In a message dated 96-12-03 00:05:32 EST, you write: << Chylothorax >> What causes the problem Chylothorax, or chylous effusion, is the result of damage or obstruction to the thoracic lymph duct that causes it to leak chyle into the pleural space. Possible causes include traumatic chest injury, tumor, and surgery involving the heart, aorta, esophagus, or left subclavian vessels. Rapid accumulation of chyle compresses the lungs, reducing lung ventilation and perfusion and shifting the mediastinum. This distorts the great vessels and causes hemodynamic compromise. Chyle contains fat, protein, and lymphocytes. The removal of chyle from the lymphatic system in chylothorax reduces the number of circulating lymphocytes, predisposing the patient to infection. The loss of proteins, fats, and fat-soluble vitamins may also cause serious metabolic deficits. If the effusion develops suddenly with rapid loss of intravascular volume, the patient will have severe respiratory distress, tachycardia, hypotension, pallor, cyanosis, thready pulse, clammy skin, below-normal temperature, and shock. If it develops more slowly, signs and symptoms may be less specific--malaise, fatigue, dyspnea on exertion, and a sensation of heaviness on the affected side of the chest. Arnetta Dailey RN IBCLC The Woodlands Texas