Electrolyte Disorders

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Electrolyte Disorders
2012-09-03 15:25:58
Potassium Calcium Phosphate Magnesium

Normal and imbalances of electrolytes and body reactions
Show Answers:

  1. Name two mechanisms which bring K+ into the cell
    • Insulin
    • Beta adrenergic stimulation
  2. Name two mechanisms that moves K+ out of the cell
    • Acidocis
    • Depolarization
  3. What hormone regulates potassium
  4. What is the normal range of potassium level?
  5. What are symptoms of K+ overload?
    • Generalized fatigue,
    • Weakness
    • Paresthesias
    • Paralysis
    • Palpitations
  6. What will an electrocardiogram reading show in the case of high potassium
    • Tall, tented T waves (mild)
    • Depressed ST, prolonged PR, wide QRS (severe)
  7. What are causes of high potassium levels
    • renal failure
    • potassium sparing diuretics
    • urinary obstruction
  8. What are the causes of low potassium levels
    • Renal tubular acidosis
    • Hyperaldosteronism
    • Magnesium depletion
    • Vomiting or nasogastric suctioning
    • Inadequate diet
    • Medications - diuretics, beta-adrenergic agonisits, theophylline
  9. What are some physical signs of low potassium
    • Hypotension
    • Abdominal cramping
    • Hypoventilation or respiratory distress
  10. What are the cardiac responses to low potassium
    • Bradycardia
    • Ventricular arrythmia
    • Cardiac arrest
    • Premature atrial or ventricular beats
  11. What is the normal range for Calcium
  12. What causes high calcium levels?
    • Hyperparathyoridism - causes increased GI absorption without recnal excretion
    • Metastatic bone cancer - increased osteoclastic activity
    • Ingestion/infusion of calcium
  13. What are the symptoms of high calcium?
    • Nausea/vomiting
    • Alterations in mental status
    • Adominal or flank pain (think of GI manifestations and bone mets)
    • Constipation
    • Lethargy
    • Weakness and joint aches
    • Polyuria
    • Headache
  14. What are causes of low calcium?
    • Hypoparathyroidism/parathyroidectomy
    • Malabsorption of Calcium or vitamin D from gut - Crohn's, sprue, pancreatitis, gastric resection or bypass or gastrojejunostomy
    • Lack of sun exposure
  15. What are symptoms of low calcium?
    • Numbness
    • tingling
    • muscle cramping
    • irritability
    • seizures
    • respiratory disurbances
  16. What is the normal level of phosphorus?
  17. What are causes of low phorphorus?
    • Vitamin D Deficiency
    • Manesium/aluminum products (Antancids)
    • Alcohol abuse (long term)
    • Reneal excretion
  18. What are symptoms of low phosphorus levels?
    • Weakness of skelatal or smooth muscle
    • Rhabdomyolysis via ATP depletion (alcohol withdrawal)
    • Respiratory insufficiency
    • Confusion, seizures, and coma
    • Peripheral neuropathy
    • Hemolytic anemia
  19. Where is magnesium absorbed and excreted
    • Absorbed in ileium
    • excreted by stool and urine
  20. What organ regulates magnesium levels?
    Kidneys  - stores in bone may be mobilized as needed.
  21. What are causes of high magnesium?
    • Errors in administration
    • Lithium intoxication
    • Inadequate excretion from kidney or gut
    • Release of cellular manesium by tumor lysis syndrome, rhabdomylosis
    • Hypothyroidism/hypoparathyroidism
  22. What are symptoms of high magnesium
    • 2-4 - nausea and vomiting, sking flushing, weakness, lightheadedness
    • 3.5-5 - Disapperance of deep tendon reflex, Muscle weakness
    • 5-6 - Hypotension, vasodilation
    • 8-10 Arrythmia, atrial fibrillation
    • >10 asystole, heart block, coma, death
  23. What are the causes of low magnesium levels?
    • GI loss - malabsorption, radiation injury to bowel, diarrhea, laxative abuse, neoplasm
    • Malnutrition
    • Renal issues
    • Endocrine - primary aldosteronism
  24. What are symptoms of low magnesium levels
    • Hyperactive deep tendon reflexes
    • Muscle cramps
    • Muscle fibrillation
    • Troousseu and Chvostic sings
    • Dysarthria and dysphagia
    • CNS excitability - irritability and combativeness, disorientation, pyschosis, ataxia
    • Cardiac dysrhytmias
  25. Why is it important to to measure both bound and ionized calcium levels?
    • Of the calcium in plasma, 50% is bound to plasma protiens, and about 40% is in the free or ionized form.  
    • Ionzied calcium has the most important physiciolgic findings. 
  26. What functions does calcium play in the body
    • Major cation for structure of bones and teeth
    • Enzymatic cofactor for blood clotting
    • Required for hormone secretion
    • Needed for function of cell receptors
  27. Where is intracellular calcium located?
    In the mitochondria
  28. What is the function of phosphate in the body
    • Functions acts as intracellular and extracellular anion buffer in the regulation of acid-base balance.
    • In the form of ATP, it provides energy for muscle contraction.