A vivid description of the anaesthetic management in a case of congenital heart disease posted for non cardiac surgery.Briefing of the various CHD'S from basics.Clear description of the pathophysiology,Illustrated with flowcharts and understanding of the complex modified circulatory states.Completely discussed with Head Of the Department and Cardiac Anaesthetic.
2. Introduction
– CONGENITAL heart defects are the most common group of birth defects,
occurring in approximately 8 in 1,000 live births.
– Only 15–25% survive into adulthood if untreated.
– Approximately 90% of children pass to adulthood by prenatal diagnosis,
interventional cardiology, pediatric cardiac surgery, anesthesia, and
critical care.
“ The purpose of my presentation is to provide an overview of the
long-term consequences and the preoperative and intraoperative
implications of CHD for the anesthesiologist involved in the care of
adults with CHD undergoing noncardiac surgery. “
3. Epidemiology of CHD
– About 25% of adults with CHD have a mild form of the disease that has
allowed them to survive into adulthood without surgical or interventional
cardiac catheterization.
– The vast majority of adults with CHD seen in the outpatient setting,
however, are patients who have had previous surgical or catheter-based
intervention.
7. Pathophysiology of CHD
3 Main pathophysiological states
– Things that increase pulmonary blood flow
– Things that decrease pulmonary blood flow
– Lesions that obstruct flow
8. Increased pulmonary blood flow
– VSD,ASD,PDA
– Left to right shunt
– Initial good oxygenation and ventilatory efficiency
– volume/pressure overload to pulmonary circulation
If unrepaired
Pulmonary HTN >>> Eisenmenger’s syndrome(R to L ) >>Cyanosis >> CHF
9. Decreased pulmonary blood flow
– Tetralogy of fallot
– Right to left shunt
– Decreased PaO2 >> Cyanosis >> Polycythemia
– Little change in PaO2 with increased FiO2
10. Obstruction to flow
Aortic stenosis, pulmonary stenosis
Increased cardiac work load
1)CHF 2)Serious dysrhythmias
3)Fixed cardiac output 4)Myocardial ischemia
11. Anaesthetic management
Right to left shunt
– Inhibit rise in PVR
Opioids (fentanyl)
Avoid decrease in PaO2 and increased PaCO2,high airway pressures
– “Speedy” IV induction
– Theoretical delayed inhalational induction of GA
– Ketamine: increases SVR and decreases R >> L shunt
14. Anaesthetic management
LEFT to RIGHT shunt
– Agents that decrease SVR will decrease shunt
– Minimal effect on pharmacokinetics
– Onset neuromuscular blockade unaltered
15. Factors that influence the distribution of blood flow between
the systemic and pulmonary circulations are shown.
19. Patent Ductus Arteriosus
Associated with prematurity
– Usually closes 24 – 48 hrs in term neonate
– Necessary for survival for some CHD lesions
• Hypoplastic left heart syndrome
Dx: most asymptomatic (L to R)
– Continuous systolic –diastolic murmur
– If Left to Right shunt large = LVH
– If pulmonary HTN develops = RVH
Can be bidirectional (SVR vs PVR)
20. • Ligate before pulmonary HTN develops
Will see rise in diastolic pressure on ligation
Pharmacologic closure; indomethacin (PG inhibition)
• “preductal arterial catheter” , RIGHT Radial
21. Prostaglandin(PGE2) and CHD
– Used to keep ductus open
– Indications:
Transposition of great vessels
Right sided cyanotic congenital heart defects associated with reduced pulmonary
blood flow
Left sided defects including HLHS
Coarctation of Aorta
– Possible adverse effects
Apnea, hyperthermia(transient),hypotension
22. Atrial Septal Defect
– 5–10% of all congenital heart defects
– When associated with other congenital heart defects, an ASD may be a life-
saving communication allowing mixing of blood between the pulmonary and
systemic circulations.
– Examples include total anomalous pulmonary venous return (TAPVR), tricuspid
atresia, and transposition of the great arteries
– In such cases, an ASD may be iatrogenically created as a palliative measure,
often on an urgent or emergent basis (e.g. balloon atrial septostomy).
23. Pathophysiology(ASD)
– The amount of left-to-right shunting at the atrial level is dependent on two
factors: the size of the defect and the relative compliance of the right and left
ventricles.
– Shunting occurs primarily during diastole and produces a volume burden on the
cardiovascular system that is proportionate to the degree of shunting.
24. Anesthetic considerations in ASD
– The induction of anesthesia can be safely accomplished with either inhalation
or IV techniques as they are generally asymptomatic and do not have
Pulmonary HTN.
– The primary goals for the uncomplicated ASD patient should include
preparation for an early extubation either in the operating room or within the
first 4 hour postoperatively.
