3 Potassium Imbalances Free Online FlashCards

What are two essential roles of potassium?

Potassium is the major intracellular cation and is essential for skeletal-muscle contraction and cardiac electrical conduction.

How is hypokalemia defined?

Hypokalemia is a serum potassium concentration below $3.5\ \mathrm{mEq/L}$.

What is a critical safety rule for IV potassium?

Never administer potassium by IV push. Use the prescribed dilution and infusion rate, an infusion pump, and cardiac monitoring when indicated.

How does the UK Kidney Association classify hyperkalemia severity?

The UK Kidney Association classifies hyperkalemia as mild at $5.5\text{–}5.9\ \mathrm{mEq/L}$, moderate at $6.0\text{–}6.4$, and severe at $6.5$ or higher.

What is a common adult serum potassium reference range?

A common adult reference range is $3.5\text{–}5.0\ \mathrm{mEq/L}$, though laboratory ranges vary.

When does hypokalemia require urgent assessment?

Severe hypokalemia is often defined as $2.5\ \mathrm{mEq/L}$ or lower. Severe, symptomatic, or ECG-associated hypokalemia requires urgent assessment and treatment.

What are common causes of hypokalemia?

Hypokalemia can result from renal or gastrointestinal losses, low intake, or potassium shifting into cells. Insulin, beta agonists, and alkalosis can promote this shift.

Why is magnesium important when correcting hypokalemia?

Low magnesium can contribute to potassium loss and make hypokalemia difficult to correct.

What ECG changes are typical of hypokalemia?

Typical findings include flattened or inverted T waves, ST-segment depression, and prominent U waves. ECG changes may be absent and do not reliably indicate potassium level.

What are common causes of hyperkalemia?

Common causes include impaired kidney excretion, potassium-retaining medicines, and potassium release from damaged cells. Acidosis, reduced insulin, and excess intake can also contribute.

What should be considered when a high potassium result does not fit the clinical picture?

Sample hemolysis or collection problems can produce a falsely high potassium result. Alert the clinician and obtain a repeat sample as directed, but do not delay emergency care for an unstable patient or concerning ECG changes.

What ECG changes may occur with hyperkalemia?

Possible changes include tall, peaked T waves, PR prolongation, reduced or absent P waves, and QRS widening. A normal ECG does not rule out clinically important hyperkalemia.