Anesthesia In Children With Congenital Heart Disease For Non-cardiac Surgery Dr. Fady Adib Lecturer Of Anesthesia Ain-Shams University Oct. 2012.

Anesthesia In Children With

Congenital Heart Disease For

Non-cardiac Surgery

Dr. Fady AdibLecturer Of AnesthesiaAin-Shams University

Oct. 2012

The question facing anesthetists are:

1 . Should the patient be referred to specialist cardiologist before surgery?

2 . Should surgery be performed in a center specializing in congenital cardiology?

3 . How should anesthesia be conducted safely in the presence of congenital heart disease?

INTRODUCTIONINTRODUCTION

The Incidence of CHD is about 1% of the newborn infants

- Surgery:- Surgery:

- Noncardiac conditions- Noncardiac conditions ( inguinal hernia, circumcision, or tonsillectomy).

- Associated noncardiac congenital - Associated noncardiac congenital anomaliesanomalies (orthopedic or (orthopedic or genitourinary).genitourinary).

- Due to advances in diagnosis, medical, critical and surgical care for CHD

- Therefore, it is common for patients with CHD to present for non-cardiac surgery, and even in patient with corrected CHD significant residual problems (arrhythmias, ventricular dysfunction, shunts, valvular stenosis, and PH) may be exist.

Anatomical & Anatomical & PhysiologicalPhysiologicalDifferencesDifferences

CVS: Anatomical Differences

- Myocardium is less compliant:Cardiac Output is H.R. dependent.

- It can’t withstand a volume load.

- Decreased sympathetic innervation: catecholamine stores

Autonomic Development

- Beta receptors develop with age- alpha receptors less developed

So V.C response to volume loss is decreased

- Parasympathetic response supervens- Net result:

- Volume load heart failure- Volume loss decrease vasoconstriction

- Hypotension

CLASSIFICATION OF CHDI- Acyanotic congenital heart disease: 1- ASD 2- VSD 3- PDA

II- Cyanotic congenital heart disease: 1- Tetralogy of Fallot, with severe right ventricular outflow obstruction 2- TGA 3- Pulmonary atresia or severe stenosis 4- Tricuspid atresia with pulmonary stenosis 5- Truncus Arteriosus

Pathophysiological Pathophysiological classification of congenital classification of congenital

heart diseaseheart disease

- Shunt lesions

- Mixing lesions

- Obstructive lesions

- Regurgitation lesions

Shunt lesionsShunt lesions

- Direction & magnitude:- Direction & magnitude:

depends on depends on size of shunt orificesize of shunt orifice pressure on both sides of the shunt pressure on both sides of the shunt

- Lt.-to-Rt. Shunt- Lt.-to-Rt. Shunt ( e.g. VSD,PDA) VOLUME OVERLOAD ( e.g. VSD,PDA) VOLUME OVERLOAD

- Rt.-to-Lt. Shunt- Rt.-to-Lt. Shunt (e.g. Fallot 4) PRESSURE (e.g. Fallot 4) PRESSURE OVERLOADOVERLOAD

Intracadriac e.g. ASD, VSD

Extracardiac:e.g. PDA

....Shunt lesions.. Shunt lesions.. (continued)(continued)

Lt-to-Rt shunte.g. ASD, VSD

Rt-to-Lt shunte.g. F4

- Volume overload on pulmonary circulation- Increased cardiac work of Rt. Ventricle - Excessive pulmonary blood flow=++ PVR

- ↓ Pulmonary blood flow= hypoxemia

- Pressure overload of the Rt. ventricle

Mixing lesionsMixing lesions(large orifice)(large orifice)

- e.g. TGA, Univentricular heart

- Direction & Magnitude: Depend on PRESSURE on both sides of

the lesion

- Usually CYANOTIC

- With VOLUME & PRESSURE overload

Obstructive lesionsObstructive lesions

- e.g. Aortic stenosis, Coarctation of Aorta

- Pressure overload ventricular hypertrophy impaired coronary perfusion systemic hypotension

Regurgitation lesionsRegurgitation lesions(uncommon)(uncommon)

- Volume overload ventricular dilatation

Once full details of the anatomy, surgical history and current pathophysiology are obtained patient

can be divided into the following categories:

1 . Congenital heart disease, yet to be surgically treated.

2 . Surgically corrected, symptom free with no new development.

