Fig. 1From: Prone position improves lung ventilation–perfusion matching in non-intubated COVID-19 patients: a prospective physiologic studyPer-patient trajectory of PaO2/FiO2 (a), ventilation–perfusion matching (b), dead space (c) and shunt (d) at the three study time points, SP1, PP and SP2. Each line is the trajectory of one patient. PaO2, partial pressure of oxygen; FiO2, fractional concentration of oxygen in inspired air; SP1, baseline supine position; PP, 1 h after prone positioning; SP2, 1 h after resuming supine positionBack to article page