cogenital heart disease

1. Anesthesia for Congenital Heart
Disease

2. 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

3. 3

4. 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

5. 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

6. 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

7. Almost any anesthetic technic
may be used in any CHD patient
if
the anesthesiologist understands
•the pathophysiology of the lesion and
•the pharmacology of the drugs employed.

8. 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

9. 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

10. HISTORY & PHYSICAL
• Assess functional status – daily activities &
exercise tolerance
• Infants - ↓ cardiac reserve → cyanosis,
diaphoresis & respiratory distress during
feeding
• Palpitations, syncope, chest pain
• Heart murmur (s)
• Congestive heart failure
• Hypertension

11. HISTORY & PHYSICAL
• Tachypnea, dyspnea, cyanosis
• Squatting
• Clubbing of digits
• FTT d/t limited cardiac output and increased
oxygen consumption
• Medications – diuretics, afterload reduction
agents, antiplatelet, anticoagulants
• Immunosuppressants – heart transplant

12. LABORATORY EVALUATION
• BLOODWORK
• Electrolyte disturbances 2° to chronic diuretic therapy
or renal dysfunction
• Hemoglobin level best indicator of R-L shunting
magnitude & chronicity
• Hematocrit to evaluate severity of polycythemia or
iron deficiency anemia
• Screening coagulation tests
• Baseline ABG & pulse oximetry
• Calcium & glucose - newborns, critically ill children

13. LABORATORY EVALUATION
• 12 LEAD EKG
– Chamber enlargement/hypertrophy
– Axis deviation
– Conduction defects
– Arrhythmias
– Myocardial ischemia

14. 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

15. LABORATORY EVALUATION
• ECHOCARDIOGRAPHY
– Anatomic defects/shunts
– Ventricular function
– Valve function
– Doppler & color flow imaging → direction of
flow through defect/valves, velocities and
pressure gradients

16. LABORATORY EVALUATION
• CARDIAC CATHERIZATION
– Size & location of defects
– Degree of stenosis & shunt
– Pressure gradients & O2 saturation in each
chamber and great vessel
– Mixed venous O2saturation 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

17. 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

18. Congenital Cardiac Surgery
• Preoperative medication
– D/C diuretics and digoxin unless heart failure is
poorly controlled or digoxin is being used
primarily for rhythm
– Continue inotropes
– Continue prostaglandin infusions

19. 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

20. 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

21. 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 =

22. 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

23. 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

24. 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

25. 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

26. Air Bubble precautions
• To prevent paradoxical air embolism
• Remove all bubbles from iv tubing
• Connect the iv tubing to the venous cannula while there is free flowing
in fluid .
• Eject small amount of solution from syringe to clear air from the needle
hub before iv injection
• Aspirate injection port before injection to clear any air
• Hold the syringe upright to keep bubbles at the plunger end
• Do not leave a central line open to air
• Use air filters
• ? No N2O.

27. 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

28. PREMEDICATION
e) IV Premedication
• Midazolam 0.02 - 0.05 mg/kg titrated in small
increments
e) 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

29. 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

30. 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 HOCM

31. INHALATIONAL ANESTHETICS
SEVOFLURANE
• No ↓ HR
• Less myocardial depression than Halothane
• Mild ↓ SVR → improves systemic flow in L-
R shunts
• Can produce diastolic dysfunction

32. 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

33. INHALATIONAL ANESTHETICS
DESFLURANE
• Pungent → not good for induction; highest
incidence of laryngospasm
• SNS activation → ↓ with fentanyl
∀↑ HR + ↓ SVR
• Less myocardial depression than Halothane

34. 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

35. 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

36. 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

37. 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

38. 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

39. 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

40. 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

41. ANESTHETIC MANAGEMENT
ANESTHESIA INDUCTION
• Myocardial function preserved → IV or
inhalational techniques suitable
• Severe cardiac defects → IV induction
• Modify dosages in patients with severe
failure

42. ANESTHESIC MANAGEMENT
ANESTHESIA MAINTENANCE
• Depends on preoperative status
• Response to induction & tolerance of
individual patient
• Midazolam 0.15-0.2 mg/IV for amnesia

43. 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

44. ANESTHETIC MANAGEMENT
• L-R SHUNTS :
– GOAL = ↓ SVR and ↑ PVR → ↓ L-R shunt
• PPV & PEEP increases PVR
• Ketamine increases SVR
• Inhalation agents decrease SVR

