1.0 Potassium Imbalances: Hyponatremia

Potassium

the major intracellular electrolyte. It influences both skeletal and muscle activity.

98%

2%

____ of the body’s potassium is inside the cells, and the remaining ____ is in the ECF and is important for neuromuscular and cardiac function.

3.5-5 mmol/L or mEq/L

Normal Serum Potassium Concentration

80%

20%

To maintain potassium balance, the renal system must function because ____ of the potassium excreted daily leaves the body by way of the kidneys, and the other ___ is lost through the bowel and in sweat.

NSAIDS

ACE inhibitors

Are commonly associated with various diseases, injuries, medications (_____ and _____), and acid-base imbalances.

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A serum potassium level below 3.5 mEq/L (3.5 mmol/L) usually indicates a deficit in total body potassium stores.

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This may also occur in patients with normal potassium stores: when alkalosis (high blood pH) is present, serum potassium temporarily shifts into the cells.

Villous adenoma

a tumor of the intestinal tract characterized by excretion of potassium-rich mucus.

Hyperaldosteronism

causes renal potassium wasting and can lead to severe potassium depletion.

Primary Hyperaldosteronism

is seen in patients with adrenal adenomas (tumors),

Secondary Hyperaldosteronism

occurs in patients with cirrhosis, nephrotic syndrome, heart failure, or malignant hypertension.

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Metabolic Alkalosis

is commonly associated with hypokalemia.

urinary potassium excretion test

20 mEq/day

If the cause is unclear, a 24-hour ________ can be performed to distinguish between renal and extrarenal loss.

An excretion exceeding _____ suggests that renal potassium loss is the case.

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• 40 to 60 mEq/day

MEDICAL MANAGEMENT

• Administration of _______ of potassium is adequate if there are

  no abnormal losses of potassium.

• 50 to 100 mEq/day

MEDICAL MANAGEMENT

• For patients who are at risk of hypokalemia, a dietary intake of

  potassium in the average adult is _________.

50 to 60 mEq

When dietary intake is inadequate for any reason, oral or IV potassium supplementation

may be prescribed. Many salt substitutes contain ______ of potassium per teaspoon.

The IV route is mandatory for patients with severe hypokalemia (serum level of 2 mEq/L).

Potassium

Chloride

Acetate

Phosphate

usually used to correct potassium deficits,

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NURSING MANAGEMENT

Preventing Hypokalemia

• Encourage patients at risk to eat foods rich in potassium (when the diet allows).

• If this is caused by abuse of laxatives or diuretics, patient education may help alleviate the problem. Part of the health history and assessment should be directed at identifying problems that are amenable to prevention through education.

• Careful monitoring of fluid I&O is necessary because 40 mEq of potassium is lost for every liter of urine output.

• Monitor ECG for changes and check ABG values for elevated bicarbonate and pH levels.

NURSING MANAGEMENT

Correcting Hypokalemia

• The oral route is ideal for treating mild and moderate hypokalemia

• Care should be exercised when administering potassium, particularly in older adults, who have lower lean body mass and total-body potassium levels and therefore lower potassium requirements.

• The physiologic loss of renal function with advancing years, potassium may be retained more readily in older than in younger people.

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Potassium should be given only after adequate urine output has been established. It is primarily excreted by the kidneys, and when oliguria occurs, potassium administration can cause the serum potassium concentration to rise to dangerous levels.

infusion pump

Administration of IV potassium is done with extreme caution using an______, with the patient monitored by continuous ECG.

BUN and serum creatinine levels

Renal function should be monitored through ____________ and urine output if the patient is receiving potassium replacement.

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