Lactated Ringer's solution
From Wikipedia, the free encyclopedia
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). It is very similar, though not identical to, Hartmann's (Compound Sodium Lactate) Solution, the ionic concentrations of which differ.
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).
[edit] Development of Ringer's Solution
Ringer's saline solution was invented by Sydney Ringer[1], a British physiologist. The solution was further modified by Alexis Hartmann, an american MD of German background with an interest in paediatrics who lived from 1898 to 1964, for the purpose of treating acidosis in children. Hartmann modified the solution by adding lactate, which while undergoing reactions in liver, kidney and muscle cells to either produce glucose or be metabolised to water and carbon dioxide, consumes H+ ions thus acting as a base. Thus the solution became known as 'Lactated Ringer's Solution' and later, 'Hartmann's solution' [2]
[edit] 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 potassium 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 for 60% of male body weight (50% in female); 2/3 of that fluid (40% of the body weight) is in the cells and 1/3 (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.
