2. INTRODUCTION
• Number of children reaching adulthood with
CHD has increased over the last 5 decades
• D/T advances in diagnosis, medical, critical
and surgical care
• Therefore, not uncommon for adult patients
with CHD to present for non-cardiac surgery
3. INCIDENCE
• 7 to 10 per 1000 live births
• Premature infants 2-3X higher incidence
• Most common form of congenital disease
• Accounts for 30% of total incidence of all
congenital diseases
• 10% -15% have associated congenital
anomalies of skeletal, RT, GUT or GIT
• Only 15% survive to adulthood without
treatment
4. ETIOLOGY
• 10% associated with chromosomal abnormalities
• Two thirds of these occur with Trisomy 21
• One third occur with karyotypic abnormalities such
as Trisomy 13, Trisomy 18 & Turner Syndrome
• Remaining 90% are multifactorial in origin
• Interaction of several genes with or without
external factors such as rubella, ethanol abuse,
lithium and maternal diabetes mellitus
5. FETAL CIRCULATION
• There are 4 shunts in
fetal circulation:
placenta, ductus
venosus, foramen ovale,
and ductus arteriosus
• In adult, gas exchange
occurs in lungs. In fetus,
the placenta provides
the exchange of gases
and nutrients
6. CARDIOPULMONARY CHANGES AT BIRTH
• Removal of placenta results in following:
• ↑ SVR (because the placenta has lowest
vascular resistance in the fetus)
• Cessation of blood flow in the umbilical vein
resulting in closure of the ductus venosus
7. CARDIOPULMONARY CHANGES AT BIRTH
• Lung expansion →
reduction of the
pulmonary vascular
resistance (PVR), an
increase in pulmonary
blood flow, & a fall in
PA pressure
8. CARDIOPULMONARY CHANGES AT BIRTH
• LUNG EXPANSION:
– Functional closure of the foramen ovale as a result
↑ LAP in excess RAP
– The LAP increases as a result of the ↑ PBF and ↑
pulmonary venous return to the LA
– RAP pressure falls as a result of closure of the
ductus venosus
– PDA closure D/T ↑ arterial oxygen saturation
9. CARDIOPULMONARY CHANGES AT BIRTH
• PVR high as SVR near or at
term
• High PVR maintained by ↑
amount of smooth muscle in
walls of pulmonary
arterioles & alveolar
hypoxia resulting from
collapsed lungs
• Lung expansion → ↑
alveolar oxygen tension →
↓ PVR
11. CLASSIFICATION OF CHD
• L - R SHUNTS INCLUDE :
– ASD →7.5% of CHD
– VSD → COMMONEST CHD – 25%
– PDA → 7.5% of CHD
• Common in premature infants
– ENDOCARDIAL CUSHION DEFECT - 3%
• Often seen with trisomy 21
– AORTOPULMONARY WINDOW
14. L – R SHUNTS
• PERIOPERATIVE TREATMENT
– Indomethacin → PDA closure
– Digoxin, diuretics, ACE inhibitors → CHF
– Main PA band → ↑ PVR → ↓ L-R shunt
– Definitive open heart surgery
• POSTOPERATIVE PROBLEMS
– SVTs and conduction delays
– Valvular incompetence → most common after
canal defect repairs
15. CLASSIFICATION OF CHD
• R – L SHUNTS
– Defect between R and L heart
– Resistance to pulmonary blood flow → ↓ PBF →
hypoxemia and cyanosis
• INCLUDE :
– TOF – 10% of CHD, commonest R-L shunt
– PULMONARY ATRESIA
– TRICUSPID ATRESIA
– EBSTEIN’S ANOMALY
16. R – L SHUNTS
• GOAL → ↑ PBF to improve oxygenation
– Neonatal PGE1 (0.03 – 0.10mcg/kg/min)
maintains PDA → ↑ PBF
– PGE1 complications → vasodilatation,
hypotension, bradycardia, arrhythmias, apnea or
hypoventilation, seizures, hyperthermia
– Palliative shunts → ↑ PBF, improve hypoxemia
and stimulate growth in PA → aids technical
feasibility of future repair
19. TETRALOGY OF FALLOT
• 10% of all CHD
• Most common R – L shunt
• 4 anomalies:
– RVOT obstruction ( infundibular, pulmonic or
supravalvular stenosis )
– Subaortic VSD
– Overriding aorta
– RVH
25. CLASSIFICATION OF CHD
