Congenital Heart Defects Flashcards
Lance Carter, CAA
Atresia
Coarctation
Cor Pulmonale
Infundibulum
Palliative Surgery
Blaylock-Taussig (BT) Shunt
Infective Endocarditis in Congenital Heart Disease
“Compensating Polycythemia”
Paradoxical Embolism
Paradoxical Embolism In Clinical Practice
“Cardiac Shunts” (4)
Affect of SVR on Cardiac Shunts
Affect of PVR on Cardiac Shunts
Right to Left Cardiac Shunts Affect on Oxygen Saturation
Increases in PVR and Decreases in SVR in Right to Left Cardiac Shunts
Right to Left Cardiac Shunts Induction Technique (Inhalation vs. IV)
Right to Left Cardiac Shunts Affect of Air Bubbles in IV Tubing
Epidural Placement Consideration With Right to Left Cardiac Shunts
Left to Right Cardiac Shunts Affect on Pulmonary Blood Flow (2)
Left to Right Cardiac Shunts Affect on Induction Technique
Left to Right Cardiac Shunts Management of Preload
Left to Right Cardiac Shunts Affect of IV Air Bubbles
Affect on Pulmonary Blood Flow with Congenital Heart Defects
Question to Ask if a Patient has a Congenital Heart Defect
Managing Patients With TOO MUCH Pulmonary Blood Flow
Managing Patients WITHOUT ENOUGH Pulmonary Blood Flow
Description Of A Patent Ductus Arteriosus (PDA)
Flow Through The Ductus Arteriosus Before Birth
Flow Through The Ductus Arteriosus After Birth
Left To Right Shunting Across a PDA
Right To Left Shunting Across A PDA
Clinical Implications For Patients With a PDA (2)
Anesthetic Management For Patients With A PDA (3)
Surgical Repair Of a PDA
Preductal & Postductal Circulation
Connection Distal To The Subclavian
Connection of PDA Proximal To The Subclavian
Preductal Circulation Summary
Postductal Circulation Summary
Preductal & Postductal Blood Samples
Description Of A Patent Foramen Ovale
Clinical Implications Of A Patent Foramen Ovale (2)
Anesthetic Management For Patients With A PFO (2)
Clinical Implications Of An Atrial Septal Defect (ASD)
Anesthetic Management Of Patients With An ASD
Surgical Repair Of An ASD
Ventricular Septal Defect (VSD) Description
Clinical Implications & Management Of A VSD
Surgical Repair Of A VSD
Description Of Ebstein’s Anomaly
Clinical Implications Of Ebstein’s Anomaly
Anesthetic Management Of Ebstein’s Anomaly (3)
- Because of the risk of right to left shunting and decrease in pulmonary blood flow, the anesthetist should consider measures that would decrease PVR and increase pulmonary blood flow (hyperventilate, give supplementary oxygen, increase SVR, etc)
- An anesthetist should be avoid air bubbles in the IV line at all costs (due to the risk of paradoxic air embolism through the possible right to left shunt)
- If blood does in fact shunt right to left across the an open foramen ovale, we would expect the patient to be perfused with mixed/venousarterialbloodand the patient would have a lower than expected SpO2 and a possible compensating polycythemia
Description Of Eisenmenger’s Syndrome
Clinical Implications Of Eisenmenger’s Syndrome
Anesthetic Management For Left To Right Shunts That Have Possible Eisenmenger’s Physiology (3)
- Anesthetic management should be to 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 fine balance must be struck when managing oxygenation
- High FiO2 may worsen the left to right shunt and promote right heart failure
- Low FiO2 may worsen the right to left shunt and promote cyanosis -
Single shot spinal anesthesia is contraindicated
- Although a small drop in SVR could be beneficial in decreasing the left to right shunting, it could cause more right to left shunting and exacerbate hypoxemia if Eisenmenger’s physiology is present
Description Of Coarctation Of The Aorta
Types Of Coarctation Of The Aorta (3)
Clinical Implications For Coarctation Of The Aorta (4)
- The narrowing of the aorta will cause a potentially severe decrease in cardiac output, leading to poor peripheral perfusion, metabolic acidosis, and high afterload (leading to more likely congestive heart failure and aortic regurge)
- Blood pressure in the lower extremities will be lower than in the arms
- If the patient has a PREDUCTAL coarctation (meaning that the ductus arteriosus connects DISTAL to the coarctation), a patent ductus arteriosus can provide a big boost to the patient’s cardiac output via right to left shunting across the PDA from the right ventricle so keep the PDA open
Anesthetic Management For Coarctation Of The Aorta (5)
- In patients with PREDUCTAL coarctation, the ductus arteriosus should be kept open in order to allow adequate lower body perfusion
- The thinking here is that more blood flow is better than less blood flow, even if the blood is deoxygenated -
