ICU Chest Films > Lung Processes > Pulmonary Embolism

Pulmonary Embolism

Even though pulmonary embolism is the third most common cause of sudden death, it continues to be underdiagnosed in the intensive care setting. The clinical manifestations of pulmonary embolism are varied. They range from completely silent embolization to sudden death. Symptoms of dyspnea, tachypnea, hemoptysis, hypoxemia, and pleuritic chest pain have been attributed to pulmonary embolism but are neither sensitive nor specific. Indeed, the most valuable indicators of pulmonary embolism are a history of risk factors and or a previous embolic event. Many different medical and surgical conditions are associated with increased risk of pulmonary embolization, including immobilization, trauma, surgery, shock, obesity, pregnancy, polycythemia vera, and antithrombin-III deficiency. The pathophysiology of pulmonary embolism consists of both hemodynamic and respiratory embarrassment. Approximately 90% of pulmonary embolisms are the result of venous thrombosis in the lower extremities. Hemodynamic consequences occur when more than half the cross sectional area of the pulmonary vascular bed is occluded. This situation leads to pulmonary hypertension and in the acute setting right heart failure. Increased alveolar dead space (a result of ventilated but underperfused lung) leads to hypoxemia and respiratory failure. Pulmonary infarction is a rare consequence of pulmonary embolism in patients without concommitent compromise of the bronchial circulation. Generally, infarctions are hemorrhagic and located in the lower lobes.

An Inferior Vena Cava filter is a viable treatment for severe pulmonary embolism.

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