Traumatic chylothorax following blunt thoracic trauma.

Background: Chylothorax occurs when chyle from the thoracic duct leaks into the pleural space. While majority of cases are iatrogenic, traumatic chylothorax can occur when rib or vertebral fractures disrupt the thoracic duct. These occurrences are exceedingly rare, particularly following blunt traumatic insult.

Methods: We performed a retrospective review of a case of chylothorax following blunt trauma. Data was extracted from the electronic medical record.

Case: A 60-year-old female presented to the trauma bay after a motor vehicle crash as a restrained driver with bilateral chest pain. Of note, patient had three left rib fractures from fall five days prior. She was neurologically and hemodynamically normal on arrival. Physical exam was notable for chest wall tenderness. Computed tomography revealed the following: bilateral hemopneumothoraces, pneumomediastinum, manubrium fracture, retrosternal hematoma, left 2-10 and right 1-2 rib fractures along with multiple orthopedic injuries. Left tube thoracostomy yielded 150 mL of blood. She was admitted to the intensive care unit. Patient had a 48-h period of cardiogenic shock requiring vasopressors and aggressive fluid resuscitation. On post-injury day (PID) 2, the chest tube drained milky fluid. Pleural fluid sampling was significant for triglyceride levels of 1292 mg/dL. Hemodynamics then improved. Due to low output (<500 mL/day), patient was managed conservatively a fat-restricted diet supplemented with medium-chain fatty acids. Chest tube was removed PID-7 once chyle leak resolved. Repeat chest radiograph PID-10 was negative for effusion. She was discharged to rehabilitation PID-13. At one-week follow-up, repeat CXR showed a small, loculated left lateral pleural effusion. Patient had no complaints and was maintaining adequate oxygen saturations on room air.

Discussion: We present a case of delayed chylothorax after blunt trauma precipitated by increased central venous pressure secondary to right heart failure, aggressive fluid resuscitation and vasopressor use. Traumatic chylothorax should be considered in patients with pleural effusion in the setting of blunt chest trauma as sudden hyperextension of the spine can disrupt the thoracic duct. Delayed diagnosis is not uncommon due to an average latency period of 2-10 days. Pleural fluid with triglyceride level > 110 mg/dL and chylomicrons is diagnostic. Initial management consists of chyle reduction through diet modification (high protein/restricted fat diet). Octreotide can be used as a pharmacological adjunct. Refractory or high-output cases (>1000 mL/day) may require surgical ligation of the thoracic duct. Early identification and intervention are paramount as untreated chylothorax is associated with significant morbidity and mortality rates up to 50 %.