Exam 1: Magnesium Imbalances Flashcards
What does Magnesium do?
Acts as an activator for many intracellular enzyme systems and plays a role in both carbohydrate and protein metabolism.
Normal Magnesium level?
1.3-2.3 mg/dL
Where does Magnesium go?
1/3 bound to protein, and 2/3 exist as free cations.
What happens with variations of Magnesium?
It affects neuromuscular irritability and contractility
What happens with excess magnesium?
It diminishes the excitability of the muscle cells
What happens with deficit of magnesium
Deficit increases neuromuscular irritability and contractility.
Magnesiums affect on cardiovascular system?
They act peripherally to produce vasodilation and decreased peripheral resistance.
Hypomagnesemia Range?
<1.8 mg/dL
Hypermagnesemia Range?
> 3.0 mg/dL
Hypomagnesemia Contributing Factors
Chronic Alcholism, Hyperparathyroidism, Diabetic Ketoacidosis, Refeeding after Starvation, Chronic Laxative Use , Heart Failure
Hypomagnesemia Signs/Symptoms
Neuromuscular Irritability, Positive Chvostek and Trousseau Sign, Mood Changes, Anorexia, Vomiting, Increased BP
Hypermagnesemia Contributing Factors
Oliguric Phase of Acute Kidney Injury
Adrenal Insufficiency, Excessive IV Magnesium, Hypothyroidism
Hypermagnesemia Signs/Symptoms
Fluishing, Hypotension, Muscle Weakness, Drowsiness, Hypoactive Reflexes, Depressed Respirations, Cardiac Arrest
What is Hypomagnesemia commonly associated with?
Hypokalemia and Hypocalcemia . They must all be address concurrently
What similarity does Hypomagnesemia share with Calcium
- It is the ionized frction of magnesium tha tis primarily involved in neuromuscular activity and other physiologic process
- Magnesium levels should be evaluated in combination with albumin levels
Hypomagnesemia Route?
Magnesium loss occurs in the GI Tract. This includes nasogastric sunction, diarrhea, or fistulas
Hypomagnesemia: Where is the major site of magnesium absorption?
the distal small bowel. Any disruption can lead to hypomagnesemia.
How may Hypomagnesemia occur?
With withdrawal from alcohol and administrationof tube feedings or parenteral nutrition
Hypomagnesemia: Some clinical manifestations of Hypomagnesemia are due
directly to the low serum magnesium level; others are due to secondary changes in potassium and calcium metabolism
Hypomagnesemia: Chvostek and Trousseau signs occur
in part, because of accompanying hypocalcemia
Hypomagnesemia: Urine Magnesium May help
identify the cause of magnesium depletion and levels are measured after a loading dose of magnesium sulfate is given
Hypomagnesemia: Medical Management: Diet
Mild Magnesium deficiency cna be corrected by diet alone.
Sources of magnesium?
Green leafy vegetables, nuts, seeds, legums, whole grains, seafood, peanut butter, and cocoa
Hypomagnesemia: Vital Signs must be assessed frequently during magnesium administration to
detect changes in cardiac rate or rhythm, hypotension, and respiratory distress.
What is Hypermagnesemia?
It’s a rare electrolyte abnormality because the kidneys efficiently excrete magnesium.
Hypermagnesemia: Most common type of how this occurs?
This is kidney injury. Another common type is lithium intoxication and extensive soft tissue injury or necrosis
Hypermagnesemia: Acute elevation of magnesium causes
a depression of the central nervous system as well as the peripheral neuromuscular junction
What can occur when Hypermagnesemia is very elevated?
Coma, Aatrioventricular Heart Block, and Cardiac Arrest
Hypermagnesemia: What else is present when this is elevated?
Elevated levels of potassium and calcium as well
Hypermagnesemia: Medical Management
This can be prevent by avoiding the administration of magnesium to patients with kidney injury
Another major cause of symptomatic hypomanesemia in the United States is
chronic alcohol abuse
Serum magnesium should be measured when for people going through alcohol withdrawal
2-3 days
Hypomagnesemia symptoms do not occur until level has dropped below
1.8
Hypomagnesium may be accompanied by marked alterations in psychological status such as
Apathy , depressed mood, apprehension, and extreme agitation
Dizziness
Insomnia and Confusion
What must be addressed in addition to low serum magnesium levels?
Concurrent hypokalemia and hypocalcemia. These are difficult to correct until magnesium has been repleted
Hypomagnesium: If necessary, magnesium salts can be given
orally in an oxide or gluconate form to replace continuous losses but may produce diarrhea
Hypomagnesium: A bolus dose of mangesium sulfate given too rapidly can produce alterations in
cardiac conduction leading to heart block or astyole
Hypomagnesium: Monitoring what is essential before, during, and after administration of magnesium?
Urine output. Physician notified if urine volume decreases to less than 100 mL over 4 hours.
Hypermagnesium: What happens when serum magnesium levels exceed 10 mEq/L?
Respiratory center is depressed. Coma, atrioventricular heart block, and cardiac arrest can occur as well.
Hypermagnesium: Administration of what enhances magnesium excretion?
Loop diuretics andSodium Chloride or LActated Ringer Solution
Hypermagnesium: What does IV Calcium Gluconate do?
Anatagonizes the cardiovascular and neuromuscular effects of magnesium
Hypermagnesium: If present, nurse monitors the
vital signs, noting hypotension and shallow respiration .
Allow decreased deep tendon reflexes and changes in consciousness.
Magnesium produces its sedative effect at the neuromuscular junction probably by
inhibiting the releases of the neutrotransmitter acetycholine. Also increases the stimulus threshold in nerve fibers
Magnesium acts directly on the
myoneural junction. Important for neuromuscular function
