25.下列有關postobstructive diuresis的敘述，何者錯誤？
(A)發生在雙側或單側尿路完全阻塞，經過成功疏通的病人
(B)尿液為低張含大量鹽分，可能導致高血鈉
(C)致病機轉為排泄先前滯留體內的尿素，產生滲透壓利尿（osmotic diuresis）
(D)靜脈輸液治療不宜補充＞每日尿液流失量，以免發生醫源性體液容積增加

1. an accumulation of total body water, sodium, & urea
2. an impairment of tubular reabsorptive capabilities.
   1. Clinically significant POD is uncommon with a normal contralateral kidney, This reflects the continued maintenance of fluid and electrolyte homeostasis by the contralateral kidney.

1. urine production of ＞200 mL for at least 2 consecutive hours following the relief of urinary retention.　or
2. ＞3000 mL within a 24-hour period

1. The complications that may arise in patients with POD include volume depletion, hyponatremia or hypernatremia, hypo-/hyperkalemia, hypomagnesemia, metabolic acidosis, hypovolemic shock, and death.

Pathology:

• Inappropriate excretion of both water & solute as reflected by a urine osmolality >250 mOsm/kg water.

   

• Inability to concentrate urine in pathologic POD stems from defective generation and maintenance of

  a medullary solute gradient.

  • Reasons :

    • Decreased reabsorption of sodium chloride in the loop of Henle

    • Decreased reabsorption of urea in the collecting tubule. ( poor response to ADH / Aldosterone )

    • Medullary solute washout caused by increased medullary blood flow

       

    • Increased tubular flow rate and solute concentration in the distal tubule.