Cardiothoracic Procedures Flashcards
3 cardiac surgery approaches
“open” heart surgery
davinci robotic
endovascular
open heart surgery definition
any time the chest is opened (sternotomy or thoracotomy)
davinci robotic cardiac surgery definition
more laparoscopic rather than open bc small incisions and smaller insufflation is utilized
endovascular cardiac surgery definition
possible for valve repair and types of aortic repair
is sternotomy invasive or minimally invasive?
invasive
is thoracotomy invasive or minimally invasive?
minimally invasive
is davinci invasive or minimally invasive?
minimally invasive
is endovascular repair invasive or minimally invasive?
minimally invasive
invasive
open sternotomy
provides best exposure but most complications
minimally invasive cardiac surgery (MICS)
thoracotomy, davinci, endovascular
less common but gaining popularity
3 things specific to minimally invasive cardiac surgery
called MICS
double lumen tube must be used
can be off pump or on pump with femoral vessels
two types of aorta surgery
open repair with cross clamps endovascular repair (minimally invasive)
6 surgical options for CABG
full bypass with arrested or beating heart partial bypass with beating heart off pump sternotomy thoracotomy davinci
MICS CABG
small thoracotomy incision
typically 1-2 anterior vessels
off pump or on pump with femoral vessels
davinci CABG
function to harvest the LIMA then thoracotomy is used to sew on graft
hybrid coronary revascularization
anterior vessels are bypassed using MICS/thoracotomy
posterior vessels are stented by interventional cardiologist
allows cardiac option for all vessels without sternotomy
what does the hybrid room require?
built in fluoroscopy
what procedures will happen in a hybrid room?
hybrid coronary revascularization
transcatheter aortic valve replacement (TAVR)((or TAVI))
what two types of surgeons will be in the hybrid room?
cardiac surgeon
interventional cardiologist
what is a good premedication for CABG
versed– prevent anxiety and tachycardia
CABG pts need more than valve replacement
surgical options for valve repair/replacement 6
full bypass with arrested or beating heart
right heart bypass for tricuspid or pulm valve
endovascular or transapical valve replacement (off pump)
sternotomy
thoracotomy
davinci
how do we normally repair stenotic valves?
usually replaced
how do we normally repair regurgitant valves?
repaired or replaced
repair is more likely for regurg than for stenotic
can you use versed for valve repair/replacement?
NO,
these pts need to maintain their preload and afterload
are MICS valve repair/replacement more commonly performed on or off pump?
on pump via femoral arteries
endovascular valve repair, what types of patients get this surgery?
ONLY pts who dont qualify for open heart surgery
what % of pts with aortic stenosis are considered too high risk for surgery?
30-40%
endovascular aortic valve replacement two names
TAVR transcatheter aortic valve replacement
TAVI transcatheter aortic valve implantation
endovascular aortic valve replacement catheter/stent pathways 2
femoral artery (more common) axillary artery
pathway for endovascular mitral valve repair
femoral vein
intra-atrial septum
mitral valve
pathway for tricuspid and pulmonic valve repair
starts in femoral vein and goes up to valve by passing through right heart
transapical open valve replacement
valve replacement that is performed off pump with an open approach
6 risks associated with TAVR
1 stroke & TIA 2 perivalvular leak 3 vascular complications 4 acute kidney injury 5 cardiac conduction abnormalities 6 postoperative bleeding and atrial fibrillation
which is a higher risk of stroke? surgical valve replacement or TAVR
TAVR
30 day frequency is 2-6%
what is the % of aortic regurg as high as immediately post TAVR?
85%
what is the % of aortic regurg as high as at one year post TAVR?
75%
what fraction of patients have more than mild mitral regurg?