SVR should be maintained
- Apparently, since blood flow distal to the coarctation is already reduced, perfusion is seriously compromised if hypotension is also present - Preload should be maintained to ensure adequate forward flow
-
Bradycardia should be avoided
- The left ventricular stroke volume (due to the coarctation) is even more fixed, meaning that cardiac output can only be increased if the heart rate increases - The anesthetist should avoid abnormally high contractility and/or heart rate, due to an increased risk of aortic dissection
Surgical Repair For Coarctation Of The Aorta
Interrupted Aortic Arch
Clinical Implications For An Interrupted Aortic Arch (4)
- Because of the gap in the aorta, the oxygenated blood from the left ventricle is unable to perfuse the lower extremities (it is only able to perfuse the right upper extremity and part of the head)
- All blood flow to the lower extremities has to come from the right ventricle through a PDA
- Therefore, the patient A PDA is required for all lower extremity blood flow - An ASD or VSD has to be present in order for the patient to survive
- Without the ASD or VSD, all blood to the lower extremities would be come from the right ventricle and be deoxygenated
- With the ASD or VSD, it allows some oxygenated blood from the left ventricle to mix with the blood from the right ventriclebefore going to the lower extremities (so the lower extremities can at least have SOME oxygen) - The blood pressure, pulse, and SpO2 is usually higher in the right arm than the left arm, because the left subclavian artery and lower extremities are perfused with mixed venous/arterial blood
Anesthetic Management For Interrupted Aortic Arch (4)
Surgical Repair for an Interrupted Aortic Arch/VSD (2)
Description Of Tetralogy Of Fallot (4 Defects Present)
Shunting Of Blood In Tetralogy Of Fallot
Effects Of The Overriding Aorta In Tetralogy Of Fallot
Limited Pulmonary Blood Flow In Tetralogy Of Fallot
Possible Pulmonary Blood Flow In Tetralogy Of Fallot
Hypoxia In Tetralogy Of Fallot
Increasing Pulmonary Blood Flow And Decreasing Hypoxia In Tetralogy Of Fallot
Cause Of Tetralogy Spell (“Tet Spell”)
Causes Of Infundibular Spasm (3)
Treatment for a Tet Spell (6)
1. Administer 100% oxygen
- *2. Place the child in a knee chest position**
- (this increases SVR by reducing arterial blood flow to the lower extremities)
- *3. Give a fluid bolus to enhance preload**
- This increases the size of the heart, which may increase the diameter of the right ventricular outflow tract (RVOT)
- This is interesting to me because the books also say that increased preload (from spontaneous hyperventilation) can make a tet spell worse because it increases right to left shunting
- *4. Consider administration of Ketamine or phenylephrine to increase SVR**
- Just as an FYI, tetralogy of Fallot is one of very few conditions I’m aware of where phenylephrine administration can be recommended in pediatrics (it is normally NOT recommended because of the reflex bradycardia)
5. Consider moderate hyperventilation (when mechanically ventilating) to reduce PVR and right to left shunting
- *6. Consider a beta blocker** (ex: Esmolol)
- Tachycardia and increases in contractility can worsen infundibular spasm, causing an increase in the right to left shunt
- Slowing of the heart rate may allow for improved diastolic filling (increased preload), increased heart size, and an increase in the diameter of the RVOT
- Tetralogy of Fallot is one of the very few conditions in which beta blockade can be recommended in pediatrics, because cardiac output is more dependent on heart rate
7. Avoid beta agonists when trying to raise blood pressure, as increases in contractility worsen infundibular spasm
Anesthetic Management For Tetralogy Of Fallot (7)
1. The ductus arteriosus should be kept open with PGE1 to allow adequate pulmonary blood flow
- *2. The anesthetist should promote pulmonary blood flow and minimize right to left shunting.** This can be accomplished by:
- Lowering PVR (giving supplemental oxygen, hyperventilating the patient, etc)
- Increasing SVR (with ketamine or phenylephrine), or at the very least, preventing a drop in SVR
- *3. Hypotension should be avoided on induction**
- Normally, in healthy “non-tetralogy of Fallot patients,” we perform as mask induction with high concentrations of Sevoflurane
- Since the high concentrations of Sevoflurane have the potential to drop SVR and promote even more right to left shunting, mask induction should be avoided in these patients
