Anesthesia for Cardiothoracic Procedures Flashcards
3 types of Cardiothoracic surgery
- open heart surgery (sternotomy/ thoracotomy)
- Da Vinci (laparoscopic)
- endovascular (valve repair/ aortic repair)
What does “invasive” cardiac surgery refer to?
sternotomy
-best exposure but most possible complications
3 cardiac surgeries considered minimally invasive
- Da Vinci
- Thoracotomy
- Endovascular
Minimally invasive cardiac surgery is aka?
MICS
What kind of endotracheal tube may be used in a MICS?
Double lumen
-one of the lungs may need to be deflated
Can MICS be performed “off pump”?
Bypass can be instituted with cannulation through which vessels?
Yes;
femoral vessels
Which is more common for Aorta surgery?
- Invasive open repair with cross clamps
- minimally invasive endovascular repair
- minimally invasive endovascular repair
How is a MICS CABG performed?
- what incision?
- commonly performed on or off pump?
- thoracotomy incision
- reserved for 1 or 2 vessel disease due to limited exposure of anterior vessels - off pump
- bypass via femoral vessels can be an option
in a DaVinci CABG procedure, what is the main purpose of the robot?
to harvest the LIMA
in a DaVinci CABG procedure, after the LIMA is harvested, how is the graft sewn on?
Through a small thoracotomy incision
an operation in which the anterior vessels are bypassed with a MICS/thoracotomy approach (by a cardiac surgeon) and the more difficult to expose vessels are stented (by an interventional cardiologist)
Hybrid coronary revascularization
What is the benefit of Hybrid coronary revascularization?
allows multiple CAD to be performed without sternotomy while still allowing a LIMA to LAD graft
-superior to intravascular stent placement
Hybrid rooms are utilized for which 2 procedures?
- hybrid coronary revascularization
2. transcatheter aortic valve replacement/ transcatheter aortic valve implantation
Hybrid rooms are utilized for procedures that use which 2 types of doctors?
- cardiac surgeon
2. interventional cardiologist
Because CABG patients have CAD, the goal is to avoid which two occurrences?
Do we premedicate for CABG patients?
- anxiety
- tachycardia
Yes: Give higher dose of Midazolam
Patients undergoing CABG require heavier medication than valve replacement
Are stenotic heart valves typically replaced or repaired
replaced
-leads to better outcomes
Repairs involve removal of calcifications
Are regurgitant heart valves typically repaired or replaced?
Repaired
- although both repaired and replaced can be done
Do we premedicate for valve repair/replacement patients?
why or why not?
NO:
Premedication can lower blood pressure and cause vasodilation = reduced preload and afterload
Patients for valve repair need to maintain preload/afterload
In MICS valve repair/replacement surgeries:
are they most commonly performed On or Off pump?
If on pump, where are the cannulation sites?
on pump
femoral vessels
Can valve repair/replacments be done with the Da Vinci robot?
yes
-bypass is possible via femoral vessels
What are 6 surgical ways in which valves may be repaired or replaced
- MICS
- Da Vinci
- Endovascular (off pump)
- Full Bypass with an arrested/beating heart
- Right heart bypass for pulmonic/tricuspid valves
- Transapical (off pump)
When would we consider using an endovascular valve repair technique?
in patients who do not qualify for open heart surgery
Endovascular aortic valve replacement is referred to as what 2 names?
- Transcatheter aortic valve replacement (TAVR)
2. Transcatheter aortic valve implantation (TAVI)
What are the 2 catheter/stent pathways for TAVR and TAVI?
Which is most common?
- femoral artery to aortic valve (most common)
2. axillary artery to aortic valve
What is the catheter/stent pathway for endovascular mitral valve repair?
femoral vein to intra-atrial septum to mitral valve
What is the catheter/stent pathway for tricuspid and pulmonic valve repair?
femoral vein, passes through the right side of the heart to the valve
A form of TAVR/TAVI that is the only example of a valve replacement being performed “off pump” with an “open” approach
Transapical valve replacement
-mini thoracotomy
6 risks associated with Endovascular TAVR
- Associated with a higher risk of this compared to surgical replacement
- What type of leak?
- the most frequent adverse outcome associated with TAVR and can lead to life threatening hemorrhage
- risk is due in part to the large contrast load used in placing the valve with fluoroscopy
- What type of cardiac conduction abnormalities?
- What type of post op complications?
- stroke/ TIA
- perivalvular leak
- aortic regurge - vascular complications
- perforation, dissection, rupture in the arteries - Acute kidney injury
- mechanical impingement of the conduction system leading to LBBB
- complete heart block in patients with existing RBBB - bleeding and atrial fibrillation
What approach can limit vascular complications during Endovascular TAVR be limited?
transapical thoracotomy approach
anesthetic management of TAVR
- What 2 things should be administered for Renal Protection (because of contrast dye used)
- perioperative volume loading
- administration of N-acetylcysteine prior to surgery
when keeping the heart still during valve deployment, what major hemodynamic event will occur?
Do you treat this?
hypotension
- surgeon may or may not request treatment
- valve deployment is quick (12 s) and if treated could cause a rebound hypertension and increase valvular regurge
Anesthetic management for TAVR:
- What should be used for Stroke Prevention and for how long?