25. Ventricular septal defect
– Ventricular septal defect is the most common congenital heart defect, occurring in
50% of all children with congenital heart disease (CHD) and in 20% as an isolated
lesion.
VSD is associated with a variety of inherited conditions
– including trisomy 13, 18, and 21
– VACTERL (vertebral, vascular, anal, cardiac, tracheoesophageal fistula, renal, and
limb anomalies) association
– CHARGE (coloboma, heart anomaly, choanal atresia, retardation, and genital and ear
anomalies) syndrome
26.
27. Natural History
– may be asymptomatic or exhibit signs and symptoms of CHF in varying degrees
– The rate and extent of progression of symptomatology depend on the patient’s age,
the size of the defect, and the degree of left-to-right shunting.
– Infants who have non-restrictive VSDs typically develop symptoms of CHF by 3
months of age, because of the physiologic decline in PVR that occurs during early
postnatal life
– If left untreated, 15% of patients with large VSDs develop pulmonary hypertension
that will progress to the development of pulmonary vascular obstructive disease,
shunt reversal, and cyanosis (Eisenmenger syndrome) by the age of 20 years
– The irreversible changes that lead to Eisenmenger syndrome may develop by the age
of 2 years; therefore it is important to close large non-restrictive VSDs within the first
2 years of life
28. Anaesthetic considerations of
VSD
– Isolated VSDs produce left-to-right shunting at the ventricular level, predominantly
during systole.
– Both ventricles are affected by left-to-right shunting through a VSD
– Pulmonary hypertension may develop early, especially in patients with trisomy 21
– Pulmonary vascular tone should be maintained in those patients with pulmonary
overcirculation prior to repair
– may respond to the use of inhaled nitric oxide prior to termination of CPB and/or
in the postoperative period
– Right heart failure with decreased cardiac output may result if pulmonary
hypertension is not controlled, and may require the use of dopamine, milrinone,
dobutamine, or isoproterenol
29. • Be prepared to treat arrhythmias, including heart block and
junctional ectopic tachycardia, especially after repair
• Patients with uncomplicated VSDs should be considered for
early extubation
30. Atrioventricular canal
– Four to five percent of CHD involves defects of the atrioventricular Septum
– AVC is associated with multiple syndromes and occurs in approximately 20% of
persons with trisomy 21.
– It accounts for 15% of congenital heart defects in patients with Noonan
syndrome and nearly 50% in those with Ellis–van Creveld syndrome.
31. • Atrioventricular canal defect results from failure of the
endocardial cushions to fuse during the fifth week of fetal
development.
AVC consists of three basic defects:
• an ostium primum defect resulting in an interatrial
communication
• abnormal atrioventricular valves
• an inlet VSD resulting in an interventricular communication.
• 3 types of AVC: partial, transitional, and complete
32. Pathophysiology and anesthetic
considerations
– A left-to-right shunt may occur at the atrial, ventricular, and atrioventricular
valvular levels, depending on the type of AVC present
– Shunting >> volume overload >> pulm HTN >> CHF
– As with other septal defects, balancing the ratio of PVR to SVR and thereby
limiting the amount of pulmonary overcirculation is paramount to successful
management,and is usually accomplished by manipulations in FiO2 and
ventilation
33. Double outlet right ventricle
– Double outlet right ventricle comprises approximately 1–1.5% of all patients
with CHD
– Almost all patients with DORV also have a VSD.
– Double outlet right ventricle is a type of ventriculoarterial connection in which
both great vessels arise either entirely or predominantly from the right ventricle
– Embryologically, DORV is a bulboventricular malformation that results from
failure of proper alignment of the conotruncus with the ventricular septum
34. Pathophysiology
– Pathophysiology of DORV is dependent on the specific anatomy of the lesion
and relative amounts of pulmonary vs aortic blood flow as well as the degree of
mixing of pulmonary and systemic venous blood.
– Consideration of these variables serves to simplify the pathophysiology of DORV
into three basic subtypes: VSD, tetralogy of Fallot, and transposition of the great
arteries
35. Anaesthetic management
– DORV with a doubly committed or non-committed VSD is managed as a VSD.
– DORV associated with pulmonary stenosis is managed similarly to tetralogy of
Fallot.
– DORV with subpulmonary VSD without pulmonary stenosis is managed similarly
to transposition of the great vessels.
– Some patients require single-ventricle staged palliation to the Fontan procedure
– Postoperative arrhythmias are common.
36.
37. • Truncus arteriosus is an uncommon congenital heart defect
representing less than 3% of all congenital heart defects.
