Pathophysiology of congestion and oedema

Question 1

What is Darcy’s law?

Answer 1

Q = blood flow
P = pressure
R = resistance

Q = total P / R

Question 2

What law states flow is determined by total pressure divided by resistance?

Answer 2

Darcys law

Question 3

What is congestion?

Answer 3

Excess of blood in vessels or tissue, passive process secondary to something else

Question 4

Name an example of local acute congestion

Answer 4

Deep vein thrombosis

Question 5

Name an example of local chronic congestion

Answer 5

Hepatic cirrhosis

Question 6

Name an example of generalised acute congestion

Answer 6

Congestive heart failure

Question 7

What causes hepatic cirrhosis?

Answer 7

Hep B

Alcohol

Question 8

How does hepatic cirrhosis lead to congestion?

Answer 8

Damage causes fibrosis, leading to a loss of normal architecture and can block portal blood flow

Question 9

What are two possible consequences of hepatic cirrhosis and blockage of portal blood flow?

Answer 9

Oesophageal varices
Caput medusa (palm tree sign) - engorged superficial epigastric vein from umbilicus that can shunt to the femoral arteries

Question 10

Define congestive heart failure

Answer 10

heart is unable to clear blood from right and left ventricles, ineffective pumping due to ischaemia or valve disease, so it cant meet the bodies needs

Question 11

What are some signs and symptoms of CHF?

Answer 11

SOB, worse when lying down
Fatigue
Leg swelling (oedema)

Question 12

What can cause CHF?

Answer 12

Valve disease
IE
MI 
Hypertension
AF
Excessive alcohol consumption
Cardiomyopathy

Question 13

How does CHF cause oedema etc?

Answer 13

Decreased CO leads to decreased GFR. This activates the RAAS system, leading to Na and H20 retention, causing oedema and increasing blood pressure.

Question 14

How do you treat CHF?

Answer 14

Diuretics

Question 15

What are some clinical signs of CHF?

Answer 15

Pulmonary oedema
Left heart failure
Tachycardia
Right heart failure
Increased JVP
Hepatomegaly
Peripheral oedema

Question 16

What can be seen histologically in CHF?

Answer 16

Nutmeg liver - red/brown and pale spotty appearance macroscopically

Question 17

What is Starlings hypothesis?

Answer 17

Starling’s hypothesis states that the fluid movement due to filtration across the wall of a capillary is dependent on the balance between the hydrostatic pressure gradient and the oncotic pressure gradient across the capillary.

Question 18

What are the 4 starlings forces?

Answer 18

Capillary oncotic pressure
Capillary hydrostatic pressure
Interstitial oncotic pressure
Interstitial hydrostatic pressure

Question 19

What three components affect net fluid flux and filtration?

Answer 19

Hydrostatic pressure
Oncotic pressure
Permeability and area of endothelium

Question 20

What is ascites?

Answer 20

Abnormal fluid accumulation in the peritoneal/abdominal cavity

Question 21

What are effusions?

Answer 21

Fluid collections in body cavities

Question 22

What is the difference between transudates and exudates?

Answer 22

Transudates - alterations in haemodynamic forces

Exudates - changes in vascular permeability

Question 23

Which has higher protein content: transudates or exudates?

Answer 23

Exudates

Question 24

What causes transudates?

Answer 24

Cardiac failure

Fluid overload

Question 25

What causes exudates?

Answer 25

Inflammation
Tumours
Allergy
Burns

Question 26

What causes pulmonary oedema?

Answer 26

Transudates

Question 27

What type of oedema is linked to left sided failure?

Answer 27

Pulmonary oedema

Question 28

What type of oedema is linked to right sided failure?

Answer 28

Peripheral oedema

Question 29

What is the result of lymphatic blockage?

Answer 29

Lymphoedema

Question 30

What can cause hypoalbuminaemia and decreased protein levels?

Answer 30

Nephrotic syndrome
Hepatic cirrhosis
Malnutrition