Fig. 2

Influence of prone position on SpO₂. SpO₂, saturation of pulse oximetry; Pre-PP, before prone position; Post-PP, after prone position; D1, D2, D3, D4, the first 4 days after admission. There was significant difference in SpO₂ between the first 4 days after admission and the day of discharge. *, compared with D1 Pre-PP, P < 0.05, On the first day of admission, the level of SpO₂ in the prone position was higher after 5 min and 30 min than before prone position.