ACHD Critical Care Nurse Practitioner Texas Woman's University Houston, Texas, United States
Disclosure(s):
Molly Conklin Fulkerson, MSN, AGACNP-BC: No financial relationships to disclose
Background: Fontan circulation represents the most common final pathway for patients with singe-ventricle physiology. Fontan patients have the highest mortality among adults with congenital heart disease (ACHD). Progressive Fontan failure is characterized by limited preload reserve, chronically elevated systemic venous pressures, ventricular diastolic dysfunction, and increased susceptibility to malignant arrhythmias.
Methods: Many aspects of Fontan physiology are atypical for age matched adults with structurally normal hearts. We present a case of cardiogenic shock in a Fontan patient precipitated by ventricular fibrillation-induced cardiac arrest and exasperated by mechanical ventilation. This case highlights the unique hemodynamic challenges and multidisciplinary approach required for optimal care. A 42-year-old male with complex congenital cardiac physiology resulting in Fontan palliation with a systemic right ventricle and baseline spO2 < 90% had been lost to ACHD follow-up when he experienced a witnessed out-of-hospital ventricular fibrillation-induced cardiac arrest. Immediate bystander response included cardiopulmonary resuscitation and defibrillation with return of spontaneous circulation at the scene. The patient was transported to an emergency room where he was noted to be hypoxic with poor response to oxygen. He was, therefore, intubated, sedated, and paralyzed with PEEP steadily escalated during which the patient developed progressive cardiogenic shock with rising vasoactive requirements and evidence of end-organ hypoperfusion including lactic acidosis, anuria, and transaminitis.
At time of transfer request to our facility, we advised weaning PEEP and FiO2 and cessation of neuromuscular blockade. Upon arrival, ventilator pressures had been significantly reduced. Norepinephrine and phenylephrine infusions discontinued, and epinephrine and vasopressin infusions weaned.
Outcome: The patient’s shock and acidosis resolved but he had ongoing renal failure necessitating continuous renal replacement therapy with volume removal and hepatic failure resulting in severe coagulopathy and encephalopathy. Despite aspiration pneumonia, he progressed to extubation and discontinuation of all vasopressors and has since had full neurological recovery.
This case highlights the complex interplay between failing Fontan physiology, cardiogenic shock, malignant ventricular arrhythmias, respiratory failure, heart-lung interactions, and chronic organ congestion. The patient’s baseline chronic hypoxia was not initially recognized and resulted in high ventilator settings which likely compromised preload and worsened shock. Effective management focused on hemodynamic and respiratory optimization tailored to Fontan physiology. Vasopressin use limited pulmonary resistance and fluid removal minimized venous congestion. Low ventilator pressures and early extubation significantly improved hemodynamics. Care was coordinated through a multidisciplinary team including ACHD cardiology, critical care, electrophysiology, and heart failure services, with ongoing evaluation for advanced therapies. Traditional paradigms of respiratory failure and cardiogenic shock often fail in Fontan critical illness. Involvement of ACHD specialists and care in centers with expertise in ACHD management should be strongly considered.
Cardiac arrest from Fontan physiology complicated by post-resuscitation hypoxia and multi-organ failure represents a high-risk clinical scenario with unique management challenges.
Conclusion: . This case underscores the importance of anatomy-informed, individualized hemodynamic and extracardiac critical care support strategies and close collaboration among multidisciplinary teams with expertise in ACHD care. As the Fontan population continues to age, development of Fontan-specific shock frameworks will be increasingly necessary to optimize outcomes.