- INTRAVENOUS induction with Ketamine is the best way to prevent an increase in right to left shunting
4. If the patient becomes cyanotic or has a profound drop in blood pressure and/or SpO2, phenylephrine or Ketamine administration may be considered
- *5. Sympathetic stimulation should be minimized** (to prevent infundibular spasm)
- Therefore, these patients may benefit from good premedication (like a Ketamine dart), especially before IV placement
6. Air bubbles in the IV line should be avoided (because of risk of paradoxic embolism from the right to left shunting across the VSD)
- *7. Preload should be maintained/elevated with volume expansion**
- Even though this increases pressure on the right side of the heart and theoretically would increase right to left shunting, it is apparently recommended and has an overall greater benefit because it helps keep the right ventricular outflow tract (RVOT) open¯_(ツ)_/¯
Surgical Repair of TOF
Description Of TGA (Transposition of the Great Arteries)
Shunting in TPA
Additional Defects Present in TGA (For Survival)
Blood Flow In TGA
Clinical Implications Of TGA - Right to Left Shunt
Clinical Implications Of TGA - Left to Right Shunt
Clinical Implications Of TGA - Pulmonary Blood Flow
Clinical Implications Of TGA - Importance of a Patent Ductus Arteriosis
Blood Flow In TGA
Clinical Implications Of TGA - Onset Time for Inhalation Anesthetics
Clinical Implications Of TGA - Affect of IV Drugs
Clinical Implications Of TGA - Air in IV Tubing
Anesthetic Management For TGA (8)
1. The anesthetist should implement measures to increase pulmonary blood flow
-1a. Keeping the PVR lower relative to SVR will lead to increased pulmonary blood flow, increased mixing of blood, and better oxygen saturation
PVR should be maintained or decreased
SVR should be maintained or increased
-1b. Preload should be maintained or increased, because it favors right to left shunting of blood into the lungs
2. The anesthetist should keep the PDA open with PGE1, because a PDA can allow a shunt in either direction and can promote mixing of oxygenated and deoxygenated blood
3. The doses and rates of injection of intravenous drugs may have to be decreased (since minimal dilution occurs by the time they hit the heart and brain)
- *4. Intravenous induction is preferred over inhalational induction**
- Ketamine is the induction agent of choice, because it increases SVR and diverts more blood flow into the lungs (which is what we want)
- *5. TIVA (with ketamine, opioids, and midazolam) is preferred** over inhalational agents
- (due to the cardiac depressant effects of volatile agents and the fact that inhaled anesthetics have a harder time reaching the brain)
- *6. The anesthetist should avoid air bubbles in the IV line at all costs**
- The air bubble would travel straight to the aorta/brain without having to travel through the lungs or through a right to left shunt
7. The patients are often managed with inotropes and diuretics to treat symptoms of heart failure
Surgical Repair For Transposition Of The Great Arteries
Description Of Total Anomalous Pulmonary Venous Return (TAPVR)
Description Of Total Anomalous Pulmonary Venous Return (TAPVR)
Description Of Total Anomalous Pulmonary Venous Return (TAPVR)
Clinical Implications For TAPVR
1. The right side of the heart and pulmonary vasculature will most likely be congested, so the anesthetist should strive for measures that increase right to left shunting and limit pulmonary blood flow
2. Because of pulmonary congestion, patients with TAPVR often have thickened medial layers in their pulmonary vasculature, which causes PVR to be elevated for a period of time after surgical repair. In other words, patients with TAPVR are prone to postoperative pulmonary hypertension
- *3. The abnormal pulmonary vasculature is highly susceptible to changes in blood gases and lung mechanics, so the anesthetist can have a drastic effect on patient outcome by simply controlling ventilation parameters**
- “Morray et al demonstrated a 50% increase in PAP when the PaCO2 was increased from less than 30mmHg to 40-45mmHg…Thus mechanical ventilation to a PaCO2 to 30-35 mmHg is mandatory in the postoperative period
4. Postoperative cardiac output is usually compromised, probably because the left ventricle has been under filled and underutilized prior to correction, and after correction, it has to deal with this huge all of the sudden increase in blood flow
5. The patient will be perfused with mixed/venous arterial blood, which means that we can expect a low SpO2 and a possible compensating polycythemia
Anesthetic Management For TAPVR (3)
