Classification of congenital heart disease Pathophysiology of shunt lesions Major complications Cardiac failure Pulmonary hypertension Preoperative assessment Anaesthetic management Postoperative management Conclusion

1. Anesthesia & children with
congenital heart disease …..
Problems oriented
Dr. Ashraf Arafat Abdelhalim, MD
Professor
Department of Anesthesia, Faculty of
Medicine Alexandria University

2. Case Presentation
• 8 y, complex cyanotic congenital heart disease
• Clubbing , cyanosed (Double-outlet right ventricle)
• Spo2 (76-82% on room air) , (88% on oxygen
mask)
• HCT 65%
• Multiple cardiac catheterization ,
• Balloon Atrial Septostomy + multiple shunt
• Anesthetists in many places refused to give GA
according to his father.

3. Introduction
• 1 in 125 live births.
• Of these, 30% have extra-cardiac anomalies (such as TEF, anorectal
• 85% are expected to survive to adulthood in USA
• 20 -50% may develop neurological impairment
• Increased risk of perioperative cardiac arrest and 30-day mortality
• Major cardiac anomalies,
• Cyanosis,
• Pulmonary hypertension,
• Congestive cardiac failure
• <2 years of age and
• Emergency surgery.
• With the same clinical group, neonates and infants with CHD are
associated with two fold increase in mortality from non-cardiac
surgery.

4. Classification of congenital heart disease
• Simple’ left-to-right shunt lesions: these
cause an increased
• pulmonary blood flow
• a Atrial septal defect
• b Ventricular septal defect
• c Atrioventricular septal defect
• d Patent ductus arteriosus
• e Aortopulmonary window

5. • Simple’ right-to-left shunt lesions: these cause a reduction in
pulmonary blood flow with cyanosis
a Tetralogy of Fallot. Consists of right ventricular outflow tract
obstruction, right ventricular hypertrophy, VSD and an
overriding of the aorta
b Pulmonary atresia
c Tricuspid atresia
d Ebstein’s anomaly. Consists of downward displacement of an
abnormal tricuspid valve into the right ventricular cavity, part
of the right ventricle is thus incorporated into the right atrium
(atrialized right ventricle), and the remaining right ventricular
cavity is malformed

6. • Complex shunts: these cause mixing of pulmonary
blood flow and systemic blood flow WITH Cyanosis
A -Transposition of the great arteries
B - Truncus arteriosus
C- Total anomalous pulmonary venous drainage
D- Double-outlet right ventricle
E- Hypoplastic left heart syndrome
Obstructive lesions
A - Coarctation of the aorta
B -Interrupted aortic arch
C- Aortic stenosis
D- Pulmonary stenosis

7. Pathophysiology of shunt lesions
• Left to-right shunting of blood results in excessive
pulmonary blood flow (PBF), usually acynotic but
deterioration in gas exchange may result from
pulmonary congestion.
• Right-to-left shunting occur when SVR drops or PVR
increases. causes reduced PBF and cyanosis
• The amount of shunting depends on the size of the
defect and the relative pressure gradients, which
are a reflection of the resistance to flow in each
circuit.
• Changes in (SVR) and (PVR) as a result of
anaesthesia have the greatest impact on large,
unrestrictive defects.

8. Surgically created shunt
• The classic Blalock Taussig shunt: 1944 end to side
anastomosis of subclavian artery to pulmonary artery.
• Modified BT shunt is the most commonly palliative
procedure in CHD ,a synthetic graft is interpositioned
between subclavian artery and ipsilateral pulmonary
artery.
• Fontan procedure 1971, is a palliative surgical procedure
used in children with complexcongenital heart defects. It
involves diverting the venous blood from the right
atrium to the pulmonary arteries without passing through
the morphologic right ventricle.
• Glenn Procedure: connecting the superior vena cava
(which returns unoxygenated blood from the head and
upper body to the lungs) to the right pulmonary artery

9. Major complications of congenital heart
disease
Arrhythmias
• History, noting exercise tolerance, evaluation of
arrhythmia risk
• Some cardiac surgery procedures predispose patients
to the development of arrhythmias in later life.
• Children at high risk :
• Extensive atrial sutures
• Ventriculotomy.
• Damage to the sinus node causes atrial arrhythmias
• Children who have undergone a Mustard or Fontan
procedure have a risk of atrial dysrhythmias that
increases year by year.

10. • Perioperative atria tachycardias are common in
children with Ebstein’s anomaly, and malignant
arrhythmias and sudden deaths during placement
of intracardiac lines have been described.
• Damage to the AV node and bundle of His causes
ventricular arrhythmias.
• Children undergone a repair of tetralogy of Fallot
are at increased risk of sudden death or sustained
VT.
• Poor exercise tolerance is suggestive of RV failure
and this is a risk factor for VT and sudden death.
• Ventricular ectopics are an ominous sign because
30% of patients with this disorder are at risk of
sudden death.

11. • In a child at risk of arrhythmias, factors known
to lower the threshold for ventricular ectopics
• should be used with caution; for example,
- Hypercarbia,
-Acidosis,
-Hypoxia
-Large doses of local anaesthetic with
epinephrine.
Anesthetists must diagnose the rhythm first
before administering antiarrythmics.

