Journal article

Greater sympathoadrenal activation with longer preventilation intervals after immediate cord clamping increases hemodynamic lability at birth in preterm lambs

Joseph J Smolich, Kelly R Kenna, Murray D Esler, Sarah E Phillips, Gavin W Lambert

AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY INTEGRATIVE AND COMPARATIVE PHYSIOLOGY | AMER PHYSIOLOGICAL SOC | Published : 2017

Abstract

This study tested the hypothesis that varying degrees of hemodynamic fluctuations seen after birth following immediate cord clamping were related to development of asphyxia with longer cord clamp-to-ventilation intervals, resulting in higher perinatal circulating levels of the catecholamines norepinephrine (NE) and epinephrine (Epi), and thus increased heart rate, blood pressures, and cardiac contractility after birth. Anesthetized preterm fetal lambs were instrumented with 1) aortic (AoT) and pulmonary trunk (PT) micromanometers to obtain pressures and the maximal rate of pressure rise (dP/dtmax) as a surrogate measure of ventricular contractility, and 2) an AoT catheter to obtain samples f..

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