Pancreatitis

What is it?

Pancreatitis refers to inflammation of the pancreas, and can be acute or chronic. Acute attacks typically give severe abdominal pain which extends from the upper stomach through to the back and can cause effects ranging from mild swelling of the pancreas to life-threatening organ failure. Chronic pancreatitis is a slowly progressing disease that may involve a series of acute attacks, causing intermittent or constant pain as it permanently damages the pancreas.

The pancreas is a narrow, flat organ located deep in the abdominal cavity, behind the stomach and below the liver. It has exocrine tissues, which make powerful enzymes that help digest fats, proteins and carbohydrates. It also excretes bicarbonate, which helps neutralise stomach acids. It also has "islets" of endocrine tissue that produce the hormones insulin and glucagon, vital for the transport of glucose into body cells.

Normally, the pancreatic digestive enzymes are created and carried into the duodenum (first part of the small intestine) in an inactive form. It is thought that during an attack of pancreatitis these enzymes become activated while still in the pancreas and begin to digest and destroy it. Following acute pancreatitis, the gland can often heal without affecting its functions much or changing in structure, whereas chronic pancreatitis causes severe functional and structural change.

In developed countries one of the most common causes of acute pancreatitis (accounting for approximately 40% of cases) is gallstone disease. Heavy alcohol use is another major cause of acute pancreatitis accounting for at least 35% of cases. In 10-30% of cases, the cause is unknown.

The less common causes include:

  • Drugs such as sodium valproate or morphine
  • Viral infections such as mumps, Epstein-Barr or hepatitis A and B
  • High plasma triglycerides (hypertriglyceridaemia) in diabetes, alcoholism or inherited conditions
  • High plasma calcium (hypercalcaemia) in hyperparathyroidism or malignant disease
  • Cystic fibrosis or Reye's syndrome in children
  • Pancreatic cancer
  • Surgery in the pancreas area (such as bile duct surgery) or trauma

In the past, alcohol consumption was believed to cause most cases of chronic pancreatitis. However, recent evidence indicates that, although alcohol contributes significantly to development of the disease, it is not the main cause for most patients. Among these include the following:

  • Toxic and metabolic: Alcohol, high calcium in blood, rarely high lipids, some drugs, tobacco, toxins, chronic renal failure
  • Idiopathic: cause unknown (after all other causes have been excluded)
  • Genetic: Abnormal genes coding for pancreatic enzymes
  • Autoimmune: Autoimmune chronic pancreatitis associated with inflammatory bowel disease
  • Recurrent and severe acute pancreatitis
  • Obstructive: Due to blocking of structures in the pancreas area

Autoimmune causes account for 5-6% while the cause cannot be identified in10-20% of all cases of chronic pancreatitis. The other causes mentioned above account for 70-80% of all causes of chronic pancreatitis.

Signs and Symptoms

Acute pancreatitis
About 80% of acute pancreatitis attacks are mild, although they may cause the sudden onset of severe abdominal pain, sickness, vomiting, weakness and jaundice. Attacks cause local inflammation, swelling, and haemorrhage that usually get better with supportive treatment and do little or no permanent damage. In about 20% of cases complications develop, such as tissue necrosis, infection, hypotension (low blood pressure), difficulty breathing, shock, and kidney or liver failure. It is important to see your doctor if you have symptoms that suggest pancreatitis because symptom severity does not necessarily reflect the amount of damage that may be occurring and because other conditions that require different treatments may cause similar symptoms. 

Chronic pancreatitis
Patients with chronic pancreatitis may have recurring attacks with symptoms similar to those of acute pancreatitis; these attacks increase in frequency as the condition progresses. Pain with chronic pancreatitis may be intermittent or become severe and continuous. It may be made worse by eating, and by drinking, particularly alcohol. Over time, the pancreas tissue becomes increasingly scarred and the cells that produce digestive enzymes are destroyed, causing pancreatic insufficiency (inability to produce enzymes to digest fats and proteins). Other common effects are weight loss, malnutrition, ascites, the development of pancreatic pseudocysts (fluid pools and destroyed tissue that can become infected) and fatty stools. As the cells that produce insulin and glucagon are destroyed, the patient may develop diabetes. Patients with chronic pancreatitis have an increased risk of developing pancreatic cancer.