3 . Surgically corrected, symptomatic heart diseases

4 . Surgically palliated. Symptoms stable with no new development

5 . Surgically palliated with severe symptoms or no new development

Types of Cardiac SurgeryTypes of Cardiac Surgery

Univentricular Biventricular

Usually complete repair

(Corrective)

•Problems encountered:

Debubbling & Antibiotic coverage, As the lesion is still persistent e.g. VSD

Usually Palliativee.g. Shunts, Banding

-Corrective surgery: Correct anatomy

-Palliative surgery: The aim is to increase or decrease pulmonary blood flow

Corrective Surgery

Corrected ASD VSD PDA: Near normal patient. Only needs antibiotic prophylaxis.

Repaired TOF: Residual defects: VSD, outflow tract obstruction, pulmonary regurge, Heart block,

Corrected coarcitation usually require long term treatment of hypertension.

Palliative surgery

Decrease PBF: Pulmonary artery banding (VSD)

Increase PBF: In Pulmonary atresia

BT shunt: Subclavian artery to Pulmonary artery.

Gllen: SVC to Pulmonary artery

Fontan after Gllen IVC to Pulmonary artery

Physiology of different typesPhysiology of different typesof circulationof circulation

- -Normal or ‘series’ circulation.

- -Parallel or ‘balanced’ circulation.

- -Single-ventricle circulation

Risk classificationRisk classification

increased risk of mortality and morbidity.

-factors associated with a high risk ofperioperative complications,

{ -disease complexity} ,

{ -physiological status},

young age, and Hospital Stay . - type of surgery ,

Most Important

Complexity of heart diseaseComplexity of heart disease

-single-ventricle physiology

-balanced circulation physiology

-cardiomyopathy

-aortic stenosis

Physiological statusPhysiological statusPhysiological status can be divided into four major risk factors:

-Cardiac failure

-Pulmonary hypertension

-Arrhythmias

-Cyanosis

ANESTHETIC ANESTHETIC MANAGEMENTMANAGEMENT

- Perioperative management requires a team approach

- CHD is polymorphic and may clinically manifest across a broad clinical spectrum

- The plane of Anesthetic Management includes the following:

A - Preoperative Management B - Intraoperative Management C - Postoperative Management

Preoperative Anesthetic Considerations

1- Complete history and physical examin.2- Review all investigations3- Hydration should be maintained 4- All cardiac medication except possibly digitalis ,ACE and diuretics should be continued until surgery 5- Premedication should be give particularly to patients at risk for right to left shunt 6- Antibiotic prophylaxis against endocarditis must be given

Preoperative Anesthetic Management:

A- History B- physical examinationC- InvestigationsD- PremedicationsE- Fasting Guidelines

HISTORY & PHYSICAL HISTORY & PHYSICAL EXAMINATIONEXAMINATION

- Assess functional status - daily activities - exercise tolerance

- ↓ cardiac reserve - cyanosis - respiratory distress during

feeding

- Cyanosis- Dyspnea- Fainting attack- Fatigue- Palpitations- chest pain- Syncope - Abdominal fullness- Leg swelling- Medications

- Vital signs- Airway abnormality- Associated extracardiac

congenital anomalies- Tachypnea, dyspnea,

cyanosis- Squatting - Clubbing of digits- Heart murmur (s)- CHF: - Jugular venous

distention. - Hepatomegally - Ascitis - Peripheral edema

INVESTIGATIONINVESTIGATIONSS

MRI

Laboratory Evaluation

Cardiac Catheterization

12 Lead ECG

Echocardiography

chest X – Ray

Regarding investigations of CHD patients for non-cardiac surgery: A- Chest X – Ray has no rule B- Cardiac Catheterization is the first choice for diagnosis of CHD C- Echocardiography non invasive method for diagnosis of CHD D- MRI cannot give us idea about pulmonary veins

IM Premedication for CHD patients presenting for non-cardiac suergery: A- Cooperative or unable to take orally B- Ketamine 1mg/kg C- Midazolam 5 mg/kg D -Glycopyrrolate or Atropine 0.02 mg/kg

Procedural antibiotic prophylaxis is required in patients with A- Aortic valve replacement B- Mitral valve prolapse with regurge C- Previous history of infective endocarditis D- Ostium secundum ASD

