Patients with giant mediastinal tumors often experience worsened dyspnea in the supine position due to central airway stenosis, which can become life-threatening during the induction of general anesthesia with muscle relaxants. However, posture-related changes in airway morphology in such cases have not been quantitatively evaluated. A 34-year-old male with a giant mediastinal tumor presented with dyspnea in the supine position. The recently developed upright and supine multi-detector computed tomography (MDCT) scans revealed a significant decrease in airway luminal areas from the upright to the supine position: 42.5%, 36.8%, and 40.4% in the trachea, right, and left main bronchi, respectively. These reductions were significantly greater than the 4%-9% changes previously reported in healthy individuals, suggesting that tumor weight worsened airway stenosis. To prevent airway collapse during general anesthesia, awake intubation was performed in the supine position prior to surgical resection. Airway luminal areas in patients with giant mediastinal tumors can significantly decrease from the upright to the supine position, which is considered to cause worsened dyspnea. Upright and supine MDCT enables safe and quantitative assessment of posture-related airway stenosis and may serve as an adjunctive imaging modality for evaluating patients who experience dyspnea in the supine position.
Suzuki et al. (Thu,) studied this question.