Interventions Associated with Treatment of Low Cardiac Output following Stage 1 Norwood Palliation.

Abstract Background Mortality following stage one palliation of hypoplastic left heart syndrome remains significant. Both cardiac output (CO) and systemic vascular resistance (SVR) contribute to hemodynamic vulnerability. Simultaneous measures of mean arterial pressure and somatic regional NIRS saturation can classify complex hemodynamics into four distinct states, with a low-CO state of higher risk. We sought to identify interventions associated with low-CO state occupancy and transition. Methods Perioperative data were prospectively collected in an IRB approved database. Hemodynamic state was classified as high CO, high SVR, low SVR, and low CO using bivariate analysis. Associations of static and dynamic support levels and state classifications over 48 postoperative hours were tested between states and across transitions using mixed regression methods in a quasi-experimental design. Results Data from 10272 hours in 214 patients were analyzed. A low-CO state was observed in 142 patients for 1107 hours. Both low-CO and ECMO had increased mortality risk. The low-CO state was characterized by lower milrinone but higher catecholamine dose. Successful transition out of low-CO was associated with increased milrinone dose and hemoglobin concentration. Increasing milrinone and hemoglobin levels predicted reduced risk of low-CO in future states. Conclusions Bivariate classification objectively defines hemodynamic states and transitions with distinct support profiles. Maintaining or increasing inodilator and hemoglobin levels were associated with improved hemodynamic conditions and were predictive of successful future transitions from the low-CO state.