Bb Cardiopulmonary Bypass

Front 1

What is airlock when referring to a CPB machine?

Back 1

gravity siphon process of venous drainage that is disrupted by a large bubble

Front 2

What is the usual reading on the arterial inflow line pressure gauge? what is it prebypass?

Back 2

200-300mm Hg; the pressure reading on the guage prebypass should correlate with the arterial pressure tracing

Front 3

What are the indications if pulsations are absent from the arterial inflow line pressure guage?

Back 3

cannula has not been properly placed(and major dissection is about to occur with start of CPB), or the patient has been attached to the circuit backwards

Front 4

What should you do if pressure on the arterial inflow line pressure guage rises rapidly with the onset of bypass?

Back 4

turn off the pump, failure to do so will result in disruption of one or more of the fittings causing an explosion

Front 5

Why should MAP during CPB be maintained at 50?

Back 5

lowest normal pressure at which autoregulation is maintained

Front 6

If the CPB pump fails what can you do?

Back 6

crank it by hand

Front 7

Where are cardioplegia catheters placed?

Back 7

through the right atrium and into the coronary sinus or the aortic root where cardioplegia can enter the coronary arteries

Front 8

How is LV venting accomplished?

Back 8

placing a cannula through the right superior pulmonary vein, into the L atrium, through the mitral valve and into the LV

Front 9

What is the purpose of the LV vent?

Back 9

prevents excessive distention of the LV due to physiologic shunting through the bronchial, thesbian, and pleural veins

Front 10

What does the cardiotomy suction do?

Back 10

adds blood to the circuit, it must be gentle so that blood cells are not traumatized

Front 11

What is the benefit of the bubble oxygenator?

Back 11

cheaper and easier to set up

Front 12

What is the benefit of the membrane oxygenator?

Back 12

less RBC damage

Front 13

What are the benefits of pulsatile pumps?

Back 13

reduce the neuroendocrine stress response

Front 14

What is the typical components of the priming solution?

Back 14

2L balanced salt solution, 20mL of 20% mannitol

Front 15

During isovolemic hemodilution what principally maintains a normal SvO2?

Back 15

decreased blood viscosity

Front 16

What are causes of high aortic line pressures?

Back 16

occlusion of the line by a kink or clamp, cannula too small for flow, improper positioning of the cannula

Front 17

What are causes of low venous return during CPB?

Back 17

pump problems, malfunction, low venous return, low peripheral resisstance caused for example by low Hct or a vasodilator

Front 18

What are causes of hypertension during CPB?

Back 18

excessive flow, inadequate anesthesia

Front 19

How does cooling and rewarming affect ACT?

Back 19

cooling prolongs ACT, rewarming shortens ACT

Front 20

What is the typical concentration of potassium in cardioplegia solution?

Back 20

25-30mEq/L

Front 21

How often should cardioplegia be given and why?

Back 21

every 20min, reestablished hypothermia and washes out lactate

Front 22

What should you worry about with difficulty separating from bypass?

Back 22

post-ischemic myocardial dysfunction

Front 23

What patient's are at risk for postischemic myocardial dysfunction?

Back 23

poor presurgical function, long cross clamp times, poor myocardial preservation during cross clamp time

Front 24

How do you treat postischemic myocardial dysfunction?

Back 24

aggressive inotropic support with agents such as epi

Front 25

What is normal ionized ca and what is the typical value after bypass?

Back 25

2-2.2mEq/L; frequently falls to <1.5mEq/L

Front 26

When is recall most likely during CPB?

Back 26

rewarming

Front 27

How does temperature affect the solubility of O2 and CO2?

Back 27

at lower temp the solubility of both in solution is higher, less molecules in the gas phase, and the partial pressure of both is decreased, pH is therefore higher at lower temperature

Front 28

What is a temperature corrected blood gas?

Back 28

utilizes a computer normogram that corrects which corrects for solubilty and pH changes which occur with temperature

Front 29

What is alpha stat for ABGs?

Back 29

uncorrected arterial blood gas values, no attempt is made to correct parital pressure of O2 and CO2 for temperature

Front 30

What is the pH stat method of analyzing ABGs?

Back 30

temperature corrected values and involves administering CO2 systemically to patients to correct for lower CO2 partial pressure secondary to it's increased solubility in solution, it aims to keep pH at 7.4 and pCO2 at 40

Front 31

On a intraaortic balloon pump tracing what is the PSP and IP?

Back 31

peak systolic pressure-highest aortic pressure produced by ventricular ejection; inflation point: the point where balloon inflation originates(immediately following closure of the aortic valve)

Front 32

On a intraaortic balloon pump tracing what is the PDP and BAEDP?

Back 32

peak diastolic pressure: the highest aortic pressure produced by balloon inflation, usually higher than PSP; Balloon aortic end diastolic pressure: the lowest pressure in the aorta reflecting balloon deflation, deflation occurs just prior to opening of the aortic valve

Front 33

On a intraaortic balloon pump tracing what is the APSP, DN, PAEDP?

Back 33

assisted peak systolic pressure: systolic pressure which reflects balloon action; dicrotic notch: the landmark on the down slope of the arterial pressure waveform that signals aortic valve closure and the beginning of diastole; patient aortic end diastolic pressure: the lowest pressure normally occuring in the aorta(diastolic pressure)

Front 34

How is the balloon triggered?

Back 34

R wave on the EKG

Front 35

How does balloon inflation affect physiology?

Back 35

increased aortic diastolic pressure and thus increased coronary perfusion

Front 36

How does balloon deflation affect cardiac physiology?

Back 36

decreased afterload, increased SV, increased CO, decreased MVO2, decreased myocardial work

Front 37

When does balloon deflation occur?

Back 37

during isovolumetric contraction(late diastole) just prior to opening of the aortic valve

Front 38

What are contraindications to IABP?

Back 38

aortic valve insufficiency, aortic aneurysm, severe aortoiliac or femoral disease

Front 39

What is the major risk of using IABP?

Back 39

inflation of the balloon during systole and subsequent impedement to CO