- *1.** The anesthetist should take measures to increase right to left shunting by increasing PVR and decreasing SVR
- Increasing PVR forces shunts more blood across away from the lungs and across the ASD, leading to increased cardiac output
- “For patients with increased pulmonary blood flow and right ventricular volume overload, ventilatory interventions should be used to increase PVR…” (Smith’s Anesthesia for Infants and
- *2.** In addition to lowering PVR intraoperatively, the anesthetist should keep PVR low postoperatively (because of the increased risk of postoperative pulmonary hypertension in patients with TAPVR)
- By stretching the lungs, positive pressure ventilation leads to release of prostaglandins which cause pulmonary vasodilation
- Nitric oxide (although expensive) is emerging as a popular drug because of it’s ability to selectively lower pulmonary artery pressure PAP without lowering systemic blood pressure
- *3. Postoperative inotropes may be necessary to prevent low cardiac output and pulmonary hypertension**
- Without inotropes, the left ventricle may have a hard time pumping the increase in blood flow that it isn’t used to, and if that occurs, blood would back up into the lungs and worsen the already high pulmonary vascular resistance
Surgical Repair For TAPVR
Blood flow in hypoplastic left heart syndrome
- Underdeveloped left ventricle
- Very small (or closed) mitral and aortic valves
- Stenotic ascending aorta
What shunts are necessary in hypoplastic left heart syndrome?
Anesthetic Management For HLHS
Surgical Repair Of HLHS
Norwood Procedure For HLHS
http://www.youtube.com/watch?v=-87kq98l1kk
- The right ventricle is attached to the aorta, increasing cardiac output
- A Blaylock Taussig (BT) shunt is placed
Benefits Of The Hemi-Fontan Procedure
Hemi-Fontan (Bidirectional Glenn) Procedure For HLHS
Fontan Procedure For HLHS
Clinical Implications:
- The venous return completely bypasses the “right side”
- All blood flow to the lungs is passive
- The right ventricle is no longer pumping deoxygenated blood
Anesthetic Management For A
Patient With Fontan Physiology (6)
- The anesthetist should maintain normal to elevated preload
- Avoid drugs that cause myocardial depression (volatile agents), etomidate is best choice
- Avoid increases in pulmonary vascular resistance (PVR)
- SVR, heart rate, and cardiac contractility should be maintained
- For short operations, spontaneous ventilation is preferred (avoid hypercarbia)
- Invasive arterial and central venous monitoring is mandatory
Protein Losing Enteropathy (PLE) In Fontan Patients
How Blood Gets Into The Lungs In Tricuspid Atresia
How Blood Gets Into The Lungs In Tricuspid Atresia
Clinical Implications of Tricuspid Atresia (5)
- The right ventricle is severely underdeveloped and probably won’t really be able to pump effectively (left ventricle does all the work)
- The left ventricle is completely overworked
- All of the blood that is able to get into the aorta is mixed/venous arterial blood, which means wecan expect a low SpO2 and a possible compensating polycythemia
- Blood flow to the lungs can be variable
- An increase in PVR will decrease pulmonary blood flow and increase cardiac output and vice versus
Anesthetic Management Of Tricuspid Atresia
Surgical Repair Options For Tricuspid Atresia (3)
- Palliative BT shunt
- They can receive a band around the pulmonary artery
- Patients with tricuspid atresia can end up with a Fontan procedure
Description Of Pulmonary Atresia
How Blood Gets Into The Lungs In Pulmonary Atresia
Clinical Implications Of Pulmonary Atresia (3)
- Blood flow to the lungs is obviously limited
- We can expect a low SpO2 and a possible compensating polycythemia
- These patients may therefore have symptoms of CHF and may require inotropic support
Anesthetic Management Of Pulmonary Atresia
Surgical Repair Of Pulmonary Atresia
Description Of Truncus Arteriosus
Clinical Implications Of Truncus Arteriosus
Anesthetic Management For Truncus Arteriosus
- Since both ventricles are pumping to both the lungs and the aorta, the anesthetist needs to properly balance the blood flow to each path by having an appropriate SVR to PVR ratio
- Pulmonary congestion will likely be present
Surgical Repair Of Truncus Arteriosus
Description Of Endocardial Cushion Defect
Clinical Implications Of Endocardial Cushion Defect (3)
- Although both right to left AND left to right shunting occur, left to right shunting is more prominent and the patient will have excessive pulmonary blood flow
- The ventricles are will most likely be volume overloaded, leading to symptoms of CHF
