Postoperative management after the Norwood procedure

Staged reconstruction has become the preferred approach to hypoplastic left heart syndrome at many centers in the United States. The overall results of this strategy are most adversely affected by a high mortality at the initial stage, the Norwood procedure. The hemodynamic instability of a single ventricle providing blood flow in parallel to the systemic and pulmonary circulations combined with the stresses of cardiopulmonary bypass and circulatory arrest result in a precarious postoperative condition. Diligent perioperative management at this stage is essential to survival. To help simplify the complexity of single-ventricle physiology, this article describes a mathematical model that identifies the key elements that affect systemic oxygen delivery. The importance of balancing the circulation is underscored. The value of monitoring both systemic arterial and venous oxygen saturations to assess systemic-to-pulmonary blood flow ratio is derived from this mathematical model and confirmed experimentally and clinically. Recent research using animal models of single-ventricle physiology is also described. Using these concepts and information, techniques for achieving adequate systemic oxygen delivery are discussed. Copyright 1998 by W.B. Saunders Company