• COMPLEX SHUNTS (MIXING LESIONS)
– Continuous mixing of venous and arterial blood –
blood saturation 70% - 80%
– May or may not be obstruction to flow
– Produce both cyanosis and CHF
– Overzealous improvement in PBF steals
circulation from aorta → systemic hypotension →
coronary ischemia
26. CLASSIFICATION OF CHD
• COMPLEX SHUNTS INCLUDE :
– TRUNCUS ARTERIOSUS
– TRANSPOSITION OF GREAT VESSELS – 5%
• Arterial switch procedure > 95% survival
– TOTAL ANOMALOUS PV RETURN
– DOUBLE OUTLET RIGHT VENTRICLE
– HYPOPLASTIC LEFT HEART SYNDROME
• Most common CHD presenting 1st week of life
• Most common cause of death in 1st month of life
44. ANESTHETIC MANAGEMENT
• Perioperative management requires a team
approach
• Most important consideration is necessity for
individualized care
• CHD is polymorphic and may clinically
manifest across a broad clinical spectrum
45. ANESTHETIC MANAGEMENT
• Unpalliated
• Partially palliated
• Completely palliated
– ASD and PDA only congenital lesions that
can be truly “corrected”
Anesthesiologists will encounter children with
CHD for elective non-cardiac surgery at one of
three stages:
46. ANESTHETIC MANAGEMENT
• 50% Dx by 1st week of life; rest by 5 years
• Child’s diagnosis & current medical condition
will determine preoperative evaluation
• Understand the anatomic and hemodynamic
function of child’s heart
• Discuss case with pediatrician and cardiologist
• Review diagnostic & therapeutic interventions
• Above will estimate disease severity and help
formulate anesthetic plan
51. LABORATORY EVALUATION
• CHEST X - RAY
– Heart size and shape
– Prominence of pulmonary vascularity
– Lateral film if previous cardiac surgery for
position of major vessels in relation to sternum
52. LABORATORY EVALUATION
• ECHOCARDIOGRAPHY
– Anatomic defects/shunts
– Ventricular function
– Valve function
– Doppler & color flow imaging direction of
flow through defect/valves, velocities and
pressure gradients
53. LABORATORY EVALUATION
• CARDIAC CATHERIZATION
– Size & location of defects
– Degree of stenosis & shunt
– Pressure gradients & O2 saturation in each
chamber and great vessel
– Mixed venous O2 saturation obtained in SVC or
proximal to area where shunt occurs
– Low saturations in LA and LV = R – L shunt
– High saturations in RA & RV = L – R shunt
54. LABORATORY EVALUATION
• CARDIAC CATHERIZATION
– Determine shunt direction: ratio of pulmonary to
systemic blood flow : Qp / Qs
– Qp / Qs ratio < 1= R – L shunt
– Qp / Qs ratio > 1= L – R shunt
55. PREMEDICATION
a) Omit for infants < six months of age
b) Administer under direct supervision of
Anesthesiologist in preoperative facility
c) Oxygen, ventilation bag, mask and pulse
oximetry immediately available
d) Oral Premedication
• Midazolam 0.25 -1.0 mg/kg
• Ketamine 2 - 4 mg/kg
• Atropine 0.02 mg/kg
56. PREMEDICATION
e) IV Premedication
• Midazolam 0.02 - 0.05 mg/kg titrated in small
increments
f) IM Premedication
• Uncooperative or unable to take orally
• Ketamine 1-2 mg/kg
• Midazolam 0.2 mg/kg
• Glycopyrrolate or Atropine 0.02 mg/kg
57. MONITORING
• Routine CAS monitoring
• Precordial or esophageal stethoscope
• Continuous airway manometry
• Multiple - site temperature measurement
• Volumetric urine collection
• Pulse oximetry on two different limbs
• TEE
58. MONITORING
• PDA
– Pulse oximetry right hand to measure pre-ductal
oxygenation
– 2nd probe on toe to measure post-ductal
oxygenation
• COARCTATION OF AORTA
– Pulse oximeter on right upper limb
– Pre and post - coarctation blood pressure cuffs
should be placed
59. ANESTHETIC AGENTS
• INHALATIONAL AGENTS
