Guo Qinghua, Lu Juming, Mu Yiming, Dou Jingtao, Pan Changyu
Department of Endocrinology, Chinese PLA General Hospital, Beijing 100853, China.
Neuro Endocrinol Lett. 2010;31(5):588-93.
Essential hypernatremia is very rare in clinical practice and the pathogenesis is unclear. We performed a set of clinical tests to a patient with chronic and sustained hypernatremia as well as absence of thirst in order to investigate the clinical characteristics and make the diagnosis, yet most importantly to analyze the possible pathogenesis and explore a possible therapy regime.
Water deprivation test and acute water intravenous loading test were performed to observe the changes of urinary osmolality, plasma osmolality and plasma sodium. Free water clearance (C(H₂O) was calculated. Osmolality was detected using the method of freezing point depression, and thirst grade using visual analogue scales. Desmopressin acetate (0.05-0.1 mg/d) was administered to the patient in order to observe the therapeutic effects to his disorder.
The patient had sustained hypernatremia over a long period of time, decreased thirst, normal renal function, as well as absence of clinical hypovoluemia. The plasma sodium was 160-190 mmol/L and plasma osmolality was 330-370 mOsm/L without any thirst perception which could not be corrected by water intake. An 18-hour period of water deprivation increased the urinary osmolality from 368 mOsm/L to 420 mOsm/L with plasma osmolality increasing from 362 mOsm/L to 369 mOsm/L and rising further to 857 mOsm/L after an injection of 5 u vasopresin. With the infusion of 1 250 ml 5%-glucose during 2 hours in an acute water loading test setting, plasma osmolality decreased from 350 mOsm/L to 334 mOsm/L associated with a plasma sodium decrease from 164.7 mmol/L to 155 mmol/L urinary osmolality dropped from a maximum of 632 mOsm/L to 135 mOsm/L urinary volume from 0.25 ml/min to 2.33 ml/min and C(H₂O) from -0.18 ml/min to 1.19 ml/min after acute water loading with 1 250 ml glucose dissolved in water. Our results reveal that treatment of the patient with Desmopressin acetate relieved the adypsia, hypernatremia and hyperosmolality effectively.
The patient was considered as suffering from essential hypernatremia which was associated with partial central diabetes insipidus and adypsia. Desmopressin acetate as a common therapeutic agent of central diabetes insipidus proved to be an effective treatment for essential hypernatremia.
原发性高钠血症在临床实践中极为罕见，其发病机制尚不清楚。我们对一名患有慢性持续性高钠血症且无口渴感的患者进行了一系列临床检查，以研究其临床特征并做出诊断，但最重要的是分析可能的发病机制并探索可能的治疗方案。
进行禁水试验和急性水负荷试验，观察尿渗透压、血浆渗透压和血浆钠的变化。计算自由水清除率（C(H₂O)）。采用冰点降低法检测渗透压，用视觉模拟量表评估口渴程度。给予患者醋酸去氨加压素（0.05 - 0.1mg/d），观察其对病情的治疗效果。
该患者长期存在持续性高钠血症，口渴感减退，肾功能正常，且无临床低血容量表现。血浆钠为160 - 190mmol/L，血浆渗透压为330 - 370mOsm/L，无任何口渴感觉，饮水无法纠正。禁水18小时使尿渗透压从368mOsm/L升至420mOsm/L，血浆渗透压从362mOsm/L升至369mOsm/L，注射5u血管加压素后进一步升至857mOsm/L。在急性水负荷试验中，2小时内输注1250ml 5%葡萄糖，血浆渗透压从350mOsm/L降至334mOsm/L，血浆钠从164.7mmol/L降至155mmol/L，尿渗透压从最高632mOsm/L降至135mOsm/L，尿量从0.25ml/min增至2.33ml/min，自由水清除率（C(H₂O)）从 - 0.18ml/min增至1.19ml/min。我们的结果显示，用醋酸去氨加压素治疗该患者有效缓解了烦渴、高钠血症和高渗状态。
该患者被认为患有原发性高钠血症，与部分中枢性尿崩症和烦渴缺失有关。醋酸去氨加压素作为中枢性尿崩症的常用治疗药物，被证明对原发性高钠血症有效。
