the use of intravascular devices). Diagnosis The main techniques of diagnosing SVCS are with chest X-rays (CXR), CT scans, transbronchial needle aspiration at bronchoscopy and mediastinoscopy. CXRs often provide the ability to show mediastinal widening and may show the presenting primary cause of SVCS. However, 16% of people with SVC syndrome have a normal chest X-ray. CT scans should be contrast enhanced and be taken on the neck, chest, lower abdomen, and pelvis. They may also show the underlying cause and the extent to which the disease has progressed. Treatment Several methods of treatment are available, mainly consisting of careful drug therapy and surgery. Glucocorticoids (such as prednisone or methylprednisolone) decrease the inflammatory response to tumor invasion and edema surrounding the tumor. Glucocorticoids are most helpful if the tumor is steroid-responsive, such as lymphomas. In addition, diuretics (such as furosemide) are used to reduce venous return to the heart which relieves the increased pressure. In an acute setting, endovascular stenting by an interventional radiologist may provide relief of symptoms in as little as 12–24 hours with minimal risks. Should a patient require assistance with respiration whether it be by bag/valve/mask, bilevel positive airway pressure (BiPAP), continuous positive airway pressure (CPAP) or mechanical ventilation, extreme care should be taken. Increased airway pressure will tend to further compress an already compromised SVC and reduce venous return and in turn cardiac output and cerebral and coronary blood flow. Spontaneous respiration should be allowed during endotracheal intubation until sedation allows placement of an ET tube and reduced airway pressures should be employed when possible. Prognosis Symptoms are usually relieved with radiation therapy within one month of treatment. However, even with treatment, 99% of patients die within two and a half years. This relates to the cancerous causes of SVC found in 90% of cases. The average age of disease onset is 54 years. See also Pemberton's sign References Further reading External links Paraneoplastic syndromes Diseases of veins, lymphatic vessels and lymph nodes Oncological emergencies