Mixed venous oxygen saturation monitoring after stage 1 palliation for hypoplastic left heart syndrome

Background. Staged palliation for hypoplastic left heart syndrome has been marked by high early mortality due to the limited cardiac output of the postischemic single right ventricle combined with the inefficiency and volatility of parallel circulation. Methods. Since July 1996, we have performed stage 1 palliation (S1P) in 178 patients. Within this group is a consecutive cohort of 116 patients with true hypoplastic left heart syndrome that underwent S1P with a modified Blalock-Taussig shunt. A prospective database containing postoperative hemodynamic data was maintained on all patients. Studied were the incidence of organ failure, extracorporeal membrane oxygenation (ECMO), and mortality, as well as the relationship between these outcomes and postoperative hemodynamics. Results. Hospital survival for this cohort was 93% (108/116). Patients who died after S1P had a lower superior vena cava oxygen saturation (SvO(2)) level compared with survivors (53.1% +/- 10.6% versus 59.3% +/- 9.2%, p = 0.034). Renal failure developed in 2 (1.7%) of the 116 patients, necrotizing enterocolitis developed in 1 (0.9%), and 5 (4.3%) had clinical seizures. ECMO support was instituted in 12 patients (10.3%). The SvO(2) level was lower in patients requiring ECMO (54.0% +/- 9.7% versus 59.9% +/- 9.2%, p = 0.031). Conclusions. Goal-directed therapy with SvO(2) as an indicator of systemic oxygen delivery is associated with excellent early survival and a low incidence of organ failure after S1P. Inability to optimize SvO(2) in the early postoperative period is associated with an increased risk of organ failure, ECMO, and death.