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Hypernatremia and hyponatremia
Hypernatremia and hyponatremia are among the most common electrolyte disorders in older people. Hypernatremia is caused by an increase in the concentration of the sodium in extracellular serum to more than 145 mEq per L. On the other hand, hyponatremia is caused by a decrease in the concentration of sodium in body, i.e. less than 135 mEq per L. Hyponatremia can be acute or chronic (Buttaro, 2013). Both hypernatremia and hyponatremia are commonly found clinical problems in critically ill patients. They are often asymptomatic, but in some patients their symptoms appear that can result in different problems ranging from minor to life-threatening problems (Vincent, Abraham, Kochanek, Moore, & Fink, 2011).
Signs and Symptoms
The signs and symptoms of hypernatremia may not appear until the sodium level in serum is increased from 150 mEq per L (Buttaro, 2013). Symptoms in hypernatremia are strongly dependent on the rapidity of the progress and development of the problem (Lindner & Funk, 2013). Some of the early signs of hypernatremia are irritability, confusion, agitation, and changes in personality. Moreover, tremor, muscle twitching, hyperreflexia, spasticity, and lethargy may also appear. In the later stages of hypernatremia, muscle weakness, seizures, and coma can also appear (Buttaro, 2013).
In hyponatremia, the signs and symptoms of the patients are often subtle, and the symptoms may not appear until the sodium level falls below 120 mEq/L. However, hyponatremia can be considered, when individual shows irritability, restlessness, history of falls, disturbed functioning of central nervous system, weight-changes, or unusual water drinking behavior. If sodium level falls below 110 mEq/L, the patient may face psychosis, seizures, and coma (Buttaro, 2013).
Potential causes of the disorder
Hypernatremia is related to a decrease in fluid volume intake. It is also caused by an excessive intake of sodium, or due to chronic kidney disorder (Buttaro, 2013). Muhsin & Mount (2016) noted that human body has an ability to maintain normal osmolality within the range of 280 to 295 mOsm per kg with the help of Arginine Vasopressin (AVP), thirst, and the renal response to AVP; disturbances of these three factors can result in hypernatremia. In non-hospital settings, hypernatremia can also be caused by free water losses from non-renal sites (Muhsin & Mount , 2016).
On the other hand, hyponatremia is commonly associated with exercise. It is also caused by traumatic brain injuries, unwanted medication effects, malignant diseases, endocrine disorders, AIDS, and other disorders such as hyperglycemia, and adrenal insufficiency. Acute hyponatremia usually develops in hospitalized patients after going through the surgical procedure, and is often related to the fluid overload; whereas, chronic hyponatremia occurs outside the hospital, and is usually associated with less serious neurologic sequelae (Buttaro, 2013).
Impact of the disorder on the patients and their body systems
Hypernatremia, if left untreated, can result in cerebrovascular damage due to brain dehydration as well as shrinkage. Significant cognitive dysfunction can occur in patients, who are not treated carefully (Buttaro, 2013). It has been reported that hypernatremic patients have dramatically increased mortality rates as compared to normonatremic controls. Mortality rates can be increased in case of even slightly elevated serum sodium levels, especially in critically ill patients (Lindner & Funk, 2013).
In case of hyponatremia, a patient may experience headache, lethargy, dizziness, blurred vision, osteoporosis, weakness, falls, muscle cramps, and fatigue. Brain damage and death could also occur in severe cases of hyponatremia that is not treated appropriately (Adams, de Jonge, van der Cammen, Zietse, & Hoorn, 2011; Buttaro, 2013).
References
Adams, D., de Jonge, R., van der Cammen, T., Zietse, R., & Hoorn, E. J. (2011). Acute kidney injury in patients presenting with hyponatremia. Journal of nephrology, 24(6), 749.
Buttaro, T. M. (2013). Primary Care: A Collaborative Practice: Elsevier/Mosby.
Lindner, G., & Funk, G.-C. (2013). Hypernatremia in critically ill patients. Journal of critical care, 28(2), 216. e211-216. e220.
Muhsin, S. A., & Mount, D. B. (2016). Diagnosis and treatment of hypernatremia. Best Practice & Research Clinical Endocrinology & Metabolism, 30(2), 189-203.
Vincent, J. L., Abraham, E., Kochanek, P., Moore, F. A., & Fink, M. P. (2011). Textbook of Critical Care: Elsevier Health Sciences.
