Cardiovascular pathophysiology 5 Flashcards
Pick the statements that MOST accurately describe an intra-aortic balloon pump. (select 2)
a. it increases afterload
b. the tip of the balloon should be positioned 2 cm proximal to the brachiocephalic artery
c. it inflates during diastole
d. it is contraindicated in severe aortic insufficiency
c. it inflates during diastole
d. it is contraindicated in severe aortic insufficiency
The intra-aortic balloon pump improves
the balance between myocardial oxygen supply and demand
Indications of the intra-aortic balloon pump include
cardiogenic shock
myocardial infarction
intractable angina
difficult separation from CPB
The intra-aortic balloon inflates during_____________. This augments __________
diastole; coronary perfusion
The balloon deflates during _______________. This causes a vacuum-like effect that ______________
systole; reduces afterload and reduces left ventricular work
The most common complications of IABP include
vascular injury
infection at the insertion site
thrombocytopenia
The balloon can be timed to inflate during
every cardiac cycle (1:1) or at some other ratio (1:2, 1:3, etc.) to facilitate weaning
Contraindications to an intra-aortic balloon pump include
severe aortic insufficiency
descending aortic disease (aneurysm)
severe peripheral vascular disease
sepsis
How is an intra-aortic balloon pump inserted?
through the femoral artery and advanced along the descending aorta
Proper position of the intra-aortic balloon pump is confirmed with
CXR, fluoroscopy, or TEE
The tip of the balloon pump should be positioned
2 cm distal to the left subclavian artery- more proximal can lead to occlusion of the left common carotid and/or brachiocephalic arteries
Patients on long term IABP therapy require
anticoagulation
In the patient with a left ventricular assist device, organ perfusion is LEAST dependent on:
a. preload
b. pump speed
c. afterload
d. inotropy
d. inotropy
An LVAD is a mechanical device that
unloads the failing heart by pumping blood from the left ventricle to the aorta
An LVAD can be used as a bridge to
recovery
transplant
or destination therapy
________ is the most common cause of death with an LVAD.
Sepsis
______________ anesthesia is avoided with an LVAD because
regional; on anticoagulant medications
Pump flow for an LVAD is highly dependent on
adequate LV preload
pump speed (RPMs)
and the pressure gradient across the pump (afterload)
Flow with an LVAD can be
pulsatile or non-pulatile
Considerations if blood flow is non-pulsatile.
SpO2 & NIBP will be ineffective
consider an arterial line, serial ABGs, and cerebral oximetry
The inflow cannula of a LVAD is inserted into
the apex of the left ventricle
The presence of the ____________, ______________, or ___________– requires a surgical correction before an LVAD can be placed
intracardiac shunt (PFO), aortic insufficiency, or tricuspid regurgitation
Mechanical shear stress with an LVAD can cause
coagulopathy & platelet dysfunction
_________ is common with a LVAD.
GI bleeding
Optimization of ___________ is critical because an imbalance between _________ and pump speed can lead to complications
intravascular volume; preload
The combination of low preload and a relatively high pump speed can produce
a suction event (LV sucks down) and occludes the inflow cannula
Consequences of a suction event include
hypotension
ventricular dysrhythmias
What is the primary treatment for a “suck down” event?
IVF
reduce pump speed
The Crawford classification classifies aortic aneurysms into four types based on
the aneurysm’s involvement in the thoracic and abdominal aorta
What aneurysm types are the most difficult to repair?
Crawford type 2 and 3 b/c they involve the thoracic and abdominal aorta
Crawford type 2 aneurysms present the most significant
perioperative risks including paraplegia and renal failure following surgery
The _______ & _____________- classifications classify various aortic dissections
DeBakey & Stanford
_________ dissection of the _______________ is a surgical emergency
Acute dissection of the ascending aorta (DeBakey 1 or 2 or Stanford A)
Which valve is often affected with acute dissection of the ascending aorta?
aortic valve- aortic insufficiency
Type 1 Crawford aortic aneurysm involves
all or most of the descending thoracic aorta
and upper only of the abdominal aorta
Type 2 Crawford involves
all or most of the descending thoracic aorta
most of the abdominal aorta
Type 3 Crawford involves
lower only of the descending thoracic aorta
most of the abdominal aorta
Type 4 Crawford involves
none of the descending thoracic aorta
most of the abdominal aorta
The Stanford type A is the same as the
Debakey Type 1 & 2
The DeBakey Type 1 involves a tear in the
ascending aorta + dissection along entire aorta
The DeBakey Type 2 involves a tear in the
ascending aorta + dissection only in ascending aorta
The DeBakey Type 3 involves
a tear in proximal descending aorta
Dissection of the descending aorta is often managed
medically (meds for HR, BP, pain) as surgical repair does not always produce a significant benefit
Identify the statement that BEST describes perioperative considerations in the patient with an abdominal aortic aneurysm. (select 2)
a. surgical intervention is recommended when the diameter is >5.5 cm
b. Risk of aneurysmal rupture is best described by Poiseuille’s Law
c. it is more common in females
d. back pain and hypotension suggest rupture
a. surgical intervention is recommended when the diameter is >5.5 cm
d. back pain and hypotension suggest rupture
Independent risk factors for AAA include
cigarette smoking
gender (male >female)
advanced age
AAA is generally
symptomless
AAA is most commonly detected as a
pulsatile abdominal mass during routine examination
What is used to determine the size of a AAA?
CT
US
MRI
Surgical correction is recommended when the aneurysm exceeds
5.5 cm or if it grows more than 0.6-0.8 cm per year
The mechanisms for the development of AAA are the
destruction of elastin & collagen (primary)
inflammation
endothelial dysfunction
platelet activation
atherosclerosis
