Theis Samuel R., Bhutta Beenish S., Khandhar Paras B.
Wright-Patterson AFB
Sheikh Zayed Hospital, Lahore
Pseudohyponatremia is a rare laboratory abnormality characterized by a serum sodium concentration below 135 mEq/L in the setting of a normal serum osmolality (280 to 300 mOsm/kg). Conversely, true hyponatremia is associated with low serum osmolality and necessitates prompt evaluation for additional abnormal solutes affecting the laboratory assessment. Pseudohyponatremia is an artifact resulting from blood sample processing for sodium measurement, and failure to promptly recognize this can lead to severe complications. Osmotically active solutes such as mannitol or hyperglycemia can contribute to pseudohyponatremia, but a severe elevation of cholesterol stands out as the primary cause. Identifying pseudohyponatremia based on false laboratory analysis is preferred. Due to the hyperosmolality and resultant fluid shifts invoked by the presence of osmotically active solutes, the serum sodium, as reported by laboratory assessment in some cases, is truly low. For this reason, one should not include hyperosmolar hyponatremia as a potential classification of pseudohyponatremia. Accurate interpretation of serum sodium values is essential for distinguishing pseudohyponatremia from other forms of hyponatremia, such as hyponatremia and hyperosmolar hyponatremia. Management primarily involves accurately interpreting serum sodium values and addressing the underlying condition responsible for elevated cholesterol levels, which may necessitate consultation with a nephrologist for proper differentiation.
假性低钠血症是一种罕见的实验室异常情况，其特征为在血清渗透压正常（280至300 mOsm/kg）的情况下血清钠浓度低于135 mEq/L。相反，真性低钠血症与血清渗透压降低相关，需要迅速评估是否存在影响实验室检测结果的其他异常溶质。假性低钠血症是血样处理用于测量钠时产生的一种假象，未能及时识别这一点可能导致严重并发症。诸如甘露醇或高血糖等具有渗透活性的溶质可导致假性低钠血症，但严重的胆固醇升高是主要原因。基于错误的实验室分析来识别假性低钠血症是可取的。由于具有渗透活性的溶质的存在引起高渗性及由此导致的液体转移，在某些情况下实验室检测报告的血清钠实际上是低的。因此，不应将高渗性低钠血症列为假性低钠血症的一种潜在分类。准确解读血清钠值对于区分假性低钠血症与其他形式的低钠血症（如低钠血症和高渗性低钠血症）至关重要。治疗主要包括准确解读血清钠值并处理导致胆固醇水平升高的潜在疾病，这可能需要咨询肾病科医生以进行正确鉴别。
