Atomic Number:	11
Atomic Symbol:	Na
Atomic Weight:	22.98977
Electron Configuration:	[Ne]3s1

About 30% of total body sodium is tightly bound in bone, and the remaining portion is located in the extracellular fluid with only 2 - 3% in intracellular sites. The amount of sodium is a reflection of the dietary intake, and the output is through the gastrointestinal tract, the skin and the urine. It is the most important extracellular osmotically active solute, required for acid?base, and water balance.

Hypernatremia occurs from loss of water (dehydration) or from sodium retention (infusion of hypertonic saline or ingestion). Sodium retention may cause an increase in extracellular water retention in tissues (edema). Hyponatremia occurs with nephrotic syndrome, mineralcorticoid deficiency and cystic fibrosis. Diuretics may cause hyponatremia. Levels below 115 mmol/L can lead to significant neurological dysfunction, cerebral edema and increased intra cranial pressure. Situations may result in "pseudohyponatremia" such as sodium dilution due to high triglycerides or proteins in the blood. The use of serum osmolality is determined and will be normal in these cases. In these circumstances, treatment would be undesirable.
Sodium (hair)?Hair sodium generally do not reflect dietary status, but very high levels may be diagnostic in cystic fibrosis (Pediatrics 1972;49:620). Retention of sodium in hair tissue may be caused by disturbances in renal function and electrolyte balance. Chronic stress syndrome can result in depressed hair sodium as a result of inadequate renal response to adrenal hormones.

Sample Requirements (click on cell)
 

Hair

Reference range
 
 

Analyte Sodium
Random Urine	24 Hr Urine	Hair
40 - 200 mmol/L	40 - 217 mmol/d	0.22 - 2.83 umol/g

 

Method of Analysis:  High Resolution ICP/MS

Test available:  Monday - Friday 0800 - 1600 h
Turnaround Time:  Average 5-10 days
Maximum 10 days

March 27, 2008