Friday June 29, 2007
Difference between Lactate Ringer's and Normal Saline solutions

Lactated Ringer's Solution was invented about 125 years ago by a British physiologist Sydney Ringer and never lost a day in its popularity. Let see its difference from normal saline.

Normal Saline is the solution of 0.9% NaCl. It has a slightly higher degree of osmolality compared to blood. One litre of Normal Saline contains

154 mEq/L of Na+ and
154 mEq/L of Cl−

Lactated Ringer's (per litre) Solution contains:

130 mEq/L of Na+ but total cations of 137 mEq/L , so still is isotonic.
109 mEq/L of Cl−
28 mEq/L of lactate
4 mEq/L of potassium
3 mEq/L of calcium.

Lactate converts to bicarbonate in liver.

Bonus Pearl: Patients with lactic acidosis usually have inadequate liver metabolism of lactate so conversion to HCO3- from the infused lactate of LR is impaired and may give false readings of serial lactate measurements but may be a better choice in regular situations where hyperchloremia restricts use of normal saline.