CHAPTER 11 Fluids and Electrolytes^431
aldosteronism), insufficient intake of potassium, and low magnesium levels can all
contribute to low potassium levels. Dietary intake is the main source of potassium,
so patients with poor nutritional intake or prolonged NPO status are also at risk for
hypokalemia.
PROGNOSIS
Low potassium levels may range from minor to life-threatening. The more abnor-
mal the level, the greater the chance the patient will develop a cardiac arrhythmia.
Correction or management of the underlying cause is necessary to help restore the
electrolyte balance.
HALLMARK SIGNS AND SYMPTOMS
- Muscle weakness due to need for greater stimulation of cell due to low potas-
sium level - Muscle cramps
- Malaise and lethargy
- Decrease in deep tendon reflex response due to lack of response of nerve
tissue to normal stimuli - Anorexia and constipation due to decrease in peristaltic activity
- Palpitations due to cardiac arrhythmias caused by excitability of cardiac muscle
- Rhabdomyolysis (destruction or degeneration of muscle tissue) in severe
hypokalemia - Cardiac arrest in severe hypokalemia
INTERPRETING TEST RESULTS
- Serum potassium level less than 3.5 mEq/L.
- EKG shows development of U-waves, ST depression, premature ventricular
contractions, AV block.
TREATMENT
- Correct fluid imbalance.
- Stop or change medications that contribute to potassium loss, if possible (for
example, Loop diuretics).