• Deletion of chromosome 22q11 is present in approximately 11–
35% of patients with truncus arteriosus, and this chromosomal
abnormality is associated with DiGeorge and velocardiofacial
syndromes
• Truncus arteriosus is defined by the presence of a single artery
arising from the base of the heart that supplies the coronary,
pulmonary, and systemic circulations.
• Embryologically, this defect results from failure of the truncus
arteriosus to divide into the aorta and pulmonary artery
38. pathophysiology
– As PVR falls in the early neonatal period, pulmonary blood flow progressively
increases and results in CHF.
– A variable degree of mixing of the systemic and pulmonary venous blood occurs
at the ventricular level through the VSD.
– The large run-off provided by the pulmonary arteries results in low diastolic
pressures, which may be worsened by the presence of truncal valve
insufficiency
– Low diastolic pressures in the face of increased myocardial work and increased
ventricular pressures place the patient at risk of developing myocardial
ischemia from coronary steal.
39. Anaesthetic considerations
– Anesthetic management is dependent on the patient’s anatomy and age at
presentation.
– Depending on the severity of CHF, the patient may require preoperative inotropic
support, and the induction of anesthesia should be accomplished with drugs
(Ketamine or etomidate, often combined with fentanyl and/or midazolam) that
maintain SVR and preserve myocardial function
– Efforts to balance PVR and SVR to make the ratio of Qp:Qs approach 1:1 are
essential.
– Care must be taken to avoid hyperventilation and excessive oxygenation, which
lower PVR and may exacerbate pulmonary overcirculation and decrease diastolic
blood pressure
40. Partial and total anomalous
pulmonary venous return
– Both PAPVR and TAPVR are rare cardiac lesions
– Partial anomalous pulmonary venous return is an anomaly in which some, but
not all, of the pulmonary veins connect to the right atrium or to one or more of
its venous tributaries.
– In TAPVR, all of the pulmonary veins connect anomalously to the right atrium
– Usually associated with ASD
– In either case, the pathophysiology is that of a left-to-right shunt.
41. Anaesthetic considerations
– PAPVR is often asymptomatic but may be associated with heart failure.
– PAPVR is managed in a similar manner to an ASD.
– TAPVR exists in four subtypes based on the anomalous connection:
supracardiac, cardiac, infracardiac, and mixed.
– The pathophysiology of TAPVR is dependent on the presence and degree of
pulmonary venous obstruction and the size of the interatrial communication.
– Obstructed TAPVR patients are particularly cyanotic and require 100% oxygen
and significant ventilatory support
43. Coarctation of aorta
– It is narrowing of the aortic lumen and is most often located just distal to the
opening of the left subclavian artery at the point of insertion of the ductus
arteriosus.
– Over 90% of untreated patients with coarctation of the aorta die by the age of
50
– Even with surgical repair, patients with aortic coarctation demonstrate an
increased predilection for hypertension, coronary artery disease stroke, heart
failure, and ruptured aortic and cerebral aneurysms
44. Closure of ductus
arteriosus
Acute rise in left
ventricular afterload
Rise in left ventricular
end diastolic pressure
Reduction in stroke
volume
Pulmonary venous
congestion
Pulmonary artery
hypertension
Pathophysiology
45. – The neonate with a severe coarctation generally presents during the first few
weeks of life with congestive heart failure, left ventricular systolic dysfunction,
and, in some cases, cardiogenic shock.
– The diagnostic feature of aortic coarctation is a systolic blood pressure
difference between the upper and lower extremities.
53. Ebstein’s anomaly
Ebstein’s anomaly is by far the most common congenital malformation of the
tricuspid valve
EA is present in only about 0.3–0.7% of patients with CHD
Ebstein’s anomaly consists of:
– A downward displacement of septal and posterior leaflet attachments at the
junction of the inlet and trabecular portions of the RV
– An “atrialized” portion of the RV between the tricuspid annulus and the attachment
of the posterior and septal leaflets
– A malformed RV chamber.
54.
55. Pathophysiology(In utero)
Tricuspid valve dysfunction
Severe tricuspid regurgitation(ballooned right atrium)
Right ventricular outflow tract obstruction
Volume overload on right ventricle
Dilated right ventricle
Impaired lv function
56. • The symptomatic neonate with EA generally shows rapid
improvement of hemodynamics in the postnatal period due to
gradual reduction of pulmonary vascular resistance (PVR)
• The neonatal clinical presentation of EA varies greatly depending
upon the extent of the downward displacement of the TV leaflets
and the consequences of severe TR to the rest of the heart
• Atrial flutter, atrial fibrillation, and paroxysmal supraventricular
tachycardia occur in 25–30% of patients
57.
58. Anaesthetic considerations
– Preoperatively patient is evaluated for symptoms of fatigue, dyspnea, and, if
there are signs of cyanotic episodes, whether these are becoming more
frequent or severe.
