Abstract 2630: Comparison of the Profiles of Postoperative Systemic Hemodynamics and Oxygen Transport in Neonates after the Hybrid or the Norwood Procedure
Objectives: Neonates after the Norwood procedure are characterized by imbalance of oxygen transport that is mainly attributed to myocardial injury and systemic inflammatory response to cardiopulmonary bypass (CPB). ‘Hybrid’ procedures (arterial duct stenting and pulmonary arterial banding) avoid CPB and may be associated with superior postoperative hemodynamics and oxygen transport.
Methods: Oxygen consumption (VO2) was continuously measured using respiratory mass spectrometry for 72 hours following ‘hybrid’ (n=6) and Norwood (n=13) procedures (with B-T shunt). Arterial, superior vena cava, and pulmonary venous blood gases and pressures were measured at 2– 4 hour intervals to calculate pulmonary and systemic blood flow (Qp, Qs) and vascular resistance (‘PVR’ including bands, and SVR), total cardiac output(CO), DO2 and oxygen extraction ratio (ERO2). The Norwood patients were treated with a standardised regime of dopamine, milrinone and pheonxybenzamine, whereas the ‘hybrid’ patients were treated expectantly with inotropes and vasodilators.
Results: See Figure⇓. Compared with the Norwood, ‘hybrid’ patients had an early phase of lower CO, higher SVR, lower Qs and DO2, and higher ERO2 despite lower VO+as compared to the Norwood procedure (p<0.01 for all). There was no significant difference by 48 hours. Arterial lactate levels remained higher throughout 72 hour study period (p=0.09).
Conclusions: The ‘hybrid’ procedure is not associated with improved early hemodynamics or oxygen transport compared with traditional Norwood procedure. Postoperative recovery after ‘hybrid’ procedure may be enhanced by vasodilator therapy to reduce SVR and improve Qs and DO2.