Kissack Christopher M, Garr Rosaline, Wardle Stephen P, Weindling A Michael
Neonatal Unit, Liverpool Women's Hospital, Crown Street, Liverpool, UK.
J Cereb Blood Flow Metab. 2005 May;25(5):545-53. doi: 10.1038/sj.jcbfm.9600046.
Cerebral blood flow (CBF) is known to be low in newborn infants, but this has not been shown to be damaging. The purpose of this study was to investigate the relationships between cerebral haemoglobin flow, blood flow, oxygen delivery, oxygen consumption, venous saturation, and fractional oxygen extraction (OEF) in newborn, preterm infants. Measurements were made by near-infrared spectroscopy in 13 very preterm, extremely low birth weight infants (median gestation 25 weeks) during the first 3 days after birth. There was a negative correlation between cerebral oxygen delivery and OEF (n=13, r=-0.5, P=0.03), which implies that when there is a reduction in cerebral oxygen delivery in sick preterm infants, increased cerebral oxygen extraction may be responsible for maintaining oxygen availability to the brain. During the first 3 days after birth CBF (n=13, r=0.7, P=0.01), oxygen delivery (n=13, r=0.5, P=0.03), and oxygen consumption (n=13, r=0.7, P=0.004) all increased. This increase in oxygen consumption indicates increased cerebral metabolic activity after birth, which is likely to be a normal adaptation to extrauterine life. The increases in blood flow and oxygen delivery may also be normal adaptations that facilitate this increase in metabolic activity. There was a decrease (P=0.04) in mean (+/-s.d.) cerebral OEF between day 1 (0.37+/-0.10) and day 2 (0.29+/-0.09), with no change between day 2 and day 3. Taking into account the negative correlation between OEF and oxygen delivery, this decrease in OEF may be because of increased oxygen delivery during this time.
众所周知，新生儿的脑血流量（CBF）较低，但尚未发现这具有损害性。本研究的目的是调查早产新生儿的脑血红蛋白流量、血流量、氧输送、氧消耗、静脉饱和度和氧摄取分数（OEF）之间的关系。对13名极早产、极低出生体重儿（中位孕周25周）在出生后的头3天内采用近红外光谱法进行测量。脑氧输送与OEF之间呈负相关（n = 13，r = -0.5，P = 0.03），这意味着当患病早产儿的脑氧输送减少时，脑氧摄取增加可能是维持大脑氧供应的原因。在出生后的头3天内，CBF（n = 13，r = 0.7，P = 0.01）、氧输送（n = 13，r = 0.5，P = 0.03）和氧消耗（n = 13，r = 0.7，P = 0.004）均增加。氧消耗的这种增加表明出生后脑代谢活动增强，这可能是对宫外生活的正常适应。血流量和氧输送的增加也可能是促进这种代谢活动增加的正常适应。第1天（0.37±0.10）至第2天（0.29±0.09）平均（±标准差）脑OEF降低（P = 0.04），第2天至第3天无变化。考虑到OEF与氧输送之间的负相关，OEF的这种降低可能是由于这段时间内氧输送增加所致。
