Cardiac Assist Devices

Question 1

ECMO

Answer 1

pt being put on bypass that is not having cardiac surgery

Question 2

is the heart arresting and cross clamp placed during ECMO?

Answer 2

no

Question 3

what is the purpose of ECMO

Answer 3

keep pt alive during ACUTE cardiac or respiratory failure

Question 4

venovenous (VV) ECMO

Answer 4

drawn from right side of heart
oxygenated by ECMO
returned to right side of heart

Question 5

when is VV ECMO indicated?

Answer 5

respiratory failure

Question 6

can you use VV ECMO for a pt with cardiac failure

Answer 6

no

Question 7

cannula for venovenous ECMO

Answer 7

outer lumen for drain blood to ECMO

inner lumen infuses blood back into RA

Question 8

Venoarterial (VA) ECMO

Answer 8

blood removed from right heart
oxygenated by ECMO
returned to left side of heart via arterial cannula

Question 9

when is VA ECMO indicated?

Answer 9

cardiac and respiratory failure

Question 10

what is the advantage of VA ECMO compared to VV ECMO

Answer 10

VA can be used in cardiac failure

oxygenation improved pulm vasculature and decrease pulm HTN then heart failure resolves

Question 11

disadvantage to VA ECMO (compared to VV ECMO) 3

Answer 11

1- non pulsatile perfusion
2- potentially less oxygen to coronary arteries
3- higher chance of emboli entering arterial circulation

Question 12

why is there potentially less oxygen to coronary arteries in VA ECMO?

Answer 12

because oxygen supply is better when it enters from the heart rather than machine

Question 13

Ventricular Assist Device (VAD)

Answer 13

artificial heart placed in pt with heart failure to help ventricle pump

Question 14

how does VAD work? 3

Answer 14

1 tubing placed inside ventricle
2- tubing withdraws some blood into a pump
3- pumps back into body through reinfusion tube

Question 15

how does VAD increase CO?

Answer 15

helps heart pump

improves hearts own ability to pump by relieving fluid overload

Question 16

what are VAD meant to be a bridge for?

Answer 16

heart transplant, they have risk of clotting and stroke

Question 17

what are the three types of VADs?

Answer 17

1-long term intracorporeal VAD
(pump and tubing in body)
2- short term intracorporeal VAD (catheter)
3- short term extracorporeal VAD (tubing inside with pump outside)

Question 18

long term intracorporeal VAD

Answer 18

long term use in pt with permanent HF

insertion with open heart surg and bypass

Question 19

internal catheter VAD other name

Answer 19

impella cardiac assist device

Question 20

how does internal catheter VAD work?

Answer 20

small pump in LV that removes blood from LV and pumps to aorta

Question 21

extracorporeal VAD other name

Answer 21

tandem heart

Question 22

when is tandem heart indicated

Answer 22

acute HF when weakened from recent heart surgery

Question 23

extracorporeal VAD how does it work

Answer 23

venous catheter inserted in femoral vein into RA then LA
draws oxygenated blood out to VAD
pumps back in via arterial cannula in femoral artery

Question 24

anesthetic implications for pt with VAD undergoing non cardiac surgery (6)

Answer 24

a line required
MAP used to trend BP
usually on anticoagulants
RSI indicated
Electromagnetic interference can alter function
more susceptible to infection
chest compression controversial

Question 25

why do we need an aline for people with VADs?

Answer 25

flow is nonpulsatile thus NIBP are inaccurate

Question 26

what should the MAP be at for people with VAD?

Answer 26

60mmHg

Question 27

why are VAD pts usually on anticoagulants

Answer 27

pumps cause hemolysis and thrombolytic events

Question 28

what causes electromagnetic interference?

Answer 28

bipolar cautery is preferred | if monopolar must be used then place grounding pad away from VAD

Question 29

why are chest compressions controversial in VAD pts

Answer 29

can dislodge cannulas and lead to immediate death | OR will die without compressions

Question 30

4 anesthetic considerations for pt with VAD

Answer 30

identify and talk to VAD team secure a power source for VAD establish safe coagulation plan with surgeon and cardiologist hemodynamic stability crucial

Question 31

what is the VAD team composed of?

Answer 31

cardiac surgeons, nurses, perfusionists etc

Question 32

What information do you need from the VAD team?

Answer 32

pump speed and flow | rpm and L/min

Question 33

How long do VAD batteries last?

Answer 33

6 hr

Question 34

what is included in coagulation plan for VAD pts?

Answer 34

get coagulation labs (PT, PTT, INR) | pts on warfarin should switch to heparin before elective surgery

Question 35

what two things do you need to be cautious of VAD patients with hemodynamic stability?

Answer 35

``` maintain preload (pump flow decrease when preload decrease) avoid hypertension (decreases output of device when afterload is increased) **blood can pool in heart and cause thrombi** ```

Question 36

intra aortic balloon pump

Answer 36

balloon inserted into aorta via femoral artery | attached to console that triggers inflation and deflation

Question 37

when does the IABP balloon inflate?

Answer 37

dichrotic notch of aline or t wave of ECG

Question 38

when does the IABP balloon deflate

Answer 38

at or prior to R wave

Question 39

what things can trigger balloon inflation?

Answer 39

ECG aline waveform pacemaker

Question 40

benefit of balloon inflation

Answer 40

diastole, increases diastolic pressure increases Coronary perfusion pressure

Question 41

benefit of ballon deflation

Answer 41

systole sucks blood forward decrease afterload and oxygen demand increases CO

Question 42

how much can a IABP increase CO by?

Answer 42

40%

Question 43

when is IABP indicated?

Answer 43

cardiogenic shock acute heart attack difficulty weaning off bypass

Question 44

c pulse heart pump

Answer 44

extra aortic balloon pump "permanent" epicardial sensing leads attached to LV

Question 45

benefits of C pulse heart pump

Answer 45

``` placed thoracotomy (not sternotomy) no anticoagulants bc external to vasculature ```

Question 46

when does the balloon inflate c pulse pump? benefit?

Answer 46

diastole increase coronary blood flow increases CO (second pulse)

Question 47

when does the balloon deflate c pulse pump? benefit?

Answer 47

prior to systole (detection of R wave) decrease afterload increases CO