Pancreatitis 

Pancreatitis is an inflammation of the pancreas. Acute pancreatitis has a sudden onset and relatively short duration. Chronic pancreatitis occurs after years of repeated inflammation, which results in permanent damage to the pancreas.

Acute Pancreatitis
Acute pancreatitis develops suddenly and usually resolves within one to two weeks. 

Causes
Acute pancreatitis is most commonly caused by gallstone or excessive alcohol. 

Gallstone pancreatitis – digestive enzymes made in the pancreas usually flow through the pancreatic duct and empty into the duodenum (the first section of the small intestine). However, a stone formed in the gall bladder can travel down and block the pancreatic duct. This then causes the pancreatic digestive enzymes to accumulate within the pancreas. The digestive enzymes damage the pancreas and cause acute inflammation. 

Alcohol induced pancreatitis – habitual and excessive alcohol intake can cause acute pancreatitis. It is not fully understood how alcohol causes pancreatitis, however it is likely that toxic substances within ethanol cause damage to the cells of the pancreas.

Other less common causes of acute pancreatitis include trauma, certain medications and accidental injury to the pancreas during surgical procedures to remove gallstones.  

Signs and symptoms 
The most common symptom is sudden abdominal pain. This is often upper abdomen (epigastric) pain but can be generalised abdominal pain. 

The pain is often described as a dull constant ache. Sometimes the pain can radiate to the back.

Bending forward or curling into a ball may help to relieve the pain (the tripod position), and lying flat on your back often makes it worse.

There may also be fever, diarrhoea, nausea and vomiting.

Investigations
Physical examination may reveal abdominal tenderness and abdominal rigidity (guarding). 

Blood tests will include amylase and lipase. These are enzymes produced by the pancreas. During an episode of pancreatitis, serum amylase and lipase levels will be elevated. 

The degree of elevation does not help determine whether the patient has a mild, moderate or severe case of acute pancreatitis. 

Serum amylase and lipase levels are important to aid diagnosis, however it should be remembered that they can also be elevated in some other conditions, and so taking a thorough clinical history is vital.

Diagnostic imaging is unnecessary to make the diagnosis in most cases but can be useful to help define the etiology and/or look for complications. Examples of imaging modalities include abdominal x-ray, abdominal ultrasound scan or abdominal CT scan. Advanced imaging modalities include endoscopic retrograde cholangiopancreatography (ERCP) and magnetic resonance cholangiopancreatography (MRCP). The choice of imaging will depend on the information required. 

A pregnancy test should be performed on all women of childbearing age, as is the case when investigating any abdominal pain in this group. 

Treatment
Treatment depends on the severity. Mild cases usually subside after a few days with rest alone. Moderate cases will require a few nights of hospitalization then usually resolve within a week or two. Severe cases are life-threatening and will require admission to intensive care. 

Moderate to severe cases may require the following treatment:

Aggressive intravenous fluid administration may be required. Acute pancreatitis causes fluid to move from the intravascular space (blood vessels) to the interstitial space, and so initially large volumes of IV fluids may be required.

Digesting food can put a strain on the pancreas, therefore the patient should be Nil By Mouth (NBM) to allow the pancreas to rest. Adequate hydration can be maintained with intravenous fluids. Severe cases with prolonged NBM may require insertion of a nasojejunal feeding tube, to enable feeds into the jejunum. 

Abdominal pain must be managed with analgesia, often strong opiates such as morphine are required. 

IV antibiotics are not routinely required, unless infection is suspected. 

It is also important to identify and treat the underlying cause, for example surgery to remove a gallstone or alcohol reduction. 

Complications
Most people with acute pancreatitis make a full recovery, however some people can go on to develop serious complications. 

Necrotizing pancreatitis is a serious complication whereby some of the pancreatic tissue dies (necrosis). The necrotic tissue can easily become infected. This is an emergency as the infection can spread to the blood, causing sepsis and organ failure. Urgent intravenous antibiotics and surgery to remove the dead tissue are required.

Any case of severe acute pancreatitis should be admitted to intensive care for close monitoring. Severe acute pancreatitis can be life-threatening. 

Chronic Pancreatitis 
Recurrent inflammation of the pancreas over years will lead to chronic pancreatitis. In chronic pancreatitis the pancreas has become gradually and permanently damaged.

Causes
Chronic alcohol abuse is the most common cause of chronic pancreatitis. Habitual and excessive alcohol abuse can cause recurring episodes of acute pancreatitis over many years. Eventually this causes gradual yet irreversible damage to the pancreas. 

Only approximately 5% of people with alcoholism develop chronic pancreatitis. It is therefore likely that other factors, such as genetic predisposition, make some people with alcoholism more prone to chronic pancreatitis than others. 

Chronic pancreatitis can also occur in people who do not abuse alcohol. In these people the cause is often not known. This is called idiopathic chronic pancreatitis. 

Rarely, chronic pancreatitis can be caused by other conditions, such as cystic fibrosis or autoimmune pancreatitis. 

Signs and symptoms
The most common symptom of chronic pancreatitis is abdominal pain. Most patients experience this as intermittent attacks of pain at unpredictable intervals. A minority of patients will experience constant pain.

Weight loss may occur, especially if pain limits food intake. 

As damage to the pancreas progresses and becomes extensive then the pancreatic cells will not function as well. This can lead to impairment of the exocrine and endocrine functions.

If the exocrine cells are damaged this can lead to malabsorption. A healthy pancreas produces digestive enzymes that digest fats from food in the small intestine. However, a damaged pancreas may produce less digestive enzymes. If less digestive enzymes are produced then fats will not be broken down and absorbed sufficiently, and instead they will be excreted in the stool. This is called steatorrhea. The stool will look oily/greasy, it floats and can be fowl smelling.

If the endocrine cells are damage this can lead to diabetes mellitus. A healthy pancreas produces insulin which is released to regulate blood sugar levels. However a damaged pancreas may produce less insulin. If inadequate insulin is produced then blood sugar levels will be elevated. 

Steatorrhea and diabetes mellitus occur at the late stage of the disease and only after a significant amount of irreversible damage has occurred.

Investigations
Blood tests may show slightly elevated amylase and lipase levels, however these will not be elevated as high as in acute pancreatitis. In late stages of the disease the serum amylase and lipase may be at normal levels because the pancreatic cells are not functioning well and therefore not producing these enzymes. 

Imaging studies such as abdominal CT scan may help aid diagnosis. A chronically damaged pancreas often has characteristic features that can be seen on CT scan.

Treatment
Treatment is directed at reducing the signs and symptoms.

Chronic abdominal pain can be debilitating, and therefore pain control is an important part of management. Various analgesics can be combined. It is important to remember the risk of opioid dependency with prolonged use of opioids. 

If steatorrhea is present then this should be managed with a low fat diet and pancreatic enzyme supplementation. Pancreatic enzyme supplementation are medications to replace the digestive enzymes that the pancreas would normally produce. This medication is taken before eating, to help digestion of the food. 

If diabetes mellitus is present then blood sugar levels will need to be managed with oral hypoglycemic medications and insulin. Careful monitoring of blood sugar levels will be required. 

Smoking cigarettes may accelerate the development of chronic pancreatitis, and so cessation of smoking is strongly advised. 

It is also important to identify and treat the underlying cause of chronic pancreatitis, for example support with alcohol cessation.