Lactated Ringer's solution is a solution that is isotonic with blood and intended for intravenous administration. Veterinary administration may also be subcutaneous.

Lactated Ringer's solution is abbreviated as "LR" or "RL". It is also known as Ringer's lactate solution (although Ringer's solution technically refers only to the saline component, without lactate) or Hartmann's solution.

Ingredients

One liter of Lactated Ringer's Solution contains:

• 130 mEq of sodium ion.
• 109 mEq of chloride ion.
• 28 mEq of lactate.
• 4 mEq of potassium ion.
• 3 mEq of calcium ion.

Generally, the sodium, chloride, potassium and lactate come from NaCl (sodium chloride), NaC₃H₅O₃ (sodium lactate), CaCl₂ (calcium chloride), and KCl (potassium chloride).

Development of Ringer's Solution

Ringer's saline solution was invented by Sydney Ringer^*, a British physiologist who was born in 1835 in Norwich, England and died October 14, 1910, in Lastingham, Yorkshire, England.

Therapy

Lactated Ringer's Solution is often used for fluid resuscitation after a blood loss due to trauma, surgery, or a burn injury. It is also used to induce urination in patients with renal failure.

Lactated Ringer's Solution is used because the byproducts of lactate metabolism in the liver counteract acidosis, which is a chemical imbalance that occurs with acute fluid loss or renal failure.

The intravenous dose of Lactated Ringer's Solution is usually calculated by estimated fluid loss and presumed fluid deficit. For fluid resuscitation the usual rate of administration is 20 to 30 ml/kg body weight/hour. Ringer's lactate is not suitable for maintenance therapy because the sodium content (130 mEq/L)is considered too high, particularly for children, whereas the potasssium content (4 mEq/L) is too low, in view of electrolyte daily requirement.

The presumed fluid volume in a human body is greatest in infants and declines with age. Fluid volumes are smaller in females than males due to differences in average body fat. Total fluid accounts of 60% of body weight, 40% of the body weight is in the cells and 20% of the body weight is outside the cells. 5% of the body weight is made up of extracellular fluid inside the blood stream and 15% outside. As muscle holds much more water than fat tissue, total fluid volumes are greater in athletic individuals than in obese people of the same weight.

Other commonly used intravenous solutions include normal saline and hespan.

Intravenous fluids

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