What is the recommended infusion rate for potassium (K+)?

From the Guidelines

Potassium should be infused at a rate that includes 20 –30 mEq/l potassium (2/3 KCl and 1/3 KPO4) until the patient is stable and can tolerate oral supplementation, as stated in the management protocol for adult patients with DKA 1.

Key Considerations for Potassium Infusion

• The infusion rate of potassium should be carefully managed to avoid complications, particularly in patients with renal or cardiac compromise.
• Monitoring of serum osmolality and frequent assessment of cardiac, renal, and mental status must be performed during fluid resuscitation to avoid iatrogenic fluid overload 1.
• The concentration and rate of potassium infusion should be adjusted based on the patient's serum potassium levels, renal function, and clinical status.
• 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, and 0.9% NaCl at a similar rate is appropriate if corrected serum sodium is low 1.
• For pediatric patients, the initial fluid therapy is directed toward expansion of the intravascular and extravascular volume and restoration of renal perfusion, with careful monitoring to avoid cerebral edema 1.

Monitoring and Adjustments

• Serum potassium levels should be monitored regularly to adjust the infusion rate as needed.
• Clinical examination and hemodynamic monitoring should be used to assess the patient's response to fluid replacement and potassium infusion 1.
• The infusion should be adjusted to correct estimated deficits within the first 24 h, with careful monitoring to avoid excessive changes in serum osmolality 1.

From the FDA Drug Label

The recommended infusion rate for administration through a peripheral venous catheter is approximately phosphorus 6. 8 mmol/hour (potassium 10 mEq/hour). Recommended administration rates should not usually exceed 10 mEq/hour or 200 mEq for a 24-hour period if the serum potassium level is greater than 2. 5 mEq/liter In urgent cases where the serum potassium level is less than 2 mEq/liter or where severe hypokalemia is a threat (serum potassium level less than 2 mEq/liter and electrocardiographic changes and/or muscle paralysis), rates up to 40 mEq/hour or 400 mEq over a 24-hour period can be administered very carefully when guided by continuous monitoring of the EKG and frequent serum K+ determinations to avoid hyperkalemia and cardiac arrest.

The infusion rate of potassium should not exceed 10 mEq/hour for routine administration, but can be increased to 40 mEq/hour in urgent cases with close monitoring 2 3. Continuous ECG monitoring is recommended for higher infusion rates.

From the Research

Infusion Rates for Potassium

• The infusion rate of intravenous potassium therapy depends on the salt used and the severity of the hypokalemia 4.
• Potassium chloride is usually infused at a rate up to 40 mmol/h 4.
• Potassium acetate and potassium monohydrogen or dihydrogen phosphate are usually infused up to 5 mmol/h and 2 mmol/h respectively 4.
• The choice of potassium salt is often guided by the presence of associated electrolyte imbalances, such as hypochloraemic alkalosis, non-anion gap acidosis, or hypophosphataemia 4.

Considerations for Infusion

• Intravenous potassium therapy is usually required for patients with severe or symptomatic hypokalemia, or those with ECG abnormalities 5, 6.
• The infusion rate should be guided by the patient's clinical condition and electrolyte levels, with careful monitoring to avoid overcorrection or undercorrection 6, 4.
• Oral replacement is often appropriate for asymptomatic patients with less severe hypokalemia 6.

Management of Potassium Disorders

• Hypokalemia and hyperkalemia can be managed with a combination of oral or intravenous potassium replacement, and treatment of the underlying cause 5, 7, 6.
• Insulin, usually with concomitant glucose, and albuterol are preferred to lower serum potassium levels in the acute setting 5.
• Sodium polystyrene sulfonate is reserved for subacute treatment, while patiromer and sodium zirconium cyclosilicate are newer potassium binders that may be used in chronic or acute hyperkalemia 7.