1/3
what is the most frequent adverse outcome associated with TAVR?
vascular complications
perforations, dissection, and/or rupture in arteries used for access
how can you limit vascular complications?
use the transapical thoracotomy approach
why is there a risk of acute kidney injury during TAVR?
large contrast load used in placing the valve with fluoroscopy
how does cardiac conduction abnormalities happen during TAVR?
final prosthesis position impinges conduction system
high incidence of LBBB
what is the incidence of complete heart block in pts that already have RBBB for TAVR surgery?
19-22%
could require pacemaker implantation
what TAVR risk is less likely to happen than with open surgical approaches?
post op bleeding and a fib
10 steps of anesthetic management for endovascular TAVR
1 renal protection
2 stroke prevention
3 lower dose of heparin
4 placement of transvenous pacing leads
5 attaching of external defibrillator pads
6 utilization of TEE
7 amicar administration UNNECESSARY
8 prep to keep heart still during valve deployment
9 hemodynamic goals for typical pt with aortic stenosis
10 continuous postop EKG monitoring for 48 hrs
renal protection steps (because of contrast dye used) TAVR
adequate periop volume loading
N-acetylcysteine prior to surgery
stroke prevention steps TAVR
dual antiplatelet therapy is started before surgery and continued for 6 months
300-325mg loading dose of aspirin
300mg clopidogrel
what is the goal ACT after heparin dose for TAVR
> 250
what are the two reasons that we place pacing leads during a TAVR
establish rapid ventricular pacing during valve placement
pace heart in case of complete heart block at end
why do we attach external defibrillator pads on TAVR pts?
life threatening arrhythmias can occur in 4% of pts
why do we use TEE during TAVR
provides information about results, position and complications of TAVR
what are the two options to keep the heart still during TAVR?
RVP rapid ventricular pacing
12 mg adenosine to stop the heart
RVP rate
180-220 bpm
what will happen to BP when you keep the heart still during TAVR? treatment?
hypotension
-ask surgeon whether or not to treat (usually not bc its short)
how long does valve deployment take?
12 seconds
what are the 3 hemodynamic goals for a pt with aortic stenosis
preload augmentation
low heart rates (50-70bpm) increase diastolic filling time
maintenance of sinus rhythm
why do you monitor EKG for 48 hr post TAVR?
monitors for onset of new rhythm disturbance
in what patients are the pacing wires left in place post op?
av block pts to prevent cardiac arrest
what are the two types of surgery to repair thoracic aorta
cross clamps with graft (open surgery)
endovascular stent
what is the more common thoracic aorta surgery?
endovascular stent
management of endovascular aortic stent
no sternotomy/bypass
less heparin
no amicar
aortic root replacement anesthetic plan
clamp placed on ascending aorta and treated as traditional bypass with arrested heart
surgical techniques for open ascending aorta repair (you can place cross clamp on ascending aorta)
tradition bypass
surgical techniques for open ascending aorta repair (you can NOT place cross clamp on ascending aorta)
deep hypothermic circulatory arrest (with or without retro or antegrade cerebral perfusion)
normothermic antegrade cerebral perfusion
what is the problem with descending aorta repair?
not possible to perfuse head and lower body with one arterial cannula
what are the bypass options for descending aorta repair?
partial cardiopulmonary bypass left heart partial bypass circ arrest (decrease risk of organ dysfunc. and paralysis)
What is the main concern of open descending aorta repair
increase the chance of paralysis from inadequate spinal cord perfusion
partial bypass descending aorta repair steps
some blood from RA through venous cannula
bypass machine
perfused lower extremities
blood that stays in heart goes through pulm and perfuses the head and upper extremities
Left heart partial bypass
some blood removed from LA reservoir cannula
bypass machine
perfuses lower extremities
blood that stays in heart perfuses head and upper extremities
anesthetic concerns for left heart bypass (3)
intensive vigilance to hemodynamics by anesthetist and perfusionist 2 alines (right radial artery and femoral artery) CVP compared to PA diastolic or wedge to assess filling of ventricles
partial left heart bypass pressure too high proximally and low distally do what?
