Congenital Heart Disease

Congenital Heart DiseaseGreg Gordon MD

American Society of Dentist Anesthesiologists Baltimore, MD, May 3, 2012

Training for Career in Pediatric Cardiac Anesthesia

Suggested training (US & UK):

Specific Fellowship: Rare

• Pediatric Anesthesia: 12 months

• Adult Cardiac Anesthesia: 6 months

• Pediatric Cardiac Anesthesia: 6 months

• Pediatric Critical Care: 6 months

Baum V & De Souza DG. Pediatric Anesthesia 17:407, 2007White MC & Murphy TWG. Pediatric Anesthesia 17:421, 2007

?Children & adults scheduled

for dental or oral surgery

and known to have CHD

Preop heart murmur:

Is it CHD?

Adults with CHD in US today

1,500,000Growing 2% per year

Cahalan MK. Anesthetic Management of Patients with Heart Disease. IARS 2003 Review Course LecturesAndropolous, D. Anesthesia for the Patient with Congenital Heart DiseaseFor Noncardiac Surgery. ASA Refresher Course Lectures 2011

Tammy

3 y/o with TOF s/p right BTS

For dental restorations

•Turns blue with crying

•Scheduled to undergo cardiac repair

in 3 months

•SpO2 93

•Systolic ejection murmur

•Slight clubbing of fingers

•Hct 52

5 year-old for dental work

Systolic murmur

Victor

VSD

Needs surgical closure

Cardiologist recommended dental restorations first

Fran

11 y/o with tricuspid atresia

s/p Fontan procedure

•Temporary BTS at age 3

weeks

•Modified Fontan at age 3

years

•Meds: digoxin, captopril

•SpO2 88 on RA, 98 in O2

•P 67, BP 99/42

•First degree AV block

For lengthy oral surgery with possible large blood loss

26 y/o with D-TGA

s/p Mustard in infancy

Dental restorations

Developmental delay

Pacemaker

Travis

4 y/o D-TGA

s/p Jatene in infancy

Dental restorations

Very active

Keeps up with peers

Never any cyanosis

Tracy

Objectives

Participants will be able to more intelligently discuss:

• Newborn and infant heart and

lungs

• Initial evaluation the child’s heart

• Pathophysiology of selected CHDs

• Anesthetic implications of CHD

Pediatric AnesthesiaCongenital Heart Disease

LessonPresentationQuiz

greggordon.org

Fetal Circulation

Placenta (oxygenation) ->Umbilical vein ->Ductus venosus (liver bypass) –>IVC ->Foramen ovale (RV bypass) ->Left atruim ->Left ventricle –>Ascending aorta (brain) ->SVC ->Right atrium ->Right ventricle ->Main pulmonary artery ->Ductus arteriosus (lung bypass) ->Descending aorta ->Placenta

Foramen Ovale

Functional closure first hours as LAP > RAP

Probe-patent

50% of 5-year-olds

25% of 20-year-olds

Paradoxical embolus

The Newborn Heart

The Newborn Heart

Ventricular tissue

•Fewer myocytes

•Greater proportion of connective tissue

•Relative RVHSo:

•Decreased compliance

•More sensitive to preload

The Newborn Heart

Normally near peak of Starling curveStroke volume relatively fixedC.O. relatively heart rate dependent

•Near peak of Starling curve

•Stroke volume relatively fixed

•C.O. relatively heart rate dependent

Ca+

+

The Newborn Heart

Newborn myocardium derives relatively high fraction of activator Ca from the extracellular pool, so

Beware Ca channel blockers

The Preterm Infant Heart

More sensitive to depressant effects of inhaled agentsDecreased response to catecholamines

Relatively high PVR persists

Pulmonary vasculature more sensitive to vasoconstriction by:

Hypoxia

Acidosis

Hypercarbia

CHD Pearl

murmur in newborn =

benign disease

Initial evaluation of child’s heart

History: To determine

Level of function

1.Well compensated with

no limitations

2. Some limitations

3. Poorly compensated with

severe limitations

CHF and/or cyanosis

Initial evaluation of child’s heart

History - cyanosis

•Turn blue?

•At rest?

•When crying?

•Passes out?

•Stops playing and squats

Initial evaluation of child’s heart

History - CHF

Run around like crazy?

Like sibs?

Or tends to be quiet, slow?

Infant – feeding behavior:

Slow to finish bottle?

Sweats when nursing?

Eyes puffy in the morning?

Initial evaluation of child’s heart

Physical exam

•Listen to heart first when/if infant quiet(warm stethoscope)

•First concentrate on S1 and especially S2

Louder than normal?Split normally?

•Systolic murmur:Starts after or obscures S1?