AHA guidelines for bacterial endocarditis Prophylaxis in

patients with cardiac conditions Endocarditis prophylaxis recommendedEndocarditis prophylaxis recommendedEndocarditis prophylaxis not recommendedEndocarditis prophylaxis not recommended

High-risk categoryHigh-risk category

-Complex cyanotic congenital heart disease:

Transposition of the great vessels

Tetralogy of Fallot

-Surgically created systemic-to-pulmonary shuntsor conduits

-Prosthetic, Bioprosthetic, Homograft valves

-Previous bacterial endocarditis

Moderate-risk categoryModerate-risk category

-Other congenital cardiac anomalies

-Acquired valvular dysfunction

-Hypertrophic cardiomyopathies

Regurg-- Mitral valve prolapse with valvar

Negligible-risk categoryNegligible-risk category

-Physiologic, or functional heart murmurs

-Surgical repair without residua beyond

6 months : ASD, PDA,VSD

-Cardiac pacemaker or

-implanted defibrillator

-Isolated secundum atrial septal defect

-Mitral valve prolapse without reg .

-Previous coronary artery bypass surgery

-Previous rheumatic heart disease without valvular dysfunction

AHA guidelines for antibiotic prophylaxis: dental, oral, Respiratory tract and esophageal procedures

Standard prophylaxis Amoxicillin 1 h before procedure-Children: 50 mg/kg p.o .

Adults: 2.0 g p.o-.

Unable to take oral medications

Ampicillin within 30 min before procedure

- Children: 50 mg/ kg i.m. or i.v.

Adults: 2.0 g i.m. or i.v.-

Allergic to penicillin Clindamycin 1 h before procedureChildren: 20 mg/kg p.o.

Adults: 600 mg p.o.

OR Azithromycin or clarithromycin 1 h before procedure

-Children: 15 mg/kg p.o.

Adults: 500 mg p.o. -

Unable to take oral medications

AND allergic to penicillin

Clindamycin within 30 min before procedur

-Children: 20 mg/ kg i.v-Adult: 600 mg i.v.. -

AHA guidelines for antibiotic prophylaxis: genitourinary and gastrointestinal procedures

High risk patients -within 30 min before procedure - Children: Ampicillin 50 mg/ kg .and

gentaicin 1.5 mg/kg i.m or i.v

-Adults: Ampicillin 2.0 g and gentamicin 1.5 mg/kg i.m or i.v

High risk patients Allergic to penicillin

-Complete infusion 30 min before procedure -Children: Vancomycin 20 mg/kg i.v over 1-

2 hr gentamicin 1.5 mg/kg i.m or i.v

-Adults: Vancomycin 1g/kg i.v over 1-2 hr gentamicin 1.5 mg/kg i.m or i.v

Moderate risk patients Ampicillin within 30 min before procedure-

- Children: 50 mg/ kg i.m. or .iv -Adults: 2.0 g i.m or i.v

Moderate risk patients AND allergic to penicillin

Complete infusion 30 min before procedure-

-Children: Vancomycin 20 mg/kg i.v over 1-2 hr

-Adults: Vancomycin 1g/kg i.v over 1-2 hr

Anesthetic Management

A - Preoperative Management B - Intraoperative Management:

1 -Monitoring 2 -Choice of anesthetic agent 3 -Maintenance of anesthesia 4 -Emergence from anesthesia

Anesthetic Management

Preoperative Assessment- Associated congenital anomalies (difficult

airway)- Chest: signs of H.F.& chest infection…

postpone- Liver: ●enlarged in Rt. Sided failure ●shrunken in Lt. sided failure, diuretics,

↓feeding- Cyanotic spells- Acute hypertensive pulmonary crisis

Anesthetic ManagementInvestigations

- Hematocrit:….thromboembolism- Electrolytes:…..arrhythmias..(should be

corrected)- Blood gases:…cyanotic may be acidotic- Echocardiography: satisfactory in simple

cases- Catheterization:- Coagulation profile: cyanotic patients

usually suffer from coagulopathies.

