A rare case of Platypnoea-Orthodeoxia syndrome in COVID-19: BMJ report

Clinical manifestations of COVID-19 which is caused by SARS-CoV2 range from mild upper respiratory symptoms to life-threatening severe acute respiratory distress syndrome (ARDS) requiring invasive mechanical ventilatory support. Dr.Adarsh et al from AIIMS, New Delhi reported a rare case of platypnoea-orthodeoxia syndrome (POS) in a patient recovering from COVID-19 ARDS.

A 46-year old patient presented with history of fever of 7 days and dyspnea of 3 days duration. He had severe breathlessness both in lying down as well as supine position and had grade 4 dyspnoea. His past history was notable for diffuse large B-cell lymphoma for which he received chemotherapy and autologous stem cell transplantation 5 years ago.

Upon examination, patient had tachycardia, tachypnea, hypoxemia with oxygen saturation of 90%-94% on non-rebreathing mask at 10L/min of oxygen. Respiratory system examination revealed normal vesicular breath sounds with bilateral diffuse crepitations. Examination of other systems including CVS was within normal limits.

His blood investigations showed anemia, thrombocytopenia and raised inflammatory markers including CRP, Ferritin, Il-6 and LDH. Throat swab and nasopharyngeal swab for SARS-Cov2 RTPCR was positive. HRCT revealed bilateral diffuse ground-glass opacities throughout lung fields. ECG and ECHO done to rule out pulmonary embolism were normal.

Henceforth, a diagnosis of severe COVID-19 ARDS was made and initiated on treatment with remedesivir, dexamethasone and oxygen support with high flow nasal cannula at 60L/min and 60% FiO2. He also received IV antibiotics for neutropenia and PRBC and platelet transfusion.

On day 3 of admission he showed signs of improvement with decrease in oxygen requirement to 4L/min via nasal prongs. However on day 4 he complained of worsening dyspnea in sitting posture but felt comfortable on assuming supine posture. His SpO2 decreased from 94% in supine posture to 88% in recumbent posture. This finding was confirmed by ABG analysis as evidenced by drop in SaO2 by 7% from sitting to supine position.

Hence a diagnosis of platypnoea-orthodeoxia syndrome was made, he was continued on oxygen support, chest physiotherapy and other supportive measures. His POS improved and oxygen support was withdrawn on day 8 of admission and subsequently discharged.

In COVID-19 there may be preferential involvement of posterior and lower zones of lung parenchyma. Underlying pathophysiology for lung-related POS could be due to severe ventilation-perfusion mismatch in upright posture owing largely to the effect of gravity-dependent blood flow to the basal areas.

Authors conclude- "COVID-19 related POS may be reversible with good response to physiotherapy and supportive measures."

Source: Aayilliath K A, Singh K, Ray A, et al Platypnoea–orthodeoxia syndrome in COVID-19 BMJ Case Reports CP 2021;14:e243016.