Potassium
Potassium is a major intracellular electrolyte. About 98% of potassium is found inside the cells of the body while the remaining 2% is located extracellular and maintains neuromuscular irritability. Potassium is crucial to heart function and plays a key role in skeletal and smooth muscle contraction, making it important for normal digestive and muscular function (Ehrlich, 2005). The sodium-potassium pump is a process wherein potassium along with other minerals in the body work together in order to yield energy and maintain homeostasis.
The normal serum potassium concentration ranges from 3.5 mEq/L to 5 mEq/L (3.5 to 5 mmol/L) and even minor variations are significant (Smetzer, 2010).
Sources of potassium
Common food sources of potassium include banana, carrots, apple, tomatoes, fruit juices, melon, citrus fruits, and fresh vegetables.
Hypokalemia
Hypokalemia is a serum potassium level less than 3.5 mEq/L or 3.5 mmol/L. This indicates depletion in the normal potassium levels in the body, a potential life-threatening emergency and can be fatal.
Acute hypokalemia is a serum potassium level less than 3.5 mEq/L to 2.0 mEq/L. It results from the rapid loss of extracellular potassium, either from shifting of potassium from the blood into the cells or by gastrointestinal or renal losses.
Chronic hypokalemia is a serum potassium level less than 2.0 mEq/L. Potassium depletion is caused by decreased potassium intake or increased gastrointestinal or renal losses.
Medical Management
Potassium replacement:
- Oral potassium supplements
Oral potassium supplements are administered to correct imbalances and restore normal levels in the blood. It may cause GI irritation such as nausea and vomiting therefore, should not be given on an empty stomach.
- Intravenous replacement therapy
If hypokalemia cannot be prevented by conventional measures such as increased intake in the daily diet or by oral potassium supplements for deficiencies, then it is treated cautiously with IV replacement therapy (Hayes, 2007). Potassium is never given by IV push and should be administered via infusion pump to avoid potential life-threatening cardiac arrhythmias. Potassium infusion can cause phlebitis; therefore warrants assessment of IV site frequently for signs of phlebitis. If this occurs, the infusion is discontinued immediately.
- Increased dietary intake of potassium
A potassium-rich diet should be included in the management of patient with hypokalemia. Dietary intake of potassium in the average adult is 50 to 100 mEq/day (Smeltzer, 2010).
