Test 1 content Flashcards
When using 4 to 1 cardioplegia set how much blood/cardioplegia solution is delivered when giving a 1000 cc dose of cardioplegia?
800cc blood and 200cc cardioplegia solution
The difference between traditional buckburg type (4:1) cardioplegia and Del Nido cardioplegia is:
Del nido is given at a ratio of 1:4
What effect does severe aortic insufficiency have on cardioplegia delivery?
Decreases aortic root pressure between the aortic cross clamp and the aortic valve
What pressure should be monitored when giving retrograde cardioplegia?
Coronary sinus
What effect does biocompatible coating have on tubing?
Internal components of the circuit “wet” more easily
The purpose of a “safety time out” in the OR is to:
Introduce OR team and discuss procedure
What factor is most important when setting up a sterile pump circuit?
Room logistics
When setting up a sterile pump circuit you should:
Use an organized routine, avoid letting the tube touch the ground and wear a mask
Coronary artery bypass graft procedures are performed on patients with:
Ischemic heart disease
One of the main differences between a roller pump and centrifugal pump when being used as an arterial pump is:
A centrifugal pump is non-occlusive
To de-air a heart is to:
flood with Co2
Del nido is a _______ tinged solution and is ___ part blood to ____ part crystaloid. Given about ___ every hour
- Blood tinged
- 1 part blood to 4 parts crystalloid
- Used about once an hour
_____Reserved for patients with end-stage heart disease not amenable to optimal medical therapy or other surgical procedures
Cardiac transplantation
End-stage cardiac failure is characterized by:
- Irreversible, severe ventricular dysfunction
- Low cardiac output
- Poor end-organ perfusion
- Activation of compensatory neurohumoral pathways
In the early stages of heart failure, stroke volume is maintained by:
- Increase in LV end diastolic volume
* Increase in myocardial fiber length
Active ingredients of del nido cardioplegia?
Plasma lyte A, mannitol 20%, sodium bicarb 8.4%, potassium chloride 2 mEq/ml, Magnesium sulfate 4.06 mEq/ml, lidocaine
(In other solutions High K+, low K+ can be used)
What is myocardial preservation?
The need to protect the myocardium from intraoperative and postoperative damage.
Addresses injury that can be caused by ischemia.
Allows surgeon to work in on a still heart.
Facilitates certain intra-cardiac procedures.
Extends the amount of time the surgeon has for certain procedures that require disrupting blood flow to the myocardium.
What is the end result of prolonged ischemia?
Tissue death!
3 Methods of myocardial preservation
Temperature
Chemical arrest
Continuous perfusion
In terms of myocardial energy consumption what uses the least or most energy?
- Beating Non working heart-LEAST
* Fibrillating heart - MOST
Solutions for chemical arrest:
Hyperkalemic solution del Nido solution Custodial solution St. Thomas solution Plegisol solution
Antegrade Cardioplegia delivery
Should monitor line pressure and/or aortic root pressure.
Aortic valve must be competent
Does not address distal ischemic heart disease (CAD)
Relatively easy to administer
Hypothermia has what 4 benefits?
- Reduces metabolic activity
- Increases margin of safety
- Facilitates lower systemic flows
- Causes constriction
Potassium concentrations between _____ mEq/L for complete asystole arrest.
Redosed every ______ minutes during periods of ischemia.
- 18-24 mEq/L
* every 10-30 mins
Potassium concentrations between ______ mEq/L for maintenance.
4-6 mEq/L
Order of anastomoses
- left atrium
- right atrium
- pulmonary artery
- aorta
Irreversible, severe ventricular dysfunction leads to low ______
CO-Cardiac output
Increase in mycardial fiber length means heart gets ________
distended (becomes baggy)
______ can develop b/c kidneys are not working properly
Edema
______ is a common anti inflammatory, typical one they use. A lot of bad things can happen to you on this. Used for ______
- Prednisone
* Immunosuppression
You don’t want to treat a rejection so well cause it could hurt the _______
Kidneys
Bicaval cannulation used cause you don’t want blood Q going back where?
