Evans N, Kluckow M, Simmons M, Osborn D
Department of Neonatal Medicine, Royal Prince Alfred Hospital, University of Sydney, New South Wales, Australia.
Arch Dis Child Fetal Neonatal Ed. 2002 Nov;87(3):F181-4. doi: 10.1136/fn.87.3.f181.
To describe, in very preterm babies, postnatal changes in measures of middle cerebral artery (MCA) Doppler variables. To relate these peripheral measures to echocardiographic measures of systemic blood flow and ductal shunting, and to study their relation to subsequent intraventricular haemorrhage (IVH).
126 babies born before 30 weeks were studied with serial echocardiography and cerebral and Doppler ultrasound of the MCA at 5, 12, 24, and 48 hours of age. Echocardiographic measures included superior vena cava (SVC) flow and colour Doppler diameter of the ductal shunt. MCA Doppler measures included mean velocity, pulsatility index (PI), and estimated colour Doppler diameter.
MCA mean velocity increased whereas the PI decreased significantly over the first 48 hours. Babies with low SVC flow had significantly lower MCA mean velocity and estimated diameter than babies with normal SVC flow. There was no difference in PI. On multivariant analysis, the significant associations with MCA mean velocity were mean blood pressure (MBP), heart rate, SVC flow, and lower calculated vascular resistance. The significant associations with PI were larger ductal diameter and lower mean MBP. The significant associations with MCA diameter were higher SVC flow and lower calculated vascular resistance. After controlling for gestation, there was a highly significant association between lowest SVC flow and subsequent IVH but no association between IVH and lowest MCA mean velocity, estimated diameter, PI, or MBP.
These data are consistent with the speculation that SVC flow is a reflection of cerebral blood flow. Low SVC flow is more strongly associated with subsequent IVH than cerebral artery Doppler measures or MBP.
描述极早产儿出生后脑中动脉（MCA）多普勒变量测量值的产后变化。将这些外周测量值与体循环血流和导管分流的超声心动图测量值相关联，并研究它们与随后的脑室内出血（IVH）的关系。
对126例孕30周前出生的婴儿在出生后5、12、24和48小时进行了系列超声心动图检查以及MCA的脑部和多普勒超声检查。超声心动图测量包括上腔静脉（SVC）血流和导管分流的彩色多普勒直径。MCA多普勒测量包括平均速度、搏动指数（PI）和估计的彩色多普勒直径。
在出生后的头48小时内，MCA平均速度增加而PI显著降低。SVC血流低的婴儿的MCA平均速度和估计直径显著低于SVC血流正常的婴儿。PI没有差异。多变量分析显示，与MCA平均速度显著相关的因素有平均血压（MBP）、心率、SVC血流以及较低的计算血管阻力。与PI显著相关的因素有较大的导管直径和较低的平均MBP。与MCA直径显著相关的因素有较高的SVC血流和较低的计算血管阻力。在控制了孕周后，最低SVC血流与随后的IVH之间存在高度显著的关联，但IVH与最低MCA平均速度、估计直径、PI或MBP之间没有关联。
这些数据与SVC血流反映脑血流的推测一致。与脑动脉多普勒测量值或MBP相比，低SVC血流与随后的IVH的关联更强。
