Ringer's lactate solution

Ringer's lactate solution (RL), also known as sodium lactate solution, Lactated Ringer's (LR), and Hartmann's solution, is a mixture of sodium chloride, sodium lactate, potassium chloride, and calcium chloride in water. It is used for replacing fluids and electrolytes in those who have low blood volume or low blood pressure. It may also be used to treat metabolic acidosis and to wash the eye following a chemical burn. It is given by intravenous infusion or applied to the affected area.

Side effects may include allergic reactions, high blood potassium, hypervolemia, and high blood calcium. It may not be suitable for mixing with certain medications and some recommend against use in the same infusion as a blood transfusion. Ringer's lactate solution has a lower rate of acidosis as compared with normal saline. Use is generally safe in pregnancy and breastfeeding. Ringer's lactate solution is in the crystalloid family of medications. It is isotonic, i.e. it has the same tonicity as blood.

Ringer's solution was invented in the 1880s; lactate was added in the 1930s. It is on the World Health Organization's List of Essential Medicines. Lactated Ringer's is available as a generic medication. For people with liver dysfunction, Ringer's acetate may be a better alternative with the lactate replaced by acetate. In Scandinavia, Ringer's acetate is typically used.

Ringer's lactate solution is commonly used for fluid resuscitation after blood loss due to trauma or surgery.

It is extensively used in aggressive volume resuscitation, e.g. for patients with pancreatitis, hemorrhagic shock or major burn injuries. Since the lactate is converted into bicarbonate, caution should be used as patients may become alkalotic. In acidotic states, such as in acute kidney failure, Ringer's lactate solution may be advantageous as the byproducts of lactate metabolism in the liver counteract the acidosis. In a large-volume resuscitation over several hours, Ringer's lactate solution maintains a more stable blood pH than normal saline.

Ringer's lactate and other crystalloid fluids are also used as vehicles for the intravenous (IV) delivery of medications.

One liter of Ringer's lactate solution contains:

Ringer's lactate has an osmolarity of 273 mOsm L⁻¹ and a pH of 6.5. The lactate is metabolized into bicarbonate by the liver, which can help correct metabolic acidosis. Ringer's lactate solution alkalinizes via its consumption in the citric acid cycle, the generation of a molecule of carbon dioxide which is then excreted by the lungs. They increase the strong ion difference in solution, leading to proton consumption and an overall alkalinizing effect.