Factors affecting systemic oxygen delivery after Norwood procedure with Sano modification

Area of Science:

• Pediatric Cardiology
• Cardiovascular Surgery
• Critical Care Medicine

Background:

• The Norwood procedure is a complex surgery for hypoplastic left heart syndrome (HLHS).
• Optimizing systemic oxygen delivery is crucial post- Norwood procedure.
• The oxygen excess factor (OEF) indicates adequate systemic oxygen delivery.

Purpose of the Study:

• To examine factors affecting systemic oxygen delivery after the Norwood procedure with a right ventricle-to-pulmonary artery (RV-PA) conduit.
• To identify optimal postoperative management strategies for improved outcomes.

Main Methods:

• Retrospective analysis of hemodynamic data from 9 HLHS patients post-modified Norwood operation.
• Data collected via indwelling catheters (systemic artery, pulmonary artery, vena cava) for 72 hours postoperatively.
• Calculation of systemic (Qs) and pulmonary (Qp) blood flow, systemic vascular resistance (SVR), and pulmonary vascular resistance (PVR).

Main Results:

• Systemic vascular resistance (SVR) significantly increased and pulmonary vascular resistance (PVR) decreased in the first 6 hours post-op.
• SVR and PVR decreased over 24 hours, followed by a steady increase.
• Oxygen excess factor (OEF) strongly correlated with SVR (p < 0.0001) and mixed venous oxygen saturation (SVO2), but not PVR.

Conclusions:

• Maintaining low SVR, not manipulating PVR, is a rational postoperative strategy after Norwood procedure with Sano modification.
• Mixed venous oxygen saturation (SVO2) is a reliable predictor of OEF during hemodynamic recovery.
• These findings guide management to ensure adequate oxygen delivery in neonates with HLHS.