Acute pancreatitis

Pancreatitis is an inflammatory process of the pancreas. This inflammation occurs when the digestive enzymes are activated within the pancreas, rather than in duodenum, which leads to the self-digestion of the tissues of the pancreas. Depending on the length and severity of this process, it has two forms: acute and chronic.

Acute pancreatitis (also known as acute pancreatic necrosis) is a sudden aseptic inflammation of the pancreas, which is caused by the activation of pancreatic enzymes before they have time to leave the pancreas. This leads to necrosis of pancreatic cells, dystrophy of the pancreas, and results in septic complications.

Despite the use of modern treatment the lethality from acute pancreatitis ranges from 7 – 15%, while necrotic (suppurative) pancreatitis leads to death in 40 – 70% of the cases.


Causes

As it was mentioned above, acute pancreatitis occurs when pancreatic enzymes are activated within its tissues. Normally, pancreatic enzymes activate only when they enter duodenum by interacting with enteropeptidase, which is produced by special cells in the duodenum.However, when the content of the duodenum (which has enteropeptidase) enters the pancreatic ducts or when the pancreatic ducts become obstructed, the enzymes will activate before they have time to leave the pancreas. There are a vast number of factors which can cause acute pancreatitis; below we will separate them into two groups.


Most common causes of acute pancreatitis

• Alcohol – the pancreatic enzymes along with bile enter the duodenum via the major duodenal papilla (though some people have an additional minor duodenal papilla that secretes only pancreatic enzymes) passing the sphincter of Oddi. Strong alcohol (40% and above) is a very strong irritant. If for some reason this strong alcohol leaves the stomach before properly mixing with its content, it can irritate the major (and minor) duodenal papilla and sphincter of Oddi causing them to spasm. This spasm leads to a buildup of pressure within the pancreatic ducts, which in turn causes the enzymes to be activated within the tissues of the pancreas.
  
  Important! – one of the most common reasons why strong alcohol reaches duodenum too soon, is when a person washes the strong alcohol down with any kind of liquid (water, juice, etc.). The liquid may cause a reflectory opening of the pyloric sphincter. If you wish to drink strong alcohol, it is recommended to eat right after you have a shot, to remove the unpleasant taste.
• Gallstones – are probably the most common cause of acute pancreatitis, with alcohol being a close second (though that depends on the country). Due to the fact that bile ducts and pancreatic ducts join together before entering the duodenum via major duodenal papilla, any gallstones that get stuck after the joining of the ducts can prevent the pancreatic enzymes from leaving the pancreas, causing them to activate.
• Endoscopic retrograde cholangiopancreatography (ERCP) – even though this procedure is used to diagnose and treat problems of the pancreatic and biliary duct system, it can also be the cause of acute pancreatitis (5% of all procedures). As the endoscope is passes through duodenum it can bring enteropeptidase and bacteria into the pancreatic ducts, causing pancreatic enzymes to active and possibly causing bacterial infection.
• Abdominal trauma – lipolytic enzymes of pancreas are secreted in already activated form; however, they can only breakdown already damaged cells. Therefore, if the tissues of pancreas become damaged due to some outside force, it can lead to the self-digestion of the pancreas.
• Penetrating ulcers – especially the ones located in the duodenum can provide the pathway for enteropeptidase to enter the pancreas causing a chain reaction of enzyme activation.
• Carcinoma of the pancreas (especially its head) and cancer of other localization – any cancer located in the region can obstruct the pancreatic ducts, causing a buildup of pancreatic enzymes and their activation. This condition can also be worsened by jaundice, as the carcinoma of the head of the pancreas can obstruct not only the pancreatic ducts but also the bile ducts.
• Structural abnormalities can sometimes obstruct pancreatic ducts, causing acute pancreatitis.
• There are also a number of drugs which can trigger acute gastritis, which include sitagliptin, vildagliptin, linagliptine, saxagliptin, sulfonamides, tetracycline, azathioprine, estrogens, salicylates, pentamidine, and steroids. For most of the drugs the direct cause of acute pancreatitis is unknown; however, drugs such as salicylates, just like alcohol, cause an irritation of the major duodenal papilla, which could be the cause of acute pancreatitis.
• Radiation treatment – of the pancreas itself or the organs nearby can trigger acute gastritis as a result of the damage done to the tissues of the pancreas.

Less common causes of acute pancreatitis

There are a number of other causes which can trigger acute pancreatitis; however, in most of them it is unclear what exactly triggers the activation of the pancreatic enzymes. These causes include scorpion venom, ischemia caused by bypass surgery, pregnancy, repeated marathon running, valproic acid, hyperparathyroidism, bulimia or anorexia, obesity, mumps, codeine phosphate reaction, and a number of others.


Causes of acute pancreatitis by demographic

It is interesting to note that depending on the origin of the person, the main cause of acute pancreatitis will change. For example, in United States, alcohol is the main culprit, accounting for 65% of the cases, while in Sweden and United Kingdom it is 20% and 5% respectively. In all Eastern countries the main cause of acute pancreatitis is gallstones. Also, people in developed countries suffer from acute pancreatitis more than people in developing countries due to a larger percent of obesity in population.

The cause also varies depending on the age of the person. Children usually get acute pancreatitis due to trauma. Before the development of vaccines, mumps used to cause a considerable amount of cases of acute pancreatitis in young adults.