Anesthesia for Congenital Heart Disease Flashcards
____ refers to a normal opening in the body that has been narrowed or closed
atresia
______ means “narrowing
coartication
another name for right ventricular hypertrophy (RVH)
cor pulmonale
____ a muscle below the pulmonic valve
infundibulum
to an operation that is intended to decrease the severity of symptoms until a patient can tolerate an operation that will fix their condition
palliative surgery
-An example of a palliative operation would be placement of a Blaylock-Taussig (BT) shunt to keep a child alive until they are old enough to better tolerate an operation to repair their tetralogy of Fallot (TOF)
an artificial connection between the aortic arch and the pulmonary artery
aka an artificial ductus arteriosus
BT shunt
-It allows blood to get into the lungs from the aorta, and can be placed in patients that have reduced blood flow to the lungs (ex: pulmonary stenosis)
The risk of ______ remains a major concern in patients with congenital heart disease (CHD), whether unrepaired, palliated, or corrected
infective endocarditis (IE)
- Abx prophylaxis has long been recommended in patients with a history of congenital heart disease who need to undergo operations
Many patients with congenital heart disease suffer from hypoxia, and in an effort to compensate for the hypoxia, they make more red blood cells (which can cause them to have an abnormally high hematocrit)
The abnormally high hematocrit is referred to as ______
compensating polycythemia
- these patients are more prone to thrombosis
- generous fluid replacement can be beneficial because it can help bring the hematocrit level back to normal
A “normal” embolism will travel to the lungs and stay on the (right/left) side of the heart/pulmonary artery
right
A “paradoxical” embolism is an embolism that travels to the (right/left) side of the heart (through an ASD or a VSD) and ends up in the arterial circulation (and most likely causes a stroke)
left
If patients have a heart condition where blood shunts (right to left/ left to right) across an ASD or VSD, the risk of paradoxical embolism increases substantially, which means anesthetist need to be very vigilant in not allowing any air bubbles to in an IV line
right to left
increases in SVR promote more _____ shunting and (increase/ decrease) pulmonary blood flow
left to right
increase
decreases in SVR promote more ______ shunting and (increase/decrease) pulmonary blood flow
right to left
decrease (can lead to hypoxia)
increases in PVR promote more ______ shunting and (increase/ decrease) pulmonary blood flow
right to left
decrease (worsen hypoxemia)
decreases in PVR promote more _____ shunting and (increase/ decrease) pulmonary blood flow
left to right
increase
How can we decrease PVR?
higher FiO2 and hyperventilation
How can we increase PVR?
lower FiO2 and hypoventilation
Because of the hypoxia, patients with right to left intracardiac shunts are more prone to _______ than are patients with left to right intracardiac shunts
compensating polycythemia
is inhalational induction faster or slower in right to left cardiac shunts?
slower
Blood from the right side is entering the left side without having picked up any inhalational anesthetic
This dilutes the vapor in the arterial blood
is IV induction slower or faster in right to left cardiac shunts?
faster
Drugs get to the left side of the heart faster
How should the anesthetist manage SVR and PVR in right to left shunting?
Increase SVR
- regional and general anesthesia should be titrated slowly
- use ketamine
- single spot spinal is CONTRAINDICATED
Decrease PVR
What type of cardiac shunting are IV bubbles the most dangerous?
right to left shunting, however left to right shunting can turn into right to left shunting which makes it equally as dangerous (Eisenmenger’s syndrome)
What is “Eisenmenger’s syndrome”?
the left to right shunts can convert to a right to left shunt
before birth, blood shunts ________across the PDA
right to left
How is inhalational induction changed in left to right shunts?
Anesthetic induction is minimally affected
how is IV induction changed with left to right shunts?
slightly prolonged IV induction
-Probably due to the drug being slightly diluted
How should the anesthetist manage a left to right cardiac shunt?
increase PVR
decrease SVR
after birth, blood shunts ______ across the PDA
left to right
Assuming no other defects are present, blood is expected to shunt in a ______ fashion in patients with a PDA, leading to increased _______
left to right
pulmonary blood flow/ pulmonary congestion
Patients with a PDA often exhibit (high/ low) diastolic blood pressure
low
- some blood falls back into the pulmonary system during diastole
in patients with a PDA, how should the anesthetist control shunting?
decrease left to right shunting
good preload, lower FiO2, slight hypoventilation
what is indomethacin used for?
used to close the PDA
-up to 3 doses
to blood flow to areas of the body PROXIMAL TO THE DUCTUS ARTERIOSUS
preductal circulation
blood flow to areas of the body DISTAL TO THE DUCTUS ARTERIOSUS
postductal circulation
if the PDA connects distal to the subclavian artery, preductal circulation includes?
- head
- right arm
- left arm
if the PDA connects distal to the subclavian artery, postductal circulation includes?
- abdomen
2. lower extremities
if the PDA connects proximal to the subclavian artery, preductal circulation includes?
- head
2 right arm
if the PDA connects proximal to the subclavian artery, postductal circulation includes?
- left arm
- abdomen
- lower extremities
A paradoxic air embolism in this situation becomes much more likely
in order to obtain a preductal blood sample, the anesthetist should use?
right radial artery
in order to obtain postductal blood sample, the anesthetist should use?
femoral, dorsalis pedis, or posterior tibial artery
What does it suggest if preductal oxygen saturation is significantly different from postductal oxygen saturation?
suggests a heart defect that includes right to left shunting across a PDA that is causing hypoxemia in the postductal circulation
What is a patent foramen ovale?
the foramen ovale never closed after birth like it was supposed to
What is the anesthetic management for patent foramen ovale:
- the anesthetist should (decrease/increase) left to right shunting
- the anesthetist should not allow any _____ in the IV tubing
- decrease
- good preload, lower FiO2, slight hypoventilation - air bubbles
a hole between the right and left atria, so it can kind of be considered a “larger” patent foramen ovale
ASD
How should patients with an ASD be anesthetically managed?
same way as patients with a PFOs and PDAs
decrease left to right shunting
hole between the left and right ventricles
VSD
What is the most common congenital cardiac defect in adults?
VSD
How should patients with a VSD be anesthetically managed?
same as ASD, PFO, and PDA
decrease left to right shunting
a malformation of the tricuspid valve that results in tricuspid regurgitation
Ebstein’s Anomaly
-eventually results in high right atrial pressure & right atrial enlargement
2 problems with Ebstein’s anomaly
- heart defect?
- which way will blood shunt?
- the increase in right sided heart pressures makes it 80% more likely an ASD will be present
- If an ASD were present, blood would most likely shunt right to left
- decrease pulmonary blood flow, increase hypoxia, and increase the chances of a paradoxic air embolism and compensating polycythemia
How should Ebstein’s anomaly be managed?
1. decrease or increase PVR?
- decrease PVR
What is the main problem with Eisenmenger’s physiology/
pulmonary blood flow is 4X greater than systemic blood flow
What is the anesthetic management of Eisenmenger’s physiology?
1. SVR? PVR?
maintain SVR and PVR
-because a disruption one way or the other could cause a reversal of the shunt, leading to either heart failure or cyanosis
a narrowing of the aorta DISTAL to the left subclavian artery
coarctation of the aorta
-Postductal coarctation is more common