Question

A patient with severe hypokalemia from an accidental overdose of furosemide is to receive IV potassium replacement through a peripheral inserted central catheter placed in the right upper arm. The ordered IV solution contains 120 mEq (mmol/L) of potassium chloride in 1000 mL of normal saline to be infused at a rate of 150 mL/hr.

1. Should this solution be infused using a pump or controller? Why or why not?

2. How many mEq of potassium per hour will the patient receive at this rate?

3. Is this rate permissible? Explain your rationale.

4. Which parameter changes would indicate to you that the patient is responding well to this therapy?

5. For which changes should you assess to determine whether the patient is becoming hyperkalemic?

Answer 1

1

• Administration should be via a volumetric infusion pump.
• Higher concentrations have been given in severe cases of hypokalaemia but should be given via the central venous route and require infusion pump control.
• The immediate goal of treatment is the prevention of potentially life-threatening cardiac conduction disturbances and neuromuscular dysfunction by raising serum potassium to a safe level.
• Careful monitoring during treatment is essential because supplemental potassium is a common cause of hyperkalemia in hospitalized patients.
• The risk of rebound hyperkalemia is higher when treating redistributive hypokalemia.

2

• The rate of administration should not normally exceed 10mmol/hour.
• Administration rates above 20mmol/hour require cardiac monitoring.

3

• No ,this rate is not permissable.
• When intravenous potassium is used, standard administration is 20 to 40 mmol of potassium in 1 L of normal saline. Correction typically should not exceed 20 mmol per hour, although higher rates using central venous catheters have been successful in emergency situations. Continuous cardiac monitoring is indicated if the rate exceeds 10 mmol per hour. In children, dosing is 0.5 to 1.0 mmol per L per kg over one hour (maximum of 40 mmol).
• Potassium should not be given in dextrose-containing solutions because dextrose-stimulated insulin secretion can exacerbate hypokalemia.
• Medication use is a common cause of hyperkalemia, particularly in patients with baseline renal dysfunction or hypoaldosteronism. Medication-induced hyperkalemia is most often a result of the medication interfering with potassium excretion. Also, the administration of potassium to treat or prevent hypokalemia can inadvertently cause hyperkalemia.

4

• Electrolytes should be monitored to determine the need for further infusions and to avoid hyperkalaemia.
• Treatment of hypokalaemia may require both potassium and magnesium repletion.

5

• The immediate danger of hyperkalemia is its effect on cardiac conduction and muscle strength, and initial efforts should focus on determining the need for urgent intervention .The absence of symptoms does not exclude severe hyperkalemia, because hyperkalemia is often asymptomatic. Because of their increased risk of developing hyperkalemia, patients with underlying renal dysfunction merit special attention.

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