Premedication- Oral Premedication: - Midazolam 0.25 -1.0 mg/kg

- Ketamine 2 - 4 mg/kg - Atropine 0.02 mg/kg

- IV Premedication: - Midazolam 0.02 - 0.05 mg/kg titrated in small

increments - Ketamine 1-2 mg/kg

- IM Premedication: - Uncooperative or unable to take orally

- Ketamine 5 – 10 mg/kg - Midazolam 0.2 mg/kg

- Glycopyrrolate or Atropine 0.02 mg/kg

Fasting Guidelines

Anesthetic ManagementPremedication

- Fasting: clear sugar fluid allowed till 4 hours

- ↓ 6 months: No premedication

- 6-9 months: optional e.g. to avoid spell or crisis

- ↑9 months: -atraumatic (oral midazolam)

-IM: ketamine 2mg/kg add Atropine 0.02mg/kg

Anesthetic ManagementO.R. preparation

- Temperature control: mattress & O.R. temp.

- Anesthetic machine: with O2, Air, N2O

- Infusion set…… free of air bubbles- Drugs: Atropine, Bicarb., Epinephrine, Phenylephrine- Inotropic infusion should be premixed

before induction in high risk patient (e.g.Dobutamine)

Anesthetic Management

Monitoring & Lines- ECG- Pulse Oximetry: inaccurate in deep

hypothermia- Invasive B.P.: Lt. Radial, Rt. Radial,

Femoral art.- CV. Cannulation: Rt. & Lt. IJV, Femoral

vein- Temperature: central & peripheral- Urine output:- Capnography:- Blood gases & electrolytes.

MonitoringMonitoring

Non-invasive Invasive

-Clinical observation -ECG -NIBP

-Pulse oximetry -Precordial

stethoscope -Continuous airway

manometry -Multiple site

temperature measurement

-Volumetric urine collection

-Art. catheterization - CVP - PAC - TEE

Inraoperative management

The goals of Intraoperative management

- Prophylaxis against Subacute bacterial endocarditis.

- Prophylaxis against Air bubble embolism.

- Hemodynamic management.

PVR

SVR

Contractility

Air bubble precautions - Check and remove all air bubbles from IV tubing, injection ports, and stopcocks

- Connect the IV tubing to the venous cannula while there is a free flowing IV fluid and blood.

- Before IV injection into the cannula, small amount if fluid is injected into the hub of the cannula.

Air bubble precautions

Aspiration before injection to clear any air.

Hold the syringe upright to keep the bubbles away.

Do not inject the last milliliters from the syringe.

Do not leave the central line open to air.

N2O is better avoided.

Hemodynamic management

Left to right shunts: ( pulmonary blood flow)

- The aim is to prevent:

in SVR

in PVR

contractility

Avoid vasodilators

high FiO2

hypocapnea and alkalosis

Right to left shunts: ( pulmonary blood flow)

- - The aim is to prevent:

in SVR

in PVR

contractility

Avoid Sympathetic

stimulation low FiO2

hypercapnea acidosis.

Avoid N2O

Anesthetic Management

Induction- Aim: to preserve SVR & PVR- Method: ● Inhalational: Sevoflurane ● I.V.: ketamine 2 mg/kg + fentanyl

2-3μg/kg+ Pancuronium 0.1 mg/kg- Antibiotic Prophylaxis:- Intubation: Oral/ Nasal (postoperative)- Corticosteroids: decrease systemic

inflammatory response

The effect of shunt on the speed of induction of anesthesia:

- In patients with a right-to-left shunt:

Inhalation induction is prolonged.

Intravenous induction is more rapid..

- In patients with left-to-right shunting, , the speed of inhalation or intravenous induction is not changed.

Factors Affecting PVRFactors Affecting PVRFactors

Increasing:- PEEP- High airway

pressureAtelectasis,hypo

xia,hypercarbia

- Acidosis- Catecholamine-High

hematocrite

Factors Decreasing:- No PEEP- Low airway pressure- High FiO2, hypocarbia- Alkalosis- Vasodilators- Low hematocrite- Nitric oxide

Anesthetic Management

Maintenance- Patient with Poor Myocardium: - Narcotic based....Extubation not

advisable- Patient with Good Myocardium: - Inhalational (isoflurane, sevoflurane)- Most Stressful Situations: - Skin incision - Sternotomy - Major vessels cannulation (Aorta,

SVC,IVC)

Choice of anesthetic Regimen

●Development of anesthetic regimen is based on various factors such as presence and direction of shunts , HF, arrhythmia , pulmonary circulation, and lowering or

maintenance of PVR

Choice of Anesthetic Agent

Intravenous

anesthetics

Volatile anesthetic

s

Muscle relaxants

-•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) •Etomidate : Induction dose of 0.3mg/kg no change in mean pulmonary artery pressure and PVR, pulmonary blood flow, PHT or myocardial function

•Propofol : decrease in SBP and SVR, and increase in SBF in all patients, whereas HR ,PAP, PBF remained unchanged

•OPIOD: Excellent induction agents in very sick children No cardiodepressant effects if bradycardia avoided Fentanyl 15-25 µg/kg IV , Sufentanil 5-20 µg/kg IV

•Barbiturates : Not recommended in patients with severe cardiac reserve

Choice of Anesthetic Agent (Cont.)

