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Question 1

What is cardiogenic shock?When does it occur?

Answer 1

Inability of heart to eject enough blood MI, serious arrhythmias, acute worsening on heart failure

Question 2

What is mechanical shock?When does it occur?

Answer 2

Due to:1. Restriction on heart filling e.g. Cardiac tamponade2. Obstruction to blood flow thorough lungs e.g. Pulmonary embolism

Question 3

What happens in cardiogenic shock?

Answer 3

Heart fills, but can’t pump effectivelyDrop in arterial BPTissues are poorly perfused

Question 4

What happens in cardiac tamponade?

Answer 4

Blood in pericardial space, restricts heart filling, lowers end diastolic volHave high CVP and low arterial BP

Question 5

What happens in a pulmonary embolism?

Answer 5

embolus occludes large pulmonary artery, RV cant empty, incerase pulmonary artery pressure, limits left heart filling, low left arterial pressure, low arterial blood pressure –> shockCauses chest pain and dyspnoea

Question 6

What causes hypovolaemic shock?

Answer 6

Reduced blood volumeUsually due to haemorrhage 20-30% loss = some signs of shock30-40% loss = substantial mean BP decrease, serious shock response– severe burns– sever diarrhoea, vomiting and loss of Na+

Question 7

What is the severity of hypovolaemic shock related to?

Answer 7

amount and speed of blood loss

Question 8

What are the effects of hypovolaemic shock?What is the compensatory response of the body?

Answer 8

Venous pressure falls causing cardiac output to fall. Arterial pressure falls, detected by baroreceptors which causes:– increased sympathetic stimulation– tachycardia– increase force of contraction– peripheral vasoconstriction– venoconstriction

Question 9

Describe internal transfusion and why it is present in hypovolaemic shock

Answer 9

Increased peripheral resistance decreases the capillary hydrostatic pressure. Fluid moves into capillaries from tissue

Question 10

What are the clinical signs of hypovolaemic shock?

Answer 10

TachycardiaWeak pulsepale skincold and clammy extremities

Question 11

What are the overall effects of peripheral vasoconstriction?

Answer 11

Impairs tissue perfusion– hypoxia causes tissue damage– vasodilators released– TPR falls– BP falls– vital organs aren’t perfused– multi-system failure

Question 12

What is distributive shock also known as?What is distributive shock?When does it occur?

Answer 12

Normovolaemic shockDue to uncontrolled falls in peripheral resistance. There is increased peripheral vasodilation decreasing TPR(Blood vol is constant, but the volume of the circulation has increased)Toxic and anaphylactic shock

Question 13

Describe what happens in toxic shock

Answer 13

Endotoxins are released by circulating bacteria– cause vasodilation, decreased TPR, decreased arterial pressure, impaired perfusion of vital organs, capillaries become leaky reducing blood volume– decreased arterial pressure increases sympathetic output, increasing HR and stroke volume

Question 14

What are the clinical signs of toxic shock?

Answer 14

TachycardiaWarm, red extremities

Question 15

What are the clinical signs of anaphylactic shock?

Answer 15

– difficulty breathing – bronchoconstriction and laryngeal oedema – collapsed– rapid heart rate– red, warm extremities

Question 16

What happens in tissues in an anaphylactic shock?

Answer 16

Release of histamine from mast cells as well as leukotrienes and bradykininCauses fall in TPR due to vasodilator effectsFall in arterial pressure, increasing sympathetic response to increase COVital organ perfusion is preventedBronchoconstriction and laryngeal oedema occur

Question 17

What is the treatment for anaphylactic shock? What does it do?

Answer 17

AdrenalineCauses vasoconstriction via actin present at alpha one receptor in blood vessels Causes and increase in TPR, increasing arterial pressure

Question 18

How can you treat cardiogenic shock?

Answer 18

Getting fluids into the patient

Question 19

What is the pulmonary arterial occlusion pressure?How is it measured?

Answer 19

Catheter which is entered into femoral vein and travels up to heart to measure pressure in pulmonary artery. A pressure transducer on the end of the catheter is wedged into a small pulmonary artery to measure pressure in the left atrium.

Question 20

How would you treat septic shock?

Answer 20

Fluids and antibiotics

Question 21

How would you treat hypovolaemic shock?

Answer 21

Infuse 500ml of fluids then measure to see if BP and HR have stabilised. If not, measure central venous pressure by JVP to see if they have fluid overload.

Question 22

What are some chemical mediators released in anaphylaxis?

Answer 22

HistamineLeukotrienesBradykinin

Question 23

Define general shock

Answer 23

Acute circulatory failure as a result of inadequate or inappropriately distributed tissue perfusion, resulting in generalised lack of O2