NCLEX RN Practice Question # 670
NCLEX Examination.
Practice Question # 670.
NCLEX Quiz
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.