From the Guidelines
Lactated Ringer's (LR) solution contains 4 mmol/L of potassium. This is based on the most recent and highest quality study available, which provides the composition of commonly used fluids, including LR 1. The key components of LR are:
- Sodium (Na+): 130 mmol/L
- Chloride (Cl-): 109 mmol/L
- Potassium (K+): 4 mmol/L
- Calcium (Ca2+): 1.4 mmol/L (although not directly stated in the table for LR, this value is mentioned for Hartmann’s, but according to other sources, LR typically contains 1.4-2.0 mmol/L of calcium)
- Lactate: 28 mmol/L (which is metabolized to bicarbonate in the liver) Considering the potassium level in LR, it is generally safe for most patients requiring intravenous fluid therapy, but caution should be exercised in patients with severe hyperkalemia, renal failure, or those receiving potassium-sparing medications, as they may require alternative fluids like normal saline to avoid additional potassium load. The provided evidence from the BMJ study 1 supports the use of LR as a balanced solution for fluid resuscitation, highlighting its composition and the potential considerations for its use in different patient populations.
From the Research
Potassium Content in Lactated Ringer's Solution
- The exact amount of potassium in Lactated Ringer's (LR) solution is not explicitly stated in the provided studies 2, 3.
- However, it is mentioned that LR inherently contains potassium, which has raised concerns about its potential to cause hyperkalemia, especially in patients with reduced kidney function 3.
- One study found that LR was associated with less hyperkalemia compared to normal saline in patients undergoing kidney transplantation, suggesting that the potassium content in LR may not be a significant concern in this context 2.
- Another study found that serum potassium prior to LR use was highly correlated and predictive of the serum potassium after LR use, and that LR use was not independently associated with the development of hyperkalemia in patients with reduced kidney function 3.
Hyperkalemia Risk
- The risk of hyperkalemia associated with LR use is a concern, particularly in patients with reduced kidney function 3.
- However, the studies suggest that this risk may be lower than previously thought, and that LR may be a safe choice for IV fluid therapy in certain patients 2, 3.
- Factors such as the amount of LR administered, medication, tube feeds, potassium supplements, and red blood cell transfusion may influence the risk of hyperkalemia, but the evidence is limited 3.