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Lactated Ringers And Normosol In Hyperkalemia

As an intensivist and anesthesiologist, I spend considerable time pondering the physiology and evidence for practices and questioning dogma rampant in the ICU/OR settings. I’ve heard one recurrent theme: the fear of using Lactated Ringers (LR) and Normosol in patients with renal impairment. Why? Because they both contain potassium (K+), and patients with renal impairment not only tend to be hyperkalemic and acidotic but have difficulty in clearing potassium.

LR and Normosol have 4 mEq/L and 5 mEq/L, respectively, of potassium. In the context of acidosis, H+/K+ channels exchange protons for potassium, thereby increasing serum potassium. Additionally, potassium equilibrates between the intracellular AND extracellular compartments (high volume of distribution). Therefore, you can’t just “add” the potassium from intravenous fluids to the patient’s baseline serum concentration.

In reality, infusing a solution with less potassium than the patient will actually DECREASE the serum concentration to that of the infused solution – couple this with the fact that LR and Normosol are both alkalinizing solutions. Thus, the acidosis is offset, shifting the H+/K+ ATPase channel back in the opposite direction (more potassium shifted intracellularly, thereby DECREASING serum concentration). Also, don’t forget that NS can potentially complicate matters with a superimposed non-anion gap, hyperchloremic metabolic ACIDOSIS due to the chloride load.

Finally, several prospective RCTs in renal transplantation looked at potassium changes with LR versus NS administration. Surprise! Patients who received NS had a greater increase in potassium and often a lower serum pH. Admittedly, the intraoperative administration of fluid is somewhat different than maintenance fluid/boluses, but it sure makes you feel reassured that LR is safe in patients with renal impairment.

Drop me a comment below with questions! 🙂

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6 Comments

  1. Thank you so much all these days I was thinking Ns is the best option and preferred less LR over Ns and this information has really helped me in choices I make.

  2. This is incredibly helpful. It makes me want to start using LR for aggressive resuscitation in my DKA’s. My attending tends to use NS. I feel like LR is very underused.

    1. In the course of treating DKA, at some point, you’ll need to supplement some potassium anyways. Might as well not compound their anion gap metabolic acidosis with a non-anion gap acidosis too from liters of not-so-normal saline!

  3. Thanks for this post! As a nurse who follows you, your posts like this that relate to more than just critical care or OR really help me understand how the simple day to day treatments I’m administering on the floor work. Questions are the best way to learn anything in medicine, eye-roll or not ????

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