Chylothorax
- the accumulation of chyle in the pleural space.
- Chest and neck surgeries are common causes of chylothorax because of the
proximity of the thoracic duct to the
great vessels in the
mediastinum and lower aspect of
the neck.
- Chylothorax usually presents within days of surgery, often when patients
resume normal feeding.
- Symptoms depend on both the rate at which chyle accumulates and the amount
of fluid present.
- A subtle pleural effusion may have minimal symptoms.
- Respiratory distress is noted with larger effusions.
- Fever and signs of infection are uncommon.
Diagnosis
- Pleurocentesis is usually diagnostic of chylothorax, when milky fluid is
withdrawn.
- A triglyceride content of greater than 1.25 mmol/L (110 mg/dL), as noted
for the girl in the vignette, probably is chylous; less than 0.56 mmol/L (50
mg/dL) probably is not.
Treatment
- Initial treatment for chylothorax is to modify the diet to a
low-fat, medium-chain triglyceride
diet, which is available as a commercial formula.
Medium-chain triglycerides are directly absorbed into the intravascular space,
decreasing lymphatic flow. Total parenteral nutrition is necessary in
recalcitrant cases.
- If the chylothorax persists or is associated with significant symptoms,
surgical management is required, including ligation of the thoracic duct and
insertion of a chest tube.
- Low-protein diets, high-fat diets, and high-carbohydrate diets do not
improve the outcome in chylothorax. The method of feeding is not important.
References:
Orenstein DM. Chylothorax. In: Behrman RE, Kliegman RM, Jenson HB,
eds. Nelson Textbook of Pediatrics. 16th ed. Philadelphia, Pa: WB
Saunders Co; 2000:1333
Parrish DA, Seilheimer DK. Pulmonology: considerations for the
pediatric cardiologist. In: Garson A Jr, Bricker JT, McNamara DG, eds.
The Science and Practice of Pediatric Cardiology. Philadelphia, Pa:
Lea & Febiger; 1990:2813-2832