Tee Kristen, Dang Jerry
Aust Fam Physician. 2017 Sep;46(9):677-680.
Hyponatraemia is one of the most commonly encountered electrolyte abnormalities in general practice. Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is an important but under-recognised cause.
This article explores the presentation, investigation, diagnosis and management of SIADH.
SIADH can occur secondary to medications, malignancy, pulmonary disease, or any disorder involving the central nervous system. Diagnosis is made on the basis of clinical euvolaemic state with low serum sodium and osmolality, raised urine sodium and osmolality, and exclusion of pseudohyponatraemia and diuretic use. Fluid restriction of 800-1200 mL/24 hours is the mainstay of treatment. Patients with severe hyponatraemia and symptoms of altered mental state or seizures should be admitted to hospital for monitoring of fluid restriction and consideration of hypertonic saline. A rapid increase in sodium levels can precipitate osmotic demyelination and, as such, the increase in serum sodium should not exceed 10 mmol/L in 24 hours or 18 mmol/L in 48 hours.
低钠血症是全科医疗中最常见的电解质异常之一。抗利尿激素分泌不当综合征（SIADH）是一个重要但未得到充分认识的病因。
本文探讨SIADH的临床表现、检查、诊断和管理。
SIADH可继发于药物、恶性肿瘤、肺部疾病或任何累及中枢神经系统的疾病。诊断基于临床血容量正常状态、低血清钠和渗透压、升高的尿钠和渗透压，以及排除假性低钠血症和利尿剂使用情况。24小时液体摄入量限制在800 - 1200毫升是主要治疗方法。严重低钠血症且有精神状态改变或癫痫发作症状的患者应住院，以监测液体摄入量限制并考虑使用高渗盐水。钠水平快速升高可引发渗透性脱髓鞘，因此，血清钠升高在24小时内不应超过10毫摩尔/升，在48小时内不应超过18毫摩尔/升。