flow increased through circuit
partial left heart bypass both proximal and distal pressures are low do what?
consider vasoconstrictor or fluids
partial left heart bypass both proximal and distal pressures are high do what?
consider vasodilator
anesthetic management for open descending aorta repair (4)
place aline in right arm
insert a double lumen tube
prepare cardiac drugs
consider techniques for spinal protection
why do we need to place the aline in the right arm for open descending aorta repair?
bc the clamp may need to be placed proximal to the left subclavian
why do we need a double lumen tube for open descending aorta repair?
bc a thoracotomy approach will most likely be used
spinal cord protection techniques for open descending aorta repair (4)
SSEP/MEP monitoring
Lumbar drain
Steroids (decrease swelling)
Consider Mannitol
what does a lumbar drain do?
increases spinal cord perfusion pressure
spinal cord perfusion pressure equation
= MAP- CSF pressure
why use mannitol to protect the spine?
increases spinal cord perfusion (decreasing CSF production)
improves renal perfusion
aortic wrapping procedure description
open chest procedure to treat aortic aneurysm
less common
reserved for those concomitant aortic valve replacement and too high risk
what are the two ways that heart transplants can be classified as
orthotopic heart transplant
heterotopic heart transplant (piggyback)
orthotopic heart transplant description and techiques used
replaced recipient heart with donor heart
biatrial, bicaval, or total heart transplant
heterotopic heart transplant (piggyback)
donor heart is placed in right chest next to recipient heart and anastomosed so blood can flow through either or both
biatrial heart transplant
only ventricles are removed
donor heart attach at midatrial level
biatrial heart transplant anastomosis required
4 aorta pulmonary artery left atrium right atrium
bicaval heart transplant
entire right atrium is removed but the left atrium remains intact
bicaval heart transplant anastomosis required
5 SVC IVC aorta pulmonary artery left atrium
total heart transplant
removes the entire heart including left atrium
total heart transplant anastomosis required
6 aorta pulmonary artery SVC IVC pulmonary veins (x2)
what are the advantages of having less anastomosis (comparing heart transplant techniques)
shorter operation times
less anastomotic complications
what are the disadvantages to biatrial technique
higher risk of: post op atrial arrhythmias atrial enlargement atrial thrombi tricuspid valve regurge
What heart transplant method gives the best post op function? downfall?
total heart transplant
downfall: longer operation times
explain normal heart vagus nerve and SA node mechanism
presynaptic vagus nerve releases Ach binds to MR on SA node and slows HR (balances to prevent tachy)
explain normal heart when atropine/robinul are given
atropine/robinul block the MR on the SA node and the Ach does not bind thus the HR increases
pt with heart transplant is denervated, what does this mean
not connected to sym or parasym nerves
So the SA node does not have the constant vagus nerve input
pt expected to have higher resting HR
do atropine/robinul increase the HR in pts with heart transplants?
no
effect of atropine/robinul on pt with heart transplant
will still bind MR on heart but there is no Ach to block so no effect on HR
can neostigmine cause bradycardia in patients with heart transplant?
yes
bc neostigmine floods the BODY with Ach and that can reach the SA node
when can atropine/robinul increase the HR of a pt that had a heart transplant?
when the bradycardia was caused by neostigmine
do you still give atropine/robinul with neostigmine in pts with heart transplants?
yes, you still need to prevent the bradycardia due to neostigmine
what happens to the heart when you have HF and pulmonary HTN?
right ventricular hypertrophy
this is needed to effectively pump blood into the lungs against higher resistance
in pts with HF and pulmonary HTN which ventricle is strong and which is weak?
left ventricle weak
right ventricle strong
– left can’t effectively pump blood to body
what is the main problem with heart transplants and pumonary HTN
you put a normal sized right ventricle that may not be able to pump enough against the high pulm resistance
could have right heart failure
what is the heart transplant option for patients with pulmonary HTN?
