Hypokalemia

Introduction:

Hypokalemia is a lower-than-normal level of potassium in the blood. A balance
between the amount of potassium within the cell (intracellular) and outside the cell
(extracellular) is necessary. This allows the resting potential of the cell membrane
to be maintained. When there are low potassium levels, a greater-than-normal stim-
ulus is needed to depolarize the cell membrane. Many cells become more sluggish,
especially nerve cells. However, cardiac cells become more excitable. Fluid losses
due to diuretics or diarrhea, endocrine disorders (such as hyperthyroidism, hyper-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.

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

TREATMENT
• Correct fluid imbalance.
• Stop or change medications that contribute to potassium loss, if possible (for
example, Loop diuretics).
• Encourage potassium-rich foods.
• Administer potassium supplements.
• Administer potassium in intravenous fluids:
• Avoid glucose in fluid which will shift potassium into cells.
• Potassium concentration of no more than 40 mEq/L in peripheral lines
• Monitor cardiac rhythm.

NURSING DIAGNOSIS
• Activity intolerance
• Decreased cardiac output
• Fatigue

NURSING INTERVENTIONS
• Monitor vital signs for change.
• Monitor cardiac system for rate, rhythm, and pulse deficit.
• Monitor intake and output.
• Monitor intravenous site for redness, swelling, warmth, and pain.
• Teach patient about medication and diet changes:
• Foods rich in potassium (bananas, tomatoes, orange juice)