Question

Complete systems disorder form for potassium imbalances

Answer 1

Potassium is the major intracellular cation in the human body. Over 98% of total body potassium is located within the intracellular compartment. In healthy adults, the total intracellular content of potassium is equivalent to 3000-3500 mmol .Approximately 70% of this amount is found in skeletal muscle with lesser amount in bone, red blood cells, liver and skin

The extracellular compartment contains 1-2% of total body potassium. This uneven distribution of total body potassium is the result of an electrogenic pump, Na+, K+, ATPase.

Maintenance of this potassium ratio and membrane potential is vital for normal nerve conduction and muscular contraction.

Disorder for potassium imbalance

Potassium disorders may take the form of hyperkalemia (high serum potassium) or hypokalemia (low serum potassium). The most common cause of hyperkalemia is decreased kidney function.

1. HYPERKALEMIA

Hyperkalemia, a serum potassium level of greater than 5.5 mEq/L, most commonly occurs secondary to an increase in total potassium stores and can be classified as mild, moderate or severe. During hyperkalemia the cells will absorb potassium in an effort to reduce serum potassium levels and thereby release hydrogen, causing a metabolic acidosis. Because of this mechanism, shifting hydrogen and potassium between the ICF (intra cellular fluid) and ECF(extra cellular fluid), acidosis can cause hyperkalemia, and hyperkalemia can cause acidosis.

As with hypokalemia, it is nearly impossible for someone with normal renal function to spontaneously become hyperkalemic. Although it is much less common than hypokalemia, hyperkalemia is much more dangerous, and when unrecognized or untreated it may result in cardiac arrest.

Hyperkalemia is generally caused by decreased or impaired renal excretion, the addition of potassium to the extracellular space or transmembrane shifts of potassium. Simply increasing the dietary intake of potassium rarely causes hyperkalemia, as it is rapidly excreted by the kidneys.

The signs and symptoms of hyperkalemia extend from the neuromuscular and cardiovascular systems. The most common finding is vague muscle weakness starting in the legs and ascending to the trunk and arms, and which can result in flaccid paralysis. Bradycardia in the hyperkalemic patient is often a preterminal event. Death is generally secondary to cardiac arrhythmias which may include various heart blocks, ventricular tachycardia, ventricular fibrillation and asystole.

Maintain an increased suspicion of hyperkalemia in patients presenting with weakness or in arrest if they have chronic renal failure or are on dialysis

2. HYPOKALEMIA

Hypokalemia is one of the most common electrolyte disorders. It clinically defined as a serum potassium level of less than 3.5 mEq/L. Severe hypokalemia is a serum level of less than 2.5 mEq/L (although life-threatening hypokalemia is rare). Hypokalemia is generally the result of a decrease in total stored potassium, but it can also occur when the body has normal potassium stores in the presence of an alkalotic state

Potassium plays a key role in the maintenance of pH levels. In alkalosis, where the percentage of hydrogen in the ECF is low, the cells will release hydrogen into the ECF to increase acidity, and will absorb potassium from the serum. This results in a lowering of serum potassium levels. Although total body potassium is normal in this situation, the serum potassium will be lower.

The signs and symptoms of hypokalemia are nonspecific and depend on the individual patient. They generally originate in the nervous and muscular systems and are often not present until the potassium levels are less than 3.0 mEq/L. As the hypokalemia progresses, the cardiovascular system may become involved. Early symptoms often noted by patients are muscular fatigue and weakness, particularly in the lower extremities. Death from hypokalemia is usually caused by anoxia secondary to paralysis of the respiratory muscles, which in turn leads to cardiac arrest.

The prehospital treatment of hypokalemia is difficult and rare. The only potassium-containing fluid that may be found in the prehospital setting is lactated Ringer's (LR); however, this is not a very effective treatment and is not commonly stocked on ambulances General treatment includes addressing any immediate life threats, avoiding hypoxia and anoxia by supporting respirations as needed, and providing standard treatment for cardiac arrhythmias. If the patient is severely hypokalemic, potassium chloride may be administered intravenously.