Risk factors for pancreatic cellular injury after cardiopulmonary bypass

Heart-related deaths following heart surgery have decreased, and any further declines will probably result from the prevention of other types of complications. Pancreatitis (inflammation of the pancreas, a gland in the abdomen) occurs in as many as 5 percent of patients after any type of cardiac surgery, evidently caused by decreased blood flow or as a side effect of some drugs. Mortality is high. In order to determine the cause of pancreatitis, 300 patients about to undergo heart surgery with cardiopulmonary bypass (in which the circulation is routed outside the body while the heart is being operated on) were examined. Hyperamylasemia (increased concentrations of the enzyme amylase in the blood) indicates pancreatic injury, and was found in 27 percent of the patients. Because pancreatic involvement ranged from acute pancreatitis to a level of disease that could only be determined by biochemical analysis, the entire cluster was referred to as 'pancreatic cellular injury.' One factor that was closely associated with pancreatic complications was administration of calcium chloride at the time of the operation. The higher the dose of calcium chloride, the higher the risk of injury, with the risk rising very rapidly when the dose exceeded 800 mg. per square meter of body surface area. The use of calcium chloride is controversial, but it is routinely used at many medical centers because it is thought to improve heart function. However, if vasoconstriction (constriction of the blood vessels) is required, other drugs can be used. The other risk factor for pancreatic injury was ischemia (decreased blood flow) from low blood pressure (hypotension), low cardiac output, and a longer time spent in surgery. Heart valve surgery and previous kidney insufficiency also raised the risk of pancreatic cellular injury. (Consumer Summary produced by Reliance Medical Information, Inc.)