- The patient is perfused with mixed venous/arterial blood, which we can expect a low SpO2 and a possible compensating polycythemia
Anesthetic Management For Endocardial Cushion Defect
Surgical Repair For Endocardial Cushion Defect
Description Of Double Outlet Right Ventricle
Clinical Implications Of Double Outlet Right Ventricle (4)
- A ASD or a VSD is required
- The right ventricle is overworked
- The patient is perfused with mixed venous/arterial blood, which we can expect a low SpO2 and a possible compensating polycythemia
- Pulmonary stenosis may or may not be present
Anesthetic Management For Double Outlet Right Ventricle
Surgical Repair Of Double Outlet Right Ventricle
Description Of Vascular Rings
Anesthetic Management For Vascular Rings (4)
- Most often the surgery is accomplished via thoracotomy, although a median sternotomy with bypass may be necessary
- Smaller sized tubes should be available, and it wouldn’t be a bad idea to intubated with an armored (reinforced) endotracheal tube(because it would ensure that the tube wouldn’t be compressed by the vascular rings)
- Extubation may be considered if tracheomalacia or stenosis is not anticipated
- “An inhalational induction with spontaneous ventilation is recommended. Similar to an anterior mediastinal mass, the tracheal compression may worsen during induction and the patient may decompensate when neuromuscular blocking agents are given.”
Dextrocardia
The Two Types Of Dextrocardia
Clinical Implications And Management Of Dextrocardia
Ductal Dependent Systemic Blood Flow
Symptoms Of Patients With Ductal Dependent Systemic Blood Flow (3)
Ductal Dependent Pulmonary Blood Flow
Atresia
Coarctation
Cor Pulmonale
Infundibulum
Blaylock-Taussig (BT) Shunt
Infective Endocarditis in Congenital Heart Disease
“Compensating Polycythemia”
Paradoxical Embolism
Affect of SVR on Cardiac Shunts
Affect of PVR on Cardiac Shunts
Increases in PVR and Decreases in SVR in Right to Left Cardiac Shunts
Right to Left Cardiac Shunts Induction Technique (Inhalation vs. IV)
Description Of Ebstein’s Anomaly
Clinical Implications Of Ebstein’s Anomaly
Anesthetic Management Of Ebstein’s Anomaly (3)
- Because of the risk of right to left shunting and decrease in pulmonary blood flow, the anesthetist should consider measures that would decrease PVR and increase pulmonary blood flow (hyperventilate, give supplementary oxygen, increase SVR, etc)
- An anesthetist should be avoid air bubbles in the IV line at all costs (due to the risk of paradoxic air embolism through the possible right to left shunt)
- If blood does in fact shunt right to left across the an open foramen ovale, we would expect the patient to be perfused with mixed/venousarterialbloodand the patient would have a lower than expected SpO2 and a possible compensating polycythemia
Description Of Eisenmenger’s Syndrome
Clinical Implications Of Eisenmenger’s Syndrome
Description Of Coarctation Of The Aorta
Types Of Coarctation Of The Aorta (3)
Clinical Implications For Coarctation Of The Aorta (4)
- The narrowing of the aorta will cause a potentially severe decrease in cardiac output, leading to poor peripheral perfusion, metabolic acidosis, and high afterload (leading to more likely congestive heart failure and aortic regurge)
- Blood pressure in the lower extremities will be lower than in the arms
- If the patient has a PREDUCTAL coarctation (meaning that the ductus arteriosus connects DISTAL to the coarctation), a patent ductus arteriosus can provide a big boost to the patient’s cardiac output via right to left shunting across the PDA from the right ventricle so keep the PDA open
Anesthetic Management For Coarctation Of The Aorta (5)
- In patients with PREDUCTAL coarctation, the ductus arteriosus should be kept open in order to allow adequate lower body perfusion
- The thinking here is that more blood flow is better than less blood flow, even if the blood is deoxygenated -
SVR should be maintained
- Apparently, since blood flow distal to the coarctation is already reduced, perfusion is seriously compromised if hypotension is also present - Preload should be maintained to ensure adequate forward flow
-
Bradycardia should be avoided
- The left ventricular stroke volume (due to the coarctation) is even more fixed, meaning that cardiac output can only be increased if the heart rate increases - The anesthetist should avoid abnormally high contractility and/or heart rate, due to an increased risk of aortic dissection
Surgical Repair For Coarctation Of The Aorta
Interrupted Aortic Arch
Clinical Implications For An Interrupted Aortic Arch (4)
