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
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..View full abstract
Awarded by National Health and Medical Research Council of Australia (NHMRC)
This work was supported by Project Grant 1105137 from the National Health and Medical Research Council of Australia (NHMRC) and the Victorian Government's Operational Infrastructure Support Program. G. Lambert and M. Esler are supported by Research Fellowships from the NHMRC.