A.20%~25% B.20%~33% C.30%~35% D.30%~40% E.>60%
A.1:1~1:1.5 B.1:1.5~1:2 C.1:2~1:2.5 D.1:2.5~1:3 E.1:2~1:3
A.增加通氣量 B.減輕呼吸肌做功 C.改善換氣功能 D.提高動脈血氧含量 E.促進(jìn)機體無氧代謝