What is clinically significant hyponatremia?
What is clinically significant hyponatremia?
Hyponatremia—defined as a serum sodium concentration of less than 135 mEq/L—is a common and important electrolyte imbalance that can be seen in isolation or, as most often is the case, as a complication of other medical illnesses (eg, heart failure, liver failure, kidney failure, pneumonia).
What is the differential diagnosis for hyponatremia?
Differential Diagnosis and Treatment of Hyponatremia
| Condition | Diagnosis |
|---|---|
| Euvolemic hyponatremia | |
| 3,4-methylenedioxymeth-amphetamine (“Ecstasy”) use | Urine drug screen |
| Beer potomania syndrome | Excessive alcohol consumption, low serum osmolality |
| Exercise-associated hyponatremia | Clinical |
What cells are affected by hyponatremia?
It helps maintain normal blood pressure, supports the work of your nerves and muscles, and regulates your body’s fluid balance. A normal blood sodium level is between 135 and 145 milliequivalents per liter (mEq/L). Hyponatremia occurs when the sodium in your blood falls below 135 mEq/L.
What is the test for hyponatremia?
There are three essential laboratory tests in the evaluation of patients with hyponatremia that, together with the history and the physical examination, help to establish the primary underlying etiologic mechanism: urine osmolality, serum osmolality, and urinary sodium concentration.
How do you assess a patient with hyponatremia?
- Step 1: Plasma osmolarity.
- Step 2: Assess volume status with physical exam, urine sodium (UNa)
- Step 3: Urine osmolarity.
- Severe symptomatic hyponatremia.
- Asymptomatic or mildly symptomatic hyponatremia.
How do you assess volume status in hyponatremia?
Although volume status is difficult to assess with any accuracy at the bedside, a clinical assessment with attention to the patient’s history, heart rate, blood pressure, jugular venous pressure, the presence of pedal and sacral edema, the presence of a postural drop, and point-of-care ultrasound is usually adequate to …
Why does dehydration cause hyponatremia?
Inadequate volume (hypovolemic) hyponatremia The amount of water in the body is too low as can occur in dehydration. The anti-diuretic hormone is stimulated, causing the kidneys to make very concentrated urine and hold onto water.
How do you read hyponatremia labs?
A urine osmolality value of less than 100 mOsm/kg indicates complete and appropriate suppression of antidiuretic hormone secretion. A urine sodium level less than 20 mmol/L is indicative of hypovolemia, whereas a level greater than 40 mmol/L is suggestive of the syndrome of inappropriate antidiuretic hormone secretion.
What are the clinical manifestations of hyponatremia?
The clinical manifestations of hyponatremia are especially related to dysfunction of the central nervous system, and they are more dramatic when a marked decrease of serum [Na+] occurs acutely [7].
What is the difference between acute and chronic hyponatremic encephalopathy?
Hyponatremic encephalopathy is a well-known consequence of the brain swelling secondary to acute hyponatremia and is associated with an overall mortality of 34% [8]. Chronic hyponatremia is associated to adaptive responses counteracting swelling in brain cells and is traditionally defined as an asymptomatic or pauci-symptomatic condition [7,9].
What happens if sodium levels are low in diabetic ketoacidosis?
As the serum sodium falls to < 115 mEq/L (< 115 mmol/L), stupor, neuromuscular hyperexcitability, hyperreflexia, seizures, coma, and death can result.
How are renal causes of hypovolemic hyponatremia differentiated from extrarenal causes?
Renal causes of hypovolemic hyponatremia can usually be differentiated from extrarenal causes by the history. Patients with ongoing renal fluid losses can also be distinguished from patients with extrarenal fluid losses because the urine sodium concentration is inappropriately high ( > 20 mEq/L [> 20 mmol/L]).
