Flashcards in Cardiac Assist Devices Deck (51)
refers to a patient being placed on the bypass machine in times where the patient is not in heart surgery
Extracorporeal membrane oxygenation
In ECMO the patient is on bypass and the heart (is/is not) arrested and an aortic cross clamp (is/ is not) placed
the heart is NOT arrested
an aortic cross clamp is NOT placed
What is the main purpose of ECMO
to keep the patient alive during ACUTE cardiac or respiratory failure
1. Blood is drawn from the (left/right) side of the heart
2. oxygentated by the (lungs/ECMO)
3. Returned to the (right side/aorta) of the heart
What patients is Venovenous ECMO indicated for?
Patients with respiratory failure
-the heart must be working properly in order to get the blood to the left side of the heart
What type of cannula does Venovenous ECMO use?
Double lumen cannula
Where does the double lumen cannula in Venovenous ECMO enter?
the right atrium
In venovenous ECMO:
The (outer/inner) lumen drains the heart and sends the deoxygenated blood to the ECMO machine
The (outer/ inner) lumen infuses oxygenated blood from the ECMO machine into the Right atrium
In Venoarterial (VA) ECMO blood is
1. withdrawn from the (right/left) side of the heart
2. Oxygenated by the (lungs/ECMO)
3. Returned to the (right side/ aorta) of the heart
In venoarterial ECMO:
1. the venous cannula in the ____ ____ withdraws de-oxygenated blood
2. the arterial cannula in the ____ _____ re-infuses oxygenated blood
What patients is Venarorterial ECMO indicated in?
Cardiac failure (in addition to respiratory failure)
-heart does not need to pump blood to the left side
What is the primary advantage of VA ECMO over VV ECMO?
supports the heart AND lungs
3 disadvantage of VA ECMO over VV ECMO?
-less effective perfusion
2. less O2 delivery to coronary arteries
-O2 supply to the heart appears to be better when blood can enter the coronary arteries through the heart and not the machine
3. higher chance of emboli entering the circulation
Refers to an artificial heart, and is placed in patients with heart failure to help the ventricle pump blood
Ventricular Assist Device
List the 3 step mechanism of the Ventricular Assist Device
1. Tubing is placed inside the ventricle
2. tubing withdraws some blood from the ventricle into the pump
3. The pump pumps some blood through the body via the rein fusion tube
What are 2 ways in which the Ventricular Assist Device increases cardiac output
1. helps the heart pump blood
2.improves the heart’s own ability to pump blood because it relieves the fluid overload and stretching of the ventricle
What are 2 benefits of the Ventricular Assist Device?
1. increases cardiac output
2. increased cardiac output leads to less fluid overload/edema
supports left heart failure by withdrawing blood out of the left ventricle and pumping it into the aorta
Left ventricular assist device
Where does a LVAD withdraw blood from and where does it pump to?
left ventricle to the aorta
What is the primary purpose of a LVAD?
bridge to a heart transplant
What risks do LVAD carry that make them not long term solutions?
Risk of clotting and stroke
supports right heart failure by withdrawing blood out of the right ventricle and pumping it into the pulmonary artery
Right Ventricular Assist Device
Where does a RVAD withdraw blood and where does it pump it to?
Withdraws from the right ventricle and pumps it to the pulmonary artery
3 types of VADs
1. Long term intracorpeal VAD
2. short term intracorpeal VAD
3. short term extracorpeal VAD
type of VAD that is indicated for patients with “permanent” heart failure (when no transplant is available)
long term intracorpeal VAD
Placement of this type of VAD is accomplished with open heart surgery and cardiopulmonary bypass
long term intracorpeal VAD
From an anesthetic perspective, how is long term intracorpeal VAD insertion managed?
standard CPB case
This type of VAD has the pump and tubing inside the body
long term intracorpeal VAD
What type of VAD uses a catheter?
short term intracorpeal VAD
What is another name of internal catheter VAD?
