NORCET ADVANCE TNC Series -91 || #NCLEX Pattern || Daily 5.00 Pm || AIIMS || ALL NURSING EXAM

Key Concepts

• Body Fluid Compartments: Intracellular Fluid (ICF), Extracellular Fluid (ECF), Intravascular Fluid, Interstitial Fluid, Transcellular Fluid
• Fluid Volume Imbalances: Extracellular Fluid Volume Excess (Hypervolemia), Third Spacing
• Electrolytes: Sodium (Na+), Potassium (K+), Calcium (Ca2+), Magnesium (Mg2+), Phosphate (PO43-)
• Electrolyte Imbalances: Hyperkalemia (High Potassium)
• IV Fluids: Isotonic, Hypotonic, Hypertonic solutions
• Acid-Base Balance: Acidosis (Metabolic)
• Renal Physiology: Role of kidneys in fluid and electrolyte balance
• Hormonal Regulation: Aldosterone, ADH
• Clinical Manifestations: Signs and symptoms of fluid and electrolyte imbalances
• ECG Changes: Changes associated with hyperkalemia
• Nursing Interventions: Management of fluid and electrolyte imbalances

Body Fluid Compartments and Distribution

• The human body is composed of water and solids. In adults, water accounts for approximately 60% of body weight (about 42 kg in a 70 kg individual), while solids make up the remaining 40% (about 28 kg).
• Water distribution varies with age: newborns have about 80% water, adults 60%, and older adults around 55%.
• Body water is divided into two main compartments:
  • Intracellular Fluid (ICF): Fluid inside the cells, comprising about 2/3 of total body water (approximately 66% of total body water).
  • Extracellular Fluid (ECF): Fluid outside the cells, comprising about 1/3 of total body water (approximately 33% of total body water).
• The ECF is further subdivided into:
  • Intravascular Fluid: Fluid within blood vessels (plasma), making up about 4% of body weight.
  • Interstitial Fluid: Fluid between cells, making up about 14% of body weight.
  • Transcellular Fluid: Fluid in body cavities (e.g., cerebrospinal fluid, pleural fluid, synovial fluid, aqueous humor), making up about 2% of body weight.

Electrolytes and Normal Ranges

• Key electrolytes and their normal ranges:
  • Sodium (Na+): 135-145 mEq/L
  • Potassium (K+): 3.5-5.0 mEq/L (some sources say 5.1)
  • Calcium (Ca2+): 9-11 mg/dL
  • Magnesium (Mg2+): 1.6-2.6 mg/dL
  • Phosphate (PO43-): 2.7-4.5 mg/dL
• Sodium is the most abundant extracellular ion, while potassium is the most abundant intracellular ion.

Hyperkalemia: Causes, Manifestations, and Management

Causes of Hyperkalemia (KAATA)

• K: Kidney Disease: Impaired potassium excretion.
• K: Potassium-Sparing Diuretics: (e.g., spironolactone, amiloride) block aldosterone receptors, reducing potassium excretion.
• A: Addison's Disease: Decreased production of aldosterone, leading to reduced sodium retention and potassium excretion.
• T: Tissue Damage: (e.g., burns, surgery, prolonged blood transfusions) release intracellular potassium into the bloodstream.
• A: Acidosis: (Metabolic) causes hydrogen ions to enter cells, displacing potassium into the extracellular space.

Clinical Manifestations of Hyperkalemia

• Cardiovascular:
  • Slow, weak, and irregular pulse.
  • Hypotension.
  • Dysrhythmias.
• Neuromuscular:
  • Vague muscle weakness (may be the first symptom).
  • Muscle twitching and cramps.
  • Paresthesia (numbness and tingling).
  • In severe cases, flaccid paralysis.
  • Respiratory failure (due to respiratory muscle weakness).
• Gastrointestinal:
  • Increased GI motility, leading to diarrhea.
• ECG Changes:
  • Flat P waves.
  • Widened QRS complex.
  • Prolonged PR interval.
  • Tall, peaked T waves.

