Hypokalemia

Definition

Hypokalemia is a serum potassium level less than 3.5 mEq/L. It affects excitable tissues, such as heart, skeletal muscle, smooth muscle.

Causes

• Diuretics (loop, thiazide)
• Vomiting, diarrhea, NG suctioning
• Alkalosis (H+/K+ shift)
• Insulin, beta-agonists (shift K into cells)
• Poor intake (alcoholism, anorexia)
• Hyperaldosteronism
• Medications: amphotericin B, high-dose penicillin

Signs and Symptoms

Muscle weakness, cramps, paresthesia, paralytic ileus (decreased bowel sounds), ECG: flat/inverted T waves, ST depression, U waves, prolonged QT, arrhythmias. Enhances digoxin toxicity risk.

Nursing Interventions

• Oral or IV replacement. NEVER IV push (can cause cardiac arrest)
• IV: dilute and use infusion pump, max 10 mEq/hr peripherally (20 mEq/hr central)
• Assess IV site for irritation/infiltration
• Monitor ECG and serum potassium
• Dietary sources: bananas, oranges, potatoes, spinach, avocado

NCLEX Relevance

NEVER push IV potassium. Monitor digoxin in hypokalemic patients.