Electrolytes NCLEX Cheat Sheet
As a nurse you are expected to know about electrolytes, their normal levels and what effect they have on the body if they fall outside of their usual range. Here are a few key electrolytes you’ll want to memorize!
Electrolytes Study Review
Serum sodium
Description
- A major cation of extracellular fluid
- Maintains osmotic pressure and acid-base balance, and assists in the transmission of nerve impulses
- Is absorbed from the small intestine and excreted in the urine in amounts dependent on dietary intake
- Minimum daily requirement of sodium is approximately 15 mEq.
Nursing consideration: Drawing blood samples in the extremity in which an intravenous (IV) solution of sodium chloride is infusing increases the level, producing an inaccurate result.
Serum potassium
Description
- A major intracellular cation, potassium regulates cellular water balance, electrical conduction in muscle cells, and acid-base balance.
- The body obtains potassium through dietary ingestion and the kidneys preserve or excrete potassium, depending on cellular need.
- Potassium levels are used to evaluate cardiac function, renal function, gastrointestinal function, and the need for IV replacement therapy.
Nursing considerations
- Note that the client is receiving potassium supplementation on the laboratory form.
- Clients with elevated WBC counts and platelet counts may have falsely elevated potassiumlevels.
Serum chloride
Description
- A hydrochloric acid salt that is the most abundant body anion in the extracellular fluid
- Functions to counterbalance cations, such as sodium, and acts as a buffer during oxygen and carbon dioxide exchange in red blood cells (RBCs)
- Aids in digestion and maintaining osmotic pressure and water balance
Nursing consideration:
Any condition accompanied by prolonged vomiting, diarrhea, or both will alter chloride levels.
Serum bicarbonate
Description:
- Part of the bicarbonate-carbonic acid buffering system and mainly responsible for regulating the pH of body fluids
Nursing consideration: Ingestion of acidic or alkaline solutions may cause increased or decreased results, respectively.