ELECTROLYTE DISTURBANCES

Electrolytes play a vital role in maintaining homeostasis within the body. They help to regulate myocardial and neurological function, fluid balance, oxygen delivery, acid-base balance and much more. Electrolyte imbalances can develop by the following mechanisms: excessive ingestion; diminished elimination of an electrolyte; diminished ingestion or excessive elimination of an electrolyte. The most common cause of electrolyte disturbances is renal failure.

The most serious electrolyte disturbances involve abnormalities in the levels of sodium,potassium, and/or calcium. Other electrolyte imbalances are less common, and often occur in conjunction with major electrolyte changes. Chronic laxative abuse or severe diarrhea or vomiting can lead to electrolyte disturbances along with dehydration. People suffering from bulimia or anorexia nervosa are at especially high risk for an electrolyte imbalance.

Electrolytes are important because they are what cells (especially nerve, heart, muscle) use to maintain voltages across their cell membranes and to carry electrical impulses (nerve impulses, muscle contractions) across themselves and to other cells. Kidneys work to keep the electrolyte concentrations in blood constant despite changes in your body. For example, during heavy exercise, electrolytes are lost in sweat, particularly sodium and potassium. These electrolytes must be replaced to keep the electrolyte concentrations of the body fluids constant.

Potassium is an essential intracellular cation that plays a role in nerve impulse conduction; cardiac, skeletal, and smooth muscle contraction, intracellular tonicity, and renal function. 


Hypokalemia is generally accompanied with metabolic alkalosis and may result in adverse effects including diarrhea, weakness, fatigue, and cardiac arrhythmias. An increased risk of 
hypokalemia is present in patients receiving certain diuretics or prolonged parenteral nutrition with insufficient potassium replacement, and those with vomiting and diarrhea, primary or secondary hyperaldosteronism, dialysis, and diabetic ketoacidosis.

POTASSIUM SUPPLEMENTS (eg, potassium bicarbonate, potassium chloride, potassium citrate) are used for the prevention or treatment of potassium depletion in patients in whom dietary measures are inadequate. Potassium salts differ in the milliequivalents (mEq) of potassium provided; 40mEq is provided by:

Potassium bicarbonate (eg, K-Lyte, K-Lyte DS, Klor-Con/EF) 4g
Potassium chloride (eg, K-Dur, K-Tab, Klor-Con, Klotrix, Micro-K) 3g
Potassium citrate (eg, K-Lyte, K-Lyte DS) 4.3g

Potassium supplements should, preferably, be given orally; the slower rate of absorption from the GI tract prevents sudden, large increases in plasma potassium concentrations. Dose titration must be done slowly and with caution to avoid the risk of hyperkalemia, particularly in patients with severe renal dysfunction. Hyperkalemia is associated with adverse eevents including cardiac arrhythmias, mental confusion, paresthesias, and peripheral vascular collapse. The risk of hyperkalemia can be minimized by replacing potassium gradually over 3-7 days.