Acute pericarditis is usually viral and affects men (usually under the age of 50) more frequently than women. Pericarditis affects 40% to 50% of clients with end-stage renal disease and uremia. o Postmyocardial infarction pericarditis and postcardiotomy (following open-heart surgery) pericarditis also are common. o Patho: o Pericardial tissue damage triggers an inflammatory response. Inflammatory mediators released from the injured tissue cause vasodilation, hyperemia, and edema. Capillary permeability increases, allowing plasma proteins, including fibrinogen, to escape into the pericardial space. White blood cells amass at the site of injury to destroy the causative agent. Exudate is formed, usually fibrinous or serofibrinous (a mixture of serous fluid and fibrinous exudate). In some cases, the exudate may contain red blood cells or, if infectious, purulent material. The inflammatory process may resolve without long-term effects, or scar tissue and adhesions may form between the pericardial layers. Fibrosis and scarring of the pericardium may restrict cardiac function. Pericardial effusions may develop as serous or purulent exudate (depending on the causative agent) collects in the pericardial sac. Pericardial effusion may be recurrent. Chronic inflammation causes the pericardium to become rigid. o Selected Causes of Pericarditis: Viruses, Fungi, Bacteria, Syphilis, Tuberculosis, Parasites, Myocardial and pericardial injury, Autoimmune disorders, Rheumatic fever, Uremia, Connective tissue diseases, Neoplasms, Prescription and nonprescription drugs, Radiation, Trauma, surgery, Postcardiac injury, Myxedema o Manifestations: o Abrupt-onset chest pain: most common symptom, caused by inflammation of nerve fibers; sharp, may be steady or intermittent; may radiate to the back or neck; can mimic myocardial ischemia; pain is aggravated by respiratory movements, changes in body position, or swallowing; Sitting upright and leaning forward reduces the discomfort by moving the heart away from the diaphragmatic side of the lung pleura. o Pericardial friction rub: not always present, but is the characteristic sign of pericarditis; leathery, grating sound produced by inflamed pericardial layers rubbing against the chest wall or pleura; heard most clearly at the left lower sternal border with the patient sitting up or leaning forward; usually heard on expiration; may be constant or intermittent. o Low-grade fever below 100°F r/t inflammation o Dyspnea o Tachycardia o Complications: o Pericardial effusion, cardiac tamponade, and constrictive pericarditis o are possible complications of acute pericarditis. o Pericardial Effusion - abnormal collection of fluid between the pericardial layers that threatens normal cardiac function. The fluid may consist of pus, blood, serum, lymph, or a combination. The manifestations of a pericardial effusion depend on the rate at which the fluid collects. Although the pericardium normally contains about 30 to 50 mL of fluid, the sac can stretch to accommodate a gradual accumulation of fluid. Over
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- Fall '19
- acute myocardial infarction, infarction