•Diastolic murmur?•Widely radiating murmur?•Palpate liver•BP in arm and leg•Tongue - cyanosis

CHD Pearl

Sudden CHF in ‘healthy’ 10-day-old =

complicated coarct

General Approach to CHD Patient

1. Define cardiovascular pathology

2. Predict pathophysiology

3. Determine hemodynamic goals

4. Anticipate emergency treatments

Cahalan MK. Anesthetic Management of Patients with Heart Disease. IARS 2003 Review Course Lectures

Recent Cardiologist Evaluation Needed?

Completely corrected,

Well compensated and stable:

Probably not

Complex and/or poorly compensated;

Cyanotic and/or single ventricle:

YES: Evaluation & ECHO within 3-6 mos

Don’t worry

Almost any anesthetic technicmay be used in any CHD patient

if

the anesthesiologist understands

•the pathophysiology of the lesion and

•the pharmacology of the drugs employed.

Normal Neonate

1 week SVC

RA

RV

MPA

PV

LA

LV

Ao

m=2

30/3

30/12 m=18

m=4

80/5

80/50

60

65

65

65

99

99

99

Some basic definitions

physiologicL to R shunt =

lungs to lungs shunt

Blood that is returning to the heart

from the lungs is recirculated back

to the lungs without going out to the

rest of the body.

Some basic definitions

physiologicR to L shunt =

body to body shunt

Blood that is returning to the heart

from the body is recirculated directly

back to the body without going to the

lungs to be oxygenated.

Some basic definitions

effective pulmonaryblood flow=

body to lungs flow

Blood that is returning to the heart

from the body that is actually directed

to the lungs to be oxygenated.

Some basic definitions

Nonrestrictive VSD

VSD large enough that

pressure equalizes in the two ventricles

(no pressure gradient can be maintained)

LV pressure = RV pressure

SVC

RA

RV

MPA

PV

LA

LV

AoPDA

Premature1 week old

28 weeks EGA

65/2565/30

65/1265/10

96

96

92

65

65

80

to R arm& head To L arm

MHMC PDA ligation

CHD Pearl

blue newborn +

no airway or breathing problem +

quiet heart =

decreased PBF lesion (TOF)

Tammy

Tetralogy Of Fallot

Most common cyanotic lesion

NB: cyanosis plus quiet heart

Diminished pulmonary blood flow

Ao ejection click

Hypercyanotic “tet” spells

tachypnea, pallor, LOC, less murmur

Tammy

1.Define cardiovascular pathology

2.Predict pathophysiology

3.Determine hemodynamic goals

4.Anticipate emergency treatments

3 y/o with TOF s/p right BTS

Tammy

Tetralogy Of Fallot

Essentially a duality:1. severe RVOT obstruction plus2. nonrestrictive VSD

With anatomic consequences:1.RVH2.Overriding aorta

And physiologic consequences1.R to L shunt2.Diminished pulmonary blood flow

Tetralogy of Fallot

SVC

RA

RV

MPA

LA

LV

Ao

40

40

40

96

85

50

m=5

85/6

15/10

m=4

85/5

85/45

Tammy

Tetralogy Of Fallot

s/p right BTS?

Blalock-Taussig Shunt

Thomas-Blalock-Taussig Shunt

Vivien Thomas, Partners of the Heart, 1998 andSomething the Lord Made - Best Made-for-TV Movie, 2004

Helen Taussig

Alfred Blalock

Vivien Thomas

Thomas-Blalock-Tuassig

Dr. Blalock does the Blalock(Johns Hopkins)

Systemic to Pulmonary Shunts

Tammy

Tetralogy Of Fallot - Goals

Maintain good hydration, especially if polycythemic

Maintain adequate tissue oxygenation

1.Avoid increasing O2 demand2.Maintain SVR, systemic BP3.Minimize PVR

Oral premed/inductionmidazolam + ketamine(0.6 mg/kg + 6 mg/kg)

Tetralogy Of Fallot - Goals

Minimize PVR

Oxygen to FIO2 = 1

Mild hyperventilation

PaCO2 low 30’s

pH 7.45

Adequate anesthesia

Adequate analgesia

Normothermia, warm

Nitric oxide

Tammy

Tetralogy Of Fallot - Goals

Maintain SVR

Intravascular volume

Well hydrated

IV bolus prn

Maintain BP

ketamine

phenylephrine

Tammy

Free written board answer:

Speed of induction:

R->L shunt• Inhalational: slower• IV: faster

L->R shunt• Inhalational: maybe faster• IV: slowerBut probably not clinically important

Tanner et al. Anesth Analg 64:101, 1985

Beware:

blunted chemoreceptor response to

hypoxemiaTammy

Beware:

Tammy

VD:VT may be 0.6And increase with•start of mechanical ventilation•too much PEEP•hypovolemia

ETCO2 << PaCO2

VD/VT = (PaCO2 – ETCO2)/PaCO2

Tammy

Tetralogy Of Fallot

Minimize R->L Shunt

MAINTAIN SVR•ketamine•phenylephrine

Tammy

Tetralogy Of Fallot

Minimize RVOT obst & PVR

•oxygen•beta blocker ready

Maybe:•nitroglycerin•phentolamine•tolazoline•prostaglandin E1

•nitric oxide

Tammy

Tetralogy Of Fallot

And of course:

•No Air in lines

infective endocarditis prophylaxis

and

Maybe no N2O

Infective Endocarditis Prophylaxis

Infective endocarditis prophylaxis

for dental procedures is

reasonable only for patients with

underlying cardiac conditions

associated with

the highest risk of adverse

outcome from infective

endocarditis.

Wilson W, Taubert KA et al. AHA Guidelines. Prevention of Infective Endocarditis. Circulation 116:1736-54, 2007

Infective Endocarditis Prophylaxis Recommended

Unrepaired cyanotic CHD,

including palliative

shunts and conduits.

Circulation 116:1736, 2007

Infective Endocarditis Prophylaxis Recommended

CHD completely repaired with

prosthetic material or device

less than 6 months ago.

Circulation 116:1736, 2007

Infective Endocarditis Prophylaxis Recommended

Repaired CHD with

residual defect(s) at or near

a prosthetic patch or device.

Circulation 116:1736, 2007

Infective Endocarditis Prophylaxis Recommended

Prosthetic material in a valve.

Previous infective endocarditis.

Valvulopathy after transplant.

Circulation 116:1736, 2007

Infective Endocarditis Prophylaxis Recommended

Circulation 116:1736, 2007

For patients with the above conditions,

prophylaxis is reasonable for

all dental procedures that involve

manipulation of gingival tissue or

the apical region of teeth or

perforation of the oral mucosa.

Infectious Endocarditis Prophylaxis

Circulation 116:1736, 2007

NOT Recommended

Any form of CHD not listed above

Local injection -> noninfected tissue

Shedding deciduous teeth

Bleeding/trauma to lips, oral mucosa

Tammy

Tetralogy Of Fallot

and

SVRmaintain

infective endocarditis prophylaxis

Tetralogy Of Fallot

Treatment of Tet Spell

• 100% O2

• knee-chest position

• morphine 0.05-0.1 mg/kg

• crystalloid 15-30 ml/kg

• phenylephrine to increase systolic BP 20-40

mmHg

• beta blockade: propranolol 0.1 mg/kg or

esmolol 0.5 mg/kg and 50-300 mcg/kg/min

• ABG: NaHCO3 if necessary

• ECMO/surgery DiNardo JA et al. in Davis PJ et al. Smith’s Anesthesia for Infants and Children, 8th ed. 2011

Schedule case early in the day

•Less fasting dehydration

•Less time of stress

•More time to monitor postop

•More support available

•Less team turnover

Schedule case WHERE?

•Well-compensated, no limitations, not-complex:

Ambulatory center may be OK

•Not well-compensated, complex:

Center with CHD expertise & backup available

5 year-old for dental work

Systolic murmur

VSD

Needs surgical closure

Cardiologist recommended dental restorations

first

Victor

Newborn VSD

Most common lesion

2/3rds close spontaneously

Small VSD

Definite murmur

Will probably close

Large VSD

No murmur

No problems

Home with Mom

CHF symptoms by 4-8 weeks

VSD

SVC

RA

RV

MPA

LA

LV

Ao

m=6

90/8

90/35

m=12

90/10

90/60

60

80

88

96

94

94

nonrestrictive

98

Nonrestrictive VSD

L->R shunt

Pulmonary to System Flow Ratio

QP:QS = SaO2 – SvO2__________

SpvO2 – SpaO2

=94 - 60_______98 - 88

= 3.4:1

Victor

Nonrestrictive VSD - Goals

Maintain PVR

Lower SVR better

Normal ventilation(paCO2 = 40’s)

FIO2 < 1

Major inhalational agents

Propofol, thiopental

Victor

Proper management of the physiologic

abnormalities is more important

than the choice of specific anesthetic

and pharmacologic approaches.

Nonrestrictive VSD - Goals

Of course:

•No Air in linesMaybe no N2O

infective endocarditis prophylaxis?

