Fluid, electrolyte, imbalances

Introduction

  • Overview of objectives for session: fluid electrolytes, rehydration, complications, blood products, and nurse's role.

Electrolytes

  • Definition: Minerals measured in urine, blood, and tissues.

  • Key Electrolytes: Potassium, sodium, magnesium, phosphorus.

  • Sources: Naturally occurring in body; obtained from food and drinks.

  • Testing: Physicians often order CMP (Complete Metabolic Panel) or BMP (Basic Metabolic Panel) to evaluate electrolytes.

Functions of Electrolytes

  • Maintain water volume in the body.

  • Help with pH balance (acid-base balance).

  • Facilitate nutrient absorption and waste removal from cells.

  • Support functioning of heart, muscles, nerves, and brain.

  • Significance of balance: High or low levels cause symptoms and complications.

Dehydration and Water Loss

  • Water Composition: Average person: 50-70% water by weight.

    • Males ~60%, Females ~54%, Infants ~70%.

  • Consequences of Dehydration: Leads to tachycardia, tachypnea, confusion, headaches, kidney stones.

  • Causes of Water Loss: Urine excretion, vomiting, diarrhea, sweating.

  • Homeostasis: Body works to maintain balance of water and electrolytes.

Thirst Mechanism

  • Triggered by serum osmolality and decrease in body fluid volume.

  • Antidiuretic Hormone (ADH): Increases water reabsorption, decreases urine excretion, aiding fluid retention.

  • Osmosis: Movement of water across cell membranes from low to high solute concentration.

Electrolyte Imbalances

  • Causes: Dehydration, medications, kidney/liver/heart disorders, incorrect IV fluids.

  • Potassium and Sodium: Often monitored together; potassium is critical for heart function.

  • High alert medications: Potassium (high risk if administered incorrectly).

Normal Electrolyte Values

  • Potassium: 3.5 - 5.0 mEq/L

  • Sodium: 135 - 145 mEq/L

  • Calcium: 8.5 - 10.5 mg/dL

  • Magnesium: 1.8 - 2.2 mg/dL

  • Important to recognize normal ranges for treatment decisions.

Potassium

  • Critical for nerve and muscle cell function, including heart muscle.

  • Excretion: 90% through kidneys, also through sweat and GI tract.

  • Hypokalemia: < 3.5 mEq/L

  • Hyperkalemia: > 5.0 mEq/L

  • Risks associated with administration: potential for cardiac arrest if given incorrectly.

Sodium

  • Prevalent electrolyte that regulates nerve and muscle function and blood pressure.

  • Ingested through food, primarily excreted via urine and sweat.

  • Low sodium diets limited to <2000 mg/day.

Calcium

  • Essential for strong bones/teeth and muscle function.

  • Majority stored in bones; absorption dependent on Vitamin D levels.

  • Deficiency Risk: Increased in older adults, especially post-menopause (osteoporosis risk).

Signs of Electrolyte Deficiency

  • Trousseau's Sign: Twitching from tapping facial nerve (hypocalcemia).

  • Chvostek's Sign: Spasm after blood pressure cuff applied (low calcium indicator).

Magnesium

  • Essential for nerve and muscle function, blood pressure regulation, and blood sugar control.

  • Normal range: 1.3 - 2.1 mEq/L.

Hypovolemia vs. Dehydration

  • Hypovolemia: Decreased volume of fluid in the vascular system (can be fluid loss or electrolyte loss).

  • Dehydration: General depletion of body fluid.

  • Warning signs include changes in consciousness, vital signs (increased heart rate, decreased blood pressure).

Hypervolemia

  • Excess fluid (causes: heart failure, kidney failure, excess IV fluids).

  • Signs: fluid overload, edema, altered lung sounds, shortness of breath, elevated blood pressure.

Nursing Interventions for Rehydration

  • Start with oral rehydration (glucose and electrolytes).

  • IV Fluid Types:

    • Hypotonic: e.g., 0.45% saline – treats hypernatremia.

    • Hypertonic: e.g., 3% saline – volume expansion, treat hypoglycemia.

    • Isotonic: e.g., Lactated Ringer's, normal saline to provide hydration.

Blood Products in Treatment

  • Blood loss replacement may require:

    • Packed Red Blood Cells (PRBCs): For surgery, trauma, anemia.

    • Whole Blood: Rarely used; severe cases only.

    • Plasma: Contains clotting factors, given for trauma, burns, shock.

    • Can be stored up to a year.

Intake and Output Monitoring

  • Intake: Oral and IV fluids.

  • Output: Urine, vomit, sweat.

  • Should be recorded regularly and accurately as per facility protocol.

Conclusion

  • Reiterate the importance of electrolyte balance, hydration, and nursing intervention strategies.