Bypass shannon lecture and apex Flashcards

1
Q

5 components of the cbp machine

A

venous reservoir
main pump
oxygenator
heat exchanger
artificial filter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the role of an accessory pump

A

cardioplegia delivery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How does blood drain from the patient to the reservoir

A

gravity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Roller vs centrifuge pump

A

Roller- propels blood forward, non pulsatile flow, flow remains the same regardless of afterload, traumatic to blood cells
Centrifuge- safer for RBCs, flow varies with afterload, high afterload can cause a back up of blood towards venous circulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Explain membrane oxygenator

A

tightly wound fibers
o2 can be controlled by changing fio2
co2 can be controlled by changing liter gas flow rate (sweep)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the purpose of the arterial filter

A

filter blood before returning to the arterial cannula in the ascending aorta
Prevents thrombi, fat globules, calcium and tissue debris

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the significance of aortic regurg

A

Blood and cardioplegia can backflow and fill the LV, distend the lv, raise lvedp, and oppose cardioplegic flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Standard cardiac dose of heparin

A

300-400u/kg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

ACT level for CABG

A

> 400 to initiate cpb

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

When to draw act for cpb

A

Prior to heparin
3 minutes after administration
q30 min

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

When would you suspect heparin resistant

A

recent exposure
ACT <480 despit 500u/kg IV heparin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Treatment for heparin resistance

A

2 units FFP, AT3 concentrate, recombinant AT3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

CMRO2 decreases ___ for every degree celsius decrease in brain temperature

A

7%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Anterograde vs retrograde cardioplegia

A

anterograde- coronary arteries, aortic root
retrograde- coronary sinus and cardiac veins, RA, watch for dysrhthmias and hotn

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Blood conservation meds

A

Amicar 50mg/kg over 20 min followed by 25mg/kg infusion
TXA 10mg/kg over 20 min followed by 1mg/kg infusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Blood salvage does what to the blood?

A

Removes serum, coagulation factors and platelets
HCT 55-70

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Large quantities of salvaged blood can cause what

A

dilutional coagulopathy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

ABX 1st and 2nd choice

A

1- beta lactams, q3-4 hours
2- vanco and amg, no redosing, within 2 hours of incision

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What happens if vessel damage in a redo cabg

A

emergently give 300-400u/kg heparin and cannulate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Goal BP before cannulation

A

SBP <100, MAP <70
to prevent disseciton

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Complicaitons of aortic cannulation

A

hemorrhage
plaque
air embolism
aortic arch vessel inadvertant placement

22
Q

CPB can begin after ACT is ___

A

> 400

23
Q

SVO2 goal

A

70%

24
Q

HTN may indicate ___

A

light anesthesia

25
Q

TOF goal

A

0/4

26
Q

UO goal

A

1ml/kg

27
Q

BG goal

A

increased to a level that requires insulin infusion

28
Q

Goal K when separating from cpb

A

4-5.5

29
Q

Boal bp at decannulation

A

SBP <90 MAP <70

30
Q

When to administer protamine

A

AFTER DECANNULATION
Clot in pump can kill patient

31
Q

Protamine dose

A

1mg for every 100 u of heparin

32
Q

How fast to give protamine and why

A

10-15 minutes to assess for vasodilation and increased PVR

33
Q

Why give desmopressin? Dose?

A

Increases platelet functino
0.3mcg/kg

34
Q

What do you expect if you see hotn, tachy, decrease in chest tube drainage, and inadequate filling pressures?

A

cardiac tamponade

35
Q

Which takes longer? on or off pump?

A

off

36
Q

Who is a good candidate for off pump ?

A

good lv function

37
Q

What is the key for an off pump cpb

A

fluid management, will give more,, cant give fluids like on pump

38
Q

Goal temp

A

36c

39
Q

Heparin dose for OFF pump cpb?

A

100-200u/kg

40
Q

Goal ACT of OFF pump

A

> 300

41
Q

Goal MAP when off pump surgeon is accessing PDA and CX, or during distal anastamosis

A

High, MAP 100

42
Q

Goal MAP when proximal graft aortic anastamosis

A

60

43
Q

Benefits of off pump

A

Coagulopathy
neuro defect
air embolism
aortic clamping
trauma, bleeding
recall
hypothermia
hemodilution
faster

44
Q

Why is a membrane oxygenator safer than a blood membrane gas interface?

A

Risk of air embolism

45
Q

What could be used as a priming fluid

A

Blood
Mannitol
Albumin
Heparin
HCO3

46
Q

Priming with anything other than blood causes what?

A

Decreased hct
decreased oxygen caryying capacity
decreased viscosity
decreases concentration of drugs and plasma proteins
INCREASED microvascular flow dt reduced viscosity

47
Q

What would you give in the patient whos allergic to heparin

A

Bivalrudin
Hirudin
Factor 10 inhibitor

48
Q
A
49
Q

Alpha stat vs PH stat

A

PH stat corrects for patient temperature

49
Q

Why is an LV vent used?

A

Removes blood from the LV
Removes blood from the thesbian veins and bronchial circulation

50
Q
A