Anesthesia In Children With Congenital Heart Disease For Non-cardiac Surgery Dr. Fady Adib Lecturer...
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Transcript of Anesthesia In Children With Congenital Heart Disease For Non-cardiac Surgery Dr. Fady Adib Lecturer...
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