二、 water and sodium disorders hypertonic hypertonic dehydration isotonic water excess isotonic hypotonic hypotonic ()细胞外液容量不足( extracellular fluid deficit 1. Hypotonic dehydration sodium loss water loss serum sodium 130mmolL plasma osmotic pressure 280m0sm/L二、water and sodium disorders hypertonic hypertonic dehydration isotonic water excess isotonic hypotonic hypotonic (一) 细胞外液容量不足(extracellular fluid deficit) 1. Hypotonic dehydration sodium loss ＞ water loss serum sodium ＜ 130mmol/L plasma osmotic pressure ＜ 280mOsm/L