Asphyxia by tracheobronchial thrombus

Asphyxia secondary to airway obstruction has numerous underlying causes, both acute and chronic. Causes of chronic airway obstruction, such as neoplasms and tracheal scarring, are often clinically apparent well prior to asphyxia. Causes of acute airway obstruction may not be as obvious to clinicians or investigators. These include infections, anaphylactic reactions, status asthmaticus, inhalational injuries, and aspirations, which may result in acute obstruction and sudden death. We report the deaths of 2 individuals, a 43-year-old female and a 78-year-old female, both with adenocarcinoma. The 43-year-old was hospitalized with a stage III, poorly differentiated infiltrating ductal carcinoma of the breast metastatic to the lymph nodes. She was intubated to treat poor respiratory function and acidosis. A bronchoalveolar lavage was consistent with alveolar hemorrhage; no organisms were identified. Blood and "clot" were in her endotracheal tube, so the endotracheal tube was replaced. She became comatose and life support was withdrawn. At autopsy, a large red-gray thrombus obstructed the trachea and extended into the right bronchus. Microscopically, the entire clot was composed of fibrin, red blood cells, and some mucus. Findings of acute respiratory distress syndrome with hyaline membranes were identified. The cause of death was listed as acute respiratory distress syndrome with tracheobronchial thrombus. Experiencing a decline in mental status, the 78-year-old had metastatic adenocarcinoma of unknown primary. She developed sudden respiratory distress and an airway obstruction was discovered. After failure to relieve the obstruction, she decompensated and died. At autopsy, a large, red-gray thrombus obstructed the distal trachea and both bronchi. Microscopically, the thrombus was composed of fibrin, platelets, and red blood cells. The cause of death was asphyxia secondary to airway obstruction by thrombus. We present these 2 unusual cases of asphyxia and review of the literature focusing on asphyxia and the etiology of airway thrombi.