Cardio Pulmonary Bypass Flashcards Preview

AP: Cumulative > Cardio Pulmonary Bypass > Flashcards

Flashcards in Cardio Pulmonary Bypass Deck (60):
2

During CPB, venous blood flows in a _______ via what type of drainage?

reservoir 

gravity

3

Blood flows through ______ and _____ and is then pumped via aortic cannula into aorta

oxygenator 

filter

4

Heat exchanger allows heating and cooling.  True or false?

true

5

When is a left heart bypass used?

Used for descending aortic surgery

6

During a left heart bypass, where does flow out of and then reinfused?

out of left atrium

reinfused to femoral artery or middle aorta

7

Is there an oxygenator on left heart bypass?

No

Some may have heater/cooler.

8

What does ECMO mean?

extracorporeal membrane oxygenation

Note: There are 2 types: VA (venous-arterial) and VV (veno-venous).

9

Does the ECMO system need heparinization?

Yes

10

What types of monitoring do you need on CPB? (5)

  1. ECG--need to confirm asystole after cardioplegia/cross clamp.
  2. Arterial pressure--NIBP does NOT work
  3. Temperature
  4. Perfusion
  5. Volume

11

Right radial arterial line is not accurate with right axillary cannulation.  True or false?

True.

Brain damage may occur due to inaccurate readings. Placement of art line is critical.  Left radial art line may be lost during high clamp in descending procedures.  

12

Hypothermia is utilized during CPB procedures to improve tolerance of prolonged non-pulsatile flow states and decrease ischemic injury to brain, heart and kidneys.  True or false?

True

Hypothermia decreases CMOR.

13

What can temperature be as low as during circulatory arrest?

18ºC

14

What is most sensitive to ischemic insult?

CNS

Hypothermia increases tolerance during aortic arch procedures and periods of low flow.

15

Relating to perfusion

How do you know the brain, heart, kidneys, liver and GI tract are getting adequate cardiac output? (5)

  • BIS/cerebral oximetry (frontal lobe perfusion)
  • ECG (want asystole), filling pressures
  • Urine output--best indicator for kidneys
  • Mixed Venous O2 (total body perfusion)
  • Labs galore- lactate, glucose, acid-base status, potassium

16

What drug do we administor to ensure urine production?

mannitol

17

What is the best intravascular volume estimate we have?

CPB reservoir

18

What is important to determine prior to CPB?

total body volume status

19

Ultrafiltration during CPB allows removal of excess volume, and some removal of electrolytes, similar to dialysis. True or false?

true

20

If the hemoglobin is 7 and reservoir volume is 1000ml, do you need add blood? 

Basically need more information.  What info do we need? (3)

Reservoir volume

Mixed venous

Temperature

21

What does heparin inhibit?

Thrombin via AT-III (antithrombin)

22

What do we give patients with HIT (heparin induced thrombocytopenia)? (3)

LMWH

ancrod (snake venom)

argatroban* (most common- shuts down platelet fxn)

23

Patients with ATIII deficiency--'heparin resistance' either acquired or inherited, requires therapy to ensure maximal anticoagulation for CPB, what do we give them? (2)

FFP

Emory happens to have recombinant ATIII

24

What is normal ACT?

What is ACT to go on bypass?

100 - 140

380 - 480

25

What impacts ACT?(3)

Temperature

Platelet function

Hemodilution

26

Where do you cross clamp for an arterial cannula?

below the cannula

27

Blood is pumped back into the arterial system via the cannula after being ______ and cleared of ____.

oxygenated

CO2

28

When they are sewing the aorta cannnula in, what do we need to be doing?

decrease BP from 160 to 100 systolic 

29

Where are arterial cannulas normal placed? (3)

ascending aorta, distal to the PA (most common)

axillary artery

femoral artery

30

Where are dual or tri-stage venous cannulas normal placed? 

Can be placed in any large vein that will allow gravity drainage of blood to the reservoir.  

Cannula placed through right atrial appendage and down into SVC and IVC.

31

In what cases do we place venous cannulas? (3)

Sternotomy

CABG

Aortic valve replacement

32

What is bicaval cannulation?

separate cannulas in the SVC and IVC

(used for open chamber procedures, VSD repairs, transplants)

33

When is bicaval cannulation used?

