Pulmonary microvascular fracture in a patient with acute respiratory distress syndrome*

Objective To present electron micrographs of lung tissue obtained from a patient exposed to high ventilatory pressures in the context of pulmonary dysfunction and pulmonary hypertension. Design Case report. Setting Adult intensive care unit of a university-affiliated teaching hospital. Patients A patient exposed to high-pressure mechanical ventilation during support for acute respiratory distress syndrome; the acute respiratory distress syndrome in this case was secondary to septic shock. Measurements and main results Scanning electron micrographs of lung tissue, focusing on the internal alveolar surfaces. Findings Multiple gross disruptions of the alveolar walls, suggestive of stress fractures. Conclusion High-pressure mechanical ventilation may promote fracturing of the alveolar blood:airspace barrier.