Dopamine infusion for postresuscitation blood pressure support after profound asphyxia in near‐term fetal sheep

Abstract

New Findings r What is the central question of this study?Dopamine is commonly used for blood pressure support in the neonate, but there is limited empirical evidence that it prevents hypotension or improves survival after asphyxia. r What is the main finding and its importance? Dopamine infusion delayed but did not prevent terminal hypotension after severe asphyxia in near-term fetal sheep. We also demonstrate that hypotension is directly associated with exacerbated brain swelling, strongly supporting the concept that better ways of protecting the brain from hypotension during recovery from asphyxia are essential.

Status Epilepticus after Prolonged Umbilical Cord Occlusion Is Associated with Greater Neural Injury Fetal Sheep at Term-Equivalent

“…Previous studies of such a prolonged duration of UCO in fetal sheep at the same gestational age as the present study have reported relatively short periods of recovery, likely because of this high mortality [20], [35], [36]. This is also broadly consistent with the typical clinical experience of 30 to 40% mortality after moderate to severe HIE [9], [37], [38].…”

“…Approximately one third of fetuses in the present study died either immediately after UCO or during recovery, similarly to our previous report [20]. Previous studies of such a prolonged duration of UCO in fetal sheep at the same gestational age as the present study have reported relatively short periods of recovery, likely because of this high mortality [20], [35], [36].…”

“…It is interesting to note that despite this, fetuses were able to maintain spontaneous peripheral vasoconstriction for at least 3 days after this very severe insult. In principle, it may have been possible to improve survival by inotrope infusion, however, in practice we have previously found that infusion of the inotropic agent dopamine delayed but did not prevent secondary hypotension or death in this paradigm [20].…”

“…All surgical procedures were performed using sterile techniques [19], [20]. The uterus and either the top or bottom half of the fetus were exteriorized through a maternal midline abdominal incision.…”

“…Occlusion was terminated at a target MAP of 8 mmHg. The duration/depth of occlusion was chosen to represent an acute, severe, near-terminal insult, as determined in previous studies [14], [19], [20], [27]. After release of the umbilical cord occluder fetuses were allowed to auto-resuscitate.…”