Abstract：
Hyponatremia is a multifactorial disorder defined as a decrease in plasma sodium concentration. Its differential diagnosis requires an adequate evaluation of the extracellular volume (ECV). However, ECV determination, simply based on the clinical history, vital signs, physical examination, and laboratory findings can leads to misdiagnosis and inappropriate treatment. The use of Point-of-Care Ultrasound (POCUS), through the combination of Lung Ultrasound (LUS), Venous Excess UltraSound (VExUS) and Focused Cardiac Ultrasound (FoCUS), allows a much more accurate holistic assessment of the patient\'s ECV status in combination with the other parameters.
摘要：
低钠血症是一种多因素疾病，定义为血浆钠浓度降低。其鉴别诊断需要对细胞外体积（ECV）进行充分评估。然而,ECV测定,仅仅根据临床病史，生命体征,体检,和实验室检查结果可能导致误诊和不当治疗。点护理超声（POCUS）的使用，通过肺部超声（LUS）的组合，静脉超量超声（VExUS）和聚焦心脏超声（FoCUS），结合其他参数，可以对患者的ECV状态进行更准确的整体评估。