NO longer recommended

Wilson W, Taubert KA et al. AHA Guidelines. Prevention of Infective Endocarditis. Circulation 116:1736-54, 2007

Victor

Unrepaired nonrestrictive VSD ->

1. PVOD developing 2. Less L->R shunt3. Less CHF4. Less murmur5. PVOD irreversible6. R-L shunt7. Less PBF8. More cyanosis

Eisenmenger syndrome

Victor

Fran

11 y/o with tricuspid atresia

s/p Fontan procedure

•Temporary BTS at age 3

weeks

•Modified Fontan at age 3

years

•Meds: digoxin, captopril

•SpO2 88 on RA, 98 in O2

•P 67, BP 99/42

•First degree AV block

Oral surgery, big blood loss?

Fran

Tricuspid Atresia3rd most common cyanotic CHD1. TOF2. TGA

20% extracardiac abnormalities•GI•Musculoskeletal

Cyanosis•Mixing in LA•Decreased PBF•Spells

Type IB most common•Small VSD (and RV)•PS

Fontan procedure

Indicated to palliate:

Tricuspid atresia

Hypoplastic left heart syndrome

Double outlet right ventricle

Double inlet left ventricle

Unbalanced AV septal defect

Fontan physiology

Two defining features:

1. Single systemic ventricle

2. Pulmonary blood flow:

without pump!

Fontan procedure

Three main versionsAtriopulmonary connection (the original)Total cavopulmonary connection (TCPC):

Intracardiac (lateral tunnel)Extracardiac

Two stages:Bidirectional Glenn shuntFontan completion

ModifiedBidirectional

Modified

Collaborate with cardiologist

Clarify

History

Pathophysiology

Risks

Status best possible?

Explain recent studies

16/10

16/1288/6

Age 5 years

Fran

11 y/o with tricuspid atresia s/p Fontan procedure

Potential problems during surgery

CHF1. Volume shifts2. Anemia3. Hypertension

Paradoxical embolus

Thrombosis Vena cavae RA Pulmonary arteries

Hypoxemia1. Hypovolemia2. Low PBF

Fran

11 y/o with tricuspid atresia s/p Fontan procedure

Goals during surgery

Monitor RA pressure•RA catheter•Maintain starting pressure

Maintain systemic BP near baseline

Minimize myocardial depressants

NO AIR IN LINESNo N2O

Relatively high FIO2

Normal Hct

IE prophylaxis

Fran

11 y/o with tricuspid atresia s/p Fontan procedure

MAJOR GOAL

Maintain cardiac output and

transpulmonary gradient (TPG):

Adequate preload

Low PVR

Low intrathoracic pressure

Normal ventilation

Unobstructed PV return

Regular sinus rhythm

Low ventricular afterload

Normal ventricular funtion

16/10

16/1288/6

Fran

Monitor RA PressureRight IJ?

CHD Pearl

blue newborn +

no airway or breathing problem +

hyperactive heart =

TGA

26 y/o with D-TGA

s/p Mustard in infancy

Dental restorations

Developmental delay

Pacemaker

Travis

TGA s/p Mustard

D-TGA, Transposition of the Great Arteries

Newborn: 75% no VSD

PGE1 to keep PDA

BAS prior to surgery

Older: Mustard or Senning

Younger: Jatene ASO

Travis

SVC

RA

RV

LA

LV

Ao

MPA

D-TGA

PDA

99

99

BAS

65

D-TGAMustard Procedure

SVC

RV LV

Ao MPA

PV

95

D-TGA + Mustard

RV systemic ventricle

RV failure Tricuspid regurgitationVentricular arrhythmiasSudden death

Atrial injury/scarsAtrial flutter/fibSick sinus syndrome

Travis

26 y/o TGA s/p Mustard, pacemaker

Poor RV function

Consider inotrope

Arrhythmias

Pacemaker

CIED practice advisory

Travis

CIED practice advisory

Practice Advisory for the Perioperative Management of Patients with CardiacImplantable Electronic Devices: Pacemakers and Implantable Cardioverter-Defibrillators. Anesthesiology 114:247-61, 2011

Preop: What type CIED?Pacer dependent?Check function: interrogate device

EMI (e.g. Bovie) during procedure?Reprogram to asynchronous mode?Have backup pacing &

defibrillation equipmentimmediately available

4 y/o D-TGA

s/p Jatene in infancy

For dental restorations

Very active

Keeps up with peers

Never any cyanosis

Tracy

D-TGA

SVC

RA

RV

LA

LV

Ao

MPA

D-TGA

SVC

RA

RV

LA

LV

MPA Ao

4 y/o D-TGA s/p Jatene

Treat as normal, healthy child!

Be happy!

Tracy

For more cool stuff about CHDcheck out the lesson and fun Quiz at

http://greggordon.org/edu/ped/chd1.htm

Now we can more intelligently discuss:

•Newborn and infant heart and lungs

• Initial evaluation the child’s heart

• Pathophysiology of selected CHD

• Anesthetic implications of CHD