What is the appropriate CPR protocol for a patient post Fontan (Fontan procedure) procedure?

CPR Protocol for Post-Fontan Patients

For patients with Fontan physiology experiencing cardiac arrest, initiate standard pediatric CPR immediately while preparing for early extracorporeal CPR (ECPR), as conventional CPR alone is often insufficient in this population and ECPR has demonstrated successful resuscitation outcomes. 1

Immediate CPR Modifications for Fontan Physiology

Ventilation Strategy During Arrest

• Avoid hyperventilation and excessive positive pressure ventilation, as this critically impairs the passive pulmonary blood flow that Fontan circulation depends upon 1
• Target permissive hypercarbia during resuscitation, as increased CO2 tension improves pulmonary blood flow and systemic oxygen delivery in Fontan physiology 1
• Deliver breaths at the lower end of recommended rates to minimize intrathoracic pressure that impedes venous return to the lungs 1

Chest Compression Technique

• Perform standard closed-chest compressions at 100-120 compressions per minute with adequate depth 1
• Consider adding manual external abdominal compressions simultaneously with chest compressions, as case reports suggest this may augment venous return in modified Fontan patients 1
• Ensure complete chest recoil between compressions to maximize the negative intrathoracic pressure that drives pulmonary blood flow in the absence of a subpulmonary ventricle 1

Critical Pathophysiologic Considerations

The Fontan circulation lacks a subpulmonary ventricle, making passive flow from systemic veins to lungs entirely dependent on:

• Low pulmonary vascular resistance 1, 2, 3
• Adequate negative intrathoracic pressure during the decompression phase 1
• Sufficient systemic venous pressure to drive blood forward 2, 3

Standard CPR techniques that rely on generating cardiac output through ventricular compression are fundamentally less effective in Fontan patients, as the circulation depends on passive flow dynamics rather than ventricular pumping 1, 2.

Early ECPR Consideration

• Strongly consider ECPR early in the resuscitation for Fontan patients who do not achieve rapid return of spontaneous circulation (ROSC) 1
• ECPR was successful in resuscitating Fontan patients in case series, whereas conventional CPR alone frequently fails 1
• The unique hemodynamics of Fontan circulation make mechanical circulatory support particularly beneficial, as it bypasses the compromised passive flow system 1, 3

Pre-Arrest State Management

If the patient is in a pre-arrest state (hemodynamically unstable but not yet pulseless):

• Induce controlled hypercarbia through hypoventilation to increase pulmonary blood flow and cardiac output 1
• Use negative-pressure ventilation if available, as this improves stroke volume and cardiac output compared to positive-pressure ventilation 1
• Avoid aggressive positive-pressure ventilation, which reduces cerebral oxygenation and systemic oxygen delivery 1

Common Pitfalls to Avoid

• Do not hyperventilate: Excessive ventilation dramatically reduces venous return and pulmonary blood flow in Fontan physiology, worsening outcomes 1
• Do not delay ECPR: Standard CPR has limited efficacy in Fontan patients; early transition to mechanical support is critical 1
• Recognize that standard hemodynamic monitoring may be misleading: End-tidal CO2 may not reliably reflect cardiac output due to altered pulmonary blood flow patterns 1
• Avoid excessive positive-pressure ventilation even with advanced airways: The typical recommendation of 10 breaths per minute may still be too aggressive for Fontan physiology 1

Medication Administration

• Establish IV or intraosseous (IO) access for medication delivery 4
• Administer standard pediatric doses of epinephrine (0.01 mg/kg IV/IO) at appropriate intervals during CPR 4
• Consider that medication delivery and circulation may be impaired due to elevated systemic venous pressures and reduced cardiac output inherent to failing Fontan physiology 2, 3