Saline (medicine)

The isotonic saline solution is an iso-osmotic solution to the blood plasma of common salt ( sodium chloride ) in water. Containing 9 g of sodium chloride per liter ( 9 g / l ) and has an osmolarity of 308 mosmol / l. The isotonic saline solution is reasonably priced and the most widely used solution for infusion.

Composition

The term " saline solution " should not be used because, although the osmolarity is physiological and not the concentration of sodium and chloride ions. Both ions are concentrated with 154 mmol / l significantly higher than in human serum ( serum sodium: 135-145 mmol / l serum chloride: 98-109 mmol / l). This imbalance is necessary as the osmotic action of the other ingredients contained in the human blood (such as other electrolytes, other ingredients such as proteins) must be considered.

As a solution for the medical application of the sterile and pyrogen-free isotonic saline in containers ( plastic or glass vials or bottles and plastic bags ) is from two to 30,000 ml ( veterinary medicine ) are available.

Application

The isotonic saline solution is used as a carrier solution for medication or for holding open of a venous access in patients. Furthermore, the solution is also used to flush catheters and wounds, nose or eyes.

With infusion of electrolyte solution, there is no significant fluid shifts between the intracellular and extracellular space due to the osmolarity. The overload of the body of sodium and chloride ions resulting in an inhibition of the renin -angiotensin -aldosterone system and to a stimulation of ANFs. The absence of other electrolytes in blood plasma, especially bicarbonate may lead to a dilution acidosis. There are, for these reasons only a few indications, use isotonic saline solutions for fluid therapy, standing there with balanced electrolyte solutions are better alternatives available.