Inflammation of the Pancreas: Classification

When 2 of the following 3 criteria are met, a diagnosis of acute pancreatitis can be made:

Typical abdominal pain: typically, there is severe, penetrating, and persistent visceral pain in the upper abdomen (epigastrium) that may also radiate to the back (girdled), thorax (chest), flanks, or lower abdomen and improves in a sitting or crouching position
Amylase or lipase elevation > 3 times the norm.
Typical imaging findings* .

* Computed tomography (CT)/magnetic resonance imaging (MRI) is necessary to confirm the diagnosis only in exceptional cases, when other differential diagnoses of acute upper abdominal pain are in the room.

Severity classification of acute pancreatitis according to the Atlanta Classification.

Severity	Explanation
Mild acute pancreatitis	No local or systemic complications No organ failure
Moderate acute pancreatitis	Transient (transient) organ failure (< 48 h) and/or Local or systemic complications without persistent organ failure > 48 h or Exacerbation of comorbid disease (onset of concomitant disease).
Severe acute pancreatitis	Persistent organ failure > 48 h of one or more organs/multi-organ failure.

Local complications: peripancreatic fluid collections, pancreatic and peripancreatic necrosis (“local tissue death”; sterile or infected), pseudocysts (cyst-like structure but which, unlike the cyst, has no epithelial lining), walled-off necrosis (WON) organ necrosis [visible on pancreatic sonography/ultrasound examination of the pancreas].

Bedside-index-of-severity-in-acute-pancreatitis (BISAP) scores.

	Criterion	Points
B	Urea nitrogen (BUN, “blood urea nitrogen”) > 25 mg/dl	1
I	Impaired mental state: Glasgow Coma Scale < 15	1
S	SIRS (> 1 SIRS criterion)
	– 1. fever (> 38 °C) or hypothermia (hypothermia; < 36 °C)	1 (for ≥ 2 SIRs criteria.
	– 2. heart rate > 90/min
	– 3. tachypnea (respiratory rate: > 20/min) or paCO2 < 32 mmHg.
	– 4. leukocytosis (increased white blood cells: > 12,000/mm3) or leukopenia (decreased white blood cells: < 4,000/mm3)
A	Age > 60 years	1
P	Pleural effusion	1

Legend

PaCO2: arterial partial pressure of oxygen.
SIRS: systemic inflammatory response syndrome

Interpretation

BISAP score 0: <1% risk of lethality.
BISAP score ≤ 2: 1.9 % risk of lethality
BISAP score ≥ 3: good predictive value for a severe course with lethality > 5% with a sensitivity of 83.0% and a positive predictive value (PPW) of 76.9%.