– Patients with extreme cardiomegaly or perioperative ventricular arrhythmias
should receive prophylactic antiarrhythmic treatment, such as amiodarone.
– Intraoperatively efforts should be done to reduce PVR (Balance PVR vs SVR)
59.
60. TGA
– Aorta arises from the morphological right ventricle and the pulmonary artery
from the morphological left ventricle
– The two main categories are physiologically uncorrected (d-TGA) and
congenitally corrected (ccTGA or l-TGA).
– d-TGA is the second most common congenital cardiac lesion and accounts for
approximately 6% of defects.
– The outcome of d-TGA is very good, with patients expecting to lead near-normal
lives.
62. Preoperative management
– Stabilization with PGE1, urgent balloon atrial septostomy (BAS), and mechanical
ventilation may be required.
– PGE1 maintains the PDA and is effective at increasing PaO2 in most patients
with relatively unrestrictive atrial communication.
– If PGE1 does not improve oxygenation, a BAS is performed.
64. Anaesthetic goals
– Maintain the PDA with PGE1 in the duct-dependent circulation.
– Avoid increases in PVR and reductions in SVR to ensure adequate pulmonary
blood flow and avoidance of recirculation of pulmonary venous blood.
– After Cardiopulmonary bypass(CPB), the LAP needs to be low while maintaining
adequate cardiac output
– Pulmonary hypertension should be avoided.
– Intravascular volume administration should be very cautious, because even a
small amount of volume can increase LAP dramatically.
65. Congenitally corrected TGA
– Congenitally corrected transposition of the great arteries, also known as levo-
TGA (ccTGA or L-TGA), is a rare complex congenital cardiac defect
– A right-sided RA connects via a right-sided mitral valve and a morphological LV
to a right-sided PA.
– The left-sided LA connects via a left-sided tricuspid valve and RV to the aorta.
68. Univentricular Heart
– Single ventricle anatomy and physiology is probably, along with
Eisenmenger syndrome, the most challenging CHD for the
anesthesiologist to manage.
– The Fontan procedure was first described in 1971 and was applied
initially to patients with tricuspid atresia.
– Today, indications for this procedure have been extended to all forms of
single ventricles.
69. This operation bypasses the right ventricle, leaving passive, nonpulsatile
flow from both inferior and superior vena cava to the pulmonary artery.
Any factor that increases pulmonary vascular resistance will decrease
pulmonary blood flow and cause arterial desaturation.
Patients with a Fontan circulation frequently present with cardiac and
noncardiac complications that include supraventricular dysrhythmias,
restrictive lung disease, thromboembolic complications, and hepatic
dysfunction.
Both procoagulant and anticoagulant effects are observed in patients with
a Fontan as a result of liver dysfunction and/or factor loss in patients with
protein-losing enteropathy, and these abnormalities substantially increase
the risk for intraoperative bleeding.
Patients with a Fontan circulation should maintain an arterial saturation
above 90 to 95%.
Arterial saturation below 90% in these patients should be considered
abnormal and should provoke further evaluation for the presence of
venovenous collaterals, arteriovenous malformations, or a residual shunt.
70.
71.
72. Tricuspid Atresia
– a complete absence of the tricuspid valve, with no communication between the
RA and the RV results in hypoplasia of the RV
– TA also results in a functionally single LV
73. Right atrium
Left atrium(through ASD)/ stretched PFO
Mix with pulmonary venous blood
Left ventricle
VSD
Small RV infundibulum
Pulmonary arteries
In TA the systemic venous blood cannot flow directly into the RV
74.
75.
76.
77.
78.
79. Long-term Consequences of CHD
and Effect on Anesthesia
Management
– Adult patients with CHD are now surviving longer than ever before-long
term complications which include-
A)CVS related complications include:
pulmonary hypertension
ventricular dysfunction
dysrhythmias and conduction defects
residual shunts
valvular lesions (regurgitation and stenosis)
hypertension
aneurysms
80. Long-term Consequences of CHD
and Effect on Anesthesia
Management
Non cardiac sequelae:
– secondary erythrocytosis
– cholelithiasis
– nephrolithiasis
– developmental abnormalities
– central nervous abnormalities, such as seizure disorders from previous
thromboembolic events or cerebrovascular accidents
– hearing or visual loss
– restrictive and obstructive lung disease.
81. Pulmonary Hypertension
Potential etiologies include pulmonary venous hypertension secondary to
elevated ventricular end diastolic pressure, elevated pulmonary venous atrial
pressure, or pulmonary vein stenosis.
long-standing large and nonrestrictive defects (main etiology)
flow and transmission of near systemic pressure to the pulmonary vascular bed
irreversible vascular changes and elevated pulmonary vascular resistance
Vascular changes include hypertrophy of the media of small muscular arteries
and arterioles, intimal cellular proliferation, smooth muscle cell migration into
the subendothelium, progressive fibrosis, and obliteration of arterioles and
small arteries.
