Synergistic Drug-Induced Diffuse Alveolar Hemorrhage in a Polysubstance User: A Case of Inhaled Cocaine and Fentanyl Toxicity.

Diffuse alveolar hemorrhage (DAH) is a rare but life-threatening pulmonary condition characterized by bleeding into the alveolar spaces, most commonly associated with autoimmune or vasculitic disorders. However, drug-induced DAH, particularly from the inhalation of substances like cocaine and fentanyl, is an emerging concern. A 37-year-old homeless male with a history of intravenous and inhaled polysubstance abuse was found unresponsive and treated with intranasal naloxone for presumed opioid overdose. Upon arrival, he exhibited respiratory distress, pink frothy sputum, severe hypoxemia, and acute renal failure with refractory hyperkalemia. Imaging revealed diffuse bilateral alveolar infiltrates, and large volumes of bright red blood were suctioned during intubation. Bronchoalveolar lavage confirmed DAH with numerous hemosiderin-laden macrophages. Infectious and autoimmune workups were negative, while urine toxicology was positive for both fentanyl and cocaine. Management included lung-protective mechanical ventilation, high-dose corticosteroids, and continuous renal replacement therapy, with clinical improvement and successful extubation after ten days. This case underscores the importance of considering drug-induced DAH in patients with acute respiratory failure and polysubstance use, even in the absence of hemoptysis.