Right atrium. Look like they cannulate the IVC and SVC to completely bypass RA.
_________ gives you option to perfuse the head vessels
Axillary Cannulation
_____ is used on a descending aneurysm
Thoracotomy
We need full bypass for which aneurysm?
Decending aneurysm (might leave heart beating in this case)
Includes dissections that involve the proximal aorta, arch, and descending aorta
DeBakey type I
Only involves the ascending aorta
DeBakey type II
Dissections that originate in the descending thoracic and thoracoabdominal aorta regardless of retrograde involvement
DeBakey type III
Involvement of the descending thoracic aorta
DeBakey type IIIa
Involvement of the thoracoabdominal aorta
DeBakey type IIIb
All dissections that involve the ascending aorta regardless of where the primary tear occurs is a _________
Type A dissection
stanford classification
Stanford type A includes ___________
DeBakey types I and II
Stanford type B Includes______
DeBakey types IIIa & IIIb
Thoracoabdominal Aneurysms
- Crawford Classification
- Has permitted a standardized reporting of aneurysm extent allowing for appropriate stratification of risks and treatment modalities
Crawford classification can be in how many types?
I, II, III, IV
Thoracoabdominal Aneurysm Extent I involves:
Involves most of the descending thoracic aorta from the left subclavian down to the vessels in the abdomen
Usually the renal vessels are not involved
Thoracoabdominal Aneurysms Extent II involves:
Begin at the left subclavian and extend to the infrarenal abdominal aorta even as far as the inguinal area
Thoracoabdominal Aneurysms extent III involve:
Extent III
Involve the distal half of the descending thoracic aorta and substantial segments of the abdominal aorta
Thoracoabdominal Aneurysms extent IV involve:
Extent IV
Involve the upper abdominal aorta and all or none of the infrarenal aorta
Aortic Aneurysms risk factors:
Smoking
Hypertension
Atherosclerosis
Genetic disorders: Marfans Syndrome, Ehlers-Danlos syndrome
Aneurysm etiology include:
Loss of elastic fibers and smooth muscle cells leading to cystic medial necrosis
The weakening of the aortic wall and loss of elasticity leads to an increase in the diameter of the aorta and dilation of the vessel
Dilation results in increased wall tension relative to aortic pressure
Aneurysm Preemptive surgery is recommended when:
Ascending aneurysm is at 5.5 cm
Descending aneurysm is at 6.5 cm
_________procedure is to save the valve if you can
Valve sparing procedure
Other procedures include:
- Simple tube graft
- Ross procedure
Aortic arch aneurysms usually require ______
DHCA
May employ antegrade or retrograde cerebral perfusion)
Bentall Procedure (5 steps)
Right axillary artery and right atrial cannulation
Placed on CPB and cooled to 16-18 degrees
Aorta is cross clamped and opened
Heart is arrested with cardioplegia infusion into the coronary ostia
Aortic valve is removed
(((Composite prosthesis is sutured to the aortic annulus
Coronary buttons are attached to the graft
The patient is completely cooled, the pump is stopped and the aortic cross clamped is removed
The distal ascending aorta and the proximal arch is excisedThe distal anastomosis is completed
Pump flow is initiated slowly to deair the graft
Rewarming is begun)))
Ascending and arch replacement (5 steps)
Right axillary and right atrial cannulation
Cooling to 16-18 degrees
Aortic cross clamp and opening of the aorta
Cardioplegia via coronary ostia
Aorta is reconstructed with Teflon impregnated Dacron graft (Hemashield®)
(((After adequate cooling, the pump flow is stopped (circulatory arrest) the cross clamp is removed, and the arch is opened
A graft is anastomosed to the head vessels
A cross clamp is applied to the graft
Antegrade cerebral perfusion is begunAn “elephant trunk” graft is placed into the descending aorta
The proximal end of the elephant trunk graft is then anastomosed to the ascending graft
The graft from the head vessels in then anastomosed to the graft to complete the procedure)))
