Anesthetic Implications of Congenital Heart Disease

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Anesthetic Implications of Congenital Heart
Disease

• Laura K. Diaz, M.D.
• Department of Anesthesiology and Critical Care
  Medicine
• The Childrens Hospital of Philadelphia
• The Perelman School of Medicine at the University
  of Pennsylvania
• The Childrens Hospital of Philadelphia
• Department of Anesthesiology and Critical Care
  Medicine
• Perelman School of Medicine at the University of
  Pennsylvania

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Congenital heart disease

• A rapidly growing patient population
• gt95 of patient surviving to adulthood
• Increasing survival of sickest patients
• Preponderance of PS 3 and 4 patients
• Diversity of diagnostic categories
• Extremes of age frequently represented
• Increasing number of ACHD patients

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An at risk population

• Review of cardiac arrests in 92,881 pediatric
  anesthetics
• Incidence highest in cardiac cases
• Incidence and mortality highest in neonates
• 88 of patients experiencing cardiac arrest had
  congenital heart disease
• Independent of procedure type

Flick R, Anesthesiology 2007 106226-37
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Spectrum of CHD

• A heterogeneous patient group
• Diverse pathophysiology
• Spectrum of disease within diagnostic categories
• NOT ALL require special anesthetic consideration
• Post PDA ligation
• Uncomplicated ASD or VSD closures
• Straightforward TOF repair

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• SOwho should we worry about most, and what do we
  do differently?

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Planning an anesthetic for a CHD patient

• Overriding considerations
• Preoperative information
• Effect of disease on perioperative care
• Potential complications
• Post-anesthetic management

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OVERRIDING CONSIDERATIONS

• Is cardiac disease a primary consideration?
• 2 kg infant with HLHS for TEF repair
• Is it one of several considerations?
• 3 yo with repaired CAVC and OSA for T A
• Is it a minor consideration?
• 10 yo with repaired VSD for appendectomy

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Defining high risk patients

• Unrepaired or palliated physiology
• Single ventricle physiology
• Shunt dependent pulmonary blood flow
• Severe cyanotic heart disease
• Significant ventricular dysfunction
• Cardiomyopathy or myocarditis
• Congestive heart failure
• Patients awaiting transplantation
• Significant dysrhythmias
• Pacemaker dependent patients

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High risk CHD patients

• Pulmonary hypertension
• CICU patients
• Patients less than 14 days postop
• Mechanical circulatory support
• Patients at extremes of age
• Patients lt1 year of age
• Adults with congenital heart disease

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PREOPERATIVE VISIT

• REVIEW history, previous records, and perform
  physical examination
• IDENTIFY any new medical issues
• COORDINATE subspecialty consults and additional
  studies or labs
• ASSEMBLE information into an accessible,
  comprehensive report

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Medical history

• Allergies
• Birth history/associated syndromes
• Past noncardiac surgical history
• Evidence of other systemic issues
• Recent illnesses
• Recent or current URI
• Increases in PVR, airway reactivity

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Cardiac history

• Nature of cardiac disease
• History of interventions and studies
• Recent exacerbations or change from baseline
• Presence of a pacemaker or ICD
• Current clinical status
• Previous anesthetics
• Anesthetic related complications
• Airway management
• Vascular access difficulties

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Medications

• Antithrombotic therapies
• Systemic-PA shunts
• Prosthetic valves
• History of thrombotic events
• Kawasaki disease
• High risk for thromboembolic events
• ACE inhibitors
• Diuretics
• Immunosuppressants
• Meds for RAD, GER, seizures

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Physical examination

• Airway
• General
• Appearance Color, activity level, nutritional
  status
• Vital signs HR, BP, respiratory rate and SpO2
• Vascular access
• Respiratory
• Tachypnea, rales, wheezing, quality of breath
  sounds
• Cardiac
• Rhythm, murmurs, character of pulses
• Neurologic/developmental

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Laboratory studies

• CBC with platelet count
• Electrolytes
• Coagulation studies
• Liver enzymes
• Type and cross for blood products
• Other CXR, Echo, cardiac MR

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Preoperative instructions

• NPO instructions
• Avoid dehydration, especially in cyanotic
  patients
• Administration of medications
• Diuretics, afterload reduction agents, digoxin,
  anti-arrhythmic medications
• Anti-platelet and/or anticoagulation drugs
• Immunosuppressant drugs
• Noncardiac medications

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Is Day Surgery appropriate?

