From the Guidelines
Lactated Ringer's (LR) is generally preferred over Normal Saline (0.9% NaCl) for most fluid resuscitation scenarios, particularly in large volume resuscitation, as it more closely mimics human plasma composition and has a lower risk of causing hyperchloremic metabolic acidosis 1. When considering the choice between Normal Saline and Lactated Ringer's, several factors come into play.
- Normal Saline is preferred for patients with severe metabolic alkalosis, hyperkalemia, or those receiving blood transfusions, as the calcium in LR can cause clotting 1.
- Normal Saline is also better for patients with traumatic brain injury or at risk for cerebral edema, as it has a slightly higher osmolarity 1.
- Lactated Ringer's is better for patients with metabolic acidosis (including diabetic ketoacidosis after initial resuscitation), renal failure, or liver disease, as it has a balanced electrolyte composition and lower chloride content, making it less likely to cause acid-base disturbances 1.
- For routine maintenance fluids in stable patients, either solution can be appropriate, though many clinicians now favor balanced crystalloids like LR for most situations 1. The choice ultimately depends on the patient's specific clinical condition, underlying electrolyte abnormalities, and the purpose of fluid administration.
- A recent study found that balanced solutions, such as LR, may have a favorable effect on renal function and survival in patients receiving high volumes of fluid resuscitation 1.
- Another study suggested that LR may be associated with lower perioperative blood transfusion requirements in patients at high haemorrhagic risk 1. Overall, the decision to use Normal Saline or Lactated Ringer's should be based on the individual patient's needs and the specific clinical scenario, with a preference for balanced crystalloids like LR in most cases 1.
From the Research
Normal Saline vs Lactated Ringer's
- Normal saline is often used in clinical practice, but it can lead to hyperchloremic metabolic acidosis and renal vasoconstriction 2.
- Lactated Ringer's is a balanced solution that can be used as an alternative to normal saline, but it should not be given to patients with severe metabolic alkalosis, lactic acidosis, or severe hyperkalemia 2.
- In patients with diabetic ketoacidosis (DKA), lactated Ringer's has been shown to be associated with faster resolution of high anion gap metabolic acidosis compared to normal saline 3, 4.
- A study comparing lactated Ringer's to normal saline in patients undergoing renal transplantation found that lactated Ringer's was associated with less hyperkalemia and metabolic acidosis 5.
- The use of lactated Ringer's in patients with reduced kidney function has been evaluated, and it was found that lactated Ringer's was not independently associated with the development of hyperkalemia 6.
- The choice between normal saline and lactated Ringer's should be guided by the cause of hypovolemia, cardiovascular state, renal function, and coexisting acid-base and electrolyte disorders 2.
Specific Situations
- In patients with DKA, lactated Ringer's may be preferred over normal saline due to its ability to resolve high anion gap metabolic acidosis faster 3, 4.
- In patients with reduced kidney function, lactated Ringer's can be used safely without increasing the risk of hyperkalemia 6.
- In patients undergoing renal transplantation, lactated Ringer's may be a better choice than normal saline due to its association with less hyperkalemia and metabolic acidosis 5.