PT  - JOURNAL ARTICLE
AU  - Graeme R Polglase
AU  - Douglas A Blank
AU  - Samantha K Barton
AU  - Suzanne L Miller
AU  - Vanesa Stojanovska
AU  - Martin Kluckow
AU  - Andrew W Gill
AU  - Domenic LaRosa
AU  - Arjan B te Pas
AU  - Stuart B Hooper
TI  - Physiologically based cord clamping stabilises cardiac output and reduces cerebrovascular injury in asphyxiated near-term lambs
AID  - 10.1136/archdischild-2017-313657
DP  - 2018 Nov 01
TA  - Archives of Disease in Childhood - Fetal and Neonatal Edition
PG  - F530--F538
VI  - 103
IP  - 6
4099  - http://fn.bmj.com/content/103/6/F530.short
4100  - http://fn.bmj.com/content/103/6/F530.full
SO  - Arch Dis Child Fetal Neonatal Ed2018 Nov 01; 103
AB  - Background Physiologically based cord clamping (PBCC) has advantages over immediate cord clamping (ICC) during preterm delivery, but its efficacy in asphyxiated infants is not known. We investigated the physiology of PBCC following perinatal asphyxia in near-term lambs.Methods Near-term sheep fetuses (139±2 (SD) days’ gestation) were instrumented to measure umbilical, carotid, pulmonary and femoral arterial flows and pressures. Systemic and cerebral oxygenation was recorded using pulse oximetry and near-infrared spectroscopy, respectively. Fetal asphyxia was induced until mean blood pressure reached ~20 mm Hg, where lambs underwent ICC and initiation of ventilation (n=7), or ventilation for 15 min prior to umbilical cord clamping (PBCC; n=8). Cardiovascular parameters were measured and white and grey matter microvascular integrity assessed using qRT-PCR and immunohistochemistry.Results PBCC restored oxygenation and cardiac output at the same rate and in a similar fashion to lambs resuscitated following ICC. However, ICC lambs had a rapid and marked overshoot in mean systemic arterial blood pressure from 1 to 10 min after ventilation onset, which was largely absent in PBCC lambs. ICC lambs had increased cerebrovascular injury, as indicated by reduced expression of blood–brain barrier proteins and increased cerebrovascular protein leakage in the subcortical white matter (by 86%) and grey matter (by 47%).Conclusion PBCC restored cardiac output and oxygenation in an identical time frame as ICC, but greatly mitigated the postasphyxia rebound hypertension measured in ICC lambs. This likely protected the asphyxiated brain from cerebrovascular injury. PBCC may be a more suitable option for the resuscitation of the asphyxiated newborn compared with the current standard of ICC.