82. – Eisenmenger syndrome refers to the development of pulmonary
hypertension secondary to long-standing left to right shunting.
– Perioperative mortality is increased, and noncardiac surgery should only
be performed if absolutely essential in patients with Eisenmenger
physiology
– Predictors of mortality include syncope, age at presentation or
development of symptoms, poor functional class, supraventricular
dysrhythmias, elevated right atrial pressures, low oxygen saturation (less
than 85%), renal insufficiency, severe right ventricular dysfunction, and
trisomy 21.
83. Anesthetic management in patients
with Pulmonary Hypertension
– minimize increases in pulmonary vascular resistance and to maintain
systemic vascular resistance (primary goal)
– Abrupt increases in pulmonary vascular resistance may precipitate acute
right ventricular failure and decreased cardiac output in patients without
intracardiac shunting or oxygen desaturation followed by decreased
cardiac output in patients with intracardiac shunting.
– In both cases, severe bradycardia may occur with progression to cardiac
arrest
84. Prevention and treatment of
pulmonary hypertensive crisis
Includes:
– hyperventilation
– correction of acidosis
– avoidance of sympathetic nervous system stimulation
– maintenance of normothermia
– minimization of intrathoracic pressure
– use of inotropic support
– nitric oxide usage
– Preference to regional anaesthesia
85. 1) spinal or epidural anesthesia may produce
unacceptable decreases in systemic vascular
resistance in patients with unrestrictive
intracardiac shunts> right to left shunting.
2)Conversely, general anesthesia allows for
optimal control of ventilation and may be
preferable in patients undergoing high-risk
surgery.
86. Bleeding and Thrombosis Risk
– Most patients with Eisenmenger syndrome will be severely cyanotic (oxygen
saturation < 85%).
Cyanotic patients
abnormalities in
platelets and
coagulation system
perioperative bleeding and
thrombosis
•1)low levels of circulating vitamin K–dependent clotting factors
• 2)factor V
•3)von Willebrand factor.
elevated International
Normalized Ratio
prolonged activated partial
thromboplastin time
87. Chronic hypoxia(cyanosis)
Secondary erythrocytosis(increased erythropoietin)
Increased blood viscosity
Decreased flow in small arterioles & capillaries
Increased wall sheer stress
Increased release of endothelium derived nitric oxide & prostaglandins
Arteriolar dilatation and increased tissue vascularity
Increased bleeding risk
88. 1)Blood viscocity is further exacerbated in the setting of
preoperative fasting,iron deficiency and dehydration
2)Iron-deficient red blood cells are less deformable
and have been found to be one of the strongest
independent predictors of thrombosis in the setting of
Eisenmenger syndrome
3)These patients, however, do not have an elevated
bleeding time, likely secondary to increased blood
viscosity and decreased flow
4) preoperative phlebotomy to improve surgical
hemostasis may be useful when hematocrit levels
exceed 65%.
89. Heart failure
– Right-sided and left-sided heart failure are common complications of both
corrected and uncorrected CHD.
– Abnormal cardiac autonomic nervous system regulation and altered
hemodynamics contribute to the development of heart failure in these
patients.
– In contrast to left ventricular failure, there are no evidence-based
guidelines for the management of heart failure in patients with a systemic
right ventricle (congenitally corrected transposition of the great arteries,
Mustard, or Senning repairs of transposition of the great arteries, and
single ventricles).
– Further clinical trials are warranted..
90. Dysrhythmias
– Atrial and ventricular dysrhythmias are common in adults
with CHD.
– Dysrhythmias arise in patients who have undergone previous
curative or palliative surgery as a primary consequence of
the underlying congenital defect or secondary to surgical
repair.
– For example, supraventricular dysrhythmias occur in 20–
45% of patients with previous atrial surgery (late atrial septal
defect closure, Mustard, Senning, or Fontan procedures) or
in those with atrial distension.
91. • The most common form of tachyarrhythmia observed is intraatrial
reentrant tachycardia originating from the right atrium.
• Atrial tachyarrhythmias are often resistant to pharmacological
treatment and can result in rapid hemodynamic deterioration.
• Ventricular dysrhythmias are most frequently encountered in
patients who have significantly decreased right or left ventricular
function.
• Other risk factors include previous ventriculotomy, earlier surgical
era, or older age at initial surgery.
• Patients who were repaired late are exposed to longer periods of
cyanosis, volume overload, and pressure overload.
