Pancreatitis

From Ganfyd

Acute pancreatitis is a common surgical problem, defined as an 'acute inflammatory process of pancreas, with variable involvement of regional tissues or remote organ systems'.

It accounts for 4% of admissions to hospital with abdominal pain in the UK. The severity of the disease is variable: most mild to moderate cases are self-limiting, but severe cases often require aggressive supportive care and there is a mortality of about 10% in this subset of patients. Although treatment is largely supportive, invasive intervention may be indicated in gallstone-related pancreatitis and also in the presence of severe necrosis or haemorrhagic complications.

In April 2005, a UK working party with contributors drawn from various GI organisations updated the previous 1998 guidelines for the management of acute pancreatitis. Both the 1998 and 2005 guidelines are available online. ^{[1] [2]}

The topic is comprehensively reviewed in ^{[3] [4]}

Aetiology

Causes of Pancreatitis

• Gallstone disease
• Alcohol
• Hypercalcaemia
• Hyperlipidaemia
• Mumps
• Drugs, e.g. steroids, azathioprine
• Trauma
• Hypothermia

Diagnosis

The pancreas lying at the back of the abdominal cavity, some people with pancreatitis find the position of choice is on all fours, thus removing the weight of the intestines from the inflamed organ.

History and examination. Part of diagnosis involves excluding other intra-abdominal disasters.

The main diagnostic investigation in clinical use is serum amylase, although lipase is often used in America.^[5] 3-4 times the upper limit of normal amylase is highly suggestive of pancreatitis, although hyperamylasaemia can be caused by other conditions, e.g. renal failure, mumps, salivary gland problems and other GI conditions.

False negatives can occur in:

• Hyperlipidaemia (which interferes with assay).
• Assay several days after initial pain (amylase levels have fallen).
• Alcohol-related pancreatitis.^[6]
• Acute exacerbations of chronic pancreatitis.

Management

• Resuscitation - patients are often hypovolaemic from prior poor oral intake, vomiting, 'third spacing' of fluids and SIRS.
• Assess likely severity (see Risk stratification below)
• Supportive care
  • Nutrition
  • Fluid balance
  • Anticipate and treat complications
  • Alcohol withdrawal treatment, if required.
• Identify cause
  • Treat if appropriate (e.g. cholecystectomy within 4-6 weeks)
• Antibiotics may be considered in infected necrosis. Its role in prophylaxis is unclear with a recent RCT suggesting no benefit.^[7]
• Surgery is rarely required, but may be necessary in certain local complications.

Analgesia

Traditional teaching is to avoid morphine as it was supposed to cause sphincter of Oddi spasm, therefore potentially worsening pain and biliary obstruction. Although pethidine has been advocated as an alternative on the basis of a diminished effect on the sphincter pressure, it is a weaker opioid and is associated with dysphoria, accumulation of metabolites and lowering of the seizure threshold in susceptible patients.^[8] The evidence suggests that an increase in sphincter pressure occurs with all opioids ^[9] and for this reason, the most effective opioid with the least side-effects is preferred.

Investigations

See also Diagnosis

Identifying Cause

USS / MRCP (useful if USS shows dilated CBD but no obvious gallstones)

Identifying Complications

• CT with contrast can show extent of necrosis
• CXR assess complications, e.g. lung injury
• ERCP

Risk Stratification

Various scores have been used to try to assess the severity of disease and to predict outcomes. Both the Ranson's score and modified Glasgow score were designed specifically for pancreatitis, whereas scores like APACHE II are more general pathophysiological scores with wider applications. The Atlanta criteria considers several factors:^[10]

• APACHE II score >8
• Ranson's criteria 3 or more
• Pulmonary insufficiency
• Renal insufficiency
• Shock
• GI bleeding
• Hypocalcaemia
• Coagulopathy

Complications

Local

• Haemorrhage
• Necrosis
• Bacterial super-infection of necrotic tissue
• Pancreatic pseudocyst (usually 4-6 weeks after)

Systemic

• Systemic inflammatory response syndrome (SIRS)
• Acute renal failure
• Acute lung injury/Adult respiratory distress syndrome

References