458 - Evaluating Femoral Occlusion as an Alternative to Epinephrine During Neonatal Cardiopulmonary Resuscitation in an Asphyxiated Term Ovine Model.

Publication Number: 1440.458

Neel D. Mittal, Jacobs School of Medicine and Biomedical Sciences at the University at Buffalo, Bufffalo, NY, United States; Sylvia F. Gugino, SUNY at Buffalo, Buffalo, NY, United States; Justin Helman, Jacobs School of Medicine and Biomedical Sciences at the University at Buffalo, Buffalo, NY, United States; Nicole Bradley, Jacobs School of Medicine and Biomedical Sciences at the University at Buffalo, Buffalo, NY, United States; Saptadweepa Sanghamitra, Jacobs School of Medicine and Biomedical Sciences at the University at Buffalo, Buffalo, NY, United States; Rupashree R. Mandala, Jacobs School of Medicine and Biomedical Sciences at the University at Buffalo, Depew, NY, United States; TIEN T.M. PHAN, Jacobs School of Medicine and Biomedical Sciences at the University at Buffalo, Buffalo, NY, United States; Mausma Bawa, University at Buffalo, Buffalo, NY, United States; Srinivasan Mani, Jacobs School of Medicine and Biomedical Sciences at the University at Buffalo, Buffalo, 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

Background: Epinephrine is the standard pharmacologic intervention during neonatal resuscitation, augmenting vascular tone & diastolic blood pressure (DBP) to promote return of spontaneous circulation (ROSC). However, establishing umbilical venous access & preparing the drug can delay administration. Femoral occlusion (FO) performed by manual bilateral compression of femoral arteries during chest compressions has been shown to enhance diastolic BP & cerebral perfusion in an ovine model (Rawat et al). We aimed to determine whether FO alone could achieve ROSC and hemodynamics effects comparable to epinephrine.

Objective: To compare femoral occlusion without epinephrine with NRP & femoral occlusion with epinephrine, in a transitional term asphyxiated ovine model of asphyxia cardiac arrest, assessing:
1. Incidence and timing of return of spontaneous circulation
2. Systemic and pulmonary hemodynamics

Design/Methods: Term asphyxiated lambs (~139-140 days gestation) were resuscitated after cardiac arrest induced by umbilical-cord occlusion. Positive-pressure ventilation (PPV) & chest compressions (CC) were performed per NRP guidelines.
Three groups were analyzed:
• Control (NRP standard): CC + PPV + intravenous epinephrine
• FO + Epi: CC + PPV + bilateral femoral occlusion + epinephrine
• FO (No Epi): CC + PPV + bilateral femoral occlusion without epinephrine
Lambs were resuscitated until ROSC (Sustained HR > 100) or up to 20 min.
Hemodynamics (pulmonary, carotid, coronary flows and BP) & blood gases/ ventilatory parameters were continuously recorded.

Results: 15 term lambs were analyzed: 5 in each group. Baseline characteristics were comparable among groups (Table 1). ROSC occurred in 4/5 (80%) lambs in the FO + Epi group, 2/5 (40%) in the Control group, & 0/5 (0%) in the FO (No Epi) group (p=0.28). (Table 2). During resuscitation, carotid artery flow & pulmonary artery flow did not differ significantly among the groups (p = 0.60,0.53 and 0.83, respectively). However, DBP was significantly higher in the FO (No Epi) group (17.2 ± 2.7 mm Hg) compared with Control (9.7 ± 2.5 mm Hg, p = 0.0173). (Figure 1c)

Conclusion(s): FO without epinephrine did not achieve ROSC but showed a transient improvement in DBP, suggesting a circulatory benefit, as an increase in DBP is needed for ROSC (Figure 2). Nevertheless, epinephrine alone or in combination with FO was essential to generate adequate coronary perfusion & achieve ROSC in this term ovine model. This approach may potentially serve as a rapid, low-tech alternative for neonatal resuscitation, particularly in resource-limited or emergent settings. This is an ongoing study.

Table 1. Baseline characteristics


Table 2. Resuscitation Outcomes and Hemodynamic Parameters Among Groups


Figure 2. This is a BIOPAC® recording snapshot from an asphyxiated lamb in asystole during chest compressions and PPV. This snapshot shows the aortic pressure, carotid artery flow, and pulmonary artery flow. Initiation of femoral occlusion is depicted by the red arrow. The picture shows an increase in the systemic pressures, including diastolic pressures, carotid artery blood flow, and Pulmonary artery blood flow, from the baseline during the period of femoral occlusion.