Delayed Cord Clamping with Oxygen In Extremely Low Gestational Age Infants (DOXIE)

背景：目前的新生儿护理实践是延迟夹紧和切割脐带，以允许 血流动力学稳定。在大量随机对照试验和荟萃分析的支持下， 脐带夹紧术（DCC）得到了新生儿和产科管理机构的认可。氧合数据有限 极早产儿的DCC表明他们在出生后立即保持缺氧。这可能是由于 婴儿在DCC期间如何过渡的差异。极早产儿在分娩后立即尝试 以启动肺通气和气体交换。动物研究表明，延迟钳夹 脐带直到呼吸建立避免不利的大脑和心脏血液动力学，这可能 减少脑出血，包括严重脑室内出血（sIVH）。在一项多中心试验中， DCC到脐带挤奶，76%的妊娠230-276周的早产新生儿接受了DCC， 在没有呼吸支持的情况下，DCC在脐带夹紧之前开始呼吸，但仍然存在相对缺氧 表现为5分钟动脉血氧饱和度较低（SpO 2 73%（95% CI 71.4，75.6））。最近的两 分析发现，5分钟SpO 2 <80%的早产儿更有可能患有sIVH， 死亡在DCC期间提供的补充氧气导致肺通气可能会显著减少 极早产儿的发病率和死亡率。详细评估血流动力学的初步研究 需要在出生后立即进行器官功能检查，以确定100% DCC期间的氧气。 设计：本随机双盲试验将纳入140例极低胎龄儿（230- 240岁）， 妊娠276周），接受至少60秒的DCC，并进行仔细详细的血流动力学评估 和同步录像。这项研究将评估婴儿提供持续气道正压通气 （CPAP）和/或通过面罩进行正压通气（PPV），吸入氧气分数（FiO 2）为1.0 (HI组）与DCC期间吸入FiO 2为0.30的面罩CPAP/PPV婴儿相比 (LO组）。由于干预的性质，双臂均接受CPAP/PPV，并使用相同的脐带夹持 时间和呼吸支持，研究可以通过覆盖氧气混合器来设盲，避免任何产后 治疗偏倚一旦脐带被夹住并切断，每个婴儿都按照常规方案（CPAP/PPV）进行复苏 初始FiO 2为0.30）。我们将收集从出生到第一个孩子的生理参数 24小时生命（包括出生/复苏室视频记录的详细呼吸评估）。如果 我们通过在延迟给药期间提供补充氧气来减少极早产儿的缺氧。 脐带夹紧，发病率和死亡率可能会大大降低。根据调查结果，结果 将用于设计更明确的大型多中心R 01试验，以获得重要的临床结局， 严重IVH或死亡和神经发育结局。

Background: Current newborn care practice is to delay clamping and cutting the umbilical cord to allow for hemodynamic stabilization. Supported by numerous randomized controlled trials and meta-analyses, delayed cord clamping (DCC) is endorsed by both neonatal and obstetrical governing bodies. Limited oxygenation data on DCC in extremely preterm infants suggests they remain hypoxic immediately after birth. This may be due to differences in how infants transition during DCC. Immediately after delivery, extremely preterm infants attempt to initiate lung aeration and gas exchange. Animal studies have demonstrated that delaying clamping of the umbilical cord until breathing is established avoids adverse cerebral and cardiac hemodynamics, which may reduce bleeding in the brain, including severe intraventricular hemorrhage (sIVH). In a multicenter trial comparing DCC to umbilical cord milking, 76 percent of preterm newborns between 230-276 weeks gestation who received DCC without respiratory support initiated respirations prior to cord clamping, yet still had relative hypoxia demonstrated by a low 5-minute arterial oxygen saturation (SpO2 73 percent (95% CI 71.4, 75.6)). Two recent analyses found that preterm infants with a 5-minute SpO2 < 80 percent were more likely to have sIVH or death. Supplemental oxygen provided during DCC with resultant lung aeration may decrease significant morbidities and death in extremely preterm infants. A pilot study with detailed assessments of hemodynamics and organ function immediately after birth is needed to determine the efficacy and safety of providing 100 percent oxygen during DCC. Design: This randomized double-blinded pilot trial will enroll 140 extremely low gestational age infants (230- 276 weeks gestation) who receive DCC of at least 60 seconds with carefully detailed hemodynamic assessments and simultaneous video recordings. The study will evaluate infants providing continuous positive airway pressure (CPAP) and/or positive pressure ventilation (PPV) by face mask with an inspired fractional oxygen (FiO2) of 1.0 (HI Group) during DCC compared to infants given mask CPAP/PPV with an inspired FiO2 of 0.30 during DCC (LO Group). Due to the nature of the intervention, both arms receive CPAP/PPV with identical cord clamping times and respiratory support, the study can be blinded by covering the oxygen blender, avoiding any postnatal treatment bias. Once the cord is clamped and cut, each infant is resuscitated as per usual protocol (CPAP/PPV with a starting FiO2 0.30) by the clinical team. We will collect physiological parameters from birth through the first 24 hours of life (including detailed breathing assessments from video recordings at birth/ resuscitation suite). If we reduce hypoxia in extremely preterm infants by providing supplemental oxygen during the period of delayed cord clamping, there may be a dramatic reduction in morbidity and mortality. Depending on the findings, results will be used to design a more definitive larger, multicenter R01 trial powered for important clinical outcomes such as severe IVH or death and neurodevelopmental outcomes.