Potassium

Question 1

Potassuim?

Answer 1

• Major cation in ICF
• Normal value is 3.5-5.0
• Regulates many metabolic activities
• Essential for transmission & conduction of nerve impulses, normal cardiac rhythms & skeletal & smooth muscle ctx
• Sodium-potassium pump critical to maintaining balance b/w intracellular & extracellular K+

Question 2

Potassuim
-Regulation

Answer 2

• Dietary intake
• Kidneys - primary regulators of K+ balance
• Aldosterone
• Insulin

Question 3

Hypokalemia?

Answer 3

• One of the most common electrolyte imbalances
• Chxs in serum K+ reflective of ECF values, not total body values
• When severe, hypokalemia can affect cardiac conduction

Question 4

Hypokalemia
-Etiology

Answer 4

• D/t loss from body or movement of K+ into cells
• Rarely result of inadequate intake

Question 5

Hypokalemia
-Clinical manifestations

Answer 5

• Rarely develop unless K+ drops below 3.0

Question 6

Hypokalemia
-Diagnostic tests

Answer 6

• Serum K+ less than 3.5
• ABG’s may show metabolic or respiratory alkalosis
• ECG: may see ST segment depression, flattened T wave, presence of U wave & ventricular dysrhythmias
• Decreased Mg+ or decreased Ca++

Question 7

Hypokalemia
-Interventions

Answer 7

• Administer K+ supplement, as ordered
• Usual dose = 40-80 mEq
• Should not administer K+ faster than 10-20 mEq/hr or in concentration higher than 30-40 mEq in Dextrose Free IV
• If giving more than 10 mEq/hr = cardiac monitor
• Never give IV push or IM!!!!
• Encourage foods high in K+
• I&O - 40 mEq of K+ lost per L of urine
• Monitor urine output
• Monitor for irregular pulse, pulse deficit, BP, resp status
• Monitor ECG
• Monitor pts receiving Dig for signs of increased Dig effect

Question 8

Hyperkalemia?

Answer 8

• Slight increase can have profound consequences
• Less common than hypokalemia, but more serious

Question 9

Hyperkalemia
-Etiology

Answer 9

• Increased intake of potassium
• Shift of K+ from ICF
• Insulin deficiency
• Decreased renal excretion
• Cell trauma

Question 10

Hyperkalemia
-Clinical manifestations

Answer 10

• Usually only apparent w/ extreme elevations
• Increased K+ muscle cells more excitable
• Difficult to differentiate K+ imbalance by sx alone

Question 11

Hyperkalemia
-Diagnositc tests

Answer 11

• Serum K+ greater than 5 mEq/L
• Be careful not to leave tourniquet on too long
• ABG’s: may see acidosis
• ECG: tall thin T waves, prolonged PR interval, ST depression, widened QRS & loss of P wave

Question 12

Hyperkalemia
-Interventions

Answer 12

• I&O
• Low K+ diet
• Increase urine output (K+ wasting diuretics, i.e., Furosemide)
• Monitor ECG, if indicated
• Medications to promote k+ loss (i.e., Kayexalate)
• Antagonize effect of potassium on cell membrane
• Force potassium into cell (i.e., Insulin)
• Eliminate from body
• Correct cause