Congestion and oedema

Question 1

What is Darcy’s law

Answer 1

Flow = pressure gradient / resistance

Question 2

What is congestion

Answer 2

Relative excess of blood in vessels of tissue or organ

Question 3

Clinical example of local acute congestion

Answer 3

Deep vein thrombosis

Question 4

Clinical example of local chronic congestion

Answer 4

hepatic cirrhosis

Question 5

Clinical example of generalised acute congestion

Answer 5

congestive cardiac failure

Question 6

Why does DVT cause congestion

Answer 6

Thrombus blocks veins causing blood to back up into veins, venules and capillaries
Reduced outflow of blood, reduced pressure gradient so reduced flow

Question 7

What does hepatic cirrhosis result from

Answer 7

Serious liver damage - eg hepatitis or alcohol

Question 8

How does hepatic cirrhosis cause congestion

Answer 8

Liver tries to regenerate and forms nodules of hepatocytes with fibrosis between
Loss of normal architecture means altered hepatic blood flow, portal vein blocked so congestion

Question 9

What is local chronic congestion at risk of

Answer 9

haemorrhage

Question 10

Congestive cardiac failure pathophysiology

Answer 10

Heart unable to clear blood either because of ischaemia or valve disease
Reduced cardiac output means reduced glomerular filtration rate and activation of renin-angiotensin-aldosterone system, increasing amount of fluid

Question 11

Effect of congestive cardiac failure on lungs

Answer 11

Pulmonary oedema

Question 12

Effect of congestive cardiac failure on liver

Answer 12

Central venous congestion

Question 13

Clinical signs of congestive cardiac failure

Answer 13

Crepitations in lungs
Tachycardia
Raised JVP
Hepatomegaly
Peripheral oedema

Question 14

What is ‘nutmeg’ liver

Answer 14

Due to hepatic central venous congestion
Pericentral hepatocytes are red (stasis of poorly oxygenated blood)
Periportal hepatocytes are pale

Question 15

What three things ultimately effect movement of fluid through capillary beds

Answer 15

Hydrostatic pressure from heart
Osmotic pressure to balance
Endothelial permeability and area

Question 16

Which side of capillaries has high capillary hydrostatic and lower capillary oncotic pressure (filtration)

Answer 16

Arterial

Question 17

Which side does reabsorption occur

Answer 17

Venous

Question 18

Which equation shows the balance of normal components of microcirculation

Answer 18

Starling’s equation

Question 19

What is oedema

Answer 19

Accumulation of abnormal amounts of fluid in the extravascular compartment

Question 20

What is oedema called when it is:

a) increased interstitial fluid in tissues
b) fluid collections in body cavities

Answer 20

a) peripheral oedema

b) effusions

Question 21

Differences between transudate and exudate oedema

Answer 21

Transudate - alterations in haemodynamic forces, cardiac failure, not much protein, lots of water and electrolytes, low specific gravity

Exudates - part of inflammatory process, tumour inflammation allergy, higher protein content, high specific gravity

Question 22

When does pitting oedema occur

Answer 22

Left and right heart failure (congestive cardiac failure)

Question 23

What happens if the lymphatic system is blocked

Answer 23

Lymphoedema