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Potassium Supplementation in IV Fluids

  • August 5, 2015 11:40 AM EDT

    Supplementing intravneous fluids with potassium (KCl) is common practice when managing hospitalized patients. Documented hypokalemia (serum potassium < 3.5 mEq/L) is certainly an indication for supplementing fluids with potassium. Patients with a variety of disease states can develop hypokalemia; Some of the common causes include:

    • Vomiting / Diarrhea
    • Fluid therapy / diuresis with IV fluids containing low levels of potassium or added glucose
    • Renal failure / Chronic renal disease
    • Hyperglycemia / Diabetic ketoacidosis / Insulin administration
    • Hypomagnesemia
    • Hypothermia

    Aside from disease states that can lead to depletion of potassium, the daily maintenance requirement of potassium is generally not met by commercially available isotonic crystalloid fluids (0.9% NaCl, 5% Dextrose, Lactated Ringer's, Plasma-Lyte 148, etc.).

    The amount of KCl (potassium chloride) supplemented to the IV crystalloid fluid of choice is usually based on a familiar "sliding scale" (dependent on the measured serum potassium of the patient). Undersupplementation can potentiate hypokalemia. Oversupplementation of fluids with KCl is also important to avoid, as this can lead to adverse (potentially fatal) cardiac effects. Caution is also exercised in patients with urinary tract obstruction and renal insufficiency, as clearance of potassium may be impaired. 

    This week's Evidence Based Update discusses the important findings of a study, recently published in the Journal of Veterinary Internal Medicine, that examined standard practices for adding KCl to bags of IV fluids, and the resulting accuracy of potassium levels in the bag (and available for delivery to the patient). These practices, which are commonly performed  by veterinarians or veterinary technicians, include:

    • handling of the injection port
    • injecting into the bag
    • bag position (while injecting into the bag)
    • handling of the bag after adding the KCl

    Important recommendations for veterinarians and veterinary technicians are summarized.

    View this Evidence Based Update - it's available for On Demand viewing (running time 10 mins; Approved for CE credit in New York and by the NJVMA, pending approval for CE credit by AAVSB RACE).