Potassium Flashcards
What is the normal serum potassium concentration?
3.5 to 5 mEq/L. Potassium is the major intracellular cation.
The Na/K/ATPase pump and the plasma K concentration are the most important in the daily regulation of potassium balance. Other factors that influence potassium distribution include those regulating the activity of theNa/K/ATPase pump, what are those factors?
Factors that influence potassium distribution via the Na/K/ATPase pump are insulin and catecholamines. Additional factors affecting K distribution are exercise, extracellular pH, and cellular breakdown.
What is hypokalemia?
Hypokalemia is defined as
- What are the most common causes of hypokalemia? 2. What other factors can cause hypokalemia?
- Hypokalemia is almost always the result of abnormal potassium losses via the stool or urine. 2. Other causes include a transcellular shift of potassium from the ECF to ICF, inadequate intake or drugs. Causes of intracellular shift of potassium are metabolic alkalosis and an increased in insulin and catecholamines (epinephrine ).
What drugs can cause hypokalemia?
The administation of oral or IV potassium supplements is the treatment of hypokalemia. IV potassium supplements are available as chloride, acetate, and phosphate salts. In what conditions is it appropriate to use each type of potassium supplement.
Potassium acetate is used as an alternative to potassium chloride in the presence of metabolic acidosis.
Potassium phosphate is used to correct coexisting hypokalemia and hypophosphatemia.
- What are the benefits of oral correction of hypokalemia?
- What are the recommended oral dosage for hypokalemia?
- Oral correction of hypokalemia is generally safer and reduces the risk of overcorrection and rebound hyperkalemia.
- Oral potassium dosage of 40 to 100 mEq/L daily divided into two or four doses are usually sufficient to correct hypokalemia.
- When is IV potassium supplement most applicable?
- In most cases, what are the maximum rate and total daily recommendations for IV potassium supplementation?
- IV potassium is reserved for the treatment of severe hypokalemia or when the GI tract precludes the use of oral agents. Recommendation of IV potassium replacement doses vary according to severity and the presence of renal insufficiency.
- In most cases, total daily potassium should not exceed 40 to 100 mEq/L/day, or a rate of 10 to 20 mEq/L/hr. Rates exceeding these values recommend continuous cardiac monitoring.
NB: In general, every 10 mEq of IV potassium administered should increase serum potassium by 0.1 mEq/L in patients with normal renal function.
- Define Hyperkalemia?
- What are the clinical manifestation of hyperkalemia?
- Serum potassium > 5.0 mEq/L.
- Clinical manifestations of hyperkalemia are related to changes in neuromuscular and cardiac functions.
NB. Patients are often asymptomatic until serum potassium concentration is > 5.5 mEq/L.
- The diluent and the presence of hypomagnesemia are additional caveats to consider when replacing potassium deficits. How do the diluent and the presence of hypomagnesemia present a problem when treating hypokalemia
- When possible, dextrose solutions should be avoided because they may worsen the hypokalemia by stimulating insulin release that promote intracellular shift of potassium. Normal saline is preferred.
- A magnesium deficit should be corrected because hypomagnesemia may result in refractory hypokalemia due to accelerated renal potassium loss or the impairment of Na/K/ATPase pump activity.
- What is the most common cause of hyperkalemia?
- What are other causes of hyperkalemia?
- Renal insufficiency
- Extracellular shift of potassium caused by metabolic acidosis, tissue catbolism and pseudohyperkalemia.
What are some drugs that are associated with hyperkalemia?
- Treatment of hyperkalemia depends upon the degree of hyperkalemia and the severity of the symptoms. When is appropriate to use calcium gluconate to treat hyperkalemia?
- What are other forms of treatment for hyperkalemia?
- IV calcium gluconate should be given to symptomatic patients or those with ECG changes to restore membrane excitability to normal.
- see attachment
NB: Serum potassium should be monitored frequently during the treatment of symptomatic patients because many of the therapies employed for acute hyperkalemia redistribute potassium and do not remove it from the body.
