Lactated ringer's solution is a type of isotonic fluid given to patients who require rehydration. The solution is made of mostly water but contains several dissolved compounds that make it easier for a patient to absorb the fluid. The solution is used in both human and veterinary medicine.
Different manufacturers may place slightly different amounts of each compound in lactated ringer's solution. Though the exact amounts differ, the solution always contains sodium chloride, potassium chloride, calcium chloride dihydrate, and sodium lactate. Sodium hydroxide and hydrochloric acid may also be added in order to keep the pH at around 6.6. Dextrose may be added to lactated ringer’s solution in order to give some nutrition to the patient receiving the fluids.
As an isotonic solution, lactated ringer's solution contains the same number of dissolved particles as the blood. The ratio of salts to fluid is equivalent to the ratio within the bloodstream so that the cells in the patient’s body will neither take on nor lose fluid. Solutions which contain more dissolved particles than the blood cause cells to lose water, while those with fewer cause cells to take on water. Isotonic solutions like this one maintain an equilibrium.
Lactated ringer's solution is given through intravenous (IV) drip. A needle is used to create an opening in a vein, through which the solution enters, and a bag containing the solution is attached to the needle by a plastic IV tube. The solution flows directly into the blood stream, where it quickly moves throughout the body. In veterinary medicine, and occasionally in human medicine, fluids can be given under the skin. They are absorbed into the bloodstream through the subcutaneous layer, though the absorption is not as rapid as it is when an IV is used.
It may be dangerous for patients with certain medical conditions to be given lactated ringer's solution. Patients who have liver conditions may be unable to process the lactate in the solution, while those with kidney problems can have a serious reaction to the potassium or sodium. Patients taking certain medications, including corticosteroids or medications that cause fluid retention should also avoid lactated ringer’s solution.