81 - Initial Elevated Midline Head Position Reduces Hemodynamic Fluctuation with Subsequent Position Change

Poster Number: 81
Publication Number: 81.437

Andreina Mari, Jacobs School of Medicine and Biomedical Sciences at the University at Buffalo, Depew, NY, United States; Mausma Bawa, Jacobs School of Medicine and Biomedical Sciences at the University at Buffalo, Buffalo, NY, United States; Sylvia Gugino, SUNY at Buffalo, Buffalo, NY, United States; Justin Helman, Jacobs School of Medicine and Biomedical Sciences at the University at Buffalo, Bufalo, NY, United States; Nicole Bradley, Jacobs School of Medicine and Biomedical Sciences at the University at Buffalo, Buffalo, NY, United States; Carmon Koenigsknecht, Canon Stroke and Vascular Research Center, Buffalo, NY, United States; Arun Prasath, Jacobs School of Medicine and Biomedical Sciences at the University at Buffalo, Williamsville, NY, United States; Praveen Chandrasekharan, Jacobs School of Medicine and Biomedical Sciences at the University at Buffalo, Buffalo, NY, United States; Munmun Rawat, University at Buffalo, Buffalo, NY, United States; Jayasree Nair, Jacobs School of Medicine and Biomedical Sciences at the University at Buffalo, Buffalo, NY, United States

Background: ELBW infants have limited ability to autoregulate cerebral blood flow (CBF) placing them at high risk for brain injury and intraventricular hemorrhage (IVH) due to systemic hemodynamic instability (Perlman, 2009). Routine head position changes may affect cerebral hemodynamics by affecting venous drainage (Liao 2015) and increased cerebral blood volume is noted with lateral head turning. We hypothesized that maintaining a 150 EMHP in the post-resuscitation period would reduce hemodynamic fluctuations and improve cerebral oxygen delivery (DO2) during subsequent position changes.

Objective: To evaluate the effect of an initial EMHP on subsequent position changes in periviable lambs.

Design/Methods: 120d gestation beta mature lambs, partially exteriorized and instrumented in utero, were randomized into the elevated midline group (ELEV: 15 deg elevation) or standard group (FLAT) from 3 min after birth. Lambs were resuscitated per NRP guidelines. 60 min after birth, each lamb was placed in the alternate position (e.g. FLAT to ELEV) for 30 min. Carotid (CBF) and pulmonary (PBF) blood flows as well as blood pressure (BP) were monitored continuously using Biopac systems. Blood gases were collected before and after position changes at 15 min intervals. GraphPad PRISM software was used for statistical analysis using appropriate statistical tests.

Results: Baseline hemodynamics were similar between groups (Table 1). Lambs that were in the ELEV position for the first hour after birth maintained stable, higher CBF and PBF (Fig 1a and 1b) during and after position change at 60 min. Systolic, diastolic, and mean BP were similar. DO2 was significantly higher and stable after position change in the initial ELEV group. pCO2 and inspired oxygen requirement did not show any significant differences before and after position change between groups.Conclusion(s): In this periviable model, we observed hemodynamic benefits of initial EMHP. Subsequent position changes led to fluctuation and decrease in CBF as well as PBF in the FLAT to ELEV group, but not in the ELEV to FLAT group. Oxygen delivery was also increased in the initial ELEV lambs. We speculate that EMHP immediately after birth improves lower segment lung recruitment leading to clinical stability and improved oxygen delivery, reducing hemodynamic fluctuations during subsequent position changes. Clinical studies are needed to evaluate benefits and outcomes of EMHP in ELBW infants.
CVAAMC CV AM.pdf
Figure 1: Hemodynamics and oxygen delivery before and after position change in each lambBlue bar represents the timing of position change. 1a) Cerebral blood flow (CBF) and 1b) Pulmonary blood flow (PBF) higher and stable in ELEV to FLAT change 1c) DBP was similar 1d) Higher and stable oxygen delivery after position change in ELEV to FLAT change.