Acute Pancreatitis
Acute pancreatitis is sudden inflammation of the pancreas that may be mild or life threatening but that usually subsides.
Gallstones and alcohol abuse account for almost 80% of the hospital admissions for acute pancreatitis. About 1½ times as many women as men experience acute pancreatitis caused by gallstones. Normally, the pancreas secretes pancreatic fluid through the pancreatic duct to the duodenum. This pancreatic fluid contains digestive enzymes in an inactive form and inhibitors that inactivate any enzymes that become activated on the way to the duodenum. Blockage of the pancreatic duct by a gallstone stuck in the sphincter of Oddi stops the flow of pancreatic fluid. Usually, the blockage is temporary and causes limited damage, which is soon repaired. But if the blockage continues, activated enzymes accumulate in the pancreas, overwhelm the inhibitors, and begin to digest the cells of the pancreas, causing severe inflammation.
Drinking as little as 2 ounces of alcohol a day (half a bottle of wine, four bottles of beer, or 5 ounces of liquor) for several years may cause the small ductules in the pancreas that drain into the pancreatic duct to clog, eventually causing acute pancreatitis. An attack of pancreatitis may be precipitated by an alcoholic binge or by an excessively large meal. Many other conditions can also cause acute pancreatitis.
Many drugs can irritate the pancreas. Usually, the inflammation resolves when the drugs are stopped. Viruses can cause pancreatitis, which is usually short-lived.


Causes of Acute Pancreatitis
· Gallstones
· Alcohol abuse
· Drugs such as furosemide and azathioprine
· Estrogen use associated with high lipid levels
· Hyperparathyroidism and high levels of calcium in the blood
· Mumps
· High levels of lipids (especially triglycerides) in the blood
· Damage to the pancreas from surgery or endoscopy
· Damage to the pancreas from blunt or penetrating injuries
· Cancer of the pancreas
· Reduced blood supply to the pancreas, for example, from severely low blood pressure
· Hereditary pancreatitis
· Kidney transplantation
Symptoms
Almost everyone with acute pancreatitis suffers severe abdominal pain in the upper midabdomen, below the breastbone (sternum). The pain often penetrates to the back. Rarely, the pain is first felt in the lower abdomen. When acute pancreatitis is caused by gallstones, the pain usually starts suddenly and reaches its maximum intensity in minutes. The pain then remains steady and severe, has a penetrating quality, and persists for days.
Coughing, vigorous movement, and deep breathing may worsen the pain; sitting upright and leaning forward may provide some relief. Most people feel nauseated and have to vomit, sometimes to the point of dry heaves—retching without producing any vomit. Often, even large doses of an injected opioid analgesic do not relieve pain completely.
Some people, especially those who develop acute pancreatitis because of alcohol abuse, may never develop any symptoms other than moderate pain. Others feel terrible. They look sick and sweaty and have a fast pulse (100 to 140 beats a minute) and shallow, rapid breathing. Rapid breathing may occur secondary to inflammation of the lungs, areas of collapsed lung tissue (atelectasis (see Atelectasis), and accumulation of fluid in the chest cavity (pleural effusion (see Pleural Disorders: Pleural Effusion). These conditions decrease the amount of lung tissue available to transfer oxygen from the air to the blood.
At first, body temperature may be normal, but it increases in a few hours to between 100° F and 101° F (37.7° C and 38.3° C). Blood pressure may be high or low, but it tends to fall when the person stands, causing faintness. As acute pancreatitis progresses, people tend to be less and less aware of their surroundings: Some are nearly unconscious. Occasionally, the whites of the eyes (sclera) become yellowish.
Complications
Damage to the pancreas may permit activated enzymes and toxins such as cytokines (see Biology of the Immune System: Cytokines) to ooze out and enter the abdominal cavity, where they cause irritation and inflammation of the lining of the cavity (peritonitis) or of other organs. Activated enzymes and cytokines may be absorbed from the abdominal cavity into lymph vessels and eventually the bloodstream, which can lead to low blood pressure and damage to organs outside of the abdominal cavity, such as the lungs. The part of the pancreas that produces hormones, especially insulin, tends not to be damaged or affected. One of five people with acute pancreatitis develops some swelling in the upper abdomen. This swelling may occur because the movement of stomach and intestinal contents stops (a condition called ileus (see Emergencies: Ileus) or because the inflamed pancreas enlarges and pushes the stomach forward. Fluid also may accumulate in the abdominal cavity (a condition called ascites (see Clinical Manifestations of Liver Disease: Ascites).
In severe acute pancreatitis (necrotizing pancreatitis), blood and pancreatic fluid may escape into the abdominal cavity, diminishing blood volume and resulting in a large drop in blood pressure, possibly causing shock (see Shock). Severe acute pancreatitis can be life threatening.
Infection of an inflamed pancreas is a risk, particularly after the first week of illness. Sometimes, a doctor suspects an infection because the person's condition worsens and because a fever and high white blood cell count develop after other symptoms had initially started to subside. The diagnosis is made by culturing blood samples (growing large numbers of bacteria) to identify bacteria that are causing the infection and performing a computed tomography (CT) scan. A doctor may be able to withdraw a sample of infected material from the pancreas by inserting a needle through the skin and into the pancreas. An infection is treated with antibiotics, and surgical removal of infected and dead tissue usually is necessary.