Platypnoea-orthodeoxia syndrome: novel cause for a known condition

Abstract

A 50-year-old man presented with dyspnoea while sitting, standing and walking but resolved completely in supine position. On cardiorespiratory examinations, fine crackles were noted over bibasal area. Chest X-ray showed bilateral reticulonodular shadows, restrictive pattern on spirometry, elevated alveolar arterial O2 gradient on arterial blood gas. High-resolution CT of the thorax revealed pattern as 'confident' or 'certain' radiographic diagnosis of idiopathic pulmonary fibrosis (IPF). Bubble-contrast echocardiography in recumbent, sitting and upright positions revealed no intracardiac (right to left shunt) or intrapulmonary shunts. This case highlights the necessity of awareness of this syndrome in cases of interstitial lung diseases (ILDs) also. Although 188 cases have been described thus far of platypnoea-orthodeoxia syndrome (P-OS) of various aetiologies, to the best of our knowledge, it is the first ever case of P-OS in ILD/IPF. Both lung bases were predominantly affected in this patient, platypnoea and orthodeoxia were attributed to areas of low/zero ventilation/perfusion (V/Q) ratio (zone 1 phenomena) as no other obvious explanation was found.

RETRACTED: Platypnea–Orthodeoxia Syndrome: Multiple Pathophysiological Interpretations of a Clinical Picture Primarily Consisting of Orthostatic Dyspnea

“…Among these case reports, the article by Takhar et al [13] refers to a case of POS combined with interstitial lung disease (ILD), where the existence of regional differences in pulmonary alveolar perfusion when comparing apical and basal regions of the lungs is strongly suspected. These regional discrepancies of respiratory function would not be uncommon in the presence of certain types of lung disease (in particular, interstitial lung fibrosis and viral or fungal pneumonia [14,15,16]) and would become more evident if the patients are asked to assume the upright position.…”

“…These regional discrepancies of respiratory function would not be uncommon in the presence of certain types of lung disease (in particular, interstitial lung fibrosis and viral or fungal pneumonia [14,15,16]) and would become more evident if the patients are asked to assume the upright position. The case described by Takhar et al [13] refers to a middle-aged man with ILD who slumped onto the floor and whose oxygen saturation was subsequently examined with a pulse oximeter that showed marked hypoxia, which gradually recovered while he was supine on the floor. The constant occurrence of marked desaturation of the blood during even short periods (a few minutes) of upright or sitting posture was put in relation to a condition of marked ventilation/perfusion mismatch caused by the so-called diffuse zone 1 phenomenon.…”

Patent foramen ovale presenting with platypnoea-orthodeoxia syndrome and stroke after multi-organ resection

“… 9 The underlying pathophysiology could be related to cardiac causes represented by intracardiac shunts, for example, PFO, ASD and ASD with fenestrations 6 10 or to pulmonary causes represented by pulmonary parenchymal ventilation/perfusion mismatch, and pulmonary arteriovenous shunts. 3 …”

“… 2 POS could also be caused by pulmonary pathologies where there is ventilation/perfusion mismatch or pulmonary arteriovenous shunting. 3 …”

Platypnoea-Orthodeoxia Syndrome: An Intriguing Diagnosis

“…POS is a rare condition characterized by dyspnoea and hypoxaemia triggered by orthostatism and relieved by lying in the supine position [ 2 ] . This entity was first reported by Burchell in 1949 and more than 180 cases have since been described in the literature.…”