Potassium Imbalances Flashcards
Normal serum potassium is in the range of…
3.5 - 5 mmol/L
Role of potassium is…
Involvement of intracellular functions
Determines resting membrane potential across cell membranes
Helps maintain blood pressure
Potassium homeostasis is affected by…
Dietary intake
GI + urinary excretion
Hormones
Acid-base balance (excessive hydrogen ions, metabolic alkalosis)
The hormones that affect potassium include…
Insulin - drives potassium into liver, muscle, fat cells
Epinephrine - stimulate potassium uptake by cells
Aldosterone - promotes urinary potassium excretion
Hypokalemia is defined with a serum potassium concentration…
Below 3.5 mmol/L
Hypokalemia may result from…
A total-body potassium deficit or intracellular shift of potassium
Potassium deficit is defined as…
Inadequate dietary intake or excessive GI/renal potassium loss
Some drugs that contribute to excessive potassium loss is…
Thiazide/loop diuretics
This electrolyte imbalance may contribute to hypokalemia via…
Hypomagnesemia - promoting renal potassium loss
Mild hypokalemia is generally…
Symptom?
Asymptomatic
Moderate hypokalemia symptoms may manifest as…
Muscle cramping
Myalgias
Weakness
Malaise
This is still relatively rare
Severe hypokalemia symptoms may manifest as…
Impaired muscle contraction
Heart issues: ECG changes, heart block, atrial flutter, atrial tachycadia, ventricular fibrilation
Mild, asymptomatic hypokalemia may respond to…
Increased dietary potassium intake
Moderate or refractory hypokalemia can be treated with…
Oral replacement
10 mmol of potassium should increase potassium by…
0.1 mmol/L
Severe hypokalemia should be treated with…
IV replacement therapy
Overly rapid administration of IV potassium can cause…
Cardiac conduction abnormalities
Continuous ECG monitoring should be performed if high doses need to be given quickly
_____ may also help prevent loop or thiazide diuretic associated hypokalemia.
Potassium-sparing diuretics
Spironolactone
If hypokalemia is refractory to usual management we should…
Test for and manage concurrent hypomagnesemia
Hyperkalemia is defined by serum potassium…
Greater than 5 mmol/L
The most common cause/contributor to hyperkalemia is…
End stage renal disease
Causes of hyperkalemia include…
Increased potassium intake
Decreased potassium excretion
Tubular unresponsiveness to aldosterone
Extracellular redistribution of potassium
Factors that decrease potassium excretion include…
Acute/chronic kidney disease
Adrenal insufficiency (lowered aldosterone)
**DRUGS - ACEI/ARB, potassium-sparing, NSAID’s, Sulfatrim, cyclosporine, tacrolimus **
Treatment of hyperkalemia depends on…
Severity and acuity of hyperkalemia
Always try to identify and address underlying cause
Asymptomatic mild hyperkalemia could be treated with…
Decreasing dietary potassium intake + monitor
Moderate, symptomatic hyperkalemia with ECG changes or severe hyperkalemia requires…
Immediate treatment
Optimal treatment of hyperkalemia involves…
Calcium gluconate
Drugs that promote intracellular potassium shift
Elimination of excess potassium from the body
Drugs that promote intracellular potassium shift include…
insulin + dextrose, beta2 agonists, sodium bicarbonate
In hyperkalemia, ways to eliminate excess potassium from the body include…
Loop diuretics, oral cation exchange resins,
hemodialysis if refractory
