When is it appropriate to use Ringer's (Ringer's lactate solution) lactate solution instead of normal saline (sodium chloride 0.9%) solution?

From the Guidelines

Ringer's lactate solution is preferred over normal saline in situations where a more physiologically balanced fluid is needed, particularly in cases of significant fluid loss or when there's a risk of metabolic acidosis, as it reduces the risk of hyperchloremic metabolic acidosis and has a composition closer to human plasma 1. The key advantage of Ringer's lactate is its composition, which more closely mimics human plasma, containing lactate that the liver converts to bicarbonate, helping to correct metabolic acidosis, and having a lower chloride content compared to normal saline, reducing the risk of hyperchloremic metabolic acidosis that can occur with large volume infusions of normal saline. Specific scenarios where Ringer's lactate is preferred include:

• Trauma with significant blood loss
• Major surgeries, especially those involving large fluid shifts
• Severe burns, as supported by a study published in Anaesthesia in 2020, which proposed Ringer's Lactate solution as the first-line balanced fluid resuscitation solution for burns victims 1
• Diabetic ketoacidosis (after initial volume resuscitation)
• Sepsis However, Ringer's lactate should be used with caution or avoided in patients with severe liver dysfunction (as they may not effectively metabolize lactate), hyperkalemia (due to its potassium content), or severe metabolic alkalosis, and it's also not ideal for patients with increased intracranial pressure due to its slightly hypotonic nature compared to plasma. In practice, the choice between Ringer's lactate and normal saline often depends on the specific clinical context, the patient's underlying conditions, and the goals of fluid therapy, with a recent study published in Anaesthesia in 2022 suggesting that balanced solutions like Ringer's lactate may be preferred over normal saline in cases of haemorrhagic shock due to their potentially deleterious effects on renal function and survival 1.

From the FDA Drug Label

These products are sterile, nonpyrogenic solutions each containing isotonic concentrations of electrolytes (with or without dextrose) in water for injection. The solutions containing dextrose and electrolytes are hypertonic; those containing only electrolytes are isotonic They are administered by intravenous infusion for parenteral replacement of extracellular losses of fluid and electrolytes, with or without minimal carbohydrate calories. Solutions containing calcium ions should not be administered simultaneously through the same administration set as blood because of the likelihood of coagulation. Solutions which contain potassium should be used with great care, if at all, in patients with hyperkalemia, severe renal failure and in conditions in which potassium retention is present Solutions containing sodium ions should be used with great care, if at all, in patients with congestive heart failure, severe renal insufficiency and in clinical states in which there exists edema with sodium retention. Solutions containing lactate ions should be used with great care in patients with metabolic or respiratory alkalosis.

Key Considerations:

• Use Ringer's lactate solution instead of normal saline in patients who require isotonic fluid and electrolyte replacement, particularly when there are significant extracellular losses of fluid and electrolytes.
• Consider using Ringer's lactate solution in patients who require lactate ions, but use with caution in patients with metabolic or respiratory alkalosis or severe hepatic insufficiency.
• Avoid using Ringer's lactate solution in patients with hyperkalemia, severe renal failure, or congestive heart failure, as it contains potassium and sodium ions.
• Always use Ringer's lactate solution with caution and monitor patients closely for signs of fluid and/or solute overloading, particularly in patients with diminished renal function 2 2.

From the Research

Appropriate Use of Ringer's Lactate Solution

Ringer's lactate solution may be preferred over normal saline in certain situations, including:

• Uncontrolled hemorrhagic shock, as it has been shown to require significantly less volume and is associated with less hyperchloremic acidosis and dilutional coagulopathy 3
• Acute diabetic ketoacidosis, as it is associated with faster resolution of high anion gap metabolic acidosis 4
• Acute pancreatitis, as it may have a potential advantage in decreasing the incidence of pancreatic necrosis and intensive care unit admission 5
• Septic shock, as it can lower blood transfusion requirement and total liquid dosage, and is associated with lower incidences of hyperlactacidemia and hyperchloremia 6

Situations Where Normal Saline May Be Preferred

Normal saline may be preferred over Ringer's lactate solution in certain situations, including:

• Traumatic brain injury, as lactated Ringer's has been associated with higher adjusted mortality compared to normal saline 7

Key Considerations

When deciding between Ringer's lactate solution and normal saline, it is essential to consider the specific clinical context and the potential benefits and drawbacks of each fluid. The choice of fluid should be based on the individual patient's needs and the underlying condition being treated.