– Safe in children with minor cardiac defects
– Most common agents used are halothane and
sevoflurane in oxygen
– Monitor EKG for changes in P wave retrograde
P wave or junctional rhythm may indicate too deep
anesthesia
60. INHALATIONAL ANESTHETICS
• HALOTHANE
– Depresses myocardial function, alters sinus
node function, sensitizes myocardium to
catecholamines
– MAP + HR
– CI + EF
• Relax infundibular spasm in TOF
• Agent of choice for HCOM
61. INHALATIONAL ANESTHETICS
SEVOFLURANE
• No HR
• Less myocardial depression than Halothane
• Mild SVR → improves systemic flow in L-R
shunts
• Can produce diastolic dysfunction
62. INHALATIONAL ANESTHETICS
ISOFLURANE
• Pungent not good for induction
• Incidence of laryngospasm > 20%
• Less myocardial depression than Halothane
• Vasodilatation leads to SVR → MAP
• HR which can lead to CI
63. INHALATIONAL ANESTHETICS
DESFLURANE
• Pungent not good for induction; highest
incidence of laryngospasm
• SNS activation → with fentanyl
• HR + SVR
• Less myocardial depression than Halothane
64. INHALATIONAL ANESTHETICS
NITROUS OXIDE
• Enlarge intravascular air emboli
• May cause microbubbles and macrobubbles to
expand obstruction to blood flow in
arteries and capillaries
• In shunts, potential for bubbles to be shunted
into systemic circulation
65. INHALATIONAL ANESTHETICS
NITROUS OXIDE
• At 50% concentration does not affect PVR and
PAP in children
• Mildly CO at 50% concentration
• Avoid in children with limited pulmonary
blood flow, PHT or myocardial function
66. IM & IV ANESTHETICS
KETAMINE
• No change in PVR in children when airway
maintained & ventilation supported
• Sympathomimetic effects help maintain HR,
SVR, MAP and contractility
• Greater hemodynamic stability in
hypovolemic patients
• Copious secretions → laryngospasm →
atropine or glycopyrrolate
67. IM & IV ANESTHETICS
KETAMINE
• Relative contraindications may be coronary
insufficiency caused by:
– anomalous coronary artery
– severe critical AS
– hypoplastic left heart syndrome with aortic atresia
– hypoplasia of the ascending aorta
• Above patients prone to VF d/t coronary
insufficiency d/t catecholamine release from
ketamine
68. IM & IV ANESTHETICS
IM Induction with Ketamine:
• Ketamine 5 mg/kg
• Succinylcholine 5 mg/kg or Rocuronium 1.5 – 2.0
mg/kg
• Atropine or Glycopyrrolate 0.02 mg/kg
IV Induction with Ketamine:
• Ketamine 1-2 mg/kg
• Succinylcholine 1-2 mg/kg or Rocuronium 0.6-1.2
mg/kg
• Atropine or Glycopyrrolate 0.01 mg/kg
69. IM & IV ANESTHETICS
OPIOIDS
• Excellent induction agents in very sick children
• No cardiodepressant effects if bradycardia avoided
• If used with N2O - negative inotropic effects of
N2O may appear
• Fentanyl 25-100 µg/kg IV
• Sufentanil 5-20 µg/kg IV
• Pancuronium 0.05 - 0.1 mg/kg IV offset
vagotonic effects of high dose opioids
70. IM & IV ANESTHETICS
ETOMIDATE
• CV stability
• 0.3 mg/kg IV
THIOPENTAL & PROPOFOL
• Not recommended in patients with severe cardiac
defects
• In moderate cardiac defects:
– Thiopental 1-2 mg/kg IV or Propofol 1-1.5 mg/kg IV
– Patient euvolemic
71. ANESTHETIC MANAGEMENT
• GENERAL PRINCIPLES
Where:
Q = Blood flow (CO)
P = Pressure within a chamber or vessel
R = Vascular resistance of pulmonary or
systemic vasculature
Ability to alter above relationship is the basic tenet of
anesthetic management in children with CHD
R
P
Q
72. ANESTHETIC MANAGEMENT
P manipulate with positive or negative
inotropic agents
Q hydration + preload and inotropes
However, the anesthesiologist’s principal focus
is an attempt to manipulate resistance, by dilators
and constrictors
