Cardio Pulmonary Bypass Flashcards
During CPB, venous blood flows in a _______ via what type of drainage?
reservoir
gravity
Blood flows through ______ and _____ and is then pumped via aortic cannula into aorta
oxygenator
filter
Heat exchanger allows heating and cooling. True or false?
true
When is a left heart bypass used?
Used for descending aortic surgery
During a left heart bypass, where does flow out of and then reinfused?
out of left atrium
reinfused to femoral artery or middle aorta
Is there an oxygenator on left heart bypass?
No
Some may have heater/cooler.
What does ECMO mean?
extracorporeal membrane oxygenation
Note: There are 2 types: VA (venous-arterial) and VV (veno-venous).
Does the ECMO system need heparinization?
Yes
What types of monitoring do you need on CPB? (5)
- ECG–need to confirm asystole after cardioplegia/cross clamp.
- Arterial pressure–NIBP does NOT work
- Temperature
- Perfusion
- Volume
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.
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.
What can temperature be as low as during circulatory arrest?
18ºC
What is most sensitive to ischemic insult?
CNS
Hypothermia increases tolerance during aortic arch procedures and periods of low flow.
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
What drug do we administor to ensure urine production?
mannitol
What is the best intravascular volume estimate we have?
CPB reservoir
What is important to determine prior to CPB?
total body volume status
Ultrafiltration during CPB allows removal of excess volume, and some removal of electrolytes, similar to dialysis. True or false?
true
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
What does heparin inhibit?
Thrombin via AT-III (antithrombin)
What do we give patients with HIT (heparin induced thrombocytopenia)? (3)
LMWH
ancrod (snake venom)
argatroban* (most common- shuts down platelet fxn)
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
What is normal ACT?
What is ACT to go on bypass?
100 - 140
380 - 480
What impacts ACT?(3)
Temperature
Platelet function
Hemodilution