Delaying cord clamping until ventilation onset improves cardiovascular function at birth in preterm lambs

Sasmira Bhatt, Beth Joyce Allison, Euan Morrison Wallace, Kelly Jane Crossley, Andrew W Gill, Martin Kluckow, Arjan B Te Pas, Colin J Morley, Graeme Polglase, Stuart Brian Hooper

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177 Citations (Scopus)

Abstract

Delayed cord clamping improves circulatory stability in preterm infants at birth, but the underlying physiology is unclear. We investigated the effects of umbilical cord clamping, before and after ventilation onset, on cardiovascular function at birth. Prenatal surgery was performed on lambs (123 days) to implant catheters into the pulmonary and carotid arteries and probes to measure pulmonary (PBF), carotid (CaBF) and ductus arteriosus blood flows. Lambs were delivered at 126 +/- 1 days and: (1) the umbilical cord was clamped at delivery and ventilation was delayed for about 2 min (Clamp 1st; n = 6), and (2) umbilical cord clamping was delayed for 3-4 min, until after ventilation was established (Vent 1st; n = 6). All lambs were subsequently ventilated for 30 min. In Clamp 1st lambs, cord clamping rapidly (within four heartbeats), but transiently, increased pulmonary and carotid arterial pressures (by approximately 30 ) and CaBF (from 30.2 +/- 5.6 to 40.1 +/- 4.6 ml min(-1) kg(-1)), which then decreased again within 30-60 s. Following ventilation onset, these parameters rapidly increased again. In Clamp 1st lambs, cord clamping reduced heart rate (by approximately 40 ) and right ventricular output (RVO; from 114.6 +/- 14.4 to 38.8 +/- 9.7 ml min(-1) kg(-1)), which were restored by ventilation. In Vent 1st lambs, cord clamping reduced RVO from 153.5 +/- 3.8 to 119.2 +/- 10.6 ml min(-1) kg(-1), did not affect heart rates and resulted in stable blood flows and pressures during transition. Delaying cord clamping for 3-4 min until after ventilation is established improves cardiovascular function by increasing pulmonary blood flow before the cord is clamped. As a result, cardiac output remains stable, leading to a smoother cardiovascular transition throughout the early newborn period.
Original languageEnglish
Pages (from-to)2113 - 2126
Number of pages14
JournalThe Journal of Physiology
Volume591
Issue number8
DOIs
Publication statusPublished - 2013

Cite this

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title = "Delaying cord clamping until ventilation onset improves cardiovascular function at birth in preterm lambs",
abstract = "Delayed cord clamping improves circulatory stability in preterm infants at birth, but the underlying physiology is unclear. We investigated the effects of umbilical cord clamping, before and after ventilation onset, on cardiovascular function at birth. Prenatal surgery was performed on lambs (123 days) to implant catheters into the pulmonary and carotid arteries and probes to measure pulmonary (PBF), carotid (CaBF) and ductus arteriosus blood flows. Lambs were delivered at 126 +/- 1 days and: (1) the umbilical cord was clamped at delivery and ventilation was delayed for about 2 min (Clamp 1st; n = 6), and (2) umbilical cord clamping was delayed for 3-4 min, until after ventilation was established (Vent 1st; n = 6). All lambs were subsequently ventilated for 30 min. In Clamp 1st lambs, cord clamping rapidly (within four heartbeats), but transiently, increased pulmonary and carotid arterial pressures (by approximately 30 ) and CaBF (from 30.2 +/- 5.6 to 40.1 +/- 4.6 ml min(-1) kg(-1)), which then decreased again within 30-60 s. Following ventilation onset, these parameters rapidly increased again. In Clamp 1st lambs, cord clamping reduced heart rate (by approximately 40 ) and right ventricular output (RVO; from 114.6 +/- 14.4 to 38.8 +/- 9.7 ml min(-1) kg(-1)), which were restored by ventilation. In Vent 1st lambs, cord clamping reduced RVO from 153.5 +/- 3.8 to 119.2 +/- 10.6 ml min(-1) kg(-1), did not affect heart rates and resulted in stable blood flows and pressures during transition. Delaying cord clamping for 3-4 min until after ventilation is established improves cardiovascular function by increasing pulmonary blood flow before the cord is clamped. As a result, cardiac output remains stable, leading to a smoother cardiovascular transition throughout the early newborn period.",
author = "Sasmira Bhatt and Allison, {Beth Joyce} and Wallace, {Euan Morrison} and Crossley, {Kelly Jane} and Gill, {Andrew W} and Martin Kluckow and {Te Pas}, {Arjan B} and Morley, {Colin J} and Graeme Polglase and Hooper, {Stuart Brian}",
year = "2013",
doi = "10.1113/jphysiol.2012.250084",
language = "English",
volume = "591",
pages = "2113 -- 2126",
journal = "The Journal of Physiology",
issn = "0022-3751",
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Delaying cord clamping until ventilation onset improves cardiovascular function at birth in preterm lambs. / Bhatt, Sasmira; Allison, Beth Joyce; Wallace, Euan Morrison; Crossley, Kelly Jane; Gill, Andrew W; Kluckow, Martin; Te Pas, Arjan B; Morley, Colin J; Polglase, Graeme; Hooper, Stuart Brian.