73. ANESTHETIC MANAGEMENT
• GENERAL CONSIDERATIONS
– De-air intravenous lines air bubble in a R-L shunt
can cross into systemic circulation and cause a
stroke
– L-R shunt air bubbles pass into lungs and are
absorbed
– Endocarditis prophylaxis
– Tracheal narrowing d/t subglottic stenosis or
associated vascular malformations
74. ANESTHETIC MANAGEMENT
– Tracheal shortening or stenosis esp. in children
with trisomy 21
– Strokes from embolic phenomena in R-L shunts
and polycythemia
– Chronic hypoxemia compensated by polycythemia
→ ↑ O2 carrying capacity
– HCT ≥ 65% → ↑ blood viscosity → tissue hypoxia
& ↑ SVR & PVR → venous thrombosis → strokes
& cardiac ischemia
75. ANESTHETIC MANAGEMENT
– Normal or low HCT D/T iron deficiency → less
deformable RBCs → ↑ blood viscosity
– Therefore adequate hydration & decrease RBC
mass if HCT > 65%
– Diuretics → hypochloremic, hypokalemic
metabolic alkalosis
76. ANESTHETIC MANAGEMENT
ANESTHESIA INDUCTION
• Myocardial function preserved IV or
inhalational techniques suitable
• Severe cardiac defects IV induction
• Modify dosages in patients with severe
failure
78. ANESTHETIC MANAGEMENT
• L - R SHUNTS :
• Continuous dilution in pulmonary
circulation may onset time of IV
agents
• Speed of induction with inhalation
agents not affected unless CO is
significantly reduced
• Degree of RV overload and/or failure
underappreciated – careful induction
82. ANESTHETIC MANAGEMENT
• R –L SHUNTS :
– Continue PE1 infusions
– Adequate hydration esp. if HCT > 50%
– Inhalation induction prolonged by limited
pulmonary blood flow
– IV induction times are more rapid d/t bypassing
pulmonary circulation dilution
– PEEP and PPV increase PVR
83. ANESTHETIC MANAGEMENT
• COMPLEX SHUNTS :
• Manipulating PVR or SVR to PBF will:
• Not improve oxygenation
• Worsen biventricular failure
• Steal circulation from aorta and cause
coronary ischemia
• Maintain “status” quo with high dose opioids
that do not significantly affect heart rate,
contractibility, or resistance is recommended
84. ANESTHETIC MANAGEMENT
• COMPLEX SHUNTS :
– Short procedures slow gradual induction with low
dose Halothane least effect on +ve chronotropy &
SVR
– Nitrous Oxide limits FiO2 & helps prevent
coronary steal & ↓ Halothane requirements
86. REGIONAL ANESTHESIA &ANALGESIA
• CONSIDERATIONS
– Coarctation of aorta dilated tortuous intercostal
collateral arteries risk for arterial puncture
and absorption of local anesthetic during
intercostal blockade
– Lungs may absorb up to 80% of local anesthetic on
first passage. Therefore risk of local anesthetic
toxicity in R-L shunts
87. • Central axis blockade may cause
vasodilation which can:
i. Be hazardous in patients with significant AS or
left-sided obstructive lesions
ii. Cause oxyhemoglobin saturation in R-L shunts
iii. Improve microcirculation flow and venous
thrombosis in patients with polycythemia
• Children with chronic cyanosis are at risk
for coagulation abnormalities
REGIONAL ANESTHESIA &ANALGESIA
88. POSTOPERATIVE MANAGEMENT
• Children with CHD are very susceptible to:
i. Deleterious effects of hypoventilation
ii. Mild decreases in oxyhemoglobin saturation
Therefore, give supplemental O2 and
maintain patent airway
• In patients with single ventricle titrate SaO2
to 85%. Higher oxygen saturations can
PVR PBF systemic blood flow
89. • Pain catecholamines which can affect
vascular resistance and shunt direction
• Anticipate conduction disturbances in septal
defects
• Pain infundibular spasm in TOF
RVOT obstruction cyanosis, hypoxia,
syncope, seizures, acidosis and death
POSTOPERATIVE MANAGEMENT
