Anesthesiology APPLIED Exam › Cardiovascular and cardiac anesthesia

Adult congenital heart disease

Cardiovascular and cardiac anesthesia·~5 min read· Physician-reviewed✓ Sourced · 4

Stem

A 27-year-old woman, 58 kg, with tricuspid atresia palliated by a fenestrated extracardiac Fontan at age 4, presents for laparoscopic cholecystectomy for recurrent biliary colic. She walks two flights of stairs before stopping. Room-air SpO2 is 91%, heart rate 74 in sinus rhythm, BP 104/62. Echo shows mildly reduced single-ventricle function. She takes aspirin and has a history of an atrial flutter ablation.

Question

How does her Fontan circulation shape your anesthetic plan for this laparoscopic cholecystectomy?

Ideal answer

HeadlinePulmonary blood flow is passive, driven by systemic venous pressure, so I protect preload and keep PVR and intrathoracic pressure low.¹

Plan with her congenital cardiologist, at an adult congenital center, before the day: Fontan physiology tolerates few errors.
Short fast, early fluid, arterial line, de-aired lines, good IV access: she is preload dependent, and her fenestration lets venous air reach systemic circulation.²
Slow induction, tone-preserving agent, since venodilation drops her driving pressure; vasopressin and milrinone ready.
Normocarbia, low rate, low PEEP, short inspiratory time; hypoxia, hypercarbia and acidosis treated at once, each raising pulmonary resistance;¹ her low 90s baseline not chased to 100%.
Insufflation below 10 mmHg, flat as long as possible, because pneumoperitoneum impedes passive pulmonary flow; low threshold to convert to open.¹

Watch for: After surgery, when up to half of complications occur: multimodal analgesia against hypoventilation, early drinking.¹

Breaking down the answer

No subpulmonary pump — the gradient from systemic veins to the atrium drives everything; a small rise in PVR sharply cuts preload and output.¹ Reasoning from physiology, not a checklist, is what the examiner grades.
Stage the patient, not just the lesion — the 2018 AHA/ACC guideline classifies adults by anatomic complexity and physiologic stage A–D, weighing functional status, arrhythmias, cyanosis, pulmonary hypertension and end-organ function.³ A Fontan is great complexity; her limitation and cyanosis raise her stage.
Ventilation is a hemodynamic drug — positive pressure reduces venous return; spontaneous breathing helps it, so I keep mean airway pressure low and extubate early.¹ Changes if: a long, steep reverse Trendelenburg case instead of a short, low-pressure laparoscopy.
Respect the end organs — Fontan-associated liver disease is universal, and protein-losing enteropathy and thrombosis are common, so I check albumin, platelets and coagulation before I plan any neuraxial technique.¹
Expect arrhythmias — atrial tachyarrhythmias and sinus node dysfunction are common and poorly tolerated, because she loses atrial kick and rate response; I have pads on and cardioversion ready.¹
Antibiotic prophylaxis is a dental question — unrepaired cyanotic disease and repaired defects with residual shunts adjacent to prosthetic material qualify for prophylaxis before dental procedures; a cholecystectomy gets standard surgical prophylaxis only.⁴

Follow-up question

Ten minutes after insufflation to 12 mmHg in reverse Trendelenburg, her BP falls to 78/45, SpO2 drops from 90% to 82%, and end-tidal CO2 falls from 36 to 28 mmHg.

What do you do?

Follow-up answer

HeadlineFalling pulmonary blood flow: insufflation and head-up tilt cut venous return and raised PVR. The surgeon releases the pneumoperitoneum and levels the table.

The fall in end-tidal CO2 with desaturation tells me less blood is crossing her lungs. I call for help, give a fluid bolus, support pressure with vasopressin rather than a pure alpha agonist, increase FiO2 to 1.0, and lower the PEEP and inspiratory time. If she does not respond, I add inhaled nitric oxide and milrinone and look with TEE for ventricular failure or a thrombus.¹ I also consider paradoxical air embolism through the fenestration.² Once she recovers, the surgeon re-insufflates below 10 mmHg or converts to open.

Pitfalls that cost points

Treating her 90% saturation as hypoxemia and escalating PEEP, which lowers pulmonary flow.
Forgetting the liver, coagulation and thrombosis issues of a long-standing Fontan.

Rapid-fire

Q: Why does hypercarbia hurt a Fontan patient? A: It raises pulmonary vascular resistance, which directly reduces the passive flow through the lungs and the preload to the single ventricle.¹

Q: Which vasopressor do you prefer? A: Vasopressin, because it raises systemic resistance without constricting the pulmonary bed; milrinone is the usual inotrope.¹

Q: How common are arrhythmias in long-term Fontan survivors? A: About 58% at 20 years and 76% at 30 years.¹

Q: How does the 2018 guideline classify adults with congenital heart disease? A: The ACHD AP system: anatomic class I–III and physiologic stage A–D.³

Q: What adult dose is used for dental endocarditis prophylaxis? A: Amoxicillin 2 g orally, 30 to 60 minutes before the procedure.⁴

Numbers to know

Item	Value
Insufflation pressure	Below 10 mmHg¹
Typical Fontan SpO2	Often below 92%, rarely above 95%¹
Thrombosis risk	Up to 20%¹
Perioperative complication rate	Up to 31%¹
Postoperative share of complications	Up to 50%¹
Amoxicillin prophylaxis (dental)	2 g PO, 30–60 min before⁴

Sources

1.Fontan Circulation · OpenAnesthesia, 2025 · openanesthesia.org
2.Anesthetic Management of Resection of Metastatic Occipital Malignancy in a Patient With Fontan Physiology · Cureus (Mehkri, Panjeton), 2021 · pmc.ncbi.nlm.nih.govCase report with review; source for de-airing lines and the paradoxical-embolism risk of a fenestrated Fontan.
3.2018 AHA/ACC Guideline for the Management of Adults With Congenital Heart Disease: Ten Points to Remember · ACC, 2018 · acc.org
4.Prevention of Viridans Group Streptococcal Infective Endocarditis: A Scientific Statement From the American Heart Association · AHA, 2021 · smilegeneration.comFull text of Wilson et al., Circulation 2021 (Table 3); scope is dental procedures.

Facts on this page were checked against these sources on Oct 16, 2026. Guidelines change; confirm doses against current institutional protocols.