• As a result, they have increased myocardial fibrosis and
associated slowing of conduction and an increased risk for
dysrhythmias
92. • Acute hypoxemia can provoke ventricular
dysrhythmias because subendocardial myocardial
perfusion is already impaired in hypertrophied
myocardium.
• Some patients will require a permanent pacemaker to
treat bradycardia secondary to postoperative
atrioventricular block.
94. Preoperative Evaluation
– Multidisciplinary approach that includes the participation of
anesthesiologists, cardiologists, intensivists, and surgeons.
– Perioperative risk is substantially increased in adults with
CHD, particularly in those with poor functional class,
pulmonary hypertension, congestive heart failure, and
cyanosis.
– Major surgery and procedures that involve one lung
ventilation or changes in position (e.g. , prone,
Trendelenburg) could produce important hemodynamic
effects that contribute to increasing risk.
95. Premedication
– Premedication with anxiolytics and hypnotics must be
undertaken very cautiously because hypoventilation and
hypercapnia may produce deleterious increases in
pulmonary vascular resistance, particularly, in patients with
underlying pulmonary hypertension or systemic to pulmonary
shunts.
96. Endocarditis Prophylaxis
– Only patients with cardiac conditions associated with the highest risk for adverse
outcomes should continue following antibiotic prophylaxis before surgery according to
guidelines of AHA.
CONDITIONS LIKE:
H/O previous endocarditis,
unrepaired cyanotic CHD,
palliative shunts and conduits
completely repaired congenital heart defects with prosthetic material or device, whether
placed by surgery or by catheter intervention, during the first 6 months after the procedure
repaired CHD with residual defects at the site or adjacent to the site of a prosthetic patch
or prosthetic device (which inhibit endothelialization)
Except for the conditions listed above, antibiotic prophylaxis is no longer recommended for
other forms of CHD.
97. Intraoperative Management
– Adults with CHD who have undergone complete anatomic repair and
have no evidence of late functional deterioration can be managed by
using conventional approaches.
– In contrast, patients with more complex CHD and moderate to major
surgery will require specific intraoperative management.
98. MONITORING
– Pulse oximetry is perhaps uniquely important in the management of CHD.
– For example, decreases in arterial saturation can signify increases in
pulmonary vascular resistance, increases in right to left shunting, or
decreases in pulmonary blood flow through systemic to pulmonary shunts.
– In contrast, increases in left to right shunting may not be detected by pulse
oximetry and arterial oxygen saturation may be maintained even if systemic
cardiac output is severely compromised.
– The capnogram is altered, and end tidal carbon dioxide concentrations
underestimate Paco2in the case of right to left shunting.
99. Knowledge of the anatomy and physiology of specific palliative repairs is
important for choosing appropriate monitoring.
• For example, congenital defects that are associated with inadequate
pulmonary blood flow (e.g. pulmonary valve atresia or univentricular heart)
are palliated with systemic to pulmonary shunts.
• In patients with a classic Blalock-Taussig shunt (end to side anastomosis of
the subclavian and pulmonary arteries) arterial pressure and Spo2cannot be
measured on the ipsilateral side.
• A Glenn shunt or bidirectional cavopulmonary anastomosis consists of an
end to side anastomosis of the divided superior vena cava to pulmonary
artery.
Continued…..
100. • Total cavopulmonary connection (Fontan circulation) is established when
the pulmonary and systemic circulations are totally separated by
diverting all the systemic venous return to the pulmonary artery, usually
without interposition of a subpulmonic ventricle.
• These alterations in intracardiac anatomy complicate the placement of
central venous catheters in palliated adults, and the anatomical
variations must be considered when interpreting values obtained from
central venous monitoring.
• For example, in patients with a Fontan circulation, central venous
pressure reflects mean pulmonary artery pressure.
continued…
101. • In patients with an intraatrial baffle (e.g. , Mustard or Senning procedure),
pulmonary artery catheter placement may be difficult or impossible.
• Vascular access may also be difficult because many of these patients have
already undergone previous vessel catheterization
• Invasive arterial pressure monitoring can be essential in managing patients
with Eisenmenger syndrome, intracardiac or systemic to pulmonary shunts
undergoing major surgery who are also sensitive to sudden changes in
preload, and systemic and pulmonary vascular resistance
• Finally, transesophageal echocardiography might be useful in adults with
CHD undergoing noncardiac surgery to monitor intravascular volume status
and ventricular function.
• In the presence of complex CHD, transesophageal echocardiography should
be performed by an individual familiar with CHD.
102. Anesthetic Technique
– There are no evidence-based recommendations to guide the anesthetic
management of patients with CHD undergoing noncardiac surgery.
