Acute pancreatitis is regarded as a medical emergency and refers to inflammation of the pancreas. It is characterised by a sudden onset of severe abdominal pain radiating to the back, and is most commonly caused by small gallstones affecting a transient obstruction of the common drainage duct of the gallbladder and pancreas. Alcohol is another important precipitating factor.
Recovery from an acute attack is mostly uneventful and complete, provided appropriate medical care is given. Early recognition of the disease and possible complications improves the outcome.
Treatment is individualised. A minority of patients with acute pancreatitis will have a more serious course, needing intensive care. If possible, the precipitating cause for the acute pancreatitis must be determined and action taken to prevent recurrence.
Of the many possible causes of acute pancreatitis, gallstones and alcohol abuse account for the majority.
Gallstones as predisposing factor (30 - 50%) are more common in women, followed by alcohol abuse in 10 - 40% of cases (more common in men). No predisposing factor is found in approximately 15% of cases, whereas trauma and cannulation with the injection of dye into the pancreatic duct during ERCP predispose in 5% of cases.
Other recognised predisposing factors are rare and include drugs (azothioprine, sulphomamides, sodium valproate, frusemide and ACE inhibitors, used for treating high blood pressure), hereditary conditions such as high blood triglyceride levels and infections such as mumps or viral hepatitis.
The sudden onset of a constant upper abdominal pain that radiates to the back with nausea and vomiting are characteristic of acute pancreatitis. This presentation must be differentiated from other medical conditions that can closely mimic acute pancreatitis.
The pain typically lasts several days and is often relieved by leaning forward. In mild cases of acute pancreatitis, the pain may be limited to slight abdominal tenderness. In about 5 - 10% of patients there is no pain at all.
Biliary colic may occur before pancreatic pain where gallstones are the causative factor. This is typically described as a moderately severe pain in the right upper region of the abdomen extending to the back and right shoulder. Biliary colic lasts six or eight hours at most and often follows a meal.
In people with alcoholic pancreatitis, the symptoms of acute pancreatitis often occur one to three days after an alcohol binge or after stopping drinking.
When acute pancreatitis is considered, certain diagnostic tests are performed to confirm the diagnosis.
Serum levels of amylase and lipase are determined. These pancreatic enzymes are increased during an attack of acute pancreatitis and start to rise within six to twelve hours, and remain elevated for three to five days. Other serum markers of inflammation, such as the C-reactive protein, are also elevated and may help to predict the outcome.
Once a diagnosis of acute pancreatitis is made, additional tests are used to determine the underlying cause. This ensures that a person will receive the correct treatment to prevent recurrence of pancreatitis. A careful medical history can implicate gallstones, alcohol or drugs as a possible causative factor. A physical examination will be performed to check for signs and symptoms of acute pancreatitis. These vary with the severity of the attack and can also help to predict the outcome.
Additional diagnostic tests include an abdominal ultrasound within 24 hours of the diagnosis. This is done to exclude gallstones and to assess the pancreatic size. A repeat ultrasound may be performed in follow-up if complications are suspected. An ERCP may be indicated urgently if a common bile duct stone is detected, or if jaundice or infection of the biliary tree is suspected. During this procedure it is possible to remove stones from the common bile duct. A plain abdominal X-ray and a chest X-ray may reveal some abnormalities associated with acute pancreatitis. It may also point to the underlying cause or help to differentiate this from other conditions with a similar clinical picture.
A CT-scan is the most useful radiology test for diagnosing acute pancreatitis and determining the extent of the condition. This test is often done if conditions other than pancreatitis are suspected, if conservative medical care fails to relieve the symptoms of acute pancreatitis, or if complications such as necrotising pancreatitis are suspected. Other investigations such as an MRI scan or an MRCP may also be indicated in certain circumstances.
Treatment of acute pancreatitis is aimed at alleviating the pancreatic inflammation and correcting the underlying cause. This normally requires hospitalisation for at least a few days.
The specific treatment measures used depend on the severity of the pancreatitis. The lesser degrees of pancreatitis usually resolve with simple supportive measures that include monitoring of vital signs, pain control and intravenous fluids. Patients are typically kept "nil per mouth" for the first couple of days and are allowed to gradually resume eating within three to seven days.
More severe pancreatitis requires more extensive monitoring and supportive care. In case of complications such as necrotising pancreatitis, treatment may also entail antibiotics and surgery. Patients are normally treated in an intensive-care unit.