Overview
This lecture explains the essential functions, symptoms, and differences of major electrolyte imbalances, focusing on sodium, potassium, chloride, magnesium, calcium, and phosphate for nursing exams.
Electrolytes: Overview
- Electrolytes are ions in body fluids that generate electrical energy for muscle, nerve, heart, and brain function.
- Fluid loss (vomiting, diarrhea, sweating, urination) leads to electrolyte depletion.
Potassium (K⁺) Imbalances
- Potassium maintains heart and muscle contraction.
- Hyperkalemia (>5.0): Heart is tight/contracted—ST elevation, peaked T waves, wide QRS, V-fib, cardiac standstill, hypotension, bradycardia.
- GI: Diarrhea, hyperactive bowel sounds.
- Neuromuscular: Paralysis, paresthesia, increased DTRs, profound muscle weakness.
- Hypokalemia (<3.5): Heart is low/slow—flat T waves, ST depression, prominent U wave.
- Muscular: Decreased DTRs, flaccid paralysis.
- GI: Decreased motility, constipation, paralytic ileus (risk for bowel obstruction).
Sodium (Na⁺) Imbalances
- Sodium regulates blood pressure, blood volume, and pH balance.
- Hypernatremia: Big, bloated—red cheeks, edema, low-grade fever, polydipsia, late signs: swollen dry tongue, N/V, increased muscle tone.
- Hyponatremia: Seizures, coma, tachycardia, weak pulse, respiratory arrest; both high and low cause neuro symptoms (restlessness, fatigue, abdominal cramping).
Chloride (Cl⁻) Imbalances
- Follows sodium; maintains blood pressure, volume, pH.
- Hyperchloremia: N/V, swollen dry tongue, confusion.
- Hypochloremia: Excessive diarrhea, vomiting, sweating, fever.
Magnesium (Mg²⁺) Imbalances
- Calms muscles, required for calcium/vitamin D absorption.
- Hypermagnesemia: Calm/quiet—heart block, bradycardia, hypotension, decreased DTRs, shallow respirations, hypoactive bowel sounds.
- Hypomagnesemia: Buck wild—torsades de pointes, V-fib, tachycardia, increased DTRs, nystagmus, diarrhea.
Calcium (Ca²⁺) Imbalances
- Strengthens bones, blood (clotting), and heartbeats.
- Hypercalcemia: Swollen/slow—constipation, bone pain, kidney stones, decreased DTRs, severe muscle weakness.
- Hypocalcemia: Trousseau's and Chvostek's signs, diarrhea, circumoral tingling, risk for fractures/bleeding/dysrhythmias.
Phosphate (PO₄³⁻) Imbalances
- Essential for bones/teeth; inversely related to calcium.
- Hyperphosphatemia: Same as low calcium—Trousseau's/Chvostek's, diarrhea, weak bones/blood/beats.
- Hypophosphatemia: Same as high calcium—constipation, decreased DTRs, muscle weakness, kidney stones.
Key Terms & Definitions
- Electrolytes — Ions in body fluids that maintain electrical energy and balance.
- Hyper- — High level of electrolyte.
- Hypo- — Low level of electrolyte.
- DTRs — Deep Tendon Reflexes, measure of neuromuscular activity.
- Trousseau's Sign — Arm spasm with BP cuff, indicates hypocalcemia.
- Chvostek's Sign — Facial muscle twitch when cheek is tapped, indicates hypocalcemia.
Action Items / Next Steps
- Review the study guide and lecture notes on electrolyte imbalances.
- Memorize key symptoms and functions for each electrolyte for exams.
- Practice identifying priority symptoms and patient assessments.