Anaesthesia for adult congenital heart disease

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Why this is examined / the one-line answer

Adults with congenital heart disease (ACHD / GUCH) increasingly appear on general, obstetric, and emergency lists. Maxwell et al. showed higher perioperative morbidity and mortality after major noncardiac surgery versus matched controls — examiners want physiology-driven plans, not sympathy.[1]

One-liner: I map native anatomy and surgical pathway, identify residual shunts, Fontan, or PHT physiology, defend PVR and SVR goals, de-air everything if right-to-left risk exists, and involve ACHD cardiology for moderate–complex disease. [1]

Preoperative assessment

History that changes the plan

• Original diagnosis and operations (arterial switch, tetralogy repair, Fontan stages, Mustard/Senning, Glenn).
• Residual lesions, exercise tolerance, cyanosis at rest or on effort.
• Arrhythmias, pacemakers/ICDs, anticoagulation.
• Pulmonary hypertension, heart failure, previous endocarditis.
• Fontan extras: liver disease, protein-losing enteropathy, plastic bronchitis, thromboembolism.
• Learning disability / transition care — consent complexity. [1]

Investigations

Recent echo/MRI/cath reports (not a decade-old letter alone), ECG, baseline saturations, Hb (secondary erythrocytosis in cyanosis), coagulation, LFTs, renal function. Functional class matters more than calendar age.[3]

Risk framing

ACHD increases adverse perioperative outcomes after major noncardiac surgery; complexity and comorbidities drive risk. Do not trivialise “simple repaired ASD” without confirming no residual lesion — and do not anaesthetise complex Fontan/Eisenmenger electively in a district list without specialist support.[1]

Applied physiology clusters

Shunt lesions

Paradoxical embolus: any right-to-left communication (including residual PFO physiology in some contexts) — air filters on IV lines, meticulous de-airing, careful drug reconstitution. [1]

Fontan circulation (single ventricle, passive pulmonary flow)

Systemic venous return enters the pulmonary arteries without a subpulmonary ventricle. Pulmonary blood flow depends on: [1]

1. Adequate preload
2. Low PVR
3. Low mean intrathoracic pressure
4. Sinus rhythm (atrial contribution and AV synchrony)
5. Competent systemic ventricle [1]

Fontan killers: hypovolaemia, high PEEP/high mean airway pressure, hypoxia/hypercarbia (↑PVR), loss of sinus rhythm, high abdominal pressure (laparoscopy), haemorrhage, positive-pressure ventilation without optimisation.[2]

Obstructive / valvular residua

Residual AS/PS/coarctation gradients — lesion-specific loading goals (e.g. maintain SVR in residual AS). [1]

Cyanotic haematology

Secondary erythrocytosis raises viscosity; baseline “high Hb” may be appropriate. Coagulopathy and bleeding can coexist with thrombosis risk — do not venesect casually on the day of surgery. [1]

Anaesthetic goals

1. Understand the circuit — draw it if needed.
2. Maintain oxygen delivery (CO × CaO2); cyanotic patients may need higher Hb.
3. Control PVR drivers (O2, CO2, pH, lung volumes, pain, temperature).
4. Avoid bubbles with shunt risk.
5. Specialist help for complex elective major cases. [1]

Technique matrix

Monitoring and equipment

Standard + arterial line for major/complex cases. Central access carefully — know Glenn/Fontan pathways before wires travel unexpected routes. TOE if major surgery or instability. Air filters on IV lines if R-to-L risk. Defibrillator pads. Vasopressors ready; pulmonary vasodilator thinking (oxygen, iNO in specialist centres). Endocarditis prophylaxis only when current guidelines indicate (not automatic for all ACHD forever). [1]

Intraoperative management

Induction: titrate; support SVR if R-to-L physiology (vasopressor ready). [1]

Ventilation: avoid hypoxia/hypercarbia; moderate tidal volumes; titrate PEEP carefully in Fontan — high mean airway pressure cuts pulmonary blood flow.[2]

Fluids: Fontan often preload-dependent, but liver/renal limits exist; use dynamic assessment. [1]

Regional: excellent for analgesia when appropriate; avoid sudden profound SVR loss in Eisenmenger without a plan (cautious titrated epidural or alternative techniques). [1]

Laparoscopy: pneumoperitoneum raises SVR and impairs venous return — lower pressures, careful ventilation, readiness to desufflate. [1]

Arrhythmia readiness: atrial arrhythmias are common and poorly tolerated in Fontan — early cardioversion if unstable. [1]

Crisis pivots

Desaturation in shunt patient

Increase FiO2; treat ↑PVR causes (hypoxia, hypercarbia, acidosis, high airway pressure, pain); raise SVR if R-to-L increasing; exclude tube problems. [1]

