Stored triglycerides in the adipocytes are released and split by pancreatic lipases into fatty acids and glycerol molecules. The resultant fatty acids react with extracellular calcium to make calcium soaps (i.e. fatty acid salts) that give fat necrosis its characteristic chalky-white appearance. Fat necrosis is an example of dystrophic calcification because the calcification occurs at normal serum calcium levels.Besides pancreatitis, fat necrosis is also associated with conditions such as pancreatic carcinoma and pancreatic trauma. Although the peripancreatic region is the most commonly affected site in pancreatic disease (due to direct contact with enzymes), associated fat necrosis can occur around the body in subcutaneous tissue, hand and foot joints, and bone marrow. These extrapancreatic complications are known as pancreatic panniculitis.Beyond saponification and calcification, fat necrosis concludes with fibrosis and the formation of grey-yellow scar tissue. It is also possible for calcification to occur around the edges of a fatty necrotic lesion, enclosing the fat in a cyst. These "oil cysts" may persist for months to years without undergoing fibrosis. This is often the case in breast fat necrosis, where the underlying oil cysts can be visualised using sonography, X-Ray, CT, or MRI. Diagnosis
Although fat necrosis can be diagnosed through a routine checkup with a physician, called a physical, a patient can also perform a physical checkup on themselves. For additional diagnosis, a physician would request one or more of the following scans or tests.
Orthopnea or orthopnoea is shortness of breath (dyspnea) that occurs when lying flat, causing the person to have to sleep propped up in bed or sitting in a chair. It is commonly seen as a late manifestation of heart failure, resulting from fluid redistribution into the central circulation, causing an increase in pulmonary capillary pressure and causing difficulty in breathing. It is also seen in cases of abdominal obesity or pulmonary disease. Orthopnea is the opposite of platypnea, shortness of breath that worsens when sitting or standing upright. Causes
Orthopnea is often a symptom of left ventricular heart failure and/or cardiogenic pulmonary edema. It can also occur in those with asthma and chronic bronchitis, as well as those with sleep apnea or panic disorder. It is also as associated with polycystic liver disease. From a neuromuscular perspective, orthopnea is potentially a sign of severe diaphragmatic weakness. Under such circumstances, patients may describe shortness of breath when they bend over (e.g. when tying shoelaces), called bendopnea. Mechanism
Orthopnea is due to increased distribution of blood to the pulmonary circulation when a person lies flat or closer to a horizontal position. Lying flat decreases the inhibitory effect that the gravity usually has on the blood when coming back to the heart from the lower extremities of the body. This increases the right sided venous return.