More than 95 percent of pulmonary emboli arise from deep venous thrombi in the legs (above the knee); the remainder arise from the right cardiac chambers or other veins. The majority of deaths occur suddenly and can be avoided only by prophylaxis. Patients who survive to reach the hospital for medical treatment generally have a good outlook, with little morbidity and resolution of the emboli.
Estimates of mortality from pulmonary embolism vary depending on the source and accuracy of data. Pulmonary emboli are probably directly responsible for 50,000 deaths annually in the United States. If untreated, recurrent episodes are frequent, and more than 25 percent will be fatal. More than 60 percent of fatalities occur within 1 hour of onset; hence pulmonary embolism is likely to be confused with sudden coronary death. It is estimated that pulmonary embolism is grossly underdiagnosed, since only 10 to 30 percent of autopsied cases with evidence of embolism had an antemortem diagnosis.46
Among the U.S. population, the age-adjusted death rate for pulmonary embolism decreased 33 percent between 1979 and 1997.4 The decline was greater in whites than in blacks and greater in men than in women. The rate of hospital discharges with a primary or secondary diagnosis of pulmonary embolism declined 38 percent from 7 per 10,000 population in 1979 to 4.3 in 1997.8 Death rates and hospital rates for pulmonary embolism increase with age and are higher in men than in women and in blacks than in whites.4 It was listed on 115,000 hospital records in 1997.8 The incidence is even more uncertain. Only 10 percent of cases occur in normal persons without predisposing factors such as chronic cardiopulmonary and malignant disease, estrogen therapy, orthopedic trauma, immobilization, operative procedures, obesity, pregnancy, or blood dyscrasias. The elderly are more vulnerable.
Postoperative pulmonary emboli alone produce 4000 to 8000 deaths annually.47 It is a major cause of death postpartum and in patients hospitalized for orthopedic conditions. Evidence from Britain suggests that the annual mortality from pulmonary embolism has been increasing for several decades despite anticoagulant drugs. More than 5 million persons over age 45 undergo major surgery each year in the United States; 1 or 2 of each 1000 will die postoperatively from pulmonary embolism. The recent advent of low-dose heparin prophylaxis may reduce this risk substantially (see Chap. 60).
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A time for giving and receiving, getting closer with the ones we love and marking the end of another year and all the eating also. We eat because the food is yummy and plentiful but we don't usually count calories at this time of year. This book will help you do just this.