- Because of the gap in the aorta, the oxygenated blood from the left ventricle is unable to perfuse the lower extremities (it is only able to perfuse the right upper extremity and part of the head)
- All blood flow to the lower extremities has to come from the right ventricle through a PDA
- Therefore, the patient A PDA is required for all lower extremity blood flow - An ASD or VSD has to be present in order for the patient to survive
- Without the ASD or VSD, all blood to the lower extremities would be come from the right ventricle and be deoxygenated
- With the ASD or VSD, it allows some oxygenated blood from the left ventricle to mix with the blood from the right ventriclebefore going to the lower extremities (so the lower extremities can at least have SOME oxygen) - The blood pressure, pulse, and SpO2 is usually higher in the right arm than the left arm, because the left subclavian artery and lower extremities are perfused with mixed venous/arterial blood
Anesthetic Management For Interrupted Aortic Arch (4)
Surgical Repair for an Interrupted Aortic Arch/VSD (2)
Description Of Tetralogy Of Fallot (4 Defects Present)
Shunting Of Blood In Tetralogy Of Fallot
Effects Of The Overriding Aorta In Tetralogy Of Fallot
Limited Pulmonary Blood Flow In Tetralogy Of Fallot
Increasing Pulmonary Blood Flow And Decreasing Hypoxia In Tetralogy Of Fallot
Causes Of Infundibular Spasm (3)
Treatment for a Tet Spell (6)
1. Administer 100% oxygen
- *2. Place the child in a knee chest position**
- (this increases SVR by reducing arterial blood flow to the lower extremities)
- *3. Give a fluid bolus to enhance preload**
- This increases the size of the heart, which may increase the diameter of the right ventricular outflow tract (RVOT)
- This is interesting to me because the books also say that increased preload (from spontaneous hyperventilation) can make a tet spell worse because it increases right to left shunting
- *4. Consider administration of Ketamine or phenylephrine to increase SVR**
- Just as an FYI, tetralogy of Fallot is one of very few conditions I’m aware of where phenylephrine administration can be recommended in pediatrics (it is normally NOT recommended because of the reflex bradycardia)
5. Consider moderate hyperventilation (when mechanically ventilating) to reduce PVR and right to left shunting
- *6. Consider a beta blocker** (ex: Esmolol)
- Tachycardia and increases in contractility can worsen infundibular spasm, causing an increase in the right to left shunt
- Slowing of the heart rate may allow for improved diastolic filling (increased preload), increased heart size, and an increase in the diameter of the RVOT
- Tetralogy of Fallot is one of the very few conditions in which beta blockade can be recommended in pediatrics, because cardiac output is more dependent on heart rate
7. Avoid beta agonists when trying to raise blood pressure, as increases in contractility worsen infundibular spasm
Anesthetic Management For Tetralogy Of Fallot (7)
1. The ductus arteriosus should be kept open with PGE1 to allow adequate pulmonary blood flow
- *2. The anesthetist should promote pulmonary blood flow and minimize right to left shunting.** This can be accomplished by:
- Lowering PVR (giving supplemental oxygen, hyperventilating the patient, etc)
- Increasing SVR (with ketamine or phenylephrine), or at the very least, preventing a drop in SVR
- *3. Hypotension should be avoided on induction**
- Normally, in healthy “non-tetralogy of Fallot patients,” we perform as mask induction with high concentrations of Sevoflurane
- Since the high concentrations of Sevoflurane have the potential to drop SVR and promote even more right to left shunting, mask induction should be avoided in these patients
- INTRAVENOUS induction with Ketamine is the best way to prevent an increase in right to left shunting
4. If the patient becomes cyanotic or has a profound drop in blood pressure and/or SpO2, phenylephrine or Ketamine administration may be considered
- *5. Sympathetic stimulation should be minimized** (to prevent infundibular spasm)
- Therefore, these patients may benefit from good premedication (like a Ketamine dart), especially before IV placement
6. Air bubbles in the IV line should be avoided (because of risk of paradoxic embolism from the right to left shunting across the VSD)
- *7. Preload should be maintained/elevated with volume expansion**
- Even though this increases pressure on the right side of the heart and theoretically would increase right to left shunting, it is apparently recommended and has an overall greater benefit because it helps keep the right ventricular outflow tract (RVOT) open¯_(ツ)_/¯
