Quiz 3: Magnesium

Question 1

Locations of Mg in the body

Answer 1

• 53% found in bone
• 46% found in muscle and other organs
• <1% Serum and RBC
  
  • 4th most abundant cation in the body and 2nd most abundant cation in cells

Question 2

Interferences in measuring Mg

Answer 2

Hemolysis

Question 3

Mg Reference Values

Answer 3

1. 2 - 2.1 mEq/L
2. 5 - 2.4 mg/dL
3. 63-1.0 mmol/L

Question 4

Methods for Measuring Mg

Answer 4

1. Photometric with specific magnesium binding dyes, calmagite dye, formazan dye. Measured at 540 nm.
2. ISE: 61% is free or ionized, which is the physiologically active form (like Ca)

Question 5

Increased Mg

Answer 5

– uncommon
Decreased excretion: Renal Failure
Increased intake: Administration of Mg

Question 6

Decreased Mg

Answer 6

Usually Hospitalized patients in ICU

• Cardiac Disorders
• Diabetes mellitus
• Diuretics, alcohol and other drugs
• Starvation, malnutrition, GI malabsorption

Question 7

Hypomagnesemia symptoms

Answer 7

Cardiovascular: arrythmias
Neuromuscular: Tetany, tremors, paralysis, comas
Psychiatric: CNS affected
Metabolic: Low K, Ca,PO4, Na