CHAPTER 11 Fluids and Electrolytes^437
PROGNOSIS
Correction of the magnesium level is necessary to prevent life-threatening com-
plications. Patients are at significant risk for cardiac arrest as the magnesium lev-
els continue to rise.
HALLMARK SIGNS AND SYMPTOMS
- Bradycardia due to slowed cellular response to normal stimuli
- Hypotension due to vasodilation
- Drowsiness or lethargy
- Weakness
- Less-than-normal deep tendon reflexes
- Confusion
- Urinary retention
- Cardiac arrest when level severely elevated
INTERPRETING TEST RESULTS
- Blood serum magnesium levels > 2.5 mEq/L.
- EKG shows widened QRS complex, prolonged PR intervals.
- BUN elevation if there is renal insufficiency.
TREATMENT
- Administer magnesium antagonist intravenously:
- calcium chloride
- Administer Loop diuretic to reduce magnesium level:
- furosemide
- Dialysis—hemodialysis or peritoneal, to remove excess magnesium (espe-
cially in patients with renal failure). - Reduce magnesium in diet (avoid meat, legumes, dark green leafy vegetables,
fish, whole grains, nuts). - Increase fluid intake to maintain hydration.