Potassium is the primary intracellular cation and plays a crucial role in maintaining electrical excitability in cardiac and skeletal muscle. Normal serum potassium level is 3.5 - 5.0 mEq/L.
Hypokalemia (Potassium < 3.5 mEq/L)
Caused by loop diuretics (e.g., Furosemide), prolonged vomiting, or inadequate intake.
- ECG Changes: Flat/inverted T waves, ST depression, and prominent U waves.
- Symptoms: Muscle weakness, leg cramps, constipation/paralytic ileus.
- Nursing Intervention: Administer oral or IV potassium. Note: Never give Potassium IV push; it must be diluted and administered slowly (usually not exceeding 10-20 mEq/hour).
Hyperkalemia (Potassium > 5.0 mEq/L)
Caused by renal failure, potassium-sparing diuretics (e.g., Spironolactone), or tissue trauma.
- ECG Changes: Tall tented T waves, prolonged PR interval, flat P waves, and widened QRS complex (which can lead to sine wave pattern/cardiac arrest).
- Symptoms: Muscle twitching, numbness, flaccid paralysis, diarrhea.
- Nursing Intervention: Prepare for administration of Calcium Gluconate (protects myocardium), Insulin with Dextrose (shifts potassium intracellularly), and Sodium Polystyrene Sulfonate (Kayexalate).
