In each group, heart rate (HR), respiratory rate (RR), parameters of gas exchange, and scale for accessory muscle use were measured at the time of enrollment (0 hour), 2 hours, 24 hours and 72 hours after randomization.

• 观察两组患者入选后0、2、24和72h的心率(HR)、呼吸频率(RR)、气体交换指标及辅助呼吸肌动用评分;