多尿症

定義: polyuria: 每天小便超過3L (UOP)

病因: Osmotic (住院病人最常見) or water diuresis

Workup: 先做禁水test, 再做 DDAVP test .

    -每6h收一次尿, 測Uosm
    -計算 24h osmole excretion rate = 24h UOP (L) x Uosm
          > 1000 mOsm/d -> osmotic diuresis
          < 800 mOsm/d   -> water diuresis


Osmotic diuresis:
    病因:
       -glucose,
       -mannitol,
       -urea (急性腎衰竭恢復期, 蛋白質攝取增加, hypercatabolism (burns, steroids, GI出血)
       -NaCl 輸注
       -propylene glycol

Water diuresis
    病因:
        DI (血鈉>140)
        Primary polydipsia (血鈉<140)


嚴重夜尿 (>1/3 daily urine):

Tx: minirin (desmopressin) (0.1mg/#) 1-4# hs