for pancreatic necrosis in patients predicted to have severe disease [7][8].
Vigilant surveillance for infected pancreatic necrosis is essential, as infection increases mortality to roughly 32 % 3.

The BISAP score shows comparable accuracy to the APACHE II system for predicting severity (area under the curve ≈ 0.81 vs 0.78) while being simpler to calculate [1][2].
Unlike the Ranson score, which requires 48 h of data, the BISAP score can be completed within the first 24 h of admission, facilitating earlier decision‑making 2.

Early risk stratification before the onset of organ failure enables timely therapeutic interventions, which is critical for improving outcomes in acute pancreatitis [1][2].

The Revised Atlanta Classification (2012) categorizes acute pancreatitis into mild, moderately severe, and severe, with the key distinction being the presence and duration of organ failure. 9
In the Determinant‑Based Classification, “severe” disease is defined by either persistent organ failure or infected necrosis. 10

Mild acute pancreatitis accounts for approximately 80‑85 % of all cases and carries a mortality of less than 1‑3 %. 10
Severe acute pancreatitis is associated with overall mortality rates ranging from 13 % to 35 %. 10
Persistent organ failure (lasting >48 h) occurs in about one‑third of affected patients, and one in three of these patients will die. 10
The combination of persistent organ failure and infected necrosis identifies the subgroup with the highest mortality risk. [9][10]

All patients who develop organ failure should be admitted to an intensive‑care unit whenever feasible. [9][10]
Patients classified as severe should receive initial management in a high‑dependency or intensive‑care setting with full organ‑support capabilities. [11][12]13

Severity stratification must be completed within the first 48 hours of hospital admission. [11][12]13
For patients with severe disease, contrast‑enhanced computed tomography should be performed dynamically between days 3 and 10 of admission to evaluate necrosis and complications. [11][12]13

The 1992 Atlanta Classification is considered outdated, frequently misapplied, and lacks the essential distinction between transient and persistent organ failure; it should no longer be used. 10