Impella cardiac assist device
3 step Mechanism of the Impella VAD
1. the catheter is inserted into the _____ artery and guided through the ____ to the _____ ventricle
2. There is a small _____ at the tip of the catheter sitting in the___ ventricle
3. The pump removes blood from the ___ ventricle and pumps it to the proximal part of the catheter in the _____
1. femoral, aorta, left
2. pump, left
3. left, aorta
is indicated for short term use (acute heart failure), like when a heart becomes weakened after recent heart surgery
short term extracorpeal VAD
The extracorpeal VAD is aka?
3 step Mechanism of the Tandem Heart
1. The venous catheter is inserted into the _____ _____ and advanced to the ____ _____
2. the catheter draws (deoxygenated/oxygenated) blood from the ____ ____ and sends it to the ____ ____
3. The ____ ____ pumps blood to the body through an arterial catheter placed in the ____ ____
1. femoral vein, left atrium
-small hole in the interatrial septum
2. oxygenated, Left atrium, extracorpeal VAD (tandem heart)
3. extracorpeal VAD, femoral artery
This type of VAD has the tubing inside the body but the pump on the outside of the body
short term extracorpeal VAD
7 anesthetic implications for Patients with VAD:
1. What type of line is required?
2. What is most commonly used to trend blood pressures?
Mean arterial pressure or systolic/ diastolic pressures?
3. What type of medication are patients usually on?
4. What type of induction should be used?
5. This type of interference can alter device function
6. What are patients more susceptible too?
7. What is controversial?
1. arterial line
-flow is non-pulsatile and non-invasive BP readings are inaccurate if flow is inaccurate
-pumps can cause hemolysis, leading to thrombolytic events
-patients are considered full stomach due to device exerting pressure on the stomach
5. electromagnetic interference (EMI)
-bipolar cautery is recommended
-due to direct route
7. Chest compressions
-the cannula or VAD may become dislodged
What is the LEAST MAP in patients with VAD?
MAP of at least 60 mmHg
4 Anesthetic considerations for patients with VAD
1. Which team should be involved?
2. The VAD needs to have?
3. What plan should be established and with who?
4. This regulation is crucial for the patient
1. the VAD team
-If it is an emergency and no VAD team is available, contact the nearest hospital with a VAD team or contact the VAD manufacturer’s number
2. reliable power source
-VAD must be switched to battery power when transferring to and from the OR
3. safe coagulation plan with the surgeon and cardiologist
-Get coagulation lab results (PT, PTT, INR) before going to surgery
4. hemodynamic stability
Patients on VAD are usually on what anticoagulant?
Should this be discontinued? If so, what should it be replaced with?
replaced with heparin before elective surgery
What 2 hemodynamics should be considered in patients with VAD?
1. maintain pre-load (avoid hypovolemia)
-pump flow decreases when pre-load decreases
2. Avoid hypertension
-increases in afterload can cause a decrease in the output of the device
An intra-aortic balloon pump is inserted into the _____ through the _____ _____
The intra-aortic balloon pump is attached to an external console that triggers (inflation/ deflation) during systole and (inflation/deflation) during diastole
on the ECG:
When does the intra-aortic balloon pump inflate?
When does the intra-aortic balloon pump deflate?
inflates during the dichrotic notch of the arterial line waveform or the T wave of the ECG
deflates at or just prior to the R wave on the ECG
3 things intra-aortic balloon pump inflation is triggered by?
2. arterial line waveform
What are the 2 benefits of the intra-aortic balloon pump inflation during diastole?
pushes blood back into the aorta
1. increases diastolic BP
2. increases coronary perfusion pressure (increase O2 supply)
What are the 2 benefits of intra-aortic balloon pump deflation during systole?
pulls blood forward
1. decreases afterload and O2 demand
2. increases cardiac output by up to 40%
What are 3 instances in which an intra aortic balloon pump is indicated
Any type of acute HF
1. cardiogenic shock
2. acute heart attack
3. difficulty weaning off bypass
-temporary left ventricular assist device
“extra-aortic” balloon pump, which basically allows the patient to have a “permanent” balloon pump, which means that it’s an alternative to open LVAD placement
C-pulse heart pump
How is a C-pulse heart pump placed?
-no sternotomy required
Are patients required to be on coagulants with a C-pulse heart pump?
no, the balloon is external to the vascular system