Description Of TGA (Transposition of the Great Arteries)
Anesthetic Management For TGA (8)
1. The anesthetist should implement measures to increase pulmonary blood flow
-1a. Keeping the PVR lower relative to SVR will lead to increased pulmonary blood flow, increased mixing of blood, and better oxygen saturation
PVR should be maintained or decreased
SVR should be maintained or increased
-1b. Preload should be maintained or increased, because it favors right to left shunting of blood into the lungs
2. The anesthetist should keep the PDA open with PGE1, because a PDA can allow a shunt in either direction and can promote mixing of oxygenated and deoxygenated blood
3. The doses and rates of injection of intravenous drugs may have to be decreased (since minimal dilution occurs by the time they hit the heart and brain)
- *4. Intravenous induction is preferred over inhalational induction**
- Ketamine is the induction agent of choice, because it increases SVR and diverts more blood flow into the lungs (which is what we want)
- *5. TIVA (with ketamine, opioids, and midazolam) is preferred** over inhalational agents
- (due to the cardiac depressant effects of volatile agents and the fact that inhaled anesthetics have a harder time reaching the brain)
- *6. The anesthetist should avoid air bubbles in the IV line at all costs**
- The air bubble would travel straight to the aorta/brain without having to travel through the lungs or through a right to left shunt
7. The patients are often managed with inotropes and diuretics to treat symptoms of heart failure
Description Of Total Anomalous Pulmonary Venous Return (TAPVR)
Clinical Implications For TAPVR
1. The right side of the heart and pulmonary vasculature will most likely be congested, so the anesthetist should strive for measures that increase right to left shunting and limit pulmonary blood flow
2. Because of pulmonary congestion, patients with TAPVR often have thickened medial layers in their pulmonary vasculature, which causes PVR to be elevated for a period of time after surgical repair. In other words, patients with TAPVR are prone to postoperative pulmonary hypertension
- *3. The abnormal pulmonary vasculature is highly susceptible to changes in blood gases and lung mechanics, so the anesthetist can have a drastic effect on patient outcome by simply controlling ventilation parameters**
- “Morray et al demonstrated a 50% increase in PAP when the PaCO2 was increased from less than 30mmHg to 40-45mmHg…Thus mechanical ventilation to a PaCO2 to 30-35 mmHg is mandatory in the postoperative period
4. Postoperative cardiac output is usually compromised, probably because the left ventricle has been under filled and underutilized prior to correction, and after correction, it has to deal with this huge all of the sudden increase in blood flow
5. The patient will be perfused with mixed/venous arterial blood, which means that we can expect a low SpO2 and a possible compensating polycythemia
Anesthetic Management For TAPVR (3)
- *1.** The anesthetist should take measures to increase right to left shunting by increasing PVR and decreasing SVR
- Increasing PVR forces shunts more blood across away from the lungs and across the ASD, leading to increased cardiac output
- “For patients with increased pulmonary blood flow and right ventricular volume overload, ventilatory interventions should be used to increase PVR…” (Smith’s Anesthesia for Infants and
- *2.** In addition to lowering PVR intraoperatively, the anesthetist should keep PVR low postoperatively (because of the increased risk of postoperative pulmonary hypertension in patients with TAPVR)
- By stretching the lungs, positive pressure ventilation leads to release of prostaglandins which cause pulmonary vasodilation
- Nitric oxide (although expensive) is emerging as a popular drug because of it’s ability to selectively lower pulmonary artery pressure PAP without lowering systemic blood pressure
- *3. Postoperative inotropes may be necessary to prevent low cardiac output and pulmonary hypertension**
- Without inotropes, the left ventricle may have a hard time pumping the increase in blood flow that it isn’t used to, and if that occurs, blood would back up into the lungs and worsen the already high pulmonary vascular resistance
Surgical Repair For TAPVR
Blood flow in hypoplastic left heart syndrome
- Underdeveloped left ventricle
- Very small (or closed) mitral and aortic valves
- Stenotic ascending aorta
What shunts are necessary in hypoplastic left heart syndrome?
