HelixTalk Episode #92 - Why You Should Stop Using (Ab)normal Saline: NS vs. LR for IV Fluids

Date posted: March 5, 2019, 6:00 am

In this episode, we discuss IV fluids for hospitalized patients, including normal saline (0.9% NaCl) and lactated ringer’s. In addition, we review the newest literature supporting the use of balanced crystalloids over normal saline from the SMART and SALT-ED trials.

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Key Concepts

1. There’s nothing normal about normal saline -- it contains too much chloride and is too acidic.  Even “standard” doses of normal saline produce electrolyte abnormalities and can be nephrotoxic compared to balanced crystalloids.
2. “Balanced” crystalloids are IV fluids that are matched to the pH and electrolyte concentrations of human plasma.  The most common balanced crystalloid is lactated ringer’s (LR), but many other products exist.
3. Largely due to its calcium content, lactated ringer’s has many IV incompatibilities that can be problematic in patients who have limited IV line access.
4. Lactated ringer’s does not worsen lactic acidosis and it does not cause hyperkalemia.

References

• Semler MW, Self WH, Wanderer JP, et al. Balanced Crystalloids versus Saline in Critically Ill Adults. N Engl J Med. 2018 Mar 1;378(9):829-839.
• Self WH, Semler MW, Wanderer JP, et al. Balanced Crystalloids versus Saline in Noncritically Ill Adults. N Engl J Med. 2018 Mar 1;378(9):819-828.