Davidson C, Smith D, Morgan D B
Am J Med. 1976 Nov;61(5):709-15. doi: 10.1016/0002-9343(76)90150-9.
The diurnal pattern of water and solute excretion and body weight were examined in five control subjects and in a patient with idiopathic orthostatic hypotension before and during treatment. The patient had a reversed diurnal pattern of excretion of sodium, urea and water but not of potassium and creatinine, and there was an excessive diurnal variation in body weight. The effects of three treatments, high salt diet alone and then with the addition of head-up tilt, and later fludrocortisone, were studied. Fludrocortisone caused marked clinical improvement and retention of sodium and water. Once a steady state was achieved none of the treatments had any significant effect either on the diurnal variation in weight or on the water and solute xcretion pattern except for a small reduction in sodium excretion at night when the patient slept with a head-up tilt. In is concluded that these treatments cause symptomatic improvement in idiopathic orthostatic hypotension through an increase in extracellular fluid volume rather than through any change in the abnormal diurnal pattern of water and salt excretion.
在五名对照受试者以及一名特发性直立性低血压患者治疗前和治疗期间，对水和溶质排泄的昼夜模式以及体重进行了检查。该患者钠、尿素和水的排泄昼夜模式相反，但钾和肌酐的排泄并非如此，且体重存在过度的昼夜变化。研究了三种治疗方法的效果，即单独采用高盐饮食，然后增加头高位倾斜，随后使用氟氢可的松。氟氢可的松使临床症状明显改善，并导致钠和水潴留。一旦达到稳定状态，除了患者头高位倾斜睡眠时夜间钠排泄略有减少外，这些治疗方法对体重的昼夜变化或水和溶质排泄模式均无任何显著影响。得出的结论是，这些治疗方法通过增加细胞外液量而非通过改变水盐排泄异常的昼夜模式来使特发性直立性低血压的症状得到改善。
