Concepts of Cardiopulmonary Bypass Flashcards

Question

Aortic Root Vent

Answer 1

During bypass the aorta is cross clamped. Blood does manage to go through pulmonary circulation with 2 stage cannulation. If proper venting does not occur then LV distention results

Answer 2

♥ Used on the valve replacement cases ♥ Mimics the same duties of the aortic root vent in limiting LV distention. “Starlings Curve”

Answer 3

Cardiac arrest is achieved via high K+ infusion via the following routes: - aortic root - coronary sinus (retrograde) - vein grafts - coronary ostia

Answer 4

♥ High K+ infusion has a significant vasodilatory effect ♥ Magnesium helps membrane stability ♥ Quest Microplegia system allows “on the fly” adjustments ♥ Built-in heat exchanger to regulate the temperature of perfusate

Answer 5

♥ Due to the fact that blood is used as the delivery solution instead of a crystalloid solution, hemodilution of the patient is significantly reduced

Answer 6

♥ Gives results for the following lab values: PH, PCo2, PO2, Na+, K+, Ca++, Glu, Lac, Hct, HCO3, BE, SO2 ♥ One located in each of the heart rooms

Answer 7

♥ Prior to the patient being put on pump systemic heparinization must be reached ♥ Levels are measured every 30 minutes or as necessary to maintain an ACT of >480 sec.

Answer 8

♥ Blood is heparinized as it is suctioned from the operative field. ♥ Suctioned blood is collected in a filtered reservoir. ♥ Filtered blood is centrifuged and washed with saline ♥ Washed RBC’s in normal saline is concentrated at Hct 50-75% and pumped to a transfusion bag. ♥ Large amounts of “cell saver” blood indicates large plasma loss.

Answer 9

♥ Even though RBC’s are saved and returned to increase the patient’s Hct, all other formed elements of the patient’s blood are “washed” off, especially clotting factors. End result is potential bleeding problems with massive blood loss

Answer 10

♥ AGF- Autologous Growth Factor ♥ Platelet “ RICH “ ♥ Platelet “ POOR” ♥ Whole blood sample which is centrifuged to obtain these products

Answer 11

Concentrated Platelets from whole blood sample. >1,000,000 platelets/ul Contains 7 growth factors Action is to stimulate and accelerate bone and soft tissue healing. Safe and free from transmissible diseases like HIV and Hepatitis Calcium & Thrombin added to produce gel formation.

Answer 12

It contains mostly plasma with few platelets Recommended for use in platelet aggregation Applied on top of “RICH” to hold it in place like a bandage

Answer 13

♥ Minimum Hct - Cold – 21% - Warm – 24% ♥ MAP 60-90mmHg ♥ Urine 1-2cc/kg/hr ♥ Temperature – Drift to 32 degrees Celsius♥ ABG’s q 30 minutes ♥ Document flows & U/O q 15 minutes ♥ Dose cardioplegia q 15-20 minutes ♥ Heparin / Protamine assays q 30 minutes ♥ Cell Saver all cases

Answer 14

Communication with all team members Prepare for RAP procedure Retrograde Cardioplegia Monitoring Thumbs UP Look over the drape and observe the heart and lungs

Answer 15

♥ Contact Activation (Inflammation) - a series of host-defense mechanisms designed to attack foreign substances or tissue injury. ♥ CPB - results from blood coming in contact with plastic tubing, filters, connectors, stainless steel heat exchangers, and blood to gas interfaces ♥ Produces an overwhelming and systemic activation of the inflammatory cascade. (Systemic Inflammatory Response Syndrome: SIRS)

Answer 16

♥ The lungs are very susceptible to the inflammatory processes. ♥ Activated WBC’s are deposited or sequestered in the lungs; where they release superoxides and lysosomal enzymes, which produce endothelial damage & in turn results in the accumulation of extravascular water. “PUMP LUNG”

Answer 17

♥ Heparin-Protamine complex in human serum is associated with activation of the classic pathway and production of C3a,C4a and C5a. ♥ Severe hemodynamic compromise can result from a particularly vigorous complement response following protamine administration. “PROTAMINE REACTION” GIVE IT SLOW!!!!!!!!!

Answer 18

♥ Triggers blood contact activation. ♥ A primary rationale for the switch from early bubble oxygenators to the present membrane oxygenators ♥ Formation of gaseous microemboli. ♥ These gaseous microemboli disrupt microcirculation by producing tissue & organ ischemia.

Answer 19

♥ Closed venous reservoirs ♥ Bio-compatible surfaces ♥ Judicious use of suction, cell savers, vents ♥ Dosing the proper amount of heparin & protamine ♥“Microcircuitry” (Smaller Compact Circuits)

Answer 20

♥ Eliminates the majority of air/blood interface. ♥ Better flow dynamics, reduced areas of stasis. ♥ No defoaming agents, no nylon filter sock.. ♥ Reduced complement activation. ♥ Preserves platelet function ♥ Reduced post-op bleeding. ♥ Improved post-op lung function.

Answer 21

♥ Heparin bonded coatings. Tip to Tip ♥ Preserves Platelet Function ♥ Reduced complement activation ♥ Reduced post-op bleeding ♥ Improved post-op lung function ♥ Unfortunately, it’s only limitation is $$$$

Answer 22

♥ Cardiopulmonary bypass is an unnatural physiological state that produces a whole-body inflammatory response ♥ If the cardiac surgical team fails to minimize blood activation the results to the patient can be catastrophic. ♥ The thoughtful and meticulous application of available perfusion technologies can dramatically improve outcomes, length of stay and healthcare costs.