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|Classification and external resources|
|Classification and external resources|
Pancreatitis is inflammation of the pancreas which requires immediate medical attention and hospitalization during an attack. It occurs when pancreatic enzymes (especially trypsin) that digest food are activated in the pancreas instead of the small intestine. It may be acute – beginning suddenly and lasting a few days, or chronic – occurring over many years. It has multiple causes and symptoms.
The most common symptoms of pancreatitis are severe upper abdominalburning pain radiating to the back, nausea, and vomiting that is worsened with eating. The physical exam will vary depending on severity and presence of internal bleeding. Blood pressure may be elevated by pain or decreased by dehydration or bleeding. Heart and respiratory rates are often elevated. The abdomen is usually tender but to a lesser degree than the pain itself. As is common in abdominal disease, bowel sounds may be reduced from reflex bowel paralysis. Fever or jaundice may be present. Chronic pancreatitis can lead to diabetes or pancreatic cancer. Unexplained weight loss may occur from a lack of pancreatic enzymes hindering digestion.
Eighty percent of pancreatitis is caused by alcohol and gallstones. Gallstones are the single most common etiology of acute pancreatitis. Alcohol is the single most common etiology of chronic pancreatitis.
Some medications are commonly associated with pancreatitis, most commonly corticosteroids such as prednisolone, but also including the HIV drugs didanosine and pentamidine, diuretics, the anticonvulsant valproic acid, the chemotherapeutic agents L-asparaginase and azathioprine, estrogen by way of increased blood triglycerides, cholesterol-lowering statins and the antihyperglycemic agent sitagliptin.
There is an inherited form that results in the activation of trypsinogen within the pancreas, leading to autodigestion. Involved genes may include Trypsin 1, which codes for trypsinogen, SPINK1, which codes for a trypsin inhibitor, or cystic fibrosis transmembrane conductance regulator.
Other common causes include trauma, mumps, autoimmune disease, scorpion stings, high blood calcium, high blood triglycerides, hypothermia, and endoscopic retrograde cholangiopancreatography (ERCP). Pancreas divisum is a common congenital malformation of the pancreas that may underlie some recurrent cases. Pregnancy can be a cause, possibly by increasing blood triglycerides. Diabetes mellitus type 2 is associated with a 2.8-fold higher risk.
Less common causes include pancreatic cancer, pancreatic duct stones, vasculitis (inflammation of the small blood vessels in the pancreas), coxsackievirus infection, and porphyria—particularly acute intermittent porphyria and erythropoietic protoporphyria.
A number of infectious agents have been recognized as causes of pancreatitis.
Diagnosing pancreatitis requires two of the following:
Amylase or lipase is frequently part of the diagnosis; lipase is generally considered a better indicator, but this is disputed. Cholecystitis, perforated peptic ulcer, bowel infarction, and diabetic ketoacidosis can mimic pancreatitis by causing similar abdominal pain and elevated enzymes. The diagnosis can be confirmed by ultrasound and/or CT.
The treatment of pancreatitis is supportive and depends on severity. Morphine generally is suitable for pain control. There is a claim that morphine may constrict the sphincter of Oddi, but this is controversial. There are no clinical studies to suggest that morphine can aggravate or cause pancreatitis or cholecystitis.
The treatment that is received for acute pancreatitis will depend on whether the diagnosis is for the mild form of the condition, which causes no complications, or the severe form, which can cause serious complications.
Mild acute pancreatitis
The treatment of mild acute pancreatitis is successfully carried out by admission to a general hospital ward. Eating should not be allowed until pancreatic inflammation has resolved, which usually takes around five days, as the digestion process places strain on the pancreas. Because pancreatitis can cause lung damage and affect normal lung function, oxygen is usually delivered through breathing tubes that are connected via the nose. The tubes can then be removed after a few days once it is clear that the condition is improving. Dehydration may result during an episode of acute pancreatitis, so fluids will be provided intravenously. The pain associated with even mild cases of acute pancreatitis can be severe, so it may require quite a strong, opiate-based painkiller.
Severe acute pancreatitis
If the patient is diagnosed with severe acute pancreatitis, they will need to be admitted to an high dependency unit or intensive care unit (ICU). It is likely that the levels of fluids inside the body will have dropped significantly as it diverts bodily fluids and nutrients in an attempt to repair the pancreas. The drop in fluid levels can lead to a reduction in the volume of blood within the body, which is known as hypovolemic shock. Hypovolemic shock can be life-threatening as it can very quickly starve the body of the oxygen-rich blood that it needs to survive. To avoid going into hypovolemic shock, fluids will be pumped intravenously. Oxygen will be supplied through tubes attached to the nose and ventilation equipment may be used to assist with breathing. Feeding tubes may be used to provide nutrients, while painkillers can help to relieve the pain. As with mild acute pancreatitis, it will be necessary to treat the underlying cause. If the cause is gallstones, it is likely that an ERCP procedure or removal of your gallbladder will be recommended. For more information about ERCP, see Acute pancreatitis - ERCP. If the cause is alcohol use, stopping drinking and receiving treatment for alcohol dependency will be recommended (as discussed above). Though, as mentioned above, even if the underlying cause is not alcohol-related, consumption should still be avoided for at least six months as this can cause further damage to the pancreas during the recovery process. Oral intake, especially fats, is generally restricted at first. Fluids and electrolytes are replaced intravenously. Nutritional support should be initiated via tube feeding to surpass the portion of the digestive tract most effected by secreted pancreatic enzymes. The underlying cause should also be treated (targeting gallstones, discontinuing medications, cessation of alcohol etc.) The patient is monitored for complications.
Severe acute pancreatitis has high mortality rates, especially where necrosis of the pancreas has occurred.
Several scoring systems are used to predict the severity of an attack of pancreatitis. They each combine demographic and laboratory data to estimate severity or probability of death. Examples include APACHE II, Ranson, and Glasgow. Apache II is available on admission; Glasgow and Ranson are simpler but cannot be determined for 48 hours. One form of the Glasgow criteria suggests that a case be considered severe if at least three of the following are true:
This can be remembered using the mnemonic PANCREAS:
Early complications include shock, infection, systemic inflammatory response syndrome, low blood calcium, high blood glucose, and dehydration. Blood loss, dehydration, and fluid leaking into the abdominal cavity (ascites) can lead to kidney failure. Respiratory complications are often severe. Pleural effusion is usually present. Shallow breathing from pain can lead to lung collapse. Pancreatic enzymes may attack the lungs, causing inflammation. Severe inflammation can lead to intra-abdominal hypertension and abdominal compartment syndrome, further impairing renal and respiratory function and potentially requiring management with an open abdomen (laparostomy) to relieve the pressure.
Late complications include recurrent pancreatitis and the development of pancreatic pseudocysts—collections of pancreatic secretions that have been walled off by scar tissue. These may cause pain, become infected, rupture and bleed, block the bile duct and cause jaundice, or migrate around the abdomen. Acute necrotizing pancreatitis can lead to a pancreatic abscess, a collection of pus caused by necrosis, liquefaction, and infection. This happens in approximately 3% of cases, or almost 60% of cases involving more than two pseudocysts and gas in the pancreas.