– It is also impossible to propose a single approach for anesthetic
management that would address every possible defect.
– Major objective of intraoperative management is to promote tissue
oxygen delivery by preventing arterial desaturation, maintaining a
balance between pulmonary and systemic flows, and by optimizing
hematocrit.
104. Congenital
Heart
Disease
Anatomy –
Physiology
Potential issues Specific anaesthetic managementAtrialseptaldefect
L-R shunt • Small to moderate size defects well tolerated.
• Atrial fibrillation(increased risk if repaired after age 40).
• Risk of paradoxical emboli.
• Large defects lead to arrhythmias,exercise intolerance,and
rarely PHT(occurs in <5% of patients).
• De-air intravenous lines
Ventricularseptaldefect
L-R shunt
May be
associated with
other defects
Unrepaired:
• Large defects risk of PHT (50% by age 2)
• Small to moderate size defects,risk for endocarditis,
sub-pulmonic obstruction,sub aortic obstruction,and aortic
regurgitation
• Right ventricular failure
Repaired:
• complete heart block in some patients(rare)
• Persistent PHT
• Dysrhythmia
• Manage L-R shunt
• Maintain pulmonary blood if
R-L shunt present
• Increased risk of post
operative pulmonary infection
• Manage pacemaker
105. Congenital
Heart
Disease
Anatomy –
Physiology
Potential issues Specific anaesthetic
management
Coarctationoftheaorta
• LV pressure overload
and hypertrophy
• Aortic branch
collaterals
• Associated with
bicuspid aortic
valve(50-80%)
• Endothelial
dysfunction
(diffuse aortopathy)
• Blood pressure gradient between upper and lower
limbs
• Risk of bleeding if thoracic surgery
• LV hypertrophy and LV diastolic dysfunction
• Systemic hypertension
• Aneurysms of ascending aorta and descending aorta
• Premature coronary artery disease
• Intracranial aneurysms
• Inaccurate blood pressure
(left arm) if previous
subclavian angioplasty
• Postoperative hypertension
• Avoid tachycardia,
• Hypotension
Aorticstenosis
LV pressure overload and
hypertrophy
Unrepaired:
• Pulmonary edema
• PHT
• Myocardial ischemia
• Syncope
• Post stenotic dilatation
Repaired:
• Aortic regurgitation
• LV diastolic dysfunction
• Avoid tachycardia,
• Hypotension
• Avoid factors that increase
myocardial oxygen
consumption
106. Congenital
Heart
Disease
Anatomy –
Physiology
Potential issues Specific anaesthetic managementL-(congenitally
corrected)
Transpositionofthe
greatarteries • LV is the
subpulmonic
ventricle
• RV is the systemic
ventricle
Unrepaired:
• Complete heart block
• Arrhythmias (atrial and ventricular)
• Anatomic right ventricular failure
• Systemic AV valve regurgitation
Repaired:
• Same
• Pacemaker management
• External pacing available
• Manage dysrhythmias
• Manage heart failure
TetralogyofFallot
• Pulmonic stenosis
• (vavular,subvalvual
, and/or
supravalvular)
• RV hypertrophy
• Overriding aortic
root
• VSD
• Cyanosis
Unrepaired:Rare,mean age of death 25 yrs of age
R-L shunt,cyanosis
Palliated:
• Blalock-Taussing shunt
• Chronic left ventricular volume overload
• Cyanosis if shunt is too small,PHT
Repaired:
• Sinus and AV node dysfunction
• Dysrhythmia:atrial and ventricular
• Ascending aortic aneurysm
• Residual pulmonary regurgitation or stenosis
• Residual VSD,Left ventricular dysfunction
• Persistant PTH fron previous shunts
• Avoid tachycardia,
• Hypovolemia,increased
contractility
• Maintain pulmonary blood flow
• Maintain systemic blood
pressure
• Detect and manage
dysrhythmias
• Manage pacemaker
• External pacing available
107. Congenital
Heart
Disease
Anatomy –
Physiology
Potential issues Specific anaesthetic managementD-transpositionofthearteries
• Pulmonary artery
arises from LV
• Aorta arises from
RV
• Possible
associated leions,
• VSD,ASD,PDA,
Pulmonary
stenosis,coarctatio
n of aorta
• Abnormal
coronary artery
anatomy
• Unrepaired:associated with VSD/ASD/PDA
• Repaired:senning or mustard
• Atrial dysrhythmia
• Sinus node dysfunction (by age 40,50% have
pacemaker)
• Systemic ventricle dysfunction
• Residual atrial or ventricular level shunts
• Repaired:Arterial switch
• Myocardial ischemia(narrowed,occluded coronary
arteries,endothelial dysfunction)
• Ascending aortic aneurysm
• Maintain pulmonary blood flow
• Manage dysrhythmia
• Manage heart failure
• Detailed preoperative
evaluation,both functional and
coronary imaging study
iventricularheart
• Double inlet
atrioventricular
connections
• Absence of one
atrioventricular
connection
• Single well-
Unrepaired:rare
• Dysrhythmias,Congestive heart failure
Bidirectional shunting, Cyanosis, PHT
Repaired:blalock-taussig shunt,glenn shunt,or fonton
• Dysrhythmias,heart failure,hepatic dysfunction
• Thromboemboli
• Restrictive lung disease
• Manage dysrhythmias
• Maintain pulmonary blood flow
• Manage dysrhythmias,maintain
low pulmonary vascular
resistance,maintain adequate
preload,replace coagulation
108. Anesthetic agents
– Most intravenous agents depress myocardial contractility and decrease systemic
vascular resistance, and these actions could have an adverse effect on tissue oxygen
delivery during induction of anesthesia.
