Division of Nephrology, San Francisco General Hospital and the University of California, San Francisco, 1001 Potrero Ave, Building 100, Rm 342, San Francisco, CA 94110-1341, USA.
Clin Exp Nephrol. 2012 Feb;16(1):136-46. doi: 10.1007/s10157-011-0537-7. Epub 2011 Sep 27.
A high incidence of hypernatremia is often observed in patients recovering from acute kidney injury (AKI) in intensive care units.
An unselected cohort of 20 adult patients recovering from AKI in the intensive care unit of a single institution during a 1-year period, were investigated. Serum and urine electrolytes, osmolality, urea nitrogen and creatinine were measured in an attempt to determine the cause of the hypernatremia.
Eighty-eight percent of patients who could not drink fluids were found to have hypernatremia (serum Na >145 mEq/L). Even though the hypernatremia was mild in most patients (146-160 mEq/L), the average rise in serum sodium concentration was 17.4 mEq/L. The average urine osmolality was 384 mmol/kg of which 47.6 and 32.8 mmol/kg were contributed by sodium and potassium, respectively. The patients had hypervolemia as evidenced by the presence of edema and an average weight gain of 21.5 kg at the onset of the hypernatremia. The rise in serum sodium level coincided with an increase in urine output.
The hypernatremia is believed to be due to post-AKI diuresis in the face of inability to maximally concentrate the urine because of renal failure. The diuresis caused a disproportionate loss of water in excess of that of sodium in the absence of replenishment of the water loss. Additionally, the patients were hypervolemic due to the retention of large quantities of sodium and water as a result of infusion of substantial volumes of physiological saline prior to the development of hypernatremia.
在重症监护病房中，急性肾损伤（AKI）恢复的患者常发生高钠血症。
对 1 年内 1 家医院重症监护病房中 20 名 AKI 恢复期的成年患者进行了一项非选择性队列研究。测量血清和尿液电解质、渗透压、尿素氮和肌酐，以确定高钠血症的原因。
发现 88%不能饮水的患者存在高钠血症（血清 Na >145 mEq/L）。尽管大多数患者的高钠血症较轻（146-160 mEq/L），但血清钠浓度平均升高 17.4 mEq/L。平均尿渗透压为 384 mmol/kg，其中 47.6 和 32.8 mmol/kg 分别由钠和钾贡献。患者存在高容量血症，表现为水肿和高钠血症发作时平均体重增加 21.5kg。血清钠水平的升高与尿量的增加相吻合。
高钠血症被认为是由于 AKI 后利尿，而由于肾功能衰竭，无法最大限度地浓缩尿液。在没有补充水分丢失的情况下，利尿导致了钠以外的水分不成比例地丢失。此外，由于在发生高钠血症之前输注了大量生理盐水，导致大量钠和水潴留，因此患者存在高容量血症。
