Description
Ringer's solution was introduced in 1880 by Sidney Ringer, a British physician.The solution was designed to promote the contraction of isolated frog hearts and contained calcium and potassium in a sodium chloride solution. In the 1930s, an American paediatrician named Alex Hartmann proposed the addition of sodium lactate buffer to Ringer's solution for the treatment of metabolic acidosis.Lactated Ringer's solution is also known as Hartmann's solution.
1. Lactated Ringer's solution contains potassium and calcium in concentrations that approximate the free (ionic) concentration in plasma.
2. The addition of these cations requires a reduction in sodium concentration for electrical neutrality, so lactated Ringer's solution has less sodium than isotonic saline.
3. The addition of lactate (28 mEq/L) and a reduction in chloride concentration in lactated Ringer's more closely approximates plasma chloride levels than does isotonic saline.
Indications
1. Ringer's lactate can be used as a replacement fluid in burns and post-operative patients.
2. lt can be safely used for initial treatment of diarrhoea induced dehydration in paediatric patients. Hypovolaemia with hypokalaemic metabolic acidosis induced by diarrhoea is effectively treated with Ringer's lactate.
3. Sodium lactate in Ringer's lactate is metabolised in the liver to bicarbonate, making it useful in the correction of metabolic acidosis.
4. Ringer's lactate is very useful in many surgical conditions because it provides bicarbonate with all electrolytes.
5. Ringer's lactate corrects metabolic acidosis, provides dextrose free water with added advantage of supplying potassium.
6. lt can be used instead of isotonic saline during surgery or in the initial management of the injured or wounded patient.
Pharmacology
1. Ringer's lactate is the most physiological fluid.Larger amounts of Ringer's lactate can be infused rapidly without risk of electrolyte imbalance as its electrolyte content (i.e. Na, K, and Ca) is nearly similar to the free concentration in plasma.
2. Ringer's lactate has a high sodium concentration 130 mEq/litre, so it rapidly expands intravascular volume like isotonic saline.
Precautions
1. There will be formation of clots in the donor blood if Ringer's lactate is given with blood transfusion simultaneously.This is due to inactivation of the anticoagulant by binding with calcium present in Ringer's lactate.Therefore, simultaneous infusion of Ringer's lactate and blood product in same intravenous line is contraindicated.
2. Ringer's lactate does not have the colloid osmotic effect to replace plasma so it should not be given during severe blood loss as a plasma substitute.
3. Ringer's lactate is unsuitable for routine use as a sole intravenous fluid in the post-operative period due to high electrolyte content.