• Preoperative considerations
• Is the cardiac disease stable?
• Is overnight observation available?
• Postoperative considerations
• Resuming medications
• Tolerating oral fluids
• Parental/patient comfort with discharge
• Distance from the hospital

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Allocating cardiac anesthesia

• Different hospital, different strategies
• Post operative lt 14 days
• Single ventricle physiology
• Shunt-dependent pulmonary blood flow
• Cyanotic heart disease
• Congestive heart failure

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Allocating cardiac anesthesia (2)

• Pulmonary hypertension
• Transplant patients
• Cardiomyopathy or myocarditis
• Adults with congenital heart disease
• Any patient in whom cardiac consultation is
  desired by practitioners or family

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PERIOPERATIVE CARE

• Premedication
• Patients wishes
• Oral vs. intravenous
• Psychological concerns
• Induction
• Generally mask induction preferred
• Only occasionally is IV induction essential

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What is an anesthetic?

• Amnesia benzodiazepines, volatile anesthetic
  agents
• Analgesia narcotics, volatile anesthetic agents
• Muscle relaxation (if required) neuromuscular
  blocking agents

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ANESTHETIC PLANWhat anesthetics to use?

• What is currently available?
• What does the surgery require?
• How long will surgery last?
• What are our goals at the end?

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ANESTHETIC PLANIntraoperative considerations

• Need for invasive monitoring
• Arterial/central access
• PA catheters RARELY used in children
• Potential issues
• Pulmonary hypertensive crisis blood loss
  exacerbation of ventricular dysfunction
• Special equipment
• Nitric oxide, TEE

Circulation 20071161736-1754
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Intraoperative Management

• What degree of baseline physiologic derangement
  does the patient have?
• What is the expected impact of the planned
  procedure?
• Do these issues affect our anesthetic plan?

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Is anesthesia dangerous for children?

• We dont know for sure but we are concerned
• Multiple animal models have demonstrated
  neuroapoptosis
• FDA sponsored SmartTots initiative
• Ongoing clinical epidemiological studies

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SBE prophylaxis and CHD

• Unrepaired/palliated cyanotic CHD
• Repaired CHD
• Prosthetic material or device
• Six months after procedure
• Residual defects adjacent to prosthetic patch

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ANESTHETIC PLANPostoperative care

• Planning for postoperative analgesia
• Regional anesthesia
• Pain team
• Postoperative sedative strategies
• Recovery
• Is an ICU bed necessary?
• Is it available?

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SPECIFIC CARDIAC CONSIDERATIONS
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1. SINGLE VENTRICLE PHYSIOLOGY

• Hypoplastic left heart syndrome
• Tricuspid atresia
• Pulmonary atresia
• Other complex CHD
• Unbalanced AV canal
• Severe Ebsteins anomaly

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SINGLE VENTRICLE PHYSIOLOGY Parallel
circulations

• VIA A SHUNT, blood may go to the systemic OR the
  pulmonary circulation
• Flow is distributed according to RELATIVE
  RESISTANCES of the two circulations
• Changes in flow can occur rapidly, affecting
  hemodynamic stability and oxygen saturations

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Hypoplastic Left Heart Syndrome

• Mitral and aortic valves are stenotic or atretic
• Tiny ascending aorta
• Ductal-dependent circulation aortic flow is
  provided by the PDA

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Unrepaired or palliated physiology

• What is the patients baseline status?
• Baseline vital signs and SpO2
• Ventilation strategies
• Use of appropriate FiO2
• Tidal volume and PEEP
• Volume and blood loss
• If shunt dependent, risk of thrombosis
• Ventricular function, AVV competence

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2. SEVERE CYANOSIS

• Coagulation abnormalities
• Thrombocytopenia
• Individual factor deficiencies
• Hemoglobin/hematocrit
• Moderately to significantly elevated
• Avoid dehydration!
• Risk of shunt thrombosis
• Respiratory abnormalities
• Decreased response to hypoxia
• Chronic alveolar hyperventilation

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3. VENTRICULAR DYSFUNCTION

• Acute vs. chronic dysfunction
• Activity level, appetite, respiratory status
• Can the patient be further optimized?
• Results of last Cardiology clinic visit
• Most recent Echo, MR or cath data
• Inotropic and fluid management
• Consider invasive monitoring
• Consider postop ICU