In what cases is this needed? (2)

When maximal drainage of the heart is needed.  

Open chamber procedures, transplant

34

Who places the SVC cannula when bicaval cannulation is needed and where is it placed?

anesthesiologist

RIJ

Note: the IVC cannula is placed in femoral.

35

Where is a vent placed?

A catheter typically placed in the right upper pulmonary vein (RUPV) and into the left atrium.

 

36

What is the function of a vent?

Vent removes blood that accumulates in the heart with a goal of preventing distention injury.

37

What is a tack?

A tack is a smaller catheter, sometimes a 14 gauge IV, placed in the ascending aorta to facilitate clearance of intracardiac air after open chamber procedures.

IThe tack is allowed to bleed in to the pericardial well until air is cleared.

38

Where is a retrograde cardioplegia catheter placed and what is it for?

By the surgeon into the coronary sinus directly, or percutaneously by anesthesia via RIJ with TEE.

Prevents injury to the coronary sinus by monitoring infusion pressure with the CVP transducer.

39

How is cardioplegia administered? 

antegrade or retrograde

40

How is antegrade catheter placed?

Into ascending aorta or directly into coronary artery which follows path of normal blood flow

Can be the same line as tack line.

41

What is the direction of flow for retrograde cardioplegia?

Retrograde flows into coronary sinus, into coronary veins and out the aorta.

42

How is temperature monitored during CPB? (3)

nasopharyngeal

bladder

PA

43

What drugs are used to target MAP?

phenylepherine

vasopressin

NOT EPI because of beta agonist activity!

44

On what 2 factors is target MAP based on?

temperature

pt baseline

45

How low can Hgb trend as low as in most circumstances?

7

46

What technique of aortic cannulation is used for major aortic surgical procedures, including aortic dissections, aneurysms and arch procedures?

axillary cannulation

Note: Used often.

47

For a patient receiving axillary aortic cannulation, Where MUST the art line be placed to avoid neurologic damage?

OTHER arm or femoral artery

48

What must you ensure before weaning a patient off CPB? (3)

  1. Ensure the pt is appropriately rewarmed
  2. Venous line is incrementally clamped to prevent blood from returning to the reservoir (blood reenters heart and ejection returns)
  3. The arterial inflow rate is decreased as the blood pressure increases.

49

Heparin is a ______ charged glycosaminoglycan.

Protamine is an _____ rich base compound.

 

negatively

arginine

Note: This is a simple acid-base reaction.

50

What blood products can be given during  CPB?

RBC and FFP

Note: Platelets and cryoprecipitate and other coagulation factors are withheld until CPB is no longer needed.

51

What is off pump heart surgery?

CABG can now be accomplished without CPB in many instances

Hemodynamic management of these patients can be difficult as we are allowing an ischemic state while grafts are completed.  

TEVAR (thoracic endostent) is an example

52

When do we perform off pump heart surgery?

valve operations such as AVR, MVR, PVR, and even TVR

TEVAR (trans endo vascular aortic repair)

53

You are on CPB and the hemoglobin is 7.  Which of these would lead you to transfuse?


A. Temperature 32C
B. MVO2 80
C. Reservoir volume 200ml
D. MAP 65

c

54

Which monitor is the most important for CPB?
A. ECG
B. Arterial line
C. Temperature
D. BIS

b

55

what is the main difference between VA and VV ECMO?

VA = some cardiac support

VV = clears CO2 better than it adds O2 (background ventilation needed)

56

What does the CPB oxygenator do?

delivers O2, Co2 and Isoflurane to patient while the patient is on bypass

57

What does DHCA stand for?

Deep Hypothermic Cardiac Arrest

-alternative to CPB 

-commonly referred to as "circ arrest"

58

how does ultrafiltration during CPB work?

removal of fluid via counter-current exchange (NB... can decrease electrolytes by down shifting concentration)

59

what is cardioplegia and how does it work?

fluid is injected into the heart (antegrade or retrograde) that stops the heart from pumping.

K+ often the drug of choice. Stops heart in diastole

60

when a patient is on CPB, the perfusionist is roughly equivalent to the patient's _____ while the anesthesia team is ______

Perfusionist = Cardiac output

Anesthesia = SVR

61

What must you always do before giving protamine?

ASK PERFUSIONIST

-protamine will clot CPB circuit (--> dead patient)