Identification of Time-Dependent Risks of Hemodynamic States After Stage 1 Norwood Palliation

Abstract

Background. Mortality after stage 1 palliation of hypoplastic left heart syndrome remains significant. Hemodynamic changes result from interaction of cardiac output (CO) and systemic vascular resistance (SVR). We sought to identify time-dependent changes in postoperative hemodynamic states and their associations with mortality. Methods. Perioperative data were prospectively collected in an institutional review board-approved database. Hemodynamic state was classified as high CO, high SVR, low SVR, and low CO using bivariate analysis of mean arterial pressure and somatic regional near-infrared spectroscopic oximetry saturation. State classifications over 48 postoperative hours were modelled using multinomial logistic regressions for association with mortality. Results. Data from 9614 of 10,272 hours in 214 patients were analyzed. Operative survival was 91%. The predominant state was high CO (46% time). Low CO state without extracorporeal membrane oxygenation (ECMO) was found in 52% of patients for 9.7% time. ECMO was employed in 24 (11.2%) patients for 10.4% time. State stability was 33%, with high SVR the least stable (17%) and high CO the most stable (53%). Transition from high CO increased in hours 1 to 12, mainly to low SVR. Transition to low CO was 18.4%, increasing in hours 1 to 12, mainly from high SVR. The transition risk to ECMO was 0.32%, and 0.74% during hours 1 to 12, only from low CO. Both low CO and ECMO had increased mortality risk. Conclusions. Bivariate classification defines hemodynamic states with distinct physiologic, transition, and mortality risk profiles. High SVR state was unstable. Transition to ECMO occurred only from low CO, while the low SVR and high CO states were safest.

Cardiovascular Drug Therapy during Interstage After Hybrid Approach: A Single-Center Experience in 51 Newborns with Hypoplastic Left Heart

“…The interstage is a particularly vulnerable time for patients with HLHS [3,19,20]. The risk is lower in patients with adequate antegrade blood flow serving the Fig.…”

“…Periods with increased myocardial metabolic demand, such as the higher HRs associated with stress and physical activity (e.g., crying), should be kept to a minimum to avoid the combination of reduced oxygen levels (additional hypoxemia in cyanotic patients) and myocardial ischemia. Patients with SV are at risk of inconsistent coronary blood flow, which is generally present because of anatomical considerations and a hypertrophied right ventricle [20]. An adequate diastolic time, which ensures adequate subendocardial blood flow, is essential for any ventricle operating at a systemic pressure level.…”

Clinical parameters to predict adverse outcomes in patients with parallel circulation with a Blalock-Taussig-Thomas shunt

“…In fact, increasing systemic vascular resistance may lead to no change or a decrease in the adequacy of systemic oxygen delivery [21,22]. Low systemic vascular resistance with high cardiac output has been demonstrated as the physiologic state associated with the lowest likelihood to be associated with poor outcomes in parallel circulation [23]. Thus, interventions to decrease systemic vascular resistance and increase cardiac output lead to optimization of systemic oxygen delivery and clinical outcome [24][25][26][27][28][29][30][31][32][33][34][35][36][37].…”

Factors Associated with Oxygen Extraction Ratio and Pulmonary to Systemic Blood Flow in Parallel Circulation: Insights From Cardiac Catheterization Data

“…In the rst scenario the decrease in stroke volume owing to the systemic circuit will result in lower systemic oxygen delivery, while in the second scenario the increase in myocardial oxygen consumption at an equal cardiac output will also lead to a decrease in systemic oxygen delivery. Thus, maintaining systemic vascular resistance at low levels is important in the setting of parallel circulation and may be achieved by agents such as phenoxybenzamine, phentolamine, sodium nitroprusside, nicardipine, or milrinone [16][17][18][19].…”