Shock

Question 0

Where does peripheral vascular disease most commonly affect?

Answer 0

The legs

Question 1

What can poor regional perfusion be caused by?

Answer 1

Arterial occlusion

Venous congestion

Question 2

What percentage of blood volume to veins contain?

Answer 2

70%

Question 3

What can varicose veins lead to?

Answer 3

Venous ulcers

Question 4

What are varicose veins?

Answer 4

Dilated, torturous superficial veins

Question 5

What is cardiac arrest?

Answer 5

When the heart has stopped or ceased to pump effectively

Patient is unresponsive and has a lack of pulse

Question 6

What are the two types of cardiac arrest?

Answer 6

Asystole - where there is a loss of electrical and mechanical activity
Ventricular fibrillation - uncoordinated electrical activity

Question 7

When may ventricular fibrillation happen?

Answer 7

Following an MI
Electrolyte imbalance
Arrhythmias such as long QT or Torsades de Pointes

Question 8

Treatment of cardiac arrest?

Answer 8

Basic life support - chest compression and external ventilation
Advanced life support - defibrillation
Adrenaline

Question 9

What does defibrillation do?

Answer 9

Electric current delivered to the heart
Depolarises cells putting them into the refractory period
Allows coordinated electrical activity to restart

Question 10

What does administration of adrenaline do in cardiac arrest?

Answer 10

Enhances myocardial function

Increases peripheral resistance

Question 11

What is shock?

Answer 11

An acute condition of inadequate blood flow throughout the body. There is a catastrophic fall in arterial blood pressure leading to circulatory shock

Question 12

Equation to find mean arterial blood pressure?

Answer 12

Mean arterial BP = CO x TPR

Question 13

What can a fall in cardiac output be due to?q

Answer 13

Mechanical where the pump cannot fill
Pump failure
Loss of blood volume

Question 14

What can a fall in peripheral resistance be due to?

Answer 14

Excessive vasodilation

Question 15

What is cardiogenic shock?

Answer 15

Acute failure of the heart to maintain cardiac out out - pump failure

Question 16

What can cardiogenic shock be due to?

Answer 16

Myocardial infarction where there is damage to the left ventricle
Serious arrhythmias
Acute worsening of heart failure

Question 17

What happens to arterial and venous blood pressure in cardiogenic shock?

Answer 17

Arterial - drops

CVP - normal or raised

Question 18

What is cardiac tamponade?

Answer 18

Blood or fluid build up in pericardial space

Question 19

What happens to CVP and arterial blood pressure in mechanical shock?

Answer 19

Arterial is low

CVP is high

Question 20

What can mechanical shock be due to?

Answer 20

Cardiac tamponade

Pulmonary embolism

Question 21

What is mechanical shock?

Answer 21

When the ventricle cannot fill properly

Question 22

Explain how a pulmonary embolism can lead to shock and leads to high CVP

Answer 22

Embolus occludes a large pulmonary artery
Pulmonary artery pressure is high
Right ventricle cannot empty
CVP is high
Reduced return of blood to left heart

Question 23

Causes of hypovolaemic shock?

Answer 23

Haemorrhage
Severe burns
Severe diarrhoea or vomiting and loss of Na

Question 24

How much blood do you need to show some signs of shock and then serious shock?

Answer 24

20-30% - some signs | 30-40% - serious

Question 25

What initially happens to blood pressure and cardiac output when there is a haemorrhage?

Answer 25

Venous pressure falls Cardiac output falls due to Starling's law Arterial pressure falls

Question 26

What is the compensatory response to haemorrhage?

Answer 26

``` Arterial pressure drop is detected by baroreceptors Increased sympathetic stimulation Tachycardia Increased force of contraction Peripheral vasoconstriction Venoconstriction ```

Question 27

Signs of hypovolaemic shock?

Answer 27

Tachycardia Weak pulse Pale skin Cold, clammy extremities

Question 28

What does peripheral vasoconstriction lead to?

Answer 28

``` Impaired tissue function Tissue damage due to hypoxia Release of vasodilators Fall in TPR Drop in blood pressure Vital organs no longer perfused ```

Question 29

What is distributive shock?

Answer 29

When the blood volume is constant, but volume of the circlulation has increased due to a drop in total peripheral resistance

Question 30

What type of shock is toxic and anaphylactic shock?

Answer 30

Distributive

Question 31

What happens in toxic shock?

Answer 31

Endotoxins are released by circulating bacteria Cause profound vasodilation Fall in TPR Fall in arterial pressure Impaired perfusion of vital organs Capillaries become leaky, reducing blood volume

Question 32

Signs of toxic shock?

Answer 32

Tachycardia Warm, red extremities Vasoconstriction in later stages

Question 33

What happens in anaphylactic shock?

Answer 33

Release of histamine from mast cells Powerful vasodilator - fall in TPR Drop in arterial pressure Increased sympathetic response but cannot overcome vasodilation Impaired perfusion of vital organs Bronchoconstriction and laryngeal oedema caused by mediators

Question 34

Signs of anaphylactic shock?

Answer 34

Difficulty breathing Collapsed Tachycardia Red, warm extremities

Question 35

What is administered in anaphylactic shock and what is its effect?

Answer 35

Adrenaline | Vasoconstriction via action at α1 receptors

Question 36

Which types of shock lead to a decrease in total peripheral resistance?

Answer 36

Distributive shock - anaphylactic - toxic

Question 37

Which types of shock lead to a decrease in cardiac output?

Answer 37

Hypovolaemic Cardiogenic Mechanical

Question 38

What are the three sites of regulation of blood pressure? How do each of these sites regulate it?

Answer 38

Kidneys - regulate blood volume Heart - alter rate and force of contraction Vasculature - regulate TPR

Question 39

What can hypertension lead to?

Answer 39

Left ventricular hypertrophy -risk of heart failure Arterial disease - coronary arteries ➡️ MI/angina - cerebrovascular system ➡️ stroke - renal vasculature ➡️ kidney failure - retina - aorta

Question 40

Treatment of hypertension?

Answer 40

Diuretics Vasodilators ACE inhibitors Beta blockers