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VENTRICULAR DYSFUNCTION (2)

• Induction of anesthesia
• Take circulation time into account
• Useful induction agents
• Ketamine tachycardia often seen
• Can act as a negative inotrope
• Etomidate myoclonic movements
• Despite side effects, best drug for severely
  compromised patients

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4. ELECTROPHYSIOLOGIC ISSUES

• Often seen in postoperative patients
• TGA S/P Mustard or Senning
• TOF with previous ventriculotomy
• Fontan
• Ebsteins anomaly
• Management of anti-arrhythmic medications

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Pacemakers and ICD Management

• YOU MUST KNOW
• Indication for and timing of device placement
• Underlying rhythm
• Date of last interrogation
• ACC/AHA guidelines recommend pre and
  postoperative interrogation
• Magnet may have unpredictable effects
• Rate-responsive and defibrillator functions
  should be disabled during surgery

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Pacemaker and ICD Intraoperative

• Mechanical vs. electrical function
• Physical exam palpation, auscultation
• Pulse oximetry/plethysmography
• Intra-arterial monitoring
• Contingency plans
• Temporary pacing support wire, lead, pads
• Isoproterenol
• Defibrillator
• Electrophysiology team

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5. PULMONARY HYPERTENSION

• Etiology and progression
• Importance of the planned procedure
• Anesthetic goals
• Avoid acute increases in PVR
• Avoid hypotension
• Maintain preload
• Inotropic support of the right ventricle
• Nitric oxide availability

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Assessing PAH

• Recent cath data
• Pulmonary vascular resistance
• Response to oxygen or nitric oxide
• Echo data
• RVH, ventricular contractility
• Position of ventricular septum
• Direction of intracardiac shunting

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PAH therapies

• Pulmonary vasodilators
• Calcium channel blockers
• Phosphodiesterase 5 inhibitors (sildenafil)
• Endothelin receptor antagonists (bosentan)
• Prostacyclin (Flolan)
• Heart failure therapy
• Oxygen
• Anticoagulation

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PAH and anesthetic risk

• PAH is a SIGNIFICANT predictor of major
  perioperative complications
• Pulmonary hypertensive crisis
• Cardiac arrest
• Death
• Patients with suprasystemic PAP are 8x more
  likely to have adverse events

Taylor CJ, Br J Anaesth 2007 98 657-61
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The CHOP approach to PAH

• No premedication
• IV induction
• ALL patients recover in an ICU setting
• If they have proven PAH OR
• If they are on PAH therapy
• Treatment of a PAH crisis
• FiO2 1.0, hyperventilation, treatment of
  acidosis, right ventricular support, NO

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6. MECHANICAL CIRCULATORY SUPPORT

• ECMO
• Rescue
• Bridge to VAD
• Ventricular assist devices
• Centrifugal VAD
• Thoratec
• Berlin Heart

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7. EXTREMES OF AGE

• Special Delivery Unit (SDU)
• Fetal interventions and delivery
• EXIT procedures
• Adult Congenital Heart Disease (ACHD)
• What is the best environment for these patients?

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Anesthetic guidelines

• Conservative airway management
• Maintain euvolemia
• Maintain normal sinus rhythm
• Avoid increasing O2 demand, HR and/or
  contractility
• Optimize ventricular function and O2 delivery
• Monitoring what is necessary and why?

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POTENTIAL COMPLICATIONS

• Excessive blood loss
• Know optimal hematocrit for patient
• Arrhythmias
• Respiratory compromise
• Ventricular dysfunction
• Shunt thrombosis

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POST ANESTHETIC MANAGEMENT

• Will the patient be better or worse
  postoperatively?
• Appropriate timing of extubation
• Venue for postoperative recovery
• Pain management
• Resumption of cardiac medications

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CONCLUSIONS

• Understand the pathophysiology
• These are less forgiving patients
• Know expected range of normal for your patient
  for your patient
• Decide on parameters for intervention
• Anticipate think one step beyond.
• Meticulous attention to detail

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KEYS TO SUCCESS

• Avoid hypoxemia, hypercarbia, acidosis,
  hypothermia
• Have a backup plan and personnel available
• Know who your resources are anesthesia,
  cardiology, cardiac surgery
• Never scruple to ask for help!

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THANK YOU!