What therapy should be used for TAVI?
- Dual antiplatelet therapy (aspirin and clopidogrel) started before the surgery and continued for 6 months
- TAVI: loading dose of 300-325mg of aspirin and 300mg of clopidogrel before the surgery
Anesthetic Management of TAVR:
- (low/high) dose of heparin and what is the goal ACT?
low dose of heparin with an ACT goal of >250
Anesthetic Management of TAVR:
- Two reasons for placement of transvenous placement leads
- establish rapid ventricular pacing during valve deployment
- can pace the heart in case of heart block following the procedure
Anesthetic Management of TAVR:
- Placement of these can treat life threatening arrhythmias
- external defibrillator pads
Anesthetic Management of TAVR:
- Purpose of TEE?
- provides info about the results of the balloon valvuloplasty and the position of the prosthetic valve and may identify procedure related complications
Anesthetic Management of TAVR:
- Amicar administration (is/ is not) necessary
- Amicar Is NOT necessary
Anesthetic Management of TAVR:
- Two options to keep the heart still during valve deployment
- a. Rapid ventricular pacing at a rate of 180-220 bpm (temporary cessation of CO)
and reduction of systolic BP below 60 mmHG
b. stopping the heart with 12mg of adenosine
Anesthetic Management of TAVR:
- 3 Hemodynamic goals for patients with aortic stenosis
Preload/afterload?
HR?
ECG?
- Preload augmentation
- Low HR (50-70 bpm)
- allow adequate diastolic filling time - maintenance of normal sinus rhythm
Anesthetic Management of TAVR:
- What continuous postop monitor should be used and for how long after?
- continuous electrocardiogram monitoring for 48 hours post-op
3 things for Endovascular Aortic Management
- no sternotomy/ bypass
- less heparin
- no Amicar
this technique of aortic surgery is the most common
endovascular
-more common than open
How is an aortic root replacement surgery performed?
traditional bypass with an arrested heart
- a clamp can be placed on the ascending aorta
Surgical techniques for open ascending aorta repair:
If a clamp can be placed on the ascending aorta, what technique can be used?
traditional bypass (without circ. arrest)
Surgical techniques for open ascending aorta repair:
If the aneurysm extends into the aortic arch, what 2 techniques can be used?
- deep hypothermic circ. arrest
- with or without antegrade or retrograde perfusion - normothermic antegrade perfusion
What is the problem with open descending open aorta repair?
It is not possible to perfuse both the head and lower extremities with one perfusion cannula
What 3 techniques can be used for open descending aorta repair?
- partial cardiopulmonary bypass
- left heart partial bypass
- Circ. arrest
- decreases the risk of post-op organ dysfunction and paralysis
Open descending aorta repair with aortic clamps:
Blood flow to the head is provided by?
Blood flow to the body is provided by?
left ventricle
bypass machine
Open descending aorta repair:
Clamps on the descending aorta increase the chance of _____ from inadequate perfusion of the spinal cord
paralysis
Descending Aorta Repair with Partial CPB:
SOME blood is removed from the ____ _____ through the venous cannula, travels to the bypass machine, and perfuses the ____ _____
right atrium lower extremities (distal to the clamp)
Descending Aorta Repair with Partial CPB:
SOME blood stays in the heart and goes to the _____ before being pumped into the left ventricle and aorta to perfuse _____ and ______.
lungs
head, upper extremities (proximal to the clamp)
In Descending Aorta Repair with Partial CPB, does the oxygenator need to be used?
YES
Descending Aorta Repair with Left Heart Partial Bypass:
SOME blood is removed from the ____ _____ through a reservoir cannula, travels to the bypass machine, and perfuses the ____ _____ through the arterial cannula
left atrium lower extremities (distal to the clamp)
Descending Aorta Repair with Left Heart Partial Bypass:
SOME blood stays in the heart and is pumped to the ____ to perfuse the _____ and _____.
aorta
head, upper extremities (proximal to the clamp)
Anesthetic Considerations for Left Heart Bypass:
- hemodynamics for left heart bypass with partial CPB
- Shared circulation in place by both the anesthetist and the perfusionist
- perfusionist can divert too much blood from the heart and deprive the heart, brain, and upper extremities of adequate blood supply
Anesthetic Considerations for Left Heart Bypass:
- What is measured to assess pressure distal to the clamp?
where should this be placed?
- arterial pressure
Right radial artery and femoral artery
Anesthetic Considerations for Left Heart Bypass:
If arterial pressure is too high proximally and too low distally, what does this mean?
Flow should be INCREASED through the CIRCUIT
Anesthetic Considerations for Left Heart Bypass:
If arterial pressure is too low proximally and too high distally, what does this mean?
Flow should be LOWERED through the CIRCUIT
Anesthetic Considerations for Left Heart Bypass:
If proximal arterial pressure and distal arterial pressure are both low, what should you do?
administer fluids or vasoconstrictors
Anesthetic Considerations for Left Heart Bypass:
If proximal arterial pressure and distal arterial pressure are both high, what should you do?
administer a vasodilator
Anesthetic Considerations for Left Heart Bypass:
- Filling of the ventricles should be assessed by what two pressures?
CVP should be compared to PA diastolic or PCWP