12. Cardiac failure
• Cardiac failure
• Cardiac reserve
• Limited cardiac reserve
• Children with limited cardiac reserve susceptible to
cardiac failure during anaesthesia.
• Presentation:
Tachypnoea, tachycardia and cool peripheries are
common to all ages.
In infants, poor feeding, failure to thrive, sweating and
hepatomegaly.
Older children manifest poor exercise tolerance,
poor weight gain and chest crackles.

13. • Preoperative optimization of following before surgery
• Gaseous or intravenous induction is possible, but
induction times will be prolonged,
• Avoid excessive administration of induction agent.
• Etomidate and fentanyl provide cardiovascular stability
Sevoflurane 4%, ??? Propofol, Ketamine
• If severe HF is suspected, attention should be given to
the use of vasoactive agents such as milrinone or
dobutamine before induction, and invasive monitoring
even for minor.
• Major surgery should be undertaken only with
the cardiologist and surgeon, parents, PICU

14. Cyanosis
• Cyanosis may be permanent or appear
intermittently.
• Cyanosis may not be seen in new born due to
presence of faetal haemoglobin which is highly
saturated at a given PaO2.
• Chronic cyanosis is associated with polycythaemia
and abnormal haemostasis.
• Blood viscosity increases SVR and PVR and reduces
coronary artery perfusion.

15. • Hyperviscosity is associated with thromboses and
infarction in renal ,pulmonary AND of intracranial
veins and sinuses, which can result in stroke.
• Haematocrit levels greater than 65% can reduce
oxygen delivery especially if iron deficiency is also
present.
• Hyperviscosity syndrome is characterized by
headache, dizziness, blurred vision, general fatigue,
muscle weakness, and reduced mentation.
• Preoperative intravenous fluid therapy should be
considered in children with a haemoglobin
greater than 18 g/dl (or haematocrit >60%)

16. • Preoperative fasting should be a minimum
• Scheduled first on the operating list.
• laboratory tests in cyanotic CHD:
Prolongation PT &PTT thrombocytopenia, platelet
dysfunction, hypofibrinogenaemia and accelerated
fibrinolysis
• Even when coagulation tests are normal, the
risk of excessive postoperative bleeding remains.
• If a child is on aspirin to FOR shunt patency, the risk
of shunt thrombosis is usually greater than that of
bleeding, so aspirin should be continued.

17. • Premedication minimizes distress, thereby reducing
oxygen consumption
• Blunted hypoxic ventilatory response. profound
hypoxia occurs without causing the normal
response of increased ventilation, especially with
opioids.
• End-tidal carbon dioxide monitoring
underestimates arterial carbon dioxide
• Close observation in the recovery room and during
the first postoperative night is recommended.

18. Pulmonary hypertension
• Mean PA pressure above 25 mm Hg at rest or 30
mm Hg on exercise.
• Develops earlier in some lesions (e.g. ASD and in
Down’s syndrome.
• A recent echocardiography.
• Previous cardiac catheterization : measure of PVR
and the degree of responsiveness to oxygen and
pulmonary vasodilators such as nitric oxide.
• a high risk of significant cardiovascular collapse
during anaesthesia, and this must be discussed with
the child’s family and full PICU should be available.

19. • Acidosis, hypercarbia, hypoxia, hypothermia, increased
sympathetic stimulation and increased airway pressure
all increase PVR.
• Understand the specific intracardiac anatomy
and the physiological
------Initially pulmonary HTN is reactive but later
pulmonary HTN becomes fixed.
• PHT crisis
-100% oxygen, inhaled nitric oxide, phosphodiesterase
inhibitors, prostacyclin analogues
- Eliminating the stimulating cause by administering
-Opioids
- deepening anaesthesia
, - α agonists (e.g. phenylephrine)
Inotropic support of the right ventricle

20. Preoperative assessment
• Underlying cardiac lesion (this helps to predict
complications. Direction and amount of shunting
• Is the lesion currently unrepaired, repaired
• Presence and severity of pulmonary hypertension
• The oxygen saturation in air ,Polycythaemia
• Cardiac function good, moderate or poor
• Coagulation abnormalities
• Is the PVR or SVR likely to need manipulation
History and examination

21. • Recent upper or lower RTI , changes in airway
reactivity and PVR, which might be poorly
tolerated in children with reduced pulmonary
compliance orPHT, especially those with a Glenn or
Fontan circulation.
ECG/chest radiograph/blood pressure (DBP)
• Children with previous surgery to the aorta should
have four-limb blood pressure recorded.
• Poor venous access, and central vessels can be hard
to recannulate.
• Medication:No specific guidelines exist for
discontinuation of aspirin before surgery

22. • Anxiety and distress increase oxygen consumption
and myocardial work
• Premedication. ……Midazolam is a preferred
facilitate induction of anaesthesia
reduce the amount of induction agent required,
so minimizing the drop in SVR.
Preoperative phlebotomy in symptomatic
hyperviscosity and hematocrit (HCT) more than
65%.

