Chylothorax Flashcards

Flashcards about Chylothorax in canines and felines.

Chylothorax

Accumulation of chyle in the pleural space.

Chyle

Triglyceride-rich fluid from the intestinal lymphatics that empties into the venous system in the thorax.

Pseudochylous effusion

Effusion that contains less triglycerides and more cholesterol compared to serum, but appears fatty grossly.

Thoracic lymphangiectasia

Tortuous, dilated lymphatics found in many animals with chylothorax.

Fibrosing pleuritis

Condition in which pleural thickening leads to constriction of lung lobes; can be caused by any chronic pleural exudate, but is most commonly associated with chylothorax and pyothorax.

Etiology of Chylothorax

Alteration of flow through thoracic duct (TD) leading to leakage of chyle. Can be related to increased pressure or permeability in TD or venous obstruction downstream.

Cardiac Causes of Chylothorax

Pericardial disease, cardiomyopathy, heartworm disease, other causes of right-sided heart failure; thrombosis around pacing lead wire.

Noncardiac Causes of Chylothorax

Neoplasia (especially mediastinal lymphoma in cats), lung lobe torsion, diaphragmatic hernia, venous granuloma, venous thrombus.

Common Cause of Chylothorax

Idiopathic.

Dog Breed Predilections for Chylothorax

Afghan hound and Shiba Inu.

Cat Breed Predilections for Chylothorax

Oriental breeds (e.g., Siamese and Himalayan).

Historical Findings of Chylothorax

Tachypnea and respiratory difficulty, coughing, lethargy, anorexia and weight loss, exercise intolerance.

Physical Examination Findings of Chylothorax

Muffled heart and lung sounds ventrally, increased bronchovesicular sounds, pale mucous membranes or cyanosis. Arrhythmia, heart murmur, signs of right-sided heart failure (e.g., jugular pulses, ascites, hepatomegaly). Decreased compressibility of anterior chest.

Diagnostics for Chylothorax

Fluid Analysis (Fluid triglycerides higher compared to serum. Fluid cholesterol— lower compared to serum), Cytology, Thoracic Radiography, Ultrasonography/Echocardiography, CT Lymphangiography, Pathologic Findings

Treatment for Chylothorax

Thoracocentesis, treat underlying cause (if possible), medical management, chest tubes, surgery.

Surgical Considerations for Chylothorax

TD Ligation and Pericardiectomy is recommended in patients that do not respond to medical management. Failure to occlude all branches results in continued pleural effusion.

Medical management for Chylothorax

Rutin; believed to increase macrophage removal of proteins, which promotes absorption of fluid. Somatostatin analog (octreotide); decreases jejunal secretion, and stimulates gastrointestinal water absorption.

Complications of Chylothorax

Fibrosing pleuritis, iatrogenic infection with repeated thoracocentesis