Saline solution is a remedy used in hospitals and the home. It cleans and treats wounds and body piercings. When used as a rinse, it eases sinus problems and toothache. Saline also stops dehydration in emergency hospital admissions when administered via a drip. Electrolytes within the salt solution help the body to hydrate faster. Different compositions of saline solution have a variety of uses from medicine to biological research. The disadvantages are that saline is not a disinfectant and if ingested in quantity, it could cause cancer.
Normal Saline Solution
Normal saline solution composition, known as 0.9 percent, is 9gm of non-iodized sodium chloride in one liter of sterile water at 22 degrees Centigrade. The origins of its medical use date from 1831 when the Blue Cholera Epidemic swept through Britain and Continental Europe when doctors treated dehydration by injecting patients with highly oxygenated salts. Years of research provided the optimal concentration of 0.9 percent. The addition of glucose or dextrose to the solution provides a nutrient for hospital patients.
Isotonic, Hypertonic and Hypotonic Solutions
The term isotonic means that the concentration of salts in the saline solution is equal or similar to that of body fluids. A hypertonic solution is one with a greater salt solution such as 1.8 percent. A hypotonic solution is one with a lower salt concentration such as 0.45 percent. A hypertonic solution helps to reduce swelling during surgery, but medical views differ about the relative qualities of isotonic and hypertonic concentrations. Hypotonic solutions with added sodium bicarbonate treat burn shock when administered orally.
Phosphate Buffered Solution
This is an isotonic, non-toxic saline solution containing additional sodium phosphate, potassium phosphate and potassium chloride. Its principal use in biological research where the compound maintains a constant pH, meaning a constant acidity or basicity of an experimental environment. This solution also has uses for cleaning experimental containers.
Lactated Ringer's Solution
Sodium lactate, a precursor in medical use to sodium bicarbonate, added to saline solution produces a product used to treat acute fluid losses. Administered subcutaneously, it relieves renal failure in small animals such as dogs. British physiologist Sidney Ringer invented the solution in the 19th century. American Pediatrician Alexis Hartmann modified it some years later.