23. • Try to avoid dehydration in cyanotic CHD
patients by allowing clear liquids two hours
• Prior to surgery ,Children also have low
glycogen stores which makes them vulnerable
to hypoglycemia. If timing of surgery uncertain
then start an intravenous line and give glucose
• If patient is on prostaglandin (PGE1) infusion
then it should be continued.

24. Endocarditis prophylaxis. American Heart
Association
Assessment of potential major complications
Lab: Serum electrolytes in patients receiving
diuretics.
WBC count and C-reactive protein (CRP)
measurement provide potential diagnosis of
infection.
ECHO , X RAY, TEE
• The right ventricular function should also be
assessed as it is equally important in paediatric
CHD patient.

25. Anaesthetic management
• Intravenous line must be placed in all patients even for
minor procedure. (free of air bubble)
• Monitoring:
ECG is mainly used for arrhythmia detection in pediatric
patients.
Arterial line :free of air, major source of fluid overload
Usually two oximeters are placed , one in the upper
limb and other in the lower extremity
Transcranial near-infrared spectroscopy (NIRS) detects
intravascular oxygen saturation of cerebral cortex.

26. • Induction and maintenance must be individualized
to the child .
• (SVR) and (PVR) balance should be considered
when using intravenous agents.
• Patients with poor cardiac function, who require
inotropes preoperatively, may not tolerate
inhalational induction, and favour the use of
ketamine.

27. • Right to left intracardiac shunts prolong inhalation
induction, while IV induction is faster.
• Hypercyanotic "tet" spell under anaesthesia
responds to volume, increase in SVR with alpha
agonists such as Phenylephrine and ceasing
infundibular spasm with beta blockade.
• Be aware that pulse oximetry overestimates
arterial oxygen saturation as saturation
decreases, When in doubt, obtain an arterial blood
gas preoperatively for baseline.

28. • The choice of airway device” in children with
pulmonary HTN undergoing non-cardiac surgery.
Reports regarding incidence of pulmonary
hypertensive crisis among tracheally intubated
adult patients with severe pulmonary HTN
encourage anaesthetists to use less-invasive airway
management if the surgical procedure permits.

29. • Fontan physiology relies on transpulmonary
gradient to direct blood into the pulmonary
circulation, Therefore, if a patient with Fontan
physiology comes in for a laparoscopic procedure,
one must take into consideration the capacity of
the patient to handle the insult of hypercarbia,
pnuemoperitoneum and extremes of positions.
• Studies have shown that insufflation pressures less
than 8-12 cm H 2 O did not decrease cardiac
output, while a decrease in cardiac performance
was seen in pressures of 15-20 cm H 2 O.

30. Postoperative
• Except for children with fully repaired ASDs, PDA
and VSDs with no residual PHT, most children with
cardiac lesions should be cared for in a high care or
intensive care facility.
• Maintenance of normothermia
• Patients who have a Glenn or Fontan circulation (i.e.
with a low pressure shunt) benefit from
spontaneous ventilation and specific positioning
(head up and feet up) and a good preload to
facilitate pulmonary perfusion and good
oxygenation.

31. PAIN
• Good intraoperative and postoperative analgesia
• Opioid infusion or patient-controlled analgesia for
major operations has been the primary
postoperative intervention for pain for patients with
CHD.
• The use of regional anaesthesia for well-
compensated patients with CHD was reported with
no complications.( The risk:benefit ratio)
(coagulation abnormalities),

32. Eisenmenger
• Most of the patients started with simple correctable
cardiac defects but eventually leads to severe
pulmonary hypertension (PVR > 800 dynes/cm-5) which
does not respond to pulmonary vasodilators.
• Hypoxaemia, myocardial dysfunction and arrhythmia is
a common finding.
• Perioperative risk includes
• 1. Arrhythmia
• 2. Cardiac arrest
• 3. Pulmonary hypertensive crisis
• 4. Bleeding
• 5. Thrombosis

33. Anaesthetic management includes
• Phlebotomy in hyperviscosity syndrome
• Avoid dehydration in preoperative period
• Avoid myocardial depressants
• Keep SVR high
• Try to reduce PVR
• Regional anaesthesia can be used but general
anaesthesia is preferred
• Postoperative pain should be adequately
managed
• Will require intensive care after surgery

34. Conclusion
• Should be anaesthetized for elective surgery only by
a fully trained pediatric anesthetist who has a
thorough understanding of the child’s specific cardio
respiratory physiology and potential complications.
• Whether surgery occurs in the local hospital or
tertiary cardiac centre depends on the skill-mix of
the team members and the support facilities
available.

35. Referral to a specialist centre
• In all situations, except life-threatening emergencies, the
following children should be referred to a specialist centre or
anaesthetised with an in-depth knowledge of anaesthesia for
children with cardiac disease:
• Cyanotic cardiac disease
• CHD plus a difficult airway
• Neonate with CHD
• Eisenmenger syndrome: irreversible PHT with a R to L shunt
• PHT
• AS
• Hypoplastic left heart syndrome
• Single ventricle pathology (e.g. Fontan circulation)
• Cardiomyopathy
• any child requiring intensive or high care where this is not
available.

36. 12/19/2017 36