Pulmonary Embolism

Pulmonary Embolism Pulmonary Embolism Blockage of pulmonary arteries by thrombus, fat or air embolus, or tumor tissue Obstructs alveolar perfusion Most commonly affects lower lobes Picture 1 Picture 2 Risk factors -Deep vein thrombosis (90%) -Immobility or reduced mobility -Surgery -History of DVT -Malignancy -Obesity -Oral contraceptives/ hormones -Smoking -Heart failure -Pregnancy/delivery -Clotting disorders -Atrial fibrillation -Central venous catheters -Fractured long bone Clinical Manifestations Signs and symptoms: -Dyspnea ,Tachypnea -Cough, chest pain -Hemoptysis, Crackles -Wheezing -Fever, tachycardia, -Syncope, change in LOC The signs and symptoms in PE are varied and nonspecific, making diagnosis difficult. Symptoms may begin slowly or suddenly. Dyspnea is the most common presenting symptom, occurring in 85% of patients with PE. A mild to moderate hypoxemia with a low PaCO2 is a common finding. Other manifestations are: -tachypnea, -cough, -chest pain, -hemoptysis, -crackles, -wheezing, -fever, -tachycardia, -syncope, and -sudden change in mental status as a result of hypoxemia. -Can also cause accentuation of pulmonic heart sound. Clinical manifestations are dependent on the size and extent of emboli. Massive emboli may produce abrupt hypotension and shock. The mortality rate for massive PE is 30-60%, with most deaths occurring within 1-2 hours of onset. Conversely, small emboli may go undetected or produce vague, transient symptoms. The exception to this is the patient with underlying cardiopulmonary disease. In these patients, even small or medium sized emboli may result in severe cardiopulmonary compromise. Repeated pulmonary emboli gradually cause a reduction in the capillary bed and eventual pulmonary hypertension. Right ventricular hypertrophy can develop secondary to pulmonary hypertension. Diagnostic Studies D-Dimer Spiral (helical) CT scan - "CT PE protocol" Ventilation - Perfusion (V/Q) scan Pulmonary Angiogram Arterial blood gases (ABGs) Complications: Pulmonary infarction -Alveolar necrosis and hemorrhage -Abscess -Pleural effusion Pulmonary infarction (death of lung tissue) is most likely when the following factors are present: (1) occlusion of a large or medium-sized pulmonary vessel (2 mm in diameter), (2) insufficient collateral blood flow from the bronchial circulation, or (3) preexisting lung disease. Infarction results in alveolar necrosis and hemorrhage. Occasionally the necrotic tissue becomes infected, and an abscess may develop. Concomitant pleural effusion is frequent. Complications: Pulmonary hypertension Results from hypoxemia associated with massive or recurrent emboli Right ventricular hypertrophy Pulmonary hypertension results from hypoxemia or from involvement of more than 50% of the area of the normal pulmonary bed. As a single event, an embolus does not cause pulmonary hypertension unless it is massive. -Recurrent emboli may result in chronic pulmonary hypertension. -Pulmonary hypertension eventually results in dilation and hypertrophy of the right ventricle. -Depending on the degree of pulmonary hypertension and its rate of development, outcomes can vary, with some patients dying within months of the diagnosis and others living for decades. Collab Care: Goals of treatment Prevent further thrombi Prevent further embolization to pulmonary system