24th July 2023

Acute pancreatitis

Acute inflammation of the pancreas. A relatively common disease and one which carries a high mortality risk.

Causes

Gallstones and alcohol excess are the 2 most common causes, accounting for the vast majority of cases. The causes can be summarised by the “I GET SMASHED” mnemonic:

• Idiopathic
• Gallstones
• Ethanol
• Trauma
• Scorpion stings and spider bites
• Mumps or malignancy
• Autoimmune
• Steroids
• Hypertriglyceridaemia and hypercalcaemia
• Endoscopic retrograde cholangiopancreatography (ERCP)
• Drugs

Clinical features

Acute pancreatitis classically presents with sudden onset epigastric pain, which may radiate to the back. The pain may also be more generalised. The pain is often associated with nausea, vomiting, and haemodynamic instability. Patients are not typically jaundiced, acutely (unless associated with obstructive gallstones). Patients will often have a history of gallstones or alcohol excess, which are important risk factors to enquire about from the history.

Examination likely reveals tenderness and guarding in the epigastrium. Patients may be peritonitic. Important signs of haemorrhagic pancreatitis (a life-threatening complication) include Cullen’s sign (periumbilical bruising) and Grey-Turner’s sign (flank bruising).

Other complications include pseudocysts (usually around 4-6 weeks after onset of acute illness), pancreatic abscesses, fistulae, AKI, acute respiratory distress syndrome (ARDS), and disseminated intravascular coagulation (DIC).

Assessment and diagnosis

Acute pancreatitis is a diagnosis that should be suspected clinically, and management started on that basis.

A raised serum amylase supports the diagnosis, and serum lipase is an even more sensitive marker. It is often associated with deranged LFTs. Imaging is not essential for diagnosis in the first instance, but an ultrasound scan (to demonstrate gallstones), CT, and MRI may be used to confirm – with a CT abdomen being considered the gold standard, as it can also assess for other causes of acute abdominal pain. If the cause is unknown, further modalities include magnetic resonance cholangiopancreatography (MRCP).

Classification of severity and risk stratification is important to guiding management. The APACHE II score and Glasgrow-Imrie criteria are two risk stratification tools in common usage.

Management

Management is supportive – including IV analgesia and IV fluids. An ABCDE approach should be initially taken for unstable patients. A nasogastric (NG) tube may also be indicated, as nutritional support. Once the cause is established, and the patient is stable, this should also be treated. Antibiotics are only indicated if there is evidence of an associated infection, rather than routinely.

There is a risk of rapid deterioration; patients with severe illness should be identified using the aforementioned risk tools, and ITU involved early if there is clinical concern.

If due to biliary disease, then ERCP may be used to relieve any obstruction. Surgical management may be indicated if there are complications, such as abscess formation, or necrosis. Patients with biliary causes should also have a cholecystectomy once the acute illness has stabilised.