What is the comparison between Lactated Ringer's (LR) solution and 0.9% Sodium Chloride (Normal Saline) solution for use in Emergency Medical Services (EMS)?

From the Guidelines

For EMS use, Lactated Ringer's solution is generally preferred over 0.9% Normal Saline for most fluid resuscitation needs, particularly in cases of haemorrhagic shock, due to its balanced electrolyte composition and lower risk of causing metabolic acidosis. The choice between Lactated Ringer's and 0.9% Normal Saline for fluid resuscitation in EMS settings is crucial, and recent studies support the use of balanced solutions like Lactated Ringer's over non-balanced solutions like 0.9% NaCl, especially in high-volume resuscitation scenarios 1. Some key points to consider include:

• Lactated Ringer's has a balanced electrolyte composition that more closely resembles human plasma, reducing the risk of metabolic acidosis during large-volume resuscitation 1.
• The lactate in Lactated Ringer's is metabolized to bicarbonate, helping buffer acidosis that often accompanies trauma and shock.
• Normal Saline, on the other hand, contains only sodium and chloride, which can lead to hyperchloremic acidosis when administered in large volumes.
• While some studies have reported no difference in mortality or acute renal failure between balanced and non-balanced solutions, these studies often involved lower volumes of fluid administration than those typically used in haemorrhagic shock resuscitation 1.
• The SMART study, which included 15,802 ICU patients, found a reduced incidence of major adverse kidney events in patients receiving balanced solutions like Lactated Ringer's compared to 0.9% NaCl 1.
• However, it's essential to note that Normal Saline may still be preferred in specific situations, such as hyponatremia, diabetic ketoacidosis, or when administering blood products, due to the potential for calcium in Lactated Ringer's to promote clotting. In terms of administration rates, EMS providers should follow local protocols, which may specify fluid choice based on available resources and regional practices, and typically range from maintenance rates of 100-150 mL/hr to boluses of 500-1000 mL for hypotensive patients.

From the Research

Comparison of Lactated Ringer's and Saline 0.9% for EMS

• Lactated Ringer's solution has been compared to normal saline (0.9% saline) in various studies to assess its effectiveness in different medical scenarios.
• A study published in 2025 2 found that initial fluid resuscitation with lactated Ringer's solution, compared to 0.9% saline, might be associated with improved survival in patients with sepsis-induced hypotension.
• Another study from 2023 3 demonstrated an association between the use of lactated Ringer's as initial resuscitation fluid and reduced 1-year mortality in patients hospitalized with acute pancreatitis.
• However, a 2019 study 4 found no difference in quality of recovery between patients receiving lactated Ringer's solution and those receiving normal saline solution in a stable emergency department setting.
• A 2024 study 5 compared plasma-lyte to lactated Ringer's in surgical intensive care unit trauma patients and found that plasma-lyte use was associated with prolonged hospital and SICU length of stay, but no difference in mortality.
• Additionally, a 2022 study 6 evaluated the effect of lactated Ringer's solution on serum potassium in patients with reduced kidney function and found that lactated Ringer's use was not independently associated with the development of hyperkalemia.

Key Findings

• Lactated Ringer's solution may be associated with improved survival in patients with sepsis-induced hypotension 2 and reduced 1-year mortality in patients with acute pancreatitis 3.
• However, the choice of fluid may not affect quality of recovery in stable emergency department patients 4.
• The use of lactated Ringer's solution does not appear to increase the risk of hyperkalemia in patients with reduced kidney function 6.

Considerations for EMS

• The choice of fluid for resuscitation may depend on the specific medical scenario and patient population.
• Lactated Ringer's solution may be a suitable choice for patients with sepsis-induced hypotension or acute pancreatitis, but normal saline may be acceptable in other situations.
• Further research is needed to fully understand the benefits and risks of different fluid choices in various medical scenarios.