Cocaine-Induced Ventilation/Perfusion Mismatch Mimicking Pulmonary Embolism.

Pulmonary complications from cocaine use can range from bronchospasm to vasospasm leading to pulmonary infarction. Profound vasospasm may also lead to perfusion defects presenting as pulmonary embolism on ventilation-perfusion scan. A 65-year-old patient with a past medical history of substance abuse and chronic kidney disease presents to the emergency department with sudden-onset chest pain and shortness of breath. Ventilation-perfusion scan revealed filling defect most notably in the lingual lobe. He was later discharged on warfarin for the management of pulmonary embolism. The patient presented to the emergency department 2 weeks later with similar complaints; the international normalized ratio was subtherapeutic, and urine drug screen was positive for cocaine. Repeat ventilation-perfusion scan revealed no filling defects. Follow-up bilateral venous Doppler of lower extremities and D-dimer were within normal limits.