Department of Diabetes and Endocrinology, Princess Alexandra Hospital, Woolloongabba, Queensland, Australia.
Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia.
Clin Endocrinol (Oxf). 2019 Apr;90(4):630-636. doi: 10.1111/cen.13930. Epub 2019 Jan 25.
Hyponatraemia in hospitalized patients is common and associated with increased mortality. International guidelines give conflicting advice regarding the role of urea in the treatment of SIADH. We hypothesized that urea is a safe, effective treatment for fluid restriction-refractory hyponatraemia.
Review of urea for the treatment of hyponatraemia in patients admitted to a tertiary hospital during 2016-2017. Primary end-point: proportion of patients achieving a serum sodium ≥130 mmol/L at 72 hours.
Urea was used on 78 occasions in 69 patients. The median age was 67 (IQR 52-76), 41% were female. Seventy (89.7%) had hyponatraemia due to SIADH-CNS pathology (64.3%) was the most common cause. The duration was acute in 32 (41%), chronic in 35 (44.9%) and unknown in the rest.
The median nadir serum sodium was 122 mmol/L (IQR 118-126). Fluid restriction was first-line treatment in 65.4%. Urea was used first line in 21.8% and second line in 78.2%. Fifty treatment episodes (64.1%) resulted in serum sodium ≥130 mmol/L at 72 hours. In 56 patients who received other prior treatment, the mean sodium change at 72 hours (6.9 ± 4.8 mmol/L) was greater than with the preceding treatments (-1.0 ± 4.7 mmol/L; P < 0.001). Seventeen patients (22.7%) had side effects (principally distaste), none were severe. No patients developed hypernatraemia, overcorrection (>10 mmol/L in 24 hours or >18 mmol/L in 48 hours), or died.
Urea is safe and effective in fluid restriction-refractory hyponatraemia. We recommend urea with a starting dose of ≥30 g/d, in patients with SIADH and moderate to profound hyponatraemia who are unable to undergo, or have failed fluid restriction.
住院患者低钠血症很常见，且与死亡率升高相关。国际指南对尿素在治疗抗利尿激素不适当分泌综合征（SIADH）中的作用存在矛盾。我们假设尿素是治疗液体限制无效的低钠血症的一种安全、有效的治疗方法。
对 2016 年至 2017 年期间在一家三级医院住院的患者使用尿素治疗低钠血症的情况进行回顾。主要终点：72 小时时血清钠≥130mmol/L 的患者比例。
69 例患者共 78 次使用了尿素。中位年龄为 67（IQR 52-76）岁，41%为女性。70（89.7%）例患者由于 SIADH-CNS 病变而出现低钠血症（64.3%），最常见的病因。病程为急性 32 例（41%），慢性 35 例（44.9%），其余为未知。
中位血清钠最低值为 122mmol/L（IQR 118-126）。液体限制是一线治疗方法，占 65.4%。尿素作为一线治疗药物占 21.8%，二线治疗药物占 78.2%。50 次治疗（64.1%）在 72 小时时血清钠≥130mmol/L。在接受其他治疗的 56 例患者中，72 小时时血清钠的平均变化（6.9±4.8mmol/L）大于前一次治疗（-1.0±4.7mmol/L；P<0.001）。17 例患者（22.7%）出现副作用（主要是味觉不佳），但均不严重。没有患者发生高钠血症、过度纠正（24 小时内>10mmol/L 或 48 小时内>18mmol/L）或死亡。
在液体限制无效的低钠血症中，尿素是安全且有效的。我们建议在不能进行或液体限制治疗失败的情况下，对患有 SIADH 和中重度低钠血症的患者，使用起始剂量≥30g/d 的尿素进行治疗。
