Electrolyte Labs for NCLEX
Sodium (Na)
- Normal Range: 135 to 145 mEq/L
- Functions: Sodium swells the body with fluid.
- Low Sodium Symptoms:
- Low and slow signs
- Mental status changes
- Seizures, coma, respiratory arrest
- High Sodium Symptoms:
- Big and bloated appearance
- Edema, increased muscle tone
- Flushed red skin
Potassium (K)
- Normal Range: 3.5 to 5.0 mEq/L
- Importance: Key electrolyte for muscle function, especially cardiac muscles.
- High Potassium (>5.0) Signs:
- High pumps: Peak T waves, ST elevation
- Low Potassium (<3.5) Signs:
- Low pumps: Flat T waves, ST depression, U wave
- Potassium Wasting Diuretics:
- Ends in "-ide" (e.g., furosemide)
- Used in acute/worsening heart failure
- Avoid in low potassium
- Potassium Sparing Diuretics:
- Spironolactone: Spares potassium
- Avoid potassium-rich foods
- IV Potassium Replacement:
- Never push IV (instant death risk)
- Administer via IV bag over 1 hour or more
- Place patient on cardiac monitor for abnormalities
Potassium Treatment for High Levels:
- Priority Treatment Order:
- IV Calcium Gluconate (prevents dysrhythmias)
- IV 50% Dextrose and Insulin (lowers potassium quickly)
- Kayexalate or Dialysis (slower)
- NCLEX Tip: Look for signs like bradycardia, weakness, lethargy, VTAC, VFIB
Case Scenarios:
- High Potassium (8.1), Wide QRS, and Bradycardia:
- First action: IV Calcium Gluconate
- End-Stage Renal Disease with High Potassium (7.2):
- First action: IV Regular Insulin and 50% Dextrose
Calcium (Ca)
- Normal Range: 9.0 to 10.5 mg/dL
- Functions: Calcium contracts muscles.
- Low Calcium Symptoms:
- Diarrhea, Trussos (twerking arm), Chvostek's sign (cheek twitch)
- High Calcium Symptoms:
- Kidney stones, constipation
Magnesium (Mg)
- Normal Range: 1.3 to 2.1 mEq/L
- Functions: Magnesium mellows muscles.
- Low Magnesium Symptoms:
- Hyperexcitability, Torsades de Pointes, VFib
- High Magnesium Symptoms:
- Hyporeflexia, decreased DTRs
Additional Resources
- SimpleNursing.com: Offers study plans, videos, practice questions.
- YouTube: Subscribe for more educational videos.
- Expert Team: Thanks to the team for content creation.
These notes provide a comprehensive overview of key electrolyte information crucial for NCLEX preparation.