Definitions / Physiology

Question 1

What is a massive transfusion

Answer 1

10 units or more of whole blood in 24 hrs or over 4 units in 1 hr

Question 2

What is pulse pressure

Answer 2

Systolic - diastolic

Question 3

What is cardiac output

Answer 3

HR x Stroke Volume

Question 4

What is stroke volume

Answer 4

Preload - End diastolic volume

Question 5

What is after load

Answer 5

the amount of pressure required for the heart to eject blood

Question 6

What affects after load

Answer 6

systemic vascular resistance

Question 7

Explain why cardiac output goes down in cariogenic shock

Answer 7

SVR increases as blood is redirected back centrally to the heart, given it is failing/not perfusing adequately.

However the increase in aferload decreases ejection fraction/ CO

To compensate HR goes up.

This is why patients in MI look clammy, pale, cold and shut down

Question 8

Explain why CO goes UP in a septic patient

Answer 8

Inflammatory changes cause chatecolemine release causing massive vasodilation.

SVR goes down. Given this perfusion through the body goes down and HR increases to compensate

Question 9

Why does base deficit increase in hypovolaemic shock / shock in general

Answer 9

a decrease in perfusion causes an increase in lactic ACID +/- an increase in CO2 .

Metabolic alkalosis will try and stabilise ph

so there will be an increase