Lecture Notes: Electrolytes and Their Functions

Introduction

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Potassium (K)

• Function: Maintains heart and muscle contraction

• Hyperkalemia (High Potassium):

  • Potassium level > 5.0
  • Symptoms:
    • Heart: Tight and contracted
      • ST elevation, peaked T-waves, wide QRS complexes
      • Severe cases: V-fib, cardiac standstill, hypotension, bradycardia
    • GI: Diarrhea, hyperactive bowel sounds
    • Neuromuscular: Paralysis, paresthesia, increased DTRs, profound muscle weakness
  • Priority: Severe/profound symptoms indicate priority patient

• Hypokalemia (Low Potassium):

  • Potassium level < 3.5
  • Symptoms:
    • Heart: Flat T-waves, ST depression, prominent U waves
    • Muscular: Decreased DTRs, paralysis
    • GI: Decreased motility, hypoactive bowel sounds, constipation, paralytic ileus
  • Priority: Paralytic ileus can lead to bowel obstruction

Sodium (Na)

• Functions: Maintains blood pressure, blood volume, and pH balance

• Hypernatremia (High Sodium):

  • Symptoms:
    • Skin: Red, rosy cheeks, edema, low-grade fever
    • Late signs: Swollen dry tongue, nausea, vomiting, increased muscle tone

• Hyponatremia (Low Sodium):

  • Symptoms:
    • Neuro: Seizures, coma
    • Heart: Tachycardia, weak pulses
    • Respiratory: Arrest

Chloride (Cl)

• Follower of Sodium: Maintains blood volume, blood pressure, and pH balance
• Hyperchloremia: Similar symptoms to high sodium
• Hypochloremia: Similar symptoms to low sodium

Magnesium (Mg)

• Function: Maintains muscle calmness

  • Partnered with calcium

• Hypermagnesemia (High Magnesium):

  • Symptoms:
    • Heart: Calm and quiet, heart blocks, prolonged PR intervals
    • Vital Signs: Bradycardia, hypotension
    • DTRs: Hyporeflexia
    • Lungs & GI: Depressed respirations, hypoactive bowel sounds

• Hypomagnesemia (Low Magnesium):

  • Symptoms:
    • Heart: Tachycardia, torsades de pointes, V-fib
    • DTRs: Hyperreflexia
    • Eyes: Nystagmus
    • GI: Diarrhea

Calcium (Ca)

• Functions: Strengthens bones, blood, and heart function

• Hypercalcemia (High Calcium):

  • Symptoms: Swollen/slow GI, bone pain, renal calculi, decreased DTRs, muscle weakness

• Hypocalcemia (Low Calcium):

  • Symptoms:
    • Neuromuscular: Chvostek's sign, Trousseau's sign
    • GI: Diarrhea
    • Risk for fractures, bleeding, cardiac dysrhythmias

Phosphate (PO4)

• Opposite of Calcium: Regulates calcium, essential for bone and teeth

• Hyperphosphatemia (High Phosphate):

  • Symptoms: Like low calcium (Chvostek's, Trousseau's), diarrhea

• Hypophosphatemia (Low Phosphate):

  • Symptoms: Like high calcium (constipation, decreased DTRs, muscle weakness, kidney stones)

Conclusion:

• Monitor electrolyte imbalances as they affect various bodily functions
• Prioritize patients based on severe symptoms
• Understand inverse relationship between calcium and phosphate