NCLEX RN Practice Question # 670

NCLEX Examination.

Practice Question # 670.

Potassium, Serum (K+) Normal Lab values

Adult: 3.5–5.0 mEq/L: SI units: 3.5–5.0 mmol/L

Child: 3.4–4.7 mEq/L; SI units: 3.4–4.7 mmol/L

Critical Levels: <2.5 or [1]>6.5 mEq/L

 Red-top tube:

■ Very narrow normal range; small changes in potassium level can have profound effects on body functions.

■ Effects of potassium include transmission of nerve impulses; contraction of skeletal, smooth, and cardiac muscle; and maintenance of acid-base balance and osmolarity.

■ Potassium levels may be decreased secondary to vomiting, diarrhea, diuretic use, insulin administration, burns, ascites, and other clinical conditions.

■ Increased levels occur with excessive IV administration, acute or chronic renal failure, potassium-sparing diuretics, infection, dehydration, transfusion of hemolyzed blood.