Platypnea-orthodeoxia Syndrome (POS) in Moderate COVID-19: An Uncommonly Common Bedside Sign?

Platypnoea-Orthodeoxia syndrome (POS) is the presence of postural hypoxaemia along with breathlessness in recumbent position. It is an uncommon syndrome with elusive pathophysiologic mechanisms. We observed POS in patients of moderate COVID-19 who required hospital admission to our indoor facility and oxygen supplementation when saturation was documented in sitting and supine positions for evaluation of platypnea.

We conducted an observational, cross sectional, retrospective analysis of pulse oximetry readings of patients with stage 2 COVID-19 admitted in ward during the period from 15th May 2020 to 30th May 2020. The difference in the peripheral oxygen saturation in sitting and supine positions, documented as a routine standard of care, especially in patients with platypnea, was calculated and demographic details and co-morbidities were noted from indoor record forms.

Of the 53 patients of stage 2 COVID-19 who were included in the study, 15 (28%) had platypnoea-orthodeoxia syndrome at the time of presentation and 18(33.9%) patients with platypnoea had ≥ 3% desaturation in sitting position as compared to supine position. Rest of the 20 (37.7%) patients had neither platypnoea nor orthodeoxia. All the patients presenting with platypnoea-orthodeoxia required oxygen therapy during the course of treatment. Amongst the 33 patients who were hypoxic and required oxygen supplementation, 15 patients (45.4%) had oxygen saturation of ≥94% in the supine position at presentation.

Platypnoea-orthodeoxia syndrome is common in patients with stage 2 COVID 19 infection who require oxygen therapy. POS can be easily documented by using pulse oximeter without the need of any specialised equipment. Hence, we propose that documentation of POS at the time of admission in primary health care or resource depleted settings would help in successful triage of the patients needing oxygen therapy. We also propose that oxygen saturation in sitting position be documented as far as possible. Further clinical studies are necessary to validate this observation.