Haemodynamic disorders

Question 1

What are the aetiologies affecting oedema?

Answer 1

Increased hydrostatic pressure
Salt/H2O retention
Reduced plasma oncotic pressure
Inflammation
Lymphatic obstruction

Question 2

What are the causes of generalised oedema?

Answer 2

Left heart failure
Inflammation
Venous hypertension
Lymphatic obstruction

Question 3

What are the causes of localised oedema?

Answer 3

Congestive heart failure
Low protein content
Nutritional oedema

Question 4

What causes of pulmonary oedema?

Answer 4

L heart failure = ↑ hydrostatic pressure in pulmonary capillary bed
∴Fluid accumulates in interstitial and alveolar space

Question 5

What causes cerebral oedema?

Answer 5

Cytotoxic derangement of Na+/K+ ATPase pumps

Vasogenic increased permeability of capillaries and venules

Question 6

What is a possible consequence of pulmonary oedema?

Answer 6

Pneumonia

- Fluid predisposes to bacterial infection

Question 7

What is a possible consequence of cerebral oedema?

Answer 7

Midline shift can occur

Question 8

Define thrombosis

Answer 8

Abnormal clot formation

Question 9

Define embolism

Answer 9

Abnormal material within circulatory system carried to distant site from origin

Question 10

Define infarction

Answer 10

isachemic necrosis caused by occlusion of venous drainage or arterial supply

Question 11

What are 3 possible causes of thrombosis (Virchow’s triad)?

Answer 11

Endothelial injury
Stasis/turbulent flow
Hypercoagulability

Question 12

What are the possible consequences of venous thrombosis?

Answer 12

Pulmonary embolism if clot travels to lung

Question 13

What are the possible consequences of arterial thrombosis?

Answer 13

Occlusion can cause tissue infarction

Stenosis causes isachemia

Question 14

What are the 4 possible fates of a thrombosis?

Answer 14

Propagation (growth)
Embolise
Dissolve
Organisation and recanalisation

Question 15

What are 5 possible causes of an embolus?

Answer 15

Dislodged thrombus
Fat
Air
Tumours
Amniotic fluid

Question 16

What are possible consequences of an embolus?

Answer 16

Lodge in larger vessels and block them off
Large emboli can lead to tissue infarction
Stroke
Bowel infarction
Limb isachemia

Question 17

What are the two types of infarct?

Answer 17

Red - caused by venous occlusion

White - caused by arterial occlusion

Question 18

How do infarcts heal?

Answer 18

Heal by repair
Structural integrity maintained
Permanent loss of functional tissue

Question 19

Define haemorrhage

Answer 19

Extraversation of blood due to vessel rupture

Question 20

What are 2 causes of haemorrhage?

Answer 20

Trauma

Intrinsic vessel disease e.g. Marfans

Question 21

What are possible consequences of a haemorrhage?

Answer 21

Hypovolaemic shock

Death

Question 22

What are the 5 main types of shock?

Answer 22

Hypovolaemic
Cardiogenic
Anaphylactic
Septic
Neurogenic

Question 23

What causes hypovolaemic shock?

Answer 23

Fluid loss

Question 24

What causes cardiogenic shock?

Answer 24

Acute myocardial infarction meaning heart cannot pump enough blood to meet the body’s demands

Question 25

What are the 4 characteristics associated with systemic inflammatory response syndrome?

Answer 25

Tachycardia Increased white cell count Temp over 38 or below 36 Tachypnoea or low CO2

Question 26

What causes septic shock?

Answer 26

SIRS + infection + organ hypoperfusion despite adequate fluid resuscitation or the use of vasopressors/inotropes to maintain BP

Question 27

What are consequences of septic shock?

Answer 27

Organ dysfunction and multi-organ failure Ischemic tissue - lactic acidosis Acute tubular necrosis

Question 28

What is the mechanism of septic shock?

Answer 28

Pathogens release endotoxins Activate complement pathway Damage endothelial cells Tumour necrosis factor