45. ANESTHETIC MANAGEMENT
• R-L SHUNTS :
– GOAL :↑ PBF by ↑ SVR and ↓ PVR
∀↑ PVR & ↓ SVR → ↓ PBF
– Hypoxemia/atelectasis/PEEP
– Acidosis/hypercapnia
↑ HCT
– Sympathetic stimulation & surgical stimulation
– Vasodilators & inhalation agents → ↓ SVR

46. ANESTHETIC MANAGEMENT
• ↓ PVR & ↑ SVR → ↑ PBF
– Hyperoxia/Normal FRC
– Alkalosis/hypocapnia
– Low HCT
– Low mean airway pressure
– Blunted stress response
– Nitric oxide/ pulmonary vasodilators
– Vasoconstrictors & direct manipulation→↑ SVR

47. 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

48. 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

49. 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

50. ANESTHETIC MANAGEMENT
• OBSTRUCTIVE LESIONS
• Lesions with > 50 mmHg pressure gradient +
CHF → opioid technique
• Optimize preload → improves flow beyond
lesion
• Avoid tachycardia → ↑ myocardial demand & ↓
flow beyond obstruction
• Inhalation agents → -ve inotropy & decrease
SVR→ worsens gradient & flow past obstruction

51. Congenital Cardiac Surgery
• Cardiopulmonary Bypass
– Differences from adult
• Lower temperatures (15-20 degrees C)
• Lower perfusion pressure (20-30mmHg)
• Very significant hemodilution (3-15 times greater)
• Pump flows range from 200ml/kg/min to zero!
• Different blood pH management (alpha-stat vs pH
stat)
• Tendency to hypoglycemia
• Cannula placement is much more critical

52. Anticoagulation and
haemostasis during CPB
Anticoagulation
Heparin
• time of administration
• Route – central line

53. Current clinical protocol
• Heparin – 300 units/kg i.v.
• Draw arterial sample for ACT in 3-5 min.
• Give additional heparin to achieve
ACT >300 (normothermic CPB)
ACT > 400 (hypothermic CPB)
• Prime extracorporial circuit with heparin 3
units/ml
•

54. • Monitor ACT every 30 min. during CPB
• If ACT decreases below desired minimum
value – supplemental dose of 50-100 units/kg

55. Haemostasis
At conclusion of CPB
• Protamine – mainstay of heparin neutralization
• Dosage – 1.3 mg to neutralise 100units of heparin
• ACT after administration
if more then baseline – additional bolus (25 -50mg)
of protamine

56. protamine reaction
• Increase in PAP & CVP
• Decrease in LAP & SAP
Precaution
• via peripheral line
• Administer slowly < 5mg/min.
• Test bolus dose 25-50 mg – look for
haemodynamics
• Careful with pt. having food allergy

57. Treatment
• Stop protamine
• Administration of fluids and epinephrine
• Steroids
• Pulmonary vasodialators - NTG, SNP

58. Congenital Cardiac Surgery
• Deep hypothermic circulatory arrest (DHCA)
– Neonates and small infant usually < 10 kg
– Oxygen consumption falls 2-2.5 times per 10
degree fall in temperature
– Allows more controlled complex surgery in a
bloodless field
– Often total CPB time is actually shortened by this
technique

59. Congenital Cardiac Surgery
• Weaning from CPB
– Heart assessed by direct visualization and right or
left atrial filling pressure, central cannula or TEE
– Pulse oximetry is also very helpful
– Problems weaning are due to:
• Inadequate repair,
• pulmonary hypertension
• And/or left or right ventricular dysfunction

60. Congenital Cardiac Surgery
• Weaning from CPB
– Problems weaning diagnosed by
• Intraoperative cardiac catheterization
• Echo-doppler
– Leaving the operating room before correcting the
problem leads to a significant INCREASE in
morbidity

61. Postoperative care
• Observation on a monitored bed in ICU/HDU for 24 hours or overnight
atleast because of their predisposition to develop ventricular/
supraventricular tachycardia, bradyarrhythmia and myocardial ischemia
• Meticulous attention to fluid balance to prevent hypovolumia
• Monitoring of blood pressure preferably invasive, Oxygen saturation and
CVP
• Position slowly- risk of postoperative postural hypotension with secondary
increase in right to left shunting
• Prevention of venous stasis by early ambulation and by applying effective
elastic stocking or periodic pneumatic compression.
• Adequate pain management – adverse hemodynamics and possibly
hypercoagulable state

62. Post op pain management
• Opioid analgesia
• Regional analgesia
• Alternative and supplementary analgesia

63. Congenital Cardiac Surgery
• Selected Specific Conditions/Procedures:
– Tetralogy of Fallot
– Patent Ductus Arteriosus(PDA)
– ASD
– VSD

64. TETRALOGY OF FALLOT

65. 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

66. CXR IN TOF
• Normal heart size
• Pulmonary oligemia
• Upturned cardiac apex
• Rt aortic arch

67. TOF : Coagulation
Abnormalities
• Thrombocytopenia
• Platelet functional defects
• Hypofibrinogenemia
• Elevated PT, APTT.

