Lecture Notes: Patient Care with Fluid, Electrolyte, and Acid-Base Imbalances

Overview

• Course Unit: 4
• Chapters Covered: 11 and 12
• Focus: Assessment and care of patients with fluid and electrolyte imbalances, and acid-base imbalances.

Fluid Imbalances

Types

• Fluid Volume Deficit

  • Commonly known as dehydration (e.g., hypovolemia)
  • Causes: Lack of fluid intake, diuretics, vomiting, diarrhea, fevers, burns, diabetes insipidus.
  • Symptoms: Rapid weight loss, thirst, hypotension, tachycardia, dry mucous membranes, reduced skin turgor, mental status changes.
  • Lab Indicators: Increased osmolality, urine specific gravity, and BUN.

• Fluid Volume Overload

  • Known as hypervolemia
  • Symptoms: Distended neck veins, lung sounds (fluid in lungs), pitting edema, rapid respirations, weight gain.

Nursing Considerations

• Monitor intake and output (I&O)
• Ensure adequate fluid intake
• Daily weights to monitor changes
• Observe mental status and physical assessments to prevent overcorrection.

Electrolyte Imbalances

Common Electrolytes

• Sodium (Na)

  • Hyponatremia: < 135 mEq/L
    • Symptoms: Headache, confusion, seizures, coma.
  • Hypernatremia: > 145 mEq/L
    • Causes: Water loss (e.g. diarrhea), excessive sodium intake.

• Potassium (K)

  • Hypokalemia: < 3.5 mEq/L
    • Causes: Diuretics (e.g., Lasix), steroids.
    • Symptoms: Cardiac issues, respiratory failure, hypoactive bowel sounds.
  • Hyperkalemia: > 5 mEq/L
    • Causes: Kidney failure, trauma, excessive potassium intake.
    • Symptoms: Cardiac dysrhythmias, muscle weakness.

• Calcium (Ca)

  • Hypocalcemia: < 4.5 mEq/L
    • Causes: Vitamin D deficiency, parathyroid disease.
    • Symptoms: Neuromuscular excitability, muscle spasms.
  • Hypercalcemia
    • Causes: Hyperparathyroidism.

• Magnesium (Mg)

  • Hypomagnesemia: < 1.5 mEq/L
    • Causes: Alcoholism, diabetes.
    • Symptoms: Seizures, GI upset.
  • Hypermagnesemia
    • Symptoms: Muscle weakness, respiratory and myocardial issues.

Acid-Base Imbalances

• pH Normal Range: 7.35 - 7.45
• Acidosis: pH < 7.35
• Alkalosis: pH > 7.45

Respiratory and Metabolic Components

• CO2 (Respiratory): 35-45 mm Hg
• HCO3 (Metabolic): 22-26 mEq/L
• ROME Mnemonic:
  • Respiratory Opposite: CO2 ↑ = pH ↓, CO2 ↓ = pH ↑
  • Metabolic Equal: HCO3 ↑ = pH ↑, HCO3 ↓ = pH ↓

Types of Imbalances

• Respiratory Acidosis

  • Causes: Respiratory depression, COPD, airway obstruction.
  • Lab: Low pH, high CO2.

• Respiratory Alkalosis

  • Causes: Hyperventilation, anxiety.
  • Lab: High pH, low CO2.

• Metabolic Acidosis

  • Causes: Diarrhea, renal failure.

• Metabolic Alkalosis

  • Causes: Vomiting (loss of stomach acid).

Nursing Responsibilities

• Monitor ABG results.
• Recognize symptoms and causes of electrolyte and acid-base imbalances.
• Understand treatment principles and patient safety.

Study Tips

• Memorize lab values for electrolytes.
• Understand associated symptoms and possible conditions.
• Learn to interpret ABG results and identify potential causes.