Wong Flora Y, Barfield Charles P, Campbell Louisa, Brodecky Vojta A, Walker Adrian M
Ritchie Centre for Baby Health Research, Monash University, Clayton, Victoria, Australia.
J Cereb Blood Flow Metab. 2008 Jan;28(1):74-80. doi: 10.1038/sj.jcbfm.9600507. Epub 2007 May 9.
Near-infrared spectroscopy combined with partial jugular venous occlusion (JVO) offers promise for determining cerebral venous saturation (CSvO(2)) in sick preterm infants, but has not been validated in the newborn brain or under conditions of hypoxaemia. We assessed the accuracy of the CSvO(2) estimate using cerebral venous oxygen saturation in superior sagittal sinus blood (SSSO(2)) as the 'gold standard'. Comparisons were made in seven newborn lambs over a wide range of arterial oxygen saturations (SaO(2)) of 20% to 100%. Overall, median (range) CSvO(2) was 49.8% (10.6% to 88.5%), whereas SSSO(2) was 45.5% (4.3% to 76.6%); Bland-Altman analysis revealed a mean difference (CSvO(2)-SSSO(2)) of 5.1% and limits of agreement of +/-27.4%. The change in cerebral blood volume (DeltaCBV) induced by JVO increased with SaO(2) (P<0.05). In addition, the strength of the correlation of CSvO(2) with SSSO(2) progressively improved with increasing change in total haemoglobin concentration (DeltaHbT) induced by JVO. With Bland-Altman analysis repeated for data with DeltaHbT >30 micromol cm, the mean difference (CSvO(2)-SSSO(2)) decreased to 2.4% with limits of agreement of +/-18.8%. We conclude that the accuracy of estimating CSvO(2) varies with the DeltaCBV induced by JVO. Potential differences of optical properties between the head of the lamb and the human infant suggest that caution be exercised in directly applying these data to the human newborn. Nevertheless, this critical aspect of the JVO technique needs to be taken into consideration in developing an accurate measurement for sick preterm human infants.
近红外光谱联合部分颈静脉闭塞（JVO）有望用于测定患病早产儿的脑静脉血氧饱和度（CSvO₂），但尚未在新生儿脑内或低氧血症条件下得到验证。我们以上矢状窦血中的脑静脉血氧饱和度（SSSO₂）作为“金标准”，评估了CSvO₂估计值的准确性。在7只新生羔羊身上，对20%至100%的广泛动脉血氧饱和度（SaO₂）范围进行了比较。总体而言，CSvO₂的中位数（范围）为49.8%（10.6%至88.5%），而SSSO₂为45.5%（4.3%至76.6%）；Bland-Altman分析显示平均差异（CSvO₂ - SSSO₂）为5.1%，一致性界限为±27.4%。JVO诱导的脑血容量变化（ΔCBV）随SaO₂升高而增加（P<0.05）。此外，随着JVO诱导的总血红蛋白浓度变化（ΔHbT）增加，CSvO₂与SSSO₂的相关性强度逐渐改善。对ΔHbT>30 μmol/cm的数据重复进行Bland-Altman分析，平均差异（CSvO₂ - SSSO₂）降至2.4%，一致性界限为±18.8%。我们得出结论，CSvO₂估计值的准确性随JVO诱导的ΔCBV而变化。羔羊头部与人类婴儿之间光学特性的潜在差异表明，将这些数据直接应用于人类新生儿时应谨慎。尽管如此，在为患病早产人类婴儿开发准确测量方法时，需要考虑JVO技术的这一关键方面。
