Neonatal Resuscitation with Intact Cord (NRIC)

描述(申请人提供)：早产儿有脑出血的风险，称为脑室出血(IVH)，通常会导致发育迟缓或其他神经问题，如脑瘫。将出生后夹住脐带的时间推迟30-60秒已被证明可以减少IVH，并已成为早产儿分娩的标准护理。然而，延迟脐带夹闭(DCC)并不能减少严重的IVH，这可能是由于有严重IVH风险的婴儿胎盘输注不足所致。最近的一项研究(Bhatt等人)在换气羔羊中比较DCC和即刻脐带夹闭(ICC)，发现DCC防止了颈动脉压的快速增加，同时增加了流向肺的肺血流量(PBF)。大多数有严重IVH风险的婴儿(受损和极早产儿)是通过剖腹产(C/S)出生的，因此无法获得通过产道的好处，因为产道有助于新生儿肺部的液体清除并增加PBF。先前的研究已经证明，对于C/S出生的婴儿，DCC胎盘输注(通过红细胞压积水平)不是最理想的。在DCC期间，用机械通气打开早产儿的肺，可以增加胎盘输注，从而改善PBF，促进生理转变。通风 在产房DCC期间，目前还没有实行。一件无菌的T恤将会是 用于在从DCC输注胎盘的同时实现肺复张。我们将检验这样一种假设，即一种简单的无菌通风回路(我们在这方面有丰富的经验)可以毫无障碍地应用于产科护理，并在DCC期间为早产儿提供好处。具体目的：1)比较胎盘延迟夹住脐带(V-DCC)与单纯延迟夹脐带(DCC)时胎盘输血量和通气量的差异。2)比较C/S和VD婴儿随机分为V-DCC组和单纯DCC组的出生前6小时的生理变化。3)比较C/S和VD出生的婴儿，随机分为V-DCC组和单纯DCC组，比较其临床结局。4)比较不同分娩方式对胎盘输血量、生理变化及临床结局的影响。设计：这是一项随机、盲法对照的临床试验。一旦脐带被夹住，两组都将接受相同的复苏干预。从产房开始持续测量脑氧合和心输出量，直到6HOL。将进行早期心脏超声检查以测量全身血流量并检测胎儿分流。胎盘输注的充分性将通过12HOL红细胞压积来评估。临床医生将对婴儿在DCC期间是否接受机械通气视而不见。这将是第一次 随机双盲研究C/S分娩的极早产儿呼吸机辅助治疗对DCC的影响，并与VD早产儿随机进行相同干预的对照组进行比较。

DESCRIPTION (provided by applicant): Premature babies are at risk for bleeding in their brain, referred to as intraventricular hemorrhage (IVH), which often results in developmental delays or other neurological problems such as cerebral palsy. Delaying the time at which the umbilical cord is clamped after birth by 30-60 seconds has been shown to reduce IVH and has become the standard of care in the delivery of preterm infants. However, delayed cord clamping (DCC) does not reduce severe IVH, which may be due to inadequate placental transfusion in infants at risk for severe IVH. A recent study (Bhatt et al.) compared DCC to immediate cord clamping (ICC) in ventilated lambs and found DCC prevented a rapid increase in carotid artery pressure while increasing pulmonary blood flow (PBF) to the lungs. The majority of infants at risk for severe IVH (compromised and extremely premature infants) are born by cesarean section (C/S) and therefore do not receive the benefit of passage through the birth canal, which facilitates fluid clearance from the newborn lungs and increases PBF. Previous studies have demonstrated suboptimal placental transfusion (via hematocrit levels) from DCC for infants born by C/S. Opening the premature infant's lungs with ventilation during DCC could increase placental transfusion, thereby improving PBF and facilitating physiological transition. Ventilation during the period of DCC in the delivery room is not currently practiced. A sterile T-piece will be used to achieve lung recruitment simultaneously with placental transfusion from DCC. We will test the hypothesis that a simple sterile ventilation circuit (with which we have extensive experience) can be employed with no impediment to obstetrical care and provide benefit to the premature infant during DCC. Specific Aims: 1) Compare the volume of placental transfusion with ventilation during delayed cord clamping (V-DCC) to delayed cord clamping alone (DCC) between infants born by C/S or vaginal delivery (VD). 2) Compare the physiological changes in the first 6 hours of life (HOL) between infants born by C/S or VD randomized to V-DCC or to DCC alone. 3) Compare the clinical outcomes between infants born by either C/S or VD, randomized to V-DCC or to DCC alone. 4) Compare the effects of mode of delivery on volume of placental transfusion, physiological changes, and clinical outcomes between all 4 groups. Design: This is a blinded randomized controlled clinical trial. Both groups will receive the same resuscitation interventions once the umbilical cord is clamped. Brain oxygenation and cardiac output will be continuously measured beginning in the delivery room until 6 HOL. An early heart ultrasound will be performed (<6 HOL) to measure systemic blood flow and detect fetal shunts. Adequacy of placental transfusion will be assessed by 12 HOL hematocrit. Clinicians will be blinded to whether the infant did or did not receive ventilation during DCC. This will be the first blinded randomized study to evaluate the effect of ventilation on DCC in very preterm infants delivered by C/S with a comparison group of VD preterm infants randomized to the same interventions.