Bronchial stenosis is known to complicate endobronchial tuberculosis despite medical therapy. It is often associated with dyspnoea. In severe cases, bronchial stenosis results in airflow obstruction, impaired secretion clearance, and can lead to respiratory failure. We present an unusual observation of platypnoea-orthodeoxia syndrome in a young woman with acute atelectasis due to post-tuberculosis bronchial stricture. Imaging revealed complete middle and right lower lobe atelectasis with a partially aerated right upper lobe. In the sitting posture, there was positional worsening of dyspnoea associated with an increase in the alveolar-arterial oxygen gradient and shunt fraction. The likely mechanism was due to gravitational difference in ventilation-perfusion matching. The platypnoea-orthodeoxia syndrome was reversible following balloon dilatation of the bronchial stenosis and expansion of the collapsed lung.
Keywords: Atelectasis; bronchial stenosis; orthodeoxia; platypnoea; ventilation–perfusion mismatch.