Management of Hyperkalemia

• Potassium Removal:
  • Furosemide (Lasix): A loop diuretic to increase potassium excretion via urine.
  • Sodium Polystyrene Sulfonate (Kayexalate): Administered orally or rectally to bind potassium in the GI tract and promote excretion. (Dosage: 30-60 grams)
• Intracellular Shifting:
  • Insulin: Promotes potassium entry into cells. Administer with dextrose to prevent hypoglycemia. (Regular insulin 8-10 units)
• Dysrhythmia Management:
  • Calcium Gluconate or Calcium Chloride: Administered to stabilize the myocardium and counteract the effects of hyperkalemia on the heart.

IV Fluids: Types and Characteristics

• Isotonic Solutions: Have similar osmolality to blood (approximately 275-295 mOsm/L).
  • 0.9% Normal Saline (NaCl): Contains 154 mEq/L of sodium and 154 mEq/L of chloride (total osmolality ~308 mOsm/L).
  • Lactated Ringer's (LR): Contains sodium, potassium, calcium, chloride, and lactate. Has an osmolality of approximately 273 mOsm/L. Contraindicated in liver disease and hyperkalemia due to lactate and potassium content. Also known as Hartmann's solution.
  • 5% Dextrose in Water (D5W): Initially isotonic but becomes hypotonic as dextrose is metabolized. Considered a "physiologic hypotonic" solution.
  • 5% Dextrose in 1/4 Normal Saline (D5 0.225% NaCl): Also becomes hypotonic after dextrose metabolism.
• Hypotonic Solutions: Have lower osmolality than blood.
  • 0.45% Normal Saline (1/2 NS): Contains 0.45% NaCl.
  • 1/3 Normal Saline: Contains 0.33% NaCl.
  • 1/4 Normal Saline: Contains 0.225% NaCl.
• Hypertonic Solutions: Have higher osmolality than blood.
  • 3% Normal Saline, 5% Normal Saline, 10% Normal Saline
  • 5% Dextrose in 0.9% Normal Saline (D5NS)
  • 5% Dextrose in 0.45% Normal Saline (D5 1/2 NS)
  • 5% Dextrose in Lactated Ringer's (D5LR)
  • 10% Dextrose in Water (D10W)

Extracellular Fluid Volume Excess (Hypervolemia)

Types of Extracellular Fluid Volume Excess

• Hypertonic: ECF volume increases, ICF volume decreases.
• Isotonic (Hypervolemia): ECF volume increases, ICF volume remains normal.
• Hypotonic: ECF volume increases, ICF volume increases.

Clinical Manifestations of Extracellular Fluid Volume Excess

• Cardiovascular:
  • Bounding pulse.
  • Distended neck and hand veins.
  • Increased central venous pressure (CVP).
  • Increased pulse rate.
• Pulmonary:
  • Crackles (rales) in the lungs.
  • Increased respiratory rate.
  • Dyspnea.
  • Shallow respirations.
• Neuromuscular:
  • Skeletal muscle weakness.
  • Headache.
  • Visual disturbances.
  • Altered level of consciousness.
  • Paresthesia.
• Gastrointestinal:
  • Diarrhea (due to increased GI motility).

Causes of Extracellular Fluid Volume Excess

• Renal failure.
• Heart failure.
• Corticosteroid use (sodium and water retention).
• Excessive sodium ingestion.
• Syndrome of Inappropriate Antidiuretic Hormone (SIADH).
• Uncontrolled IV therapy.
• Sodium bicarbonate administration.

Management of Extracellular Fluid Volume Excess

• Monitor weight.
• Administer diuretics.

IV Piggyback Administration

• Preparation:
  • Wear clean gloves to check the IV site.
  • Rotate the bag after adding medication.
  • Use sterile technique when preparing the medication.
• Administration:
  • Place the IV piggyback bag at a higher level than the primary IV solution.

Conclusion

This comprehensive summary covers the key concepts and details discussed in the YouTube video transcript. It includes information on body fluid compartments, electrolyte imbalances (particularly hyperkalemia), IV fluids, and extracellular fluid volume excess. The summary provides actionable insights and preserves the technical precision of the original transcript, making it a valuable resource for understanding and applying the information presented.