Pathophysiology of Congestion and Oedema

Question 1

Explain congestive heart failure (pathophysiology)

Answer 1

Heart unable to clear blood, right & left ventricles
- ineffective pump eg ischaemia, valve disease

• Decreased Cardiac Output (CO)
• Decreased Renal Glomerular Filtration Rate (GFR)*
  ~ activation of renin-angiotensin-aldosterone system
  ~ Increased Na and H2O retention*
• Increased amount of fluid in body

Increased Fluid (overload) in veins (Treatment: diuretics)

Question 2

List the causes of vascular congestion

Question 3

Define the term exudate

Answer 3

• Part of inflammatory process* due to  vascular permeability
• Tumour, inflammation, allergy
• Higher protein/albumin content (cells)
• H2O & electrolytes
• High specific gravity

Question 4

Define the term transudate

Answer 4

• Changes in the forces acting across capillary wall
• Cardiac failure, fluid overload
• Not much protein/albumin (few cells)
• Lots of H2O & electrolytes
• Low specific gravity

Question 5

Describe the Starling forces affecting fluid movement across the capillaries

Question 6

How do disturbances in starling forces cause oedema