Magnesium is the second most abundant intracellular cation in the body. It plays a key role in over 300 enzyme reactions involved in metabolism and acts as a calcium channel blocker. Hypomagnesemia occurs when magnesium levels drop below 1.5 mEq/L and can cause seizures, tremors, and cardiac issues. Treatment involves magnesium supplementation. Hypermagnesemia occurs when levels rise above 2.0 mEq/L due to conditions like renal failure and can cause decreased reflexes, weakness, respiratory depression, and cardiac arrest. Treatment focuses on removing magnesium from the body through diuresis or dialysis.

1. Magnesium

2. What is Magnesium?
 2nd most abundant intracellular cation in
the body.
 Supplementing a normal intake increases
urinary excretion, and serum magnesium
level remains normal.
 Low dietary intake of magnesium reduced
urinary excretion, same as in nursing
women.

3. Function:
 Stabilize the structure of ATP-dependent
enzyme reactions.
 Cofactor for more than 300 enzymes
involved in the metabolism of food
components and the synthesis of many
metabolic products.
 DNA and protein synthesis
 Important in the formation of cAMP
 Plays a role in neuromuscular
transmission and activity.
 Acts as physiologic calcium-channel
blocker and is called “nature’s blocker”
 Parathyroid hormone synthesis.
 Bone Health
 Carbohydrate Metabolism
 Blood Pressure Regulation

4. Total Body Content:
 2000 mEq or 24 grams.

5. Distribution:
 67% in bone
 31% intracellularly
 1% extracellularly
In which,
 25-30% is protein bound
 10-15% complexed
 50-60% ionized

6. Regulation and Excretion:
 Regulated by the Kidneys.
 Absorbed by the proximal convulated
tubules and thick ascending limb of Loop
of Henle.

7. Normal Serum
Concentration:
1.5 – 2.0 mEq/L
1.8 – 3.0 mg/dl
0.8 – 1.2 mmol/L
40 mEq/L (ICF)

8. RDA:
300 -350 mg; or
15 mmol

9. Food Sources:
Seeds
Nuts
Legumes
Wheat grains
Dark green vegetables
Cashews
Chili
Halibut
Swiss chard
Tofu
Banana
Avocado
Dark chocolate

10. Relation to other
Electrolytes:
Directly proportional to: K, Ca,
Phosphorus
Inversely proportional to: Na, Cl

11. HYPOMAGNESEMIA
Alterations:

12. Definition:
A plasma magnesium level less
than 1.5 mEq/L or 1.8 mg/dl.

13. Cause of Disorder:
 Chronic alcoholism
 Hyperparathyroidism
 Hyperaldosteronism
 Diuretic phase of renal failure
 Malabsorptive disorders
 Diabetic ketoacidosis
 Refeeding after starvation
 Parenteral nutrition
 Chronic laxative use
 Diarrhea
 Heart failure

14. Clinical Manefestations:
 Seizures
 Trosseau’s & Chvostek’s sign, tremors,
tetany
 Anorexia
 Rapid HR, increased BP, inverted T-
waves,
 Vomiting
 Emotional liability, insomnia
 Deep tendon increased,

15. Medical Management:
 Administer magnesium salts
 IV magnesium solution via infusion pump
at 67 mEq over 8 hours
 Notify if urine <100ml for 4 hours
 Administer IV Calcitrol
 Avoid use of diuretic medications

16. Nursing Management:
 Monitor cardiac status
 Monitor urine output
 Seizure precautions
 Assess for dysphagia
 Encourage to eat green leafy vegetables
and other magnesium-rich foods
 Assess deep tendon reflexes
 Educate patient about diuretic medications

17. HYPERMAGNESEMIA
Alterations:

18. Definition:
It is a plasma magnesium level
greater than 2.0 mEq/L or 3mg/dl.

19. Cause of Disorder:
 Oliguric phase of Renal Failure
 Excessive use of antacids
 Hyperalimentation (TPN)
 Patient who has untreated diabetic
ketoacidosis
 Excessive magnesium administered to
treat HTN in pregnancy
 Excessive use of laxatives (Milk of
Magnesia)
 Opioid and Anticholinergic medications
 Intestinal hypomotility

20. Clinical Manifestations:
 Reflexes decreased, muscle weakness,
paralysis
 ECG changes, tachycardia to bradycardia,
hypotension, prolonged PR interval and
QRS, cardiac arrest
 Nausea & vomiting, flushing,
 Lethargy, drowsiness, coma
 Depressed respiration

21. Medical Management:
 Avoid administration of Magnesium.
 Saline infusions with a loop diuretic
increases renal elimination
 Ventilatory support
 Calcium Gluconate
 Renal examinations
 Hemodialysis

22. Nursing Management:
 Monitor VS, respiratory function, ECG
recordings, I&O, LOC, deep tendon
reflexes
 Teach clients to avoid constant use of
laxatives and antacids
 Encourage eating foods containing fiber
and drinking adequate fluids to promote
fecal elimination.
 Do not administer medications with
magnesium with renal failure