Prone Position and Lung Ventilation and Perfusion Matching in Acute Respiratory Failure due to COVID-19

A 70-year-old man (body mass index = 29 kg/m2) was admitted for acute respiratory failure consequent to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. He had no disease in his past medical history and received no medication. He was intubated and mechanically ventilated with a VT of 6 ml/kg of ideal body weight, a respiratory rate of 25 breaths/min, positive end-expiratory pressure of 12 cm H2O, and an FIO2 of 0.6. As previously attempted, Zarantonello et al recorded images of lung ventilation and perfusion at the fifth intercostal space by using electrical impedance tomography (Pulmovista 500;Drager Medical), with the patient supine and after 1 hour of pronation, maintaining the ventilator settings unchanged.