The review for the determination of main extracellular cation (sodium, Na), himself a good indicator of body hydration.
For example, in cases of diarrhea and chronic vomiting, especially in a fragile patient as a person, the dosage of serum sodium becomes important.
The stability of serum sodium is essential for a good cellular and extracellular internal balance.
It is that of blood electrolytes. Sampling 5 mL of venous blood on heparin tube:
– Quickly send to the laboratory;
– Reduce to a minimum the time of the withers;
– Do not make a fist;
– Absolutely avoid hemolysis.
of 138-145 mEq / L, which represents 95% of osmolality (see ‘chemistry panel “).
– Hyponatremia rate below 136 mEq / L: sodées observed in case of urinary or digestive losses, regular use of diuretics, vomiting and / or repeated diarrhea, nephrotic syndrome, heart failure, cirrhosis:
– Up to 130 mEq / L: no neurological consequences
– Less than 130 mEq / L: onset of digestive and neurological disorders (headache, disorientation, convulsions, coma)
– Less than 110 mEq / L: coma may be irreversible;
– Hypernatremia, rate higher than 144 mEq / L: water loss is greater than the loss of salt, much rarer than hyponatremia; this is the case, for example, of a person who lost the notion of thirst and with dehydration.
Of pseudohyponatrémies may be due to hyperprotidémies, hyperlipemia, hyperglycemia, even to excess Dextran, gelatin.
We must look all medications used to assess the dosage to its fair value.
If in doubt, a urinary electrolytes can be helpful.