68. Congenital Cardiac Surgery
• Laboratory data
– Cyanosis leads to polycythemia
• May consider phlebotomy esp if no CPB
• Leads to coagulation problems
– Anemia may be “relative” and need transfusion
– Newborn infant has immature systems including
renal/hepatic/coagulation
– Hypoglycemia is much more common

69. Airway Abnormalities in
TOF
• TOF with pulmonary atresia: tracheomalacia,
bronchomalacia
• Associated syndromes – DiGeorge syndrome,
CHARGE, Goldenhar’s syndrome, Down’s
syndrome.

70. TETRALOGY OF FALLOT
• Hypercyanotic ( “tet” ) spells occur D/T
infundibular spasm, low pH or low PaO2
• In awake patient manifests as acute cyanosis &
hyperventilation
• May occur with feeding, crying, defecation or
stress
• During anesthesia D/T acute dynamic
infundibular spasm

71. Triggers
• ↑O2 demand
• crying feeding defecation
• Hypovolemia
• Relative anemia
• Anxiety
• Hypoxia hypercarbia acidosis

72. TETRALOGY OF FALLOT
• Treatment of Hypercyanotic Spells
– High FiO2 → pulmonary vasodilator → ↓ PVR
– Hydration (fluid bolus) → opens RVOT
– Morphine (0.1mg/kg/dose) → sedation,↓ PVR
– Ketamine → ↑ SVR, sedation, analgesia → ↑ PBF
– Phenylephrine (1mcg/kg/dose) → ↑ SVR
– β-blockers (Esmolol 100-200mcg/kg/min)
→ ↓HR,-ve inotropy → improves flow across
obstructed valve &↓ infundibular spasm

73. Volatile Esmolol
Propranolol
↑ depth of ↓ HR &
anesthesia contractility
↑ pre load ↓ infundibular spasm
↓ acidosis TREATMENT
(NaHCO3)
↑SVR ↓ PVR
Phenylnephrine norepinephrine posture
1-10µg/kg 0.01µg/kg

74. Congenital Cardiac Surgery
• Tetralogy of Fallot
– Preoperative Preparation
• Heavy premedication
– Consider IM ketamine or inhalation induction but
get rapid control of airway.
– Keep SVR up and PVR down, maintain heart rate
– Intraoperative TEE

75. Congenital Cardiac Surgery
• Tetralogy of Fallot
– Weaning from CPB, ratio RV:LV pressure should
be < 0.8
– May need to keep PVR low with NTG, milrinone,
dobutamine phentolamine, PGE1
– May need RV inotrope post op
– May need temporary pacing wire

76. Congenital Cardiac Surgery
• Tetralogy of Fallot
– Perioperative concerns
• Increase in PVR or decrease in SVR leading to Right to
Left shunt
• Tet Spells pre induction (crying/anxiety)
• Polycythemia and bleeding
• Air embolus
• RV failure

77. PALLIATIVE SHUNTS IN
TOF
• Blalock-Taussig shunt [anastomosis of
subclavian artery and pulmonary artery]
• Modified B-T shunt [Goretex graft used]
• Pott’s shunt [descending aorta  left
pulmonary artery]
• Waterston’s shunt [ascending aorta  right
pulmonary artery]

78. Patent Ductus Arteriosus
• Ductus Arteriosus connects the
descending aorta to the main
pulmonary trunk near the
origin of the left subclavian
• Normal postnatal closure
results in fibrosis- which
becomes the ligamentum
arteriosum.
• Small PDA does not increase
risk for heart failure- but does
carry a risk for bacterial
endocarditis.

79. Congenital Cardiac Surgery
• PATENT DUCTUS ARTERIOSUS
– 1/8000 live births, associated with prematurity
and female predominance of approx 3:1
– Left to right shunt causes pulmonary edema
– Occasionally right to left cause lower body
cyanosis
– SpO2 probe on Right hand and lower limb
• Confirms correct vessel ligated
– Vagal reflex is pronounced by lung traction
– Antibiotics required to prevent endocarditis

80. • Confirmation of crossmatched blood in OT.
• Radial arterial line preferably on opposite side
of aortic arch.
• At the time of PDA ligation SBP reduced to
80-90 mm of hg with Halothane/SNP
• Watch for haemorrhage due to rupture.

81. Thank
you!!