A Case of COVID-19 ARDS with Unusual Refractory Hypoxia

ABSTRACT

Aim and background: Since the beginning of COVID-19 pandemic, we have come across a large number of ARDS patients with different presentations and clinical manifestations. The usual management is using a lung-protective ventilatory strategy followed by proning to improve oxygenation. Here, we present a case where the usual management failed to improve oxygenation which led us to think of co-existing alternative diagnosis. Case description A 59-year-old male with a history of cardiovascular disease, presented with cough and breathing difficulty for 10 days and COVID RT PCR was positive. He was started on remdesivir, steroids, anti-coagulants, and other supportive measures but worsened and had to be intubated and mechanically ventilated. Lung-protective ventilation was initiated but the patient remained hypoxic even at 100% fiO2. Chest X-ray and HRCT did not show much severity and the measured lung compliance was also good. A transesophageal ECHO showed good LV function and no significant diastolic dysfunction. 2 sessions of proning were done and yet the oxygenation did not improve. Repeat HRCT + CTPA was done to look for pulmonary embolism but it instead revealed a pulmonary AV malformation. Coiling of the AV malformation was done. Oxygenation then substantially improved. Further sessions of proning were done and patient was gradually weaned off. Conclusion: There may be several co-existing causes of ventilation-perfusion mismatch which needs to be looked for. Pulmonary AV malformation, though rare, can cause shunting and hence persistent hypoxia.