Acute pancreatitis is a common cause of severe abdominal pain.
Your pancreas is a long, teardrop-shaped organ located deep within your upper abdomen, just beneath your diaphragm and lungs. Its broader end is sandwiched between your stomach and backbone, and its вЂњtailвЂќ stretches toward your left kidney. Acute pancreatitis is a sudden swelling and inflammation of your pancreas. Pancreatic inflammation can spread to nearby organs and may even involve organs in other areas of your body. One potential complication of acute pancreatitis is a pleural effusion, a collection of fluid at the bases of your lungs.
Your pancreas can become inflamed for a variety of reasons. Gallbladder disease and chronic alcohol consumption are the most common causes of acute pancreatitis, but infections, tumors, hypothermia, trauma, medications, toxins and autoimmune diseases, such as lupus, can also trigger pancreatic inflammation. Regardless of the underlying cause, acute pancreatitis can vary from mild to severe and life threatening. Severe cases are more likely to cause complications, such as pleural effusions.
Cause of Effusions
According to a 2006 review in the World Journal of Gastroenterology, up to 17 percent of patients with acute pancreatitis develop pleural effusions. Most pleural effusions are left-sided, but effusions may involve only the right lung or both lungs. Because your pancreas lies just beneath your diaphragm - the dome-shaped muscle at the bottom of your chest cavity - swelling of the pancreas may block the drainage of lymph on the upper side of your diaphragm. As the lymph collects at the base of your lung, an effusion forms.
Alternatively, acute pancreatitis may damage your pancreatic ducts and allow leakage of pancreatic enzymes into the surrounding tissues. If the enzymes percolate through your diaphragm, they can injure your lungs and generate a pleural effusion. In some patients, a fistula, or open tract, forms between the pancreas and the thoracic cavity, permitting the free flow of pancreatic enzymes into the area surrounding the lungs.
Pleural effusions in acute pancreatitis can vary in size. Small effusions may simply be watched. They typically resolve when the pancreatic inflammation resolves. Effusions that are large enough to interfere with your breathing may need to be surgically drained. If your pleural effusion persists or recurs, it could be an indication of a fistula, which may require surgical closure.
Pleural effusions are sometimes associated with a вЂњsystemic inflammatory response syndrome,вЂќ which is triggered by the release of inflammatory chemicals from damaged pancreatic tissue and stimulated immune cells. SIRS may lead to malfunction and failure of multiple organs throughout your body. Thus, patients with SIRS and pleural effusions may require care in an intensive care unit.
Predictor of Outcome
Pleural effusions were once considered a routine occurrence in patients with acute pancreatitis. However, it is now known they are associated with more severe pancreatic damage. According to a 2011 review in the "Canadian Medical Association Journal," pleural effusions are one of 5 criteria used in the Bedside Index of Severity in Acute Pancreatitis, a system used to identify patients who are at an increased risk of complications due to acute pancreatitis.
Ten to 20 percent of patients with acute pancreatitis have severe disease and more complicated hospital courses. A much lower number of patients - 1 to 5 percent - die from this disease. Most patients with acute pancreatitis, including many with pleural effusions, do well and eventually recover. Pleural effusions are one marker for severe acute pancreatitis, but they must be considered in conjunction with a patient's overall condition.