Tests
  • Amylase (the pancreatic enzyme responsible for digesting carbohydrates) is the most common blood test for acute pancreatitis. It increases from 2 to 12 hours after the beginning of symptoms and peaks at 12 to 72 hours. It may rise to 5 to 10 times the normal level and will usually return to normal within a week. Amylase also may be monitored in chronic pancreatitis.  It is often moderately elevated until the cells that produce it are destroyed.
  • Lipase (the enzyme that, along with bile from the liver, digests fats) increases in the blood within 4 to 8 hours of the beginning of an acute attack and peaks at 24 hours. It may rise to several times its normal level and remains elevated longer than amylase. As cells are destroyed in chronic pancreatitis and as lipase production drops to less than 10% of the normal level, steatorrhoea (fatty, foul-smelling stools) will result. The serum amylase and lipase concentrations may be slightly high but more commonly tend to be normal in patients with chronic pancreatitis.
  • An increase in plasma alanine aminotransferase (ALT) and jaundice suggest gall stones are the cause of acute pancreatitis. If the cause is not clear, plasma triglycerides and calcium should be measured.
  • Stool chymotrypsin tests can be used to exclude pancreatic insufficiency. Immunoreactive trypsin (IRT) is a blood test that may be used to check pancreatic sufficiency in those with chronic pancreatitis. Nowadays faecal fat is rarely used to check for pancreatic sufficiency.

Other tests that may be used to check for complications of acute pancreatitis include:

  • Full Blood Count (including white blood cell count)
  • Glucose. The full blood count, electrolytes, and liver function tests are typically normal in chronic pancreatitis. Elevations of serum bilirubin and alkaline phosphatase (ALP) suggest compression of the intrapancreatic portion of the bile duct by structural changes like swelling and fibrosis, or development of pancreatic cancer. Blood markers of autoimmune chronic pancreatitis include an elevated ESR, IgG4, rheumatoid factor, ANA, and anti-smooth muscle antibody titer.

Non-laboratory tests in both acute and chronic pancreatitis may include:

  • Abdominal ultrasound
  • ERCP (endoscopic retrograde cholangiopancreatography), a flexible scope used to see and sometimes remove gallstones
  • CT (computed tomography) scan to look for calcified ducts in chronic pancreatitis
  • Secretin testing (rarely used) in which a tube is positioned in the duodenum to collect pancreatic secretions stimulated by injection of the hormone secretin into a vein
  • MRI (magnetic resonance imaging)
Prevention, Early Detection, and Treatment

Pancreatitis demands prompt medical attention. During an acute attack, there is the potential for the pancreas to be severely damaged within a matter of hours and complications can be life-threatening.

Acute Pancreatitis
It is not possible to prevent attacks of acute pancreatitis attacks or to detect them early.

Patients are admitted to hospital. Treatment consists of pain control until symptoms subside and "resting" the pancreas for several days to a few weeks by giving all fluids and nutrition either enterally or intravenously (IV) depending on the severity of the inflammation. If the acute pancreatitis is due to gallstones, surgery may be needed to remove the gallbladder at a later date. If an infection is identified, antibiotics should be started but prophylactic antibiotics are not recommended in patients with acute pancreatitis, regardless of the type or disease severity.

Chronic Pancreatitis
Chronic pancreatitis is treated by trying to prevent future attacks to minimize further pancreatic damage, and by providing treatment for damage already done. Abstention from alcohol is critical in helping to prevent additional attacks. If there is evidence of impaired fat absorption, a low fat diet may be prescribed and pancreatic enzymes may be given by mouth. The patient may also need to supplement fat-soluble vitamins. Glucose intolerance or pre-diabetes state occurs with some frequency in chronic pancreatitis, but diabetes mellitus usually occurs late in the course of disease. A trial of oral antidiabetic drugs followed by insulin therapy is commonly used in these patients.

Analgesics are an important part of treatment as patients often have persistent moderate to severe pain. Some need treatment for depression. As time progresses and pancreas function diminishes, the pain level may drop.

Surgery may be necessary to relieve obstructions to the pancreatic or biliary ducts and sometimes to remove part or the entire pancreas. It should be noted that the pancreas is very difficult to operate on and requires a surgeon experienced in pancreatic surgery.