Magnesium Flashcards
1
Q
Magnesium?
A
- Body’s second most abundant cation in ICF
- 50-60% in bone
- 1% in ECF
- Remainder in cells
- Activates enzymes involved in metabolism of CHO & protien
- Triggers sodium-potassium pump
- Important in transmission of neuromuscular activity, neural transmission in CNS & myocardial fx
- 1/3-1/4 bound to protein
- Normal serum level 1.5-2.0 mEq/L
2
Q
Magnesium
-Regulation
A
- GI absorption
- Renal excretion
- Parathyroid hormone
3
Q
Hypomagnesemia?
A
- Inadequate intake
- Inadequate absorption
- Increased urinary or GI loss
- Intracellular shifts
4
Q
Hypomagnesemia
-Clinical manifestations
A
- Neuromuscular: muscle twitching, convulsions, increased DTR’s, tetany, +Chvostek, +Trouseau (in part by hypocalcemia)
- CV: Supraventricular tachycardia (SVT), HTN, increased susceptibility to digitalis toxicity
5
Q
Hypomagnesemia
-Diagnostic tests
A
- Serum total Mg level less than 1.5 mEq/L
- ECG: may see tachydysrhythmias
6
Q
Hypomagnesemia
-Nurs interventions
A
- Encourage intake of foods high in Mg++
- Administer MgSO4, as ordered (have Calcium Gluconate avail)
- Monitor urine output
- Assess LOC, neuro status, DTRs w/ V/S
- Seizure precautions, if necessary
- Monitor for signs of Digoxin toxicity
7
Q
Hypermagnesemia
-Etiology
A
- Occurs almost exclusively in renal disease
- High intake of Mg++
8
Q
Hypermagnesemia
-Clinical manifestations
A
- Neuromuscular: decreased DTR’s, CNS depression, somnolence, weakness, lethargy, coma (similar to hypokalemia)
- CV: hypotension, bradycardia, flushing sensation, possible cardiac arrest
9
Q
Hypermagnesemia
-Lab values
A
- Magnesium level greater than 2.5 mEq/L
- ECG: AV block w/ severe levels
10
Q
Hypermagnesemia
-Interventions
A
- Assess & document LOC, orientation, and neuro status with each V/S
- Administer 0.45 NaCl and diuretic to enhance excretion
- Administer Ca Gluconate, as ordered, or keep at bedside (antidote)
- Prepare for dialysis, if necessary
