Chylothorax

Chylothorax After Debridement of Necrotizing Fasciitis

A 38-year-old woman with a history of injection drug use presented with progressive pain in the left arm and neck and fever (temperature, up to 38.8°C [102°F]) of 9 days' duration. Physical findings included subcutaneous crepitus, erythema, and swelling of the left arm, chest, and neck. White blood cell count was 27,000/µL with 91% neutrophils. Chest radiographs showed gas in the subcutaneous and soft tissue of the neck (A), arm, and chest (B). Necrotizing fasciitis was suspected.

Extensive debridement of the left upper chest area was performed, and vancomycin, piperacillin/tazobactam, and clindamycin were started. Wound cultures were negative. A few days later, a white milky fluid was noted draining at the site of the debridement. A radiograph revealed pleural effusion (C), and a chest tube was inserted to drain the fluid (D). The triglyceride level in the pleural fluid was 155 mg/dL, suggestive of chylothorax. The drainage from the chest tube stopped completely after 7 days, and the patient rapidly recovered.

Necrotizing fasciitis may result in rapid, extensive destruction of the fascia and subcutaneous fat. Mixed infection with aerobic and anaerobic bacteria is a common cause of necrotizing fasciitis that develops in patients with diabetes, peripheral vascular disease, and other complicated illnesses.1 Group A streptococci are a more common cause among patients with a recent history of blunt trauma, varicella, injection drug use, penetrating injury, deep lacerations, or childbirth.1 Both types of necrotizing fasciitis may occur after surgical procedures.

The disease is treated aggressively--usually by an infectious disease physician, an intensive care specialist, and a surgeon--to prevent gangrene, septic shock, and multiple organ system failure. In addition to antibiotic therapy, complete surgical debridement of all necrotic tissue is required because mortality is high (almost 100%) without surgical intervention.1

Chylothorax usually results from surgery, trauma, or malignancy. Reports vary as to the most common cause. In one study, the most common cause was surgery or trauma (49.8% of cases); lymphoma and other malignancies were responsible for only 16.7% of cases.2 However, another study found malignancy was the most common cause.3 Iatrogenic injury of the thoracic duct accounted for most cases of surgically related chylothorax.2,3 Because of its variable course and proximity to the esophagus, aorta, and spine, the thoracic duct is vulnerable to injury during surgeries performed at these sites.2 In this patient, chylothorax may have been caused by direct injury of the thoracic duct from the extensive necrotizing fasciitis as well as from the radical debridement.

References

1. Stevens DL. Infections of the skin, muscle, and soft tissues. In: Braunwald E, Fauci AS, Kasper DL, et al, eds. Harrison's Principles of Internal Medicine. 16th ed. New York: McGraw-Hill; 2005:740-745.
2. Doerr CH, Allen MS, Nichols FC 3rd, Ryu JH. Etiology of chylothorax in 203 patients. Mayo Clin Proc. 2005;80:867-870.
3. Sassoon CS, Light RW. Chylothorax and pseudochylothorax. Clin Chest Med. 1985;6:163-171.