Position dependent dyspnea and hypoxemia

Area of Science:

• Cardiology
• Pulmonology
• Oncology

Background:

• Platypnea-orthodeoxia syndrome (POS) is a rare condition characterized by shortness of breath that worsens when sitting or standing.
• Bronchial carcinoma can lead to complex cardiopulmonary interactions, though its direct link to POS is infrequently reported.

Observation:

• A 63-year-old male patient presented with symptoms consistent with POS.
• Bronchoscopic examination revealed a complete obstruction of the left main bronchus caused by bronchial carcinoma.
• Partially absent hypoxic vasoconstriction was noted, suggesting impaired pulmonary vascular response.

Findings:

• Surgical removal of the left lung (left pneumonectomy) led to the complete resolution of POS.
• The findings support the hypothesis that bronchial carcinoma can induce POS through altered pulmonary artery dynamics and increased intrapulmonary shunting in the upright position.
• The absence of a patent foramen ovale shunt highlights the role of pulmonary vascular changes in this specific case.

Implications:

• This case highlights a potential, albeit historical, mechanism for POS development secondary to bronchial obstruction.
• It underscores the importance of considering pulmonary vascular effects in patients with central airway tumors presenting with dyspnea.
• Further investigation into the interplay between airway obstruction, pulmonary hemodynamics, and POS is warranted.