What is Acute Pancreatitis
Acute pancreatitis is an acute inflammatory process of the pancreatic gland that can range from a self-limited disease to a life-threatening condition with multiorgan failure and pancreatic necrosis 1, 2.
Definition and Pathophysiology
Acute pancreatitis represents inflammation of the pancreatic glandular parenchyma leading to injury with or without destruction of pancreatic acini 3. The underlying mechanism involves pancreatic intracellular calcium overload, mitochondrial impairment, and inflammatory responses that drive disease progression 4.
Clinical Diagnosis
The diagnosis requires meeting at least 2 of the following 3 criteria 5:
- Upper abdominal pain (characteristic of pancreatitis)
- Serum amylase or lipase ≥3 times the upper limit of normal
- Characteristic findings on cross-sectional imaging (CT or MRI)
Lipase is preferred over amylase when available, as it provides superior diagnostic accuracy 5. The correct diagnosis should be established within 48 hours of admission 5.
Disease Spectrum and Severity
Acute pancreatitis is heterogeneous and often unpredictable in its course 1. While most patients experience symptoms lasting only a few days, approximately one-fifth will develop complications including:
- Pancreatic necrosis (sterile or infected)
- Persistent organ failure
- Fluid collections and walled-off necrosis
- Local and systemic complications 1, 2
The disease is classified by severity using the Atlanta criteria, with organ failure persisting beyond 48 hours being a key indicator of severe disease 5.
Common Etiologies
The etiology should be determined in at least 75-80% of cases 6, 5. The most common causes are:
- Gallstones (most common)
- Alcohol (second most common)
- Hypertriglyceridemia
- Medications
- Hypercalcemia
- Trauma
- Autoimmune conditions
- Pancreatic malignancy (especially in patients >40 years) 6, 4
Epidemiology and Impact
Acute pancreatitis is one of the leading gastrointestinal diseases requiring hospitalization in the United States, with approximately 300,000 emergency department visits annually 1, 2. The incidence is increasing across all age groups, including children, pregnant women, and the elderly 4. While mortality has been decreasing, moderately severe disease causes substantial morbidity, and severe disease with persistent organ failure carries significant mortality risk 4, 3.
Key Clinical Pitfall
Do not confuse acute pancreatitis with chronic pancreatitis—these are distinct diseases with separate morphologic patterns 3. While recurrent acute pancreatitis can lead to chronic pancreatitis, they represent different pathologic processes requiring different management approaches.