新生儿离开母体后,各器官仍继续发育,生理功能未臻完善。在病理生理方面,有很多与年长儿及成人不同之处,尤以体液的代谢更具有显著的特点:1.新生儿的体液总量较多,约占体重的80%,其中细胞外液约占体重的30—35%;而年长儿及成人之体液总量仅为体重的70— After the newborn leaves the mother’s body, the organs still continue to develop and their physiological functions are not perfect. In the pathophysiology, there are many differences with the older children and adults, especially in the metabolism of body fluids more significant features: 1. Neonatal body fluid is more, accounting for about 80% of body weight, of which extracellular fluid Accounting for about 30-35% of body weight; while the total body fluid of elderly children and adults is only 70-