Anesthetic Management For HLHS
Norwood Procedure For HLHS
http://www.youtube.com/watch?v=-87kq98l1kk
- The right ventricle is attached to the aorta, increasing cardiac output
- A Blaylock Taussig (BT) shunt is placed
Benefits Of The Hemi-Fontan Procedure
Hemi-Fontan (Bidirectional Glenn) Procedure For HLHS
Fontan Procedure For HLHS
Clinical Implications:
- The venous return completely bypasses the “right side”
- All blood flow to the lungs is passive
- The right ventricle is no longer pumping deoxygenated blood
Anesthetic Management For A
Patient With Fontan Physiology (6)
- The anesthetist should maintain normal to elevated preload
- Avoid drugs that cause myocardial depression (volatile agents), etomidate is best choice
- Avoid increases in pulmonary vascular resistance (PVR)
- SVR, heart rate, and cardiac contractility should be maintained
- For short operations, spontaneous ventilation is preferred (avoid hypercarbia)
- Invasive arterial and central venous monitoring is mandatory
Clinical Implications of Tricuspid Atresia (5)
- The right ventricle is severely underdeveloped and probably won’t really be able to pump effectively (left ventricle does all the work)
- The left ventricle is completely overworked
- All of the blood that is able to get into the aorta is mixed/venous arterial blood, which means wecan expect a low SpO2 and a possible compensating polycythemia
- Blood flow to the lungs can be variable
- An increase in PVR will decrease pulmonary blood flow and increase cardiac output and vice versus
Anesthetic Management Of Tricuspid Atresia
Surgical Repair Options For Tricuspid Atresia (3)
- Palliative BT shunt
- They can receive a band around the pulmonary artery
- Patients with tricuspid atresia can end up with a Fontan procedure
Description Of Pulmonary Atresia
Clinical Implications Of Pulmonary Atresia (3)
- Blood flow to the lungs is obviously limited
- We can expect a low SpO2 and a possible compensating polycythemia
- These patients may therefore have symptoms of CHF and may require inotropic support
Anesthetic Management Of Pulmonary Atresia
Surgical Repair Of Pulmonary Atresia
Description Of Truncus Arteriosus
Clinical Implications Of Truncus Arteriosus
Anesthetic Management For Truncus Arteriosus
- Since both ventricles are pumping to both the lungs and the aorta, the anesthetist needs to properly balance the blood flow to each path by having an appropriate SVR to PVR ratio
- Pulmonary congestion will likely be present
Surgical Repair Of Truncus Arteriosus
Description Of Endocardial Cushion Defect
Clinical Implications Of Endocardial Cushion Defect (3)
- Although both right to left AND left to right shunting occur, left to right shunting is more prominent and the patient will have excessive pulmonary blood flow
- The ventricles are will most likely be volume overloaded, leading to symptoms of CHF
- The patient is perfused with mixed venous/arterial blood, which we can expect a low SpO2 and a possible compensating polycythemia
Anesthetic Management For Endocardial Cushion Defect
Surgical Repair For Endocardial Cushion Defect
Description Of Double Outlet Right Ventricle
Clinical Implications Of Double Outlet Right Ventricle (4)
- A ASD or a VSD is required
- The right ventricle is overworked
- The patient is perfused with mixed venous/arterial blood, which we can expect a low SpO2 and a possible compensating polycythemia
- Pulmonary stenosis may or may not be present
Anesthetic Management For Double Outlet Right Ventricle
Surgical Repair Of Double Outlet Right Ventricle
Description Of Vascular Rings
Anesthetic Management For Vascular Rings (4)
- Most often the surgery is accomplished via thoracotomy, although a median sternotomy with bypass may be necessary
- Smaller sized tubes should be available, and it wouldn’t be a bad idea to intubated with an armored (reinforced) endotracheal tube(because it would ensure that the tube wouldn’t be compressed by the vascular rings)
- Extubation may be considered if tracheomalacia or stenosis is not anticipated
- “An inhalational induction with spontaneous ventilation is recommended. Similar to an anterior mediastinal mass, the tracheal compression may worsen during induction and the patient may decompensate when neuromuscular blocking agents are given.”
Dextrocardia
The Two Types Of Dextrocardia
Clinical Implications And Management Of Dextrocardia
