Hemodynamic Basics

Question 1

What is the meaning of the term “Hemodynamics”?

What two components is taken into account?

Answer 1

The force by which blood circulates through the body

CO and BP

Question 2

Why is hemodynamics so important?

Answer 2

It helps with making sure the patient is accomplishing perfusion

Question 3

What is preload?

Answer 3

Amount of blood filling up the heart when it is relaxing at the end of diastole
- filling pressure

Question 4

What measurement reflects left ventricular preload ?

Answer 4

PCWP or wedge pressure

Question 5

What measurement goes with right ventricular pressure?

Answer 5

CVP

• central venous pressure
• fluid status measurement, remember?

Question 6

List examples that can INCREASED preload and explain why

Answer 6

Exercise (slightly)
- your heart is naturally working harder

Hypervolemia
- too much fluid so its filling more

Neuroendocrine excitement
- fight or flight

AV fistula*
- It allows you to bypass arterioles but it will increase the filling in the heart

Question 7

Name off examples that cause a DECREASE in preload and explain

Answer 7

Hypovolemia
- the heart can’t fill up if you are dry

Narrow/stenotic valves
- stops ventricle from filling adequately

A.Fib
- the quiver makes you lose the ability to fill and pump

Question 8

How would you explain Afterload?

Answer 8

The amount of pressure the heart has to overcome in order to perfuse the body

Question 9

Explain reasons for why there would be an INCREASE in Afterload

Answer 9

Increase systemic resistance (Blood pressure)

Aortic Stenosis
- the aorta supplies the body with blood ; if its valves are stenotic, you can’t push blood out which increases resistance

Myocardial Infarction/Cardiomyopathy

Polycythemia
- thicker blood can’t push out as easy to it has to overcome more pressure

Question 10

Another term for blood pressure?

Answer 10

SVR or systemic resistance
- often referred to as the same thing

note: svr also reflects after load

Question 11

What are some factors that DECREASE Afterload?

Answer 11

Decreased volume/dry
- you will have less resistance if your blood is “thinner”

Septic shock
- this is a state of vasodilation so vessel’s open up

End stage Cirrhosis
- Kidney issues are common with this. And if you’re kidneys aren’t working, your heart is affected

Vasodilating meds
- bc they widen the vessels to relax

Question 12

What happens to the fluid in a septic shock person with decreased afterload? What are the signs?

Answer 12

There can be third spacing

• Decreased BP after compensation doesn’t work
• Cap refill
• Edema

Question 13

Your patient has end state cirrhosis which is causing a decrease in their after load requirements. What might they look like?

Answer 13

Jaundice
Decrease in UO
Anemic
Bilirubin scabs

Question 14

Wha labs would you look at for a cirrhosis patient?

Answer 14

Lactate
ASLT
BUN
CR
wbc

Question 15

Contractility meaning

Answer 15

Strength of VENTRICLES contracting

Question 16

Inotropic meaning

Answer 16

Force or energy of the contraction

Question 17

Chronotropic meaning

Answer 17

Time and rate related; heart rate

Question 18

Stroke volume meaning

Answer 18

Amount o blood ejected by the ventricles

Question 19

Cardiac output meaning

What is the normal trend for this?

Answer 19

HR x SV

CO is the same for everyone

Question 20

Cardiac index meaning

Answer 20

Similar to CO but more specific to the individual patient due to taking surface area into account

• more reliable
• not the same for everyone

Question 21

Main types of invasive monitoring?

Answer 21

CVP
Art
Pulmonary artery

Question 22

How can we insure invasive monitoring is accurate?

Answer 22

Equipment needs to be zeroed to outside influences

Referencing or the positioning of transducer needs to be at the Phlebostatic axis (4th IC)

Question 23

You raise the HOB of the your patient with an invasive monitoring device. What should you do?

Answer 23

Need to reposition the reference point of the transducer so it aligns with phlebostatic axis

Question 24

What do you need for invasive monitoring?

Answer 24

Correct catheter

Special tubing system
- IV fluids of NS 
- pressure tubing
stopcocks
-flusher device
- transducer 

Pressure bag set at 300 mmhg
- flusher delivers it at 3mLs/hr

Question 25

Do you pump the pressure bag up or do you spike it?

What is the point of the pressure bag?

Answer 25

Spike it first then pump it up
- its a lot of pressure in there

Keeps you from bleeding out

Question 26

When zeroing the line, what elevation does the HOB need to be at?

Answer 26

60 degrees

Question 27

What do you do when zeroing a line?

Answer 27

Open to air
Hit zero function on monitor
And confirm

Question 28

List instances where you would want to zero the line?

Answer 28

Do it on the initial set up & do it again after the insertion

If you see any changes and need clarification

Beginning of shift

Question 29

What can you check on the monitor for a clue you’re getting an accurate line reading?

Answer 29

Waveform