Fontan low output

Fluids if empty; reduce mean airway pressure; correct CO2/O2; restore sinus rhythm; inotrope for systemic ventricle; expert help early.[2]

Unstable arrhythmia

DC cardioversion sooner rather than later in Fontan; correct electrolytes; antiarrhythmics with ACHD advice when stable enough. [1]

Bleeding + cyanotic physiology

Balanced resuscitation; remember their baseline Hb is often high — oxygen delivery mathematics differs from the anaemic elderly. [1]

Paradoxical embolus suspicion

Support ABCs; prevent further air; imaging/neurology pathways; prevention is the exam mark. [1]

Postoperative plan

Monitored bed for complex ACHD. Early ACHD cardiology review after major surgery. Thromboprophylaxis balancing polycythaemia and bleeding. Restart anticoagulation carefully. Watch liver/renal function in Fontan. [1]

Special populations

• Pregnancy in ACHD: high-stakes multidisciplinary — separate detailed topic; WHO maternal cardiovascular risk classification thinking.
• Learning disability / transition care: supported decision-making.
• Heart failure / transplant assessment patients: limited reserve.
• Home pulmonary vasodilators: do not stop without a plan.
• Pacemaker/ICD: standard peri-op device management. [1]

SAQ answer scaffold

A 28-year-old Fontan patient needs laparoscopic appendicectomy. Outline anaesthetic management. [1]

1. Anatomy map (3): single ventricle, passive PBF, residual issues, baseline sats/Hb.[2]
2. Risk (2): ACHD major NCS risk elevation; specialist input.[1]
3. Goals (3): preload, low PVR, sinus, careful ventilation/PEEP.
4. Technique (3): titrated GA or appropriate regional; low insufflation; air filters if any shunt risk.
5. Postop (2): monitored bed, early mobilisation vs VTE risk, cardiology review.

Viva stem bank and model phrases

Stem 1: “Why is ACHD higher risk for noncardiac surgery?”
Model: “Observational data show increased morbidity and mortality after major noncardiac surgery compared with matched controls — complexity and residual physiology drive risk.”[1]

Stem 2: “Fontan and PEEP?”
Model: “High mean airway pressure can reduce pulmonary blood flow because there is no subpulmonary pump — I use the least PEEP that maintains oxygenation and aim for early extubation when feasible.” [1]

Stem 3: “Air bubbles?”
Model: “With right-to-left shunt risk I use filters and meticulous de-airing to reduce paradoxical embolus.” [1]

Stem 4: “Eisenmenger for hip replacement — spinal?”
Model: “Sudden SVR fall can increase right-to-left shunt. If neuraxial is chosen it must be carefully titrated with vasopressor readiness; many prefer carefully managed GA with SVR support — individualise with ACHD team.” [1]

Stem 5: “Draw the Fontan.”
Model: “Systemic veins to PA confluence/connection, lungs, pulmonary veins to systemic ventricle, aorta to body — passive pulmonary flow.” [1]

Stem 6: “Endocarditis prophylaxis?”
Model: “Only when current guideline indications are met for the procedure and lesion — not automatic for every ACHD patient forever.” [1]

Stem 7: “Where should complex elective major surgery occur?”
Model: “In a centre with ACHD cardiology and appropriate intensive care — not as a surprise on a cold orthopaedic list.”[3]

Common traps

• Generic “keep them warm and give fluids” without circuit understanding
• Forgetting air filters
• High PEEP Fontan without thought
• Spinal in Eisenmenger without SVR plan
• No specialist referral for complex elective major surgery
• Treating cyanotic high Hb as automatic transfusion trigger
• Ignoring atrial arrhythmia risk in Fontan [1]

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Examiner mental map

1. Map anatomy and repair pathway.
2. Cluster physiology (shunt / Fontan / PHT / residua).
3. PVR/SVR and preload plan.
4. Air and arrhythmia risks.
5. Fontan specifics (FLOW).
6. Centre escalation for complex disease. [1]

Whiteboard physiology beats memorised lesion lists. [1]

References

1. [1]Maxwell BG, Wong JK, Kin C, Lobato RL Perioperative outcomes of major noncardiac surgery in adults with congenital heart disease Anesthesiology, 2013.PMID 23907357
2. [2]McNamara JR, McMahon A, Griffin M Perioperative Management of the Fontan Patient for Cardiac and Noncardiac Surgery J Cardiothorac Vasc Anesth, 2022.PMID 34023201
3. [3]Baehner T, Ellerkmann RK Anesthesia in adults with congenital heart disease Curr Opin Anaesthesiol, 2017.PMID 28306681