Lung aeration reduces blood pressure surges caused by umbilical cord milking in preterm lambs

Frontiers in Pediatrics

Pediatrics

Andrew W. Gill¹  Martin Kluckow²  Valerie Zahra³  Karyn A. Rodgers³  Alison Thiel³  Douglas A. Blank⁴  Kelly J. Crossley⁵  Stuart B. Hooper⁵  Graeme R. Polglase⁵ 

[1]Centre for Neonatal Research and Education, University of Western Australia, Perth, WA, Australia

[2]Department of Neonatology, Royal North Shore Hospital and University of Sydney, Sydney NSW, Australia

[3]The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia

[4]The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia

[5]Monash Children's Hospital, Melbourne, VIC, Australia

[6]The Department of Paediatrics, Monash University, Melbourne, VIC, Australia

[7]The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia

[8]The Department of Obstetrics and Gynaecology, Monash University, Melbourne, VIC, Australia

关键词: umbilical cord milking;    delayed cord clamping;    neonatal resuscitation;    placental transfusion;    prematurity;    mechanical ventilalion;   

DOI  :  10.3389/fped.2023.1073904

 received in 2022-10-19, accepted in 2023-02-17,  发布年份 2023

来源: Frontiers

【 摘 要 】

BackgroundUmbilical cord milking (UCM) at birth causes surges in arterial blood pressure and blood flow to the brain, which may explain the high risk of intraventricular haemorrhage (IVH) in extremely preterm infants receiving UCM. This high risk of IVH has not been reported in older infants.ObjectiveWe hypothesized that lung aeration before UCM, reduces the surge in blood pressure and blood flow induced by UCM.MethodsAt 126 days' gestation, fetal lambs (N = 8) were exteriorised, intubated and instrumented to measure umbilical, pulmonary, cerebral blood flows, and arterial pressures. Prior to ventilation onset, the umbilical cord was briefly (2–3 s) occluded (8 times), which was followed by 8 consecutive UCMs when all physiological parameters had returned to baseline. Lambs were then ventilated. After diastolic pulmonary blood flow markedly increased in response to ventilation, the lambs received a further 8 consecutive UCMs. Ovine umbilical cord is shorter than the human umbilical cord, with ∼10 cm available for UCMs. Therefore, 8 UCMs/occlusions were done to match the volume reported in the human studies. Umbilical cord clamping occurred after the final milk.ResultsBoth umbilical cord occlusions and UCM caused significant increases in carotid arterial blood flow and pressure. However, the increases in systolic and mean arterial blood pressure (10 ± 3 mmHg vs. 3 ± 2 mmHg, p = 0.01 and 10 ± 4 mmHg vs. 6 ± 2 mmHg, p = 0.048, respectively) and carotid artery blood flow (17 ± 6 ml/min vs. 10 ± 6 ml/min, p = 0.02) were significantly greater when UCM occurred before ventilation onset compared with UCM after ventilation.ConclusionsUCM after ventilation onset significantly reduces the increases in carotid blood flow and blood pressure caused by UCM.

【 授权许可】

Unknown   
© 2023 Blank, Crossley, Thiel, Rodgers, Zahra, Kluckow, Gill, Polglase and Hooper.