heterotopic heart transplant
2 hearts in pt
what do the old heart and the new heart do for the pt after heterotopic heart transplant?
old heart strong RV pumps majority through pulm circulation
new heart strong LV pumps majority of blood to body
what will happen after time with the heterotopic heart transplant?
pulm HTN will resolve and RV will return to normal size and more evenly share load with donor heart
implications of denervation (9)
1- resting HR >90bpm
2- atropine/robinul administered alone have no effect
3- neostigmine causes bradycardia (antimuscarinics used to counteract)
4- bradycardia must be treated with pacing or beta 1 agonist
5- pt cannot experience angina
6- baroreceptor reflex doesnt work (reflex brady doesnt happen)
7- sympathetic reinnervation within 12 mo for some
8- increase in CO is due to increase SV not increase HR as normal
9- biatrial technique pts will have 2 SA nodes and 2 p waves
what are the beta 1 agonists used to treat bradycardia when denervation
isoproterenol
dobutamine
epi
NE
reinnervation parasym vs sym
sym within 12 months for some
para less likely and less pronounced
degree varies and uncertain clinical significance
what is the clinical significance of 2 SA nodes
original SA node signal cannot cross suture line
thus donor SA node is the only one that effects HR of pt
anesthetic management for heart transplant procedure
1 PA pressure kept low to prevent right heart failure
2 inotropic support needed more often
3 immunosuppresive therapy implemented
4 beware of hyperkalemia post transplant
how often is RV failure an issue with heart transplants?
accounts for 20% of early deaths
what are strategies to reduce pulmonary artery pressure during heart transplant?
hyperventilation
higher FiO2
pulm artery vasodilators
avoidance of acidosis
what is methylprednisolone
steroid that is used to prevent rejection of transplant
dosed when crossclamp released
what are ways to lower plasma K?
hyperventilation
what is the bypass circuit for heart transplants
venous cannulas in SVC and IVC, arterial cannula in aorta
transmyocardial laser revascularization (TMLR) or TMR
laser creates series of holes in myocardium
relieve angina for pt not eligible for bypass/anginoplasty or have no more grafts
what are the two theories for TMR efficacy?
1- stimulates angiogenesis (new channels for blood flow)
2- destroyes nerve endings
anesthetics considerations for TMR
can be used in combination with CABG
when alone uses thoracotomy (double lumen tube)
arrhythmias and decreased CO expected when laser and pressure applied
vasopressors and inotropes need to be available
pericardial effusion
fluid around the heart
“fluid accumulation in the pericardial cavity”
cardiac tamponade
when pericardial effusion is big enough to effect cardiac function (decrease EF)
what are cardiac tamponade patients at risk for?
hypotension
cardiac arrest
especially during induction
hemodynamic effects of cardiac tamponade 2
1 decreased CO (bc of decreased SV)
2 becks triad
what is becks triad
hypotension
jugular venous distention
muffled heart tones
what are the two treatment options for cardiac tamponade
pericardiocentesis (local or sedation) pericardial window (general anesthesia)
what type of approach is used when the tamponade is an emergency?
subxiphoid approach (can be performed under local and sedation if required)
what type of tube is used in the subxiphoid approach?
single lumen ETT
what type of tube is used in the thoracotomy approach?
double lumen ETT
induction of anesthesia for pericardial window
head elevated 45 degrees
propofol avoided (ketamine or etomidate used)
surgeon ready before induction
in a patient with cardiac tamponade what does cardiac output depend on? SV or HR?
