From the Research
Normal saline IV fluid can indeed cause a rise in lactic acid levels in certain circumstances, particularly when administered in large volumes, and clinicians should consider using balanced crystalloid solutions like Lactated Ringer's as alternatives to minimize this risk. This occurs primarily through two mechanisms. First, normal saline (0.9% NaCl) has a high chloride content which can lead to hyperchloremic metabolic acidosis when administered in large volumes, as seen in a study comparing Lactated Ringer's to normal saline in the management of acute diabetic ketoacidosis 1. This acidosis can impair cellular metabolism and result in increased lactate production. Second, the acidosis from normal saline can reduce renal blood flow and glomerular filtration rate, potentially causing tissue hypoperfusion that leads to anaerobic metabolism and lactate production.
The most recent and highest quality study on this topic, published in 2024, found that Lactated Ringer's was associated with faster time to high anion gap metabolic acidosis resolution compared to normal saline in patients with diabetic ketoacidosis 1. Another study published in 2022 also found that balanced crystalloid solutions like Lactated Ringer's may be preferable alternatives to normal saline for fluid resuscitation in diabetic ketoacidosis, as they can reduce the incidence of iatrogenic hyperchloremia and support renal recovery 2.
Some key points to consider when using normal saline IV fluid include:
- The risk of hyperchloremic metabolic acidosis and increased lactate production is higher with large volume infusions, typically exceeding 2-3 liters
- Critically ill patients or those with compromised renal or hepatic function are more susceptible to these effects
- Balanced crystalloid solutions like Lactated Ringer's or Plasma-Lyte may be preferable alternatives for patients requiring large volume resuscitation
- Clinicians should monitor lactate levels in patients receiving large volumes of normal saline, especially in critical care settings, and consider switching to balanced solutions if metabolic acidosis develops, as suggested by a study comparing the efficacy of Lactated Ringer's versus normal saline in treating patients with septic shock 3.
Overall, while normal saline IV fluid can cause a rise in lactic acid levels in certain circumstances, the use of balanced crystalloid solutions like Lactated Ringer's can help minimize this risk and support better patient outcomes, as supported by the most recent and highest quality studies on this topic 1, 2.