一、前言新生儿期伴随着胎盘机能的丧失,其内外环境均发生急剧的变化。包括温热环境的变化;从低氧环境到高氧环境的变化;从无菌环境到污染环境的变化;从闭式循环到开放循环的变化。特别是新生儿的内环境,必须经历由胎盘呼吸到肺呼吸的变化;从胎儿循环到成人循环的变化;经胎 First, the introduction of neonatal period with the loss of placental function, both inside and outside the environment have undergone dramatic changes. Including the change of warm environment; the change from low oxygen environment to high oxygen environment; the change from aseptic environment to the polluted environment; the change from closed cycle to open cycle. Especially the newborn’s internal environment, must experience changes in the respiration of the lungs from the placenta to the lungs; changes from fetal circulation to adult circulation;