Hyponatraemia

概述 
理论 
诊断 
治疗 
随访 
资源 

最后审阅： 13 Feb 2025

最后更新： 28 Feb 2024

Hyponatraemia is the most common electrolyte disorder encountered in clinical practice.

Can occur in settings of volume depletion, volume overload, or euvolaemia.

Serum osmolality, urine osmolality, and urine sodium concentration help to determine the underlying cause.

Cerebral oedema is a medical emergency and occurs more frequently when hyponatraemia develops over <48 hours. Patients should be treated promptly with hypertonic 3% saline.

Other treatment depends on the underlying cause and may include fluid restriction and stopping causative medications.

Overly rapid correction of serum sodium concentration can lead to the life-threatening complication of myelinolysis and should be avoided.

定义

Hyponatraemia is defined as a serum sodium concentration of <135 mmol/L. Normal serum sodium concentration is in the range of 135-145 mmol/L.[1] It is a disorder of water balance reflected by an excess of total body water relative to electrolytes (total body sodium and potassium) leading to low plasma osmolality (i.e., <275 mmol/kg).[2] Hyponatraemia is generally caused by an increase in renal water reabsorption due to release of vasopressin (arginine vasopressin also known as antidiuretic hormone) along with water intake, and can occur in situations of volume depletion, volume overload, or normal volume. It should be noted that loss of sodium is minor compared with gains in water in most types of hyponatraemia.

This topic principally focuses on hypotonic (hypo-osmolar) hyponatraemia, the most common type of hyponatraemia.

病史和体格检查

关键诊断因素

presence of risk factors
high fluid intake
fluid losses
history of diabetes mellitus
history of cirrhosis, nephrosis, congestive heart failure
nausea/vomiting
mild cognitive symptoms
altered mental status, seizures, coma
low urine output
weight changes
orthostatic hypotension
abnormal jugular venous pressure
poor skin turgor
dry mucous membranes
absence of axillary sweat
oedema
rales or crackles on lung auscultation
polyuria

完整详情

其他诊断因素

history of hyperlipidaemia or paraproteinaemia

完整详情

危险因素

older age
hospitalisation
selective serotonin-reuptake inhibitor (SSRI) use
thiazide diuretic use
underlying medical conditions
severe hypothyroidism
adrenal insufficiency
malignancy
use of other medications
MDMA (ecstasy) use

完整详情

诊断性检查

首要检查

serum sodium concentration
serum electrolytes, urea, creatinine, and glucose
serum osmolality
urine sodium concentration
urine osmolality
urine electrolytes
urine flow rate
electrolyte-free water excretion
fractional excretion of sodium
thyroid-stimulating hormone
serum cortisol level and/or adrenocorticotrophic hormone test
serum lipids and serum protein electrophoresis

完整详情

需考虑的检查

CT brain, chest, abdomen/pelvis
other tests targeted at evaluating the underlying cause

完整详情

治疗流程

急症处理

acute onset (<48 hours) and/or symptomatic

持续性治疗

chronic onset (≥48 hours) or asymptomatic

overcorrection of serum sodium concentration

撰稿人

作者

Judith H. Veis, MD

Section Director

Nephrology

MedStar Washington Hospital Center

Washington

利益声明

JHV declares that she has no competing interests.

同行评议者

Gregor Lindner, MD

Director

Department of Internal & Emergency Medicine

Hirslanden Klinik Im Park

Zurich

Switzerland

Disclosures

GL is an author of a number of references cited in this topic.

Michael E. Ullian, MD

Professor of Medicine

Division of Nephrology

Department of Medicine

Medical University of South Carolina

Charleston

Disclosures

MEU declares that he has no competing interests.

Differentials
- Hypertonic hyponatraemia
- Pseudohyponatraemia
- Assessment of hyponatraemia
More Differentials
Guidelines
- Clinical practice guidelines for the management of exercise-associated hyponatremia: 2019 update
- Clinical practice guideline: maintenance intravenous fluids in children
More Guidelines
Patient information
Hyponatraemia
More Patient information
Calculadoras
Sodium Correction in Hyperglycemia (Hillier 1999)
Osmolality Estimator (serum)
Mais Calculadoras
Conectar-se ou assinar para acessar todo o BMJ Best Practice

O uso deste conteúdo está sujeito ao nosso aviso legal

Hyponatraemia

小结

定义

病史和体格检查

关键诊断因素

其他诊断因素

危险因素

诊断性检查

首要检查

需考虑的检查

治疗流程

acute onset (<48 hours) and/or symptomatic

chronic onset (≥48 hours) or asymptomatic

overcorrection of serum sodium concentration

撰稿人

作者

Judith H. Veis, MD

利益声明

同行评议者

Gregor Lindner, MD

Disclosures

Michael E. Ullian, MD

Disclosures

Differentials

Guidelines

Patient information

Calculadoras

Conectar-se ou assinar para acessar todo o BMJ Best Practice

Conectar-se ou assinar para acessar todo o BMJ Best Practice

Conectar-se para acessar todo o BMJ Best Practice