Pathophysiological Consequences of Edema

Homeostasis of the Internal Environment

• Maintaining the morphological and functional integrity of the organism requires:
  • Isovolemia (volume constancy)
  • Isoosmia (osmotic pressure constancy)
  • Isoionia (constancy of electrolyte composition)
  • Isohydria (acid-base status)

Distribution of Body Fluids

• Body fluid is distributed between:
  • Intracellular fluid (ICF)
  • Extracellular fluid (ECF)
• ECF includes:
  • Interstitial fluid (ISF)
  • Lymphatic system
  • Intravascular fluid
  • Transcellular fluids

Daily Traffic of Fluids in the Organism

• Daily intake: 2400-3200 ml
• Daily loss: 2400-3200 ml
• Sources of fluid intake:
  • Water and other fluids (1400-1800 ml)
  • Water in food (700-1000 ml)
  • Metabolic water (300-400 ml)
• Sources of fluid loss:
  • Urine (1400-1800 ml)
  • Feces (100 ml)
  • Skin (300-500 ml)
  • Lungs (600-800 ml)

Composition of ECF and ICF

• ECF:
  • Main cation: Na+
  • Main anion: Cl-
• ICF:
  • Main cation: K+
  • Main anion: P

Regulation of Water and Electrolyte Metabolism

• Two mechanisms regulate the total amount of water in the body:
  • Feeling thirsty
  • Secretion of ADH (Vasopressin)
• Hormonal regulation:
  • Mineralocorticoids (Aldosterone) regulate Na+ and K+ balance in the body

Disorders of Water and Electrolyte Metabolism

• Causes of hyperhydration:
  • Excess water
  • Excessive use of hypotonic i.v. solutions
  • Psychogenic polydipsia
  • Renal retention of water
  • Inadequate ADH secretion syndrome
• Causes of dehydration:
  • Water shortage in ECF
  • Reduced Na+ intake
  • Diuretic therapy
  • Extrarenal losses of Na+ (vomiting, diarrhea, suction, burns)

Pathophysiological Consequences

• Volume increase in ECF:
  • Increase in body weight
  • Increase in pulse pressure
  • Edema
  • Overflowing venous vessels
  • Congestive heart failure
• Volume reduce in ECF:
  • Reduction of body weight
  • Poorly charged pulse
  • Lowering of pressure
  • Decreased skin hydration
  • Collapsed venous vessels of the neck
  • Tachycardia
  • Decreased diuresis

Edema

• Definition: buildup of fluid in the interstitium
• Types:
  • Hemodynamic type
  • Oncodynamic type
  • Angiomural type
  • Lymphodynamic type
• Pathophysiological consequences of edema:
  • Hypoxia and insufficient energy production in cells
  • Tendency to dehydrate
  • Daily variations in body weight
  • Reduction of diuresis and sweating
  • Night urination
  • Morning darkness
  • Feeling bloated

Potassium Metabolism

• 98% of potassium is in ICF (150-160 mmol/L)
• Serum concentration: 3.5-5.5 mmol/L
• Functions:
  • Electrical activity of cells
  • Maintaining the osmolarity of the intracellular fluid
  • Glycogen deposition
  • Acid-base status
• Regulation of potassium excretion:
  • Filtration
  • Secretion (distal tubules and collecting ducts)
  • Reabsorption (end of collecting ducts)
• Etiology of hyperkalemia and hypokalemia:
  • Reduced concentration of potassium in the serum and reduced amount of potassium in the body
  • Reduced concentration of potassium in the serum and normal amount of potassium in the body
  • Normal or increased concentration of potassium in the serum, reduced amount of potassium in the body

Explore the pathophysiological consequences of edema, including volume increase in extracellular fluid, increased body weight, pulse pressure changes, edema overflow in venous vessels, heart failure, diuresis variations, and more. Learn about the definition and classification of edema.