What fluid is premixed with potassium chloride (KCl) intravenous (IV) solution?

From the Guidelines

Potassium chloride (KCl) is typically premixed with 0.9% NaCl or 0.45% NaCl for intravenous administration, with the choice depending on the patient's hydration state and serum electrolyte levels, as guided by the management protocol for adult patients with diabetic ketoacidosis (DKA) 1. When considering the management of patients with DKA, the protocol outlines the importance of correcting estimated deficits within the first 24 hours, with the induced change in serum osmolality not exceeding 3 mOsm kg–1 H2O h–1 1.

• Key considerations for fluid replacement include:
  • The state of hydration
  • Serum electrolyte levels
  • Urinary output
  • Corrected serum sodium value In general, for adult patients, 0.45% NaCl infused at 4–14 ml kg–1 h–1 is appropriate if the corrected serum sodium is normal or elevated, while 0.9% NaCl at a similar rate is used if the corrected serum sodium is low 1.
• Once renal function is assured, the infusion should include 20–30 mEq/l potassium (2/3 KCl and 1/3 KPO4) until the patient is stable and can tolerate oral supplementation, as indicated in the protocol for managing DKA 1. It is crucial to monitor serum osmolality and frequently assess cardiac, renal, and mental status during fluid resuscitation to avoid iatrogenic fluid overload, especially in patients with renal or cardiac compromise 1.

From the FDA Drug Label

This Potassium Chloride Injection is a sterile, nonpyrogenic, highly concentrated, ready-to-use solution of Potassium Chloride, USP in Water for Injection, USP for electrolyte replenishment in a single dose container for intravenous administration. The fluid premixed with KCl IV is Water for Injection, USP 2.

• The solution contains Potassium Chloride, USP (KCl) in water.
• The osmolarity of the solution ranges from 200 to 799 mOsmol/L, depending on the concentration of KCl.
• The solution has a pH range of 5.8 (4.0 to 8.0) 2.

From the Research

Fluids Premixed with KCl IV

• The study 3 found that when KCl was added to IV fluid, the mixing was often incomplete, especially in flexible polyvinylchloride bags.
• In the study 4, it was observed that in instances where the prescription matched an available premixed IV KCl infusion, the premix was used on 89% of occasions.
• The types of IV fluids that can be premixed with KCl include:
  • Dextrose, 5 g/dl, in water 3
  • Lactated Ringer's solution 5
  • 0.9% NaCl 5
• The study 6 found that inadequate mixing of KCl supplementation in IV fluids can lead to potentially life-threatening concentrations of potassium.

Administration Practices

• The study 4 found significant variability in the prescribing and administration of IV KCl in Victorian hospitals.
• The use of premixed IV KCl infusions can help minimize the risk of incorrect dosing and improve patient safety 4.
• The study 6 highlights the importance of adequate mixing of KCl supplementation in IV fluids to ensure accurate concentrations of potassium.