The pathophysiology of congestion and oedema

Question 1

Define congestion

Answer 1

Relative excess of blood in vessels to tissue or organ

Question 2

Why is congestion not like acute inflammation

Answer 2

As active hyperaemia occurs in acute inflammation due to an active process however congestion is due to a secondary process

Question 3

What is the 3 pathological examples

Answer 3

Local acute congestion
Local chronic congestion
generalised acute congestion

Question 4

What is a clinical example of local acute congestion

Answer 4

Deep vein thrombosis

Question 5

What is the pathway of deep vein thrombosis that leads to infarction

Answer 5

Their is a blockage in the vein due to thrombosis, this causes a a back up blood in the veins,
decreasing the outflow of blood = local congestion

Pressure gradient decreases, and therefore decreases flow across the system, which decreases the amount of oxygen in the tissue resulting in ischaemia and infarction

Question 6

What is a clinical example of local chronic congestion

Answer 6

Hepatic cirrhosis

Question 7

What is the cause of hepatic cirrhosis

Answer 7

Serious liver damage (due to alcohol, HBV etc)

Question 8

local chronic congestion increases the risk of what

Answer 8

Haemorrhage

Question 9

What is the consequence of hepatic cirrhosis

Answer 9

Portal systemic shunts-s a bypass of the liver by the body’s circulatory system

Question 10

What is a clinical examples of generalised acute congestion

Answer 10

Congestive cardiac failure

Question 11

What is congestive cardiac failure

Answer 11

heart unable to clear blood from the right and left ventricles

Question 12

What is the aetiology of congestive heart failure

Answer 12

Ineffective pumps due to ischaemia or valvular disease

Question 13

What is the pathophysiology of congestive heart failure

Answer 13

Ineffective pumps decrease the cardiac output,
decreasing the renal glomerular filtrate rate
which increases tubular retention of ionic water
This increases the amount of fluid in the body,
and causes a increase fluid overload in the veins that become congested

Question 14

What is the treatment for congestive heart failure to reduce the fluid overload

Answer 14

Diuretics

Question 15

How does damage to other organs occur in congestive heart failure

Answer 15

heart cannot clear the blood from ventricles, resulting in back pressure and blood draining back in the veins

Question 16

What causes central venous congestion in the liver

Answer 16

Right heart failure

Question 17

What are the clinical signs of right heart failure causing central venous congestion in the liver

Answer 17

increased JVP
Hepatomegaly
peripheral oedema

Question 18

What causes pulmonary oedema (acute or chronic) in the lungs

Answer 18

Left heart failure

Question 19

What is the clinical sings of left heart failure causing pulmonary oedema

Answer 19

Crepitations in the lungs breathlessness

tachycardia

Question 20

What is the morphology of central venous congestion

Answer 20

Nutmeg” liver red/brown (pericentral); pale spotty (periportal) appearance macroscopically

Question 21

What are the three components that affect net flux and filtration around the body

Answer 21

hydrostatic pressure from heart
Balanced by osmotic pressures
endothelial permeability

= starlings forces

Question 22

Upsetting any of the starling forces can lead to what

Answer 22

Oedema

Question 23

Define oedema

Answer 23

Accumulation of abnormal amounts of fluid in the extravascular compartment;
intercellular tissue compartment (extracellular fluid)
or
body cavities

Question 24

Increased interstitial fluid results in what type of oedema

Answer 24

Peripheral oedema

Question 25

Fluid collection in the body cavities results in what type of oedema

Answer 25

Effusion oedema

Question 26

What is the two aetiologies of oedema

Answer 26

Trasudate oedema - alteration of the haemodynamic forces which act across the capillary wall Exudate oedema - part of the inflammatory price due to an increase in vascular permeability

Question 27

What is the causes of transudate oedema

Answer 27

Cardiac failure | Fluid overload

Question 28

What is the cause of exudate oedema

Answer 28

Tumour Inflammation allergy

Question 29

What is the differences between truncate and exudate

Answer 29

Exudate; high protein and albumin content where transudate has a low content Transudate has more H2O and electrolytes than exudate Exudate is high specific gravity, where transudate has low specific gravity (due to protein contents)

Question 30

What is the different aetiologies of oedema

Answer 30

Congestive heart failure: LH- Pulmonary oedema RH -Peripheral oedema Lymphatic blockage hypoalbuminaemia abnormal renal function inflammation

Question 31

What is the aetiology of pulmonary oedema

Answer 31

Transudate - Left ventricular failure upsetting hydrostatic pressure

Question 32

What is the pathophysiology of pulmonary oedema

Answer 32

Left ventricular failure, increase left atrial pressure, this back flows to increase pulmonary vascular pressure, increasing pulmonary blood volume and concentration This increase the filtration and in the lungs water flows out into the alveolar septa - creating a accumulation f oedema fluid in alveolar spaces

Question 33

What is the aetiology of peripheral oedema

Answer 33

transudate - due right heart failure -unable to empty RV in systole or -secondary portal venous congestion via the liver

Question 34

What is the pathophysiology of peripheral oedema

Answer 34

Heart unable to empty right ventricle in systole, therefore blood is retained in the systemic veins, increasing the pressure in the capillaries, which increase the filtration, resulting in the peripheral oedema

Question 35

What can cause pulmonary oedema and peripheral oedema at the same time

Answer 35

Congestive heart failure - as right and left ventricles fail

Question 36

What is the pathophysiology of lymphedema causing oedema

Answer 36

Lymphatic system is blocked, this results in fibrosis, decreasing the outflow, therefore accumulation of fluid results in oedema

Question 37

What is the aetiology of reduced renal blood flow - decreased renal function

Answer 37

Primary to acute tubular damage e.g. hypotension | Secondary to Heart failure

Question 38

What is the pathophysiology of decreased renal function and oedema

Answer 38

Abnormal renal function results in Salt (NaCl) and H2O retention This increase intravascular fluid volume causes oedema

Question 39

What is the different clinical example of how hypoalbuminameia conditions that result oedema

Answer 39

- nephrotic syndrome leaky renal glomerular basement membrane; lose protein; - hepatic cirrhosis diffuse nodules and fibrosis in liver; liver unable to synthesise enough protein - malnutrition insufficient intake of protein

Question 40

How does hypoalbuminaemia result in oedema

Answer 40

Oncotic pressure is dependant is normal protein levels, if protein levels decrease, oncotic pressure decrease, therefor increasing filtration resulting in oedema

Question 41

What is the aetiology of permeability oedema

Answer 41

exudate - Acute inflamaation, eg pneumonia, burns etc

Question 42

What is the pathophysiology of permeability oedema

Answer 42

Damage to the endothelia lining, causes an increase in pore size in the membrane, therefore proteins and larger molecules as well as H2O can leak out resulting in oedema