- Desflurane Pungent , PAP and PVR, Less myocardial depression than Halothane HR , SVR

-Halothane PBF not affecting PVR, Depresses myocardial function, alters sinus node function, sensitizes myocardium to catecholamines

- Isoflurane Pungent, PAP not affecting PVR, Less myocardial depression than Vasodilatation leads to SVR → MAP , HR which can lead to CI

- Sevoflurane Less myocardial depression than Halothane, more in PAP compared with isoflurane, No HR, Mild SVR, Can produce diastolic dysfunction

- Nitrous oxide At 50% concentration does not affect PVR and PAP in childrenAvoid in children with limited pulmonary blood flow, PHT or myocardial function

Neuromuscular Blocking Drugs

Depolarizing

Nondepolarizing

-Succinylcholine in pediatric is controversial

-If used should be with atropine, to avoid associated brady-

cardia or sinus arrest

-also if used with potent narcotic atropine should be used to avoid severe bradycardia in

children with CR

-Atracuruim and vecronium: have few cardiovascular side effects in children when given in recommended doses.

-Pancuronuim if given slowly doesn't produce HR or BP changes. if given as bolus doses it can produce tachycardia , ↑BP (through sympathomimetic effect )

-Cisatracuruim and Rocuroinuim: safe

Anestheia of Fallot patient:

- The aim is to prevent intraoperative cyanotic spells.

- Avoid prolonged fasting- Heavy sedative premedication.- Intravenous induction.- Ketamine, Fentanyl, Pancronium, Halothane.- Adequate intravascular volume.- Avoid systemic vasodilatation.- Adequate anesthetic depth to avoid

sympathetic stimulation.

Management of intra operative cyanotic spells in

Fallot patient- Direct abdominal or aortic

compression

- IV vasoconstricror as ephedrine, phenylephrine, or dopamine

- IV fluid.

- Deep level of anesthesia.

- Beta adrenergic blockers as osmolol or propranolol

REGIONAL ANESTHESIA &ANALGESIA

• Considerations :

- Coarctation of aorta considerations

-Childern with chronic cyanosis risk of coagulation abnormality

-VD : which can : 1 -be hazardous in patients with significant

AS or left-sided obstructive lesions 2 -Cause oxyhemoglobin saturation in

R-L shunts

Postoperative Anesthetic Management- Supplemental O2 and maintain patent airway.

- In patients with single ventricle titrate SaO2 to 85%. Higher oxygen sat. can PVR PBF SBF

Pain catech. which can affect VR and shunt direction

Pain infundibular spasm in TOF RVOT obstruction cyanosis, hypoxia, syncope, seizures, acidosis and death

Anticipate conduction disturbances in septal defects

RememberRemember

Management of - Acute hypertensive pulmonary

crisis: - Ventilatory manipulation: reduce PVR

(PaO2, PaCO2, PH, Lung volumes)

- Drugs: Milrinone, Isopril, PgE2

RememberRemember

Management of- Intraoperative Cyanotic Spells

- Increase S.V.R.: by direct aortic compression ± vasopressor (phenylephrine, ephedrine…..)

- Reduce infundibular obstruction by ß-Blockers (esmolol, propranolol…), OR Halothane

- Deepen the level of anesthesia. -Adequate hydration (ample fluid and decrease viscosity)

- Familiarity with the CHD pathophysiology, adequate preoperative preparation, choice of monitors, induction, maintenance , emergence from anesthesia, and plans for the postoperative period to avoid major problems in anesthetic management

- A wide variety of anesthetic regimens is used for patients with congenital heart disease (CHD) undergoing cardiac or non-cardiac surgery, or other diagnostic or therapeutic procedures. The goal of all of these regimens is to produce anesthesia or adequate sedation, while preserving systemic cardiac output and oxygen delivery

SUMMARY