HR because the heart cannot increase SV
bradycardia must be avoided
Do you want positive pressure ventilation or spontaneous ventilation during a pericardial window?
spontaneous
PPV decreases venous return and CO
awake fiberoptic good option
mediastinoscopy
visualization of contents of space between lungs (mediastinum) usually for biopsy
what is the problem with the scope for mediastinoscopy?
ability to compress innominate (brachiocephalic) artery
surgeon not aware need to communicate this
what does the innominate artery supply blood to?
right arm (subclavian) and right common carotid
what patients are at risk for cerebral ischemia with innominate artery compression?
pts who have left carotid stenosis
aiway management for mediastinoscopy
single lumen ETT
no lungs need to be down
Spontaneous ventilation best
blood pressure monitors for mediastinoscopy
aline in right (know immediately if innominate is compressed)
NIBP left arm for when aline is jacked up
what is mandatory for mediastinoscopy?
monitor pulse in right arm
what is the less common blood pressure monitoring for mediastinoscopy?
aline in left arm (monitors continuously)
SpO2 on right (use waveform to watch for compression)
what is the primary concern with mediastinal mass?
compression of vital structures
what vital structures can be compressed by a mediastinal mass?
heart
central blood vessels
trachea
bronchi
what are the pts with mediastinal mass at risk for during induction
airway collapse
cardiovascular collapse
what are the signs/symptoms of mediastinal mass?
superior vena cava syndrome
pembertons sign
tracheobronchial compression
superior vena cava syndrome
obstruction to venous return through SVC
what is the most common cause of SVC syndrome?
malignancy
what can obstructed venous return lead to?
airway edema
decreased CO
increased ICP
syncope
what happens to a persons face during SVC syndrome
swelling in face in morning
swelling resolved after being upright all day
pembertons sign
facial congestion, cyanosis, respiratory distress when raising both arms
shifts mass to cause obstruction
what does pembertons sign illustrate about positioning
it can cause or alleviate obstruction
what patients show pembertons sign?
venous obstruction
goiters
mediastinal mass
tracheobronchial compression leads to
shortness of breath
orthopnea (when lying down)
total airway obstruction
pinch off ETT
anesthetic management for mediastinal mass
order and review diagnostic tests
what diagnostic tests should you order for mediastinal mass?
CT
CXR
ECHO
Pulm function test
what is the best diagnostic test to assess tracheal compression? at what % of occlusion is there a high risk of complications with GA
CT
<50%
what is the best diagnostic test to assess compression of the heart
ECHO
what do the results of diagnostic tests mean for anesthesia?
2 or more significant abnormal findings and there is high risk of complications for GA
-wait for tumor to be shrunk
intubation technique mediastinoscopy
awake fiberoptic intubation in sitting position
premedication limited to antimuscarinics
armored tube
armored tube
wire coil to prevent kinking or compression
inhalation induction for mediastinoscopy
may precipitate obstruction
routine induction for mediastinoscopy
pts that show no clinical or radiological evidence of airway or cardio obstruction
ventilation with tracheal compression
have plan
if distal to obstruction manual ventilation can be attempted
if unsure about distal or proximal then spontaneous should be maintained
what should you do if you are unable to place the ETT distal to the obstruction mediastinoscopy
tracheal stent used placed with rigid bronchoscopy or jet ventilation (bronchoscopy should be on standby)
jet ventilation
high pressure pt can be ventilated through small catheter
“cant intubate, cant ventilate”
how do you turn on the jet ventilator
push the lever down
what position should the patient be in during mediastinoscopy
semi upright position to maintain airway and reduce airway edema
what should be avoided in order to maintain cerebral perfusion pressure
avoid hypotension
obstructed venous drainage can cause increased ICP and compromise CPP
where should you place IVs in a person with SVC syndrome?
lower extremities
consider preload augmentation
what is important to have immediately available during mediastinoscopy?
surgical intervention
heart team on standby
groins preped for bypass
in what case for mediastinoscopy should the bypass cannulas be placed prior to GA induction
all pts with >50% reduction of airway
laser lead extraction
pacing leads may become infected and need removal
tissues grow around leads
laser sheaths used to remove tissue
laser lead extraction precautions
aline placed
cardiac team standby
could have severe hypotension and hemorrhage