– Alternatively, some evidence suggests that etomidate may provide hemodynamic
stability in the setting of CHD similarly to other settings of impaired cardiac function
– Ketamine has been suggested to increase pulmonary vascular resistance in adults
without CHD
– However, this agent produces beneficial effects in children with CHD and severe
pulmonary hypertension undergoing sevoflurane anesthesia by maintaining systemic
vascular resistance and ventricular performance, without increasing pulmonary vascular
resistance.
– The choice of a specific volatile anesthetic agent to be used should be based on the
patient's physiology and the overall goal of balancing pulmonary and systemic blood
flow.
109. Intracardiac and Systemic to Pulmonary Shunts
– Shunting has an important effect on anesthetic management
– All intravenous lines must be meticulously deaired to decrease the risk of
systemic air embolization in patients with intracardiac shunts.
– The hemodynamic effects of ventilation strategies, positioning,
pharmacological agents, and blood loss must all be considered to
appropriately balance pulmonary and systemic blood flow in patients with
intracardiac or systemic to pulmonary shunts.
– Ventilation with high airway pressures can compromise venous return,
increase pulmonary vascular resistance, and exacerbate right to left
shunting in patients with cyanotic heart disease.
continued..
110. • Inadequate anesthesia and sympathetic nervous system stimulation might
increase systemic vascular resistance, exacerbate left to right shunting, and
reduce systemic cardiac output in a patient with a large atrial septal defect.
• Trendelenburg position can increase central venous (superior vena cava)
pressure and cause cerebral hypoperfusion in a patient with a Glenn shunt
or Fontan.
• Systemic hypotension can also result in a decrease in pulmonary blood
flow, with subsequent arterial desaturation, in a patient with a systemic to
pulmonary artery shunt (Blalock-Taussig shunt, or central shunt).
111. Postoperative Management
– Patients presenting with severe CHD and/or high risk surgery should be
managed if possible in a postoperative intensive care unit experienced
with caring for adults with congenital heart disease.
– Post operative risks include bleeding, dysrhythmias, and thromboembolic
events.
– In cases of pulmonary hypertension, oral pulmonary vasodilatators such
as sildenafil and inhaled nitric oxide may be beneficial.
112. Conclusions
– The number of adult patients with CHD is rapidly increasing, and these patients will
be presenting with greater frequency for noncardiac surgery.
– The cardiovascular anatomy and physiology of CHD are complex and require
specific knowledge of the defect and its anesthetic implications.
– Adults with moderate or severe CHD requiring noncardiac surgery are at high risk,
particularly those with poor functional class, pulmonary hypertension, congestive
heart failure, and cyanosis; and these patients should receive care in a regional
adult CHD center with multidisciplinary collaboration among anesthesiologists,
cardiologists, surgeons, and intensivists.
– There are no evidence-based guidelines for the perioperative management of adults
with CHD.
– Large-scale clinical trials are required to elucidate the optimal anesthetic
management of these challenging patients.
113. References
– Anesthesia for Congenital Heart Disease 3rd edition by Dean B. Andropoulos and
co..
– Article-Anesthesia for Noncardiac Surgery in Adults with Congenital Heart
Disease Maxime Cannesson, M.D.; Michael G. Earing, M.D.; Vincent
Collange, M.D.; Judy R. Kersten, M.D., F.A.C.C.
– Video animations from Cincinnati Children’s YouTube Channel
– Video from University of Kentucky,Dept Of Anaesthesiology YouTube
channel by Randall Schell M.D. Flipped Classroom| Congenital Heart
Disease and Anesthesia: Foundational Concepts
Editor's Notes
Conditions like hypoxia,hypothermia,hypercarbia(perioperative period conditions)-return of persistant fetal circulation