In: The Journal of Physiology, Vol. 591, No. 8, 2013, p. 2113 - 2126.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Delaying cord clamping until ventilation onset improves cardiovascular function at birth in preterm lambs

AU - Bhatt, Sasmira

AU - Allison, Beth Joyce

AU - Wallace, Euan Morrison

AU - Crossley, Kelly Jane

AU - Gill, Andrew W

AU - Kluckow, Martin

AU - Te Pas, Arjan B

AU - Morley, Colin J

AU - Polglase, Graeme

AU - Hooper, Stuart Brian

PY - 2013

Y1 - 2013

N2 - Delayed cord clamping improves circulatory stability in preterm infants at birth, but the underlying physiology is unclear. We investigated the effects of umbilical cord clamping, before and after ventilation onset, on cardiovascular function at birth. Prenatal surgery was performed on lambs (123 days) to implant catheters into the pulmonary and carotid arteries and probes to measure pulmonary (PBF), carotid (CaBF) and ductus arteriosus blood flows. Lambs were delivered at 126 +/- 1 days and: (1) the umbilical cord was clamped at delivery and ventilation was delayed for about 2 min (Clamp 1st; n = 6), and (2) umbilical cord clamping was delayed for 3-4 min, until after ventilation was established (Vent 1st; n = 6). All lambs were subsequently ventilated for 30 min. In Clamp 1st lambs, cord clamping rapidly (within four heartbeats), but transiently, increased pulmonary and carotid arterial pressures (by approximately 30 ) and CaBF (from 30.2 +/- 5.6 to 40.1 +/- 4.6 ml min(-1) kg(-1)), which then decreased again within 30-60 s. Following ventilation onset, these parameters rapidly increased again. In Clamp 1st lambs, cord clamping reduced heart rate (by approximately 40 ) and right ventricular output (RVO; from 114.6 +/- 14.4 to 38.8 +/- 9.7 ml min(-1) kg(-1)), which were restored by ventilation. In Vent 1st lambs, cord clamping reduced RVO from 153.5 +/- 3.8 to 119.2 +/- 10.6 ml min(-1) kg(-1), did not affect heart rates and resulted in stable blood flows and pressures during transition. Delaying cord clamping for 3-4 min until after ventilation is established improves cardiovascular function by increasing pulmonary blood flow before the cord is clamped. As a result, cardiac output remains stable, leading to a smoother cardiovascular transition throughout the early newborn period.

AB - Delayed cord clamping improves circulatory stability in preterm infants at birth, but the underlying physiology is unclear. We investigated the effects of umbilical cord clamping, before and after ventilation onset, on cardiovascular function at birth. Prenatal surgery was performed on lambs (123 days) to implant catheters into the pulmonary and carotid arteries and probes to measure pulmonary (PBF), carotid (CaBF) and ductus arteriosus blood flows. Lambs were delivered at 126 +/- 1 days and: (1) the umbilical cord was clamped at delivery and ventilation was delayed for about 2 min (Clamp 1st; n = 6), and (2) umbilical cord clamping was delayed for 3-4 min, until after ventilation was established (Vent 1st; n = 6). All lambs were subsequently ventilated for 30 min. In Clamp 1st lambs, cord clamping rapidly (within four heartbeats), but transiently, increased pulmonary and carotid arterial pressures (by approximately 30 ) and CaBF (from 30.2 +/- 5.6 to 40.1 +/- 4.6 ml min(-1) kg(-1)), which then decreased again within 30-60 s. Following ventilation onset, these parameters rapidly increased again. In Clamp 1st lambs, cord clamping reduced heart rate (by approximately 40 ) and right ventricular output (RVO; from 114.6 +/- 14.4 to 38.8 +/- 9.7 ml min(-1) kg(-1)), which were restored by ventilation. In Vent 1st lambs, cord clamping reduced RVO from 153.5 +/- 3.8 to 119.2 +/- 10.6 ml min(-1) kg(-1), did not affect heart rates and resulted in stable blood flows and pressures during transition. Delaying cord clamping for 3-4 min until after ventilation is established improves cardiovascular function by increasing pulmonary blood flow before the cord is clamped. As a result, cardiac output remains stable, leading to a smoother cardiovascular transition throughout the early newborn period.

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U2 - 10.1113/jphysiol.2012.250084

DO - 10.1113/jphysiol.2012.250084

M3 - Article

VL - 591

SP - 2113

EP - 2126

JO - The Journal of Physiology

JF - The Journal of Physiology

SN - 0022-3751

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