Sorensen Line C, Greisen Gorm
Department of Pediatrics, National University Hospital, Hvidovre, Copenhagen, Denmark.
J Biomed Opt. 2006 Sep-Oct;11(5):054005. doi: 10.1117/1.2357730.
The use of cerebral tissue oxygenation index (c-TOI) in a clinical setting is limited by doubts concerning the accuracy of the measurements. Since there is no gold standard, validation is difficult. Our modest aim was to quantify the precision of c-TOI doing repeated measurements by reapplying the optode several times presuming no regional differences in cerebral oxygenation. Thirty-seven premature infants were examined with several measurements of c-TOI using the NIRO 300 oximeter. Three to eight measurements were done on each infant over a period of 15 to 25 min. One-way analysis of variance was used to estimate within- and between-infant variation. The median gestational age was 27.6 weeks (23.9 to 33.0). Mean c-TOI (n = 253) was 74.6+/-8.5%. The within-infant variation was 5.2% when resiting the optode. For comparison, the between-infants variation was 6.9%, while the spontaneous 2-sec variation was 2.9%. The precision of a single measurement of c-TOI was not good. By measuring five times instead of one on each subject, the precision of the mean can be assumed to be comparable to pulse oximetry. This may be too cumbersome for clinical use, but may reduce sample size in research.
脑组织氧合指数（c-TOI）在临床环境中的应用受到测量准确性疑虑的限制。由于没有金标准，验证很困难。我们的适度目标是通过多次重新应用光极来量化c-TOI的测量精度，前提是假定脑氧合不存在区域差异。使用NIRO 300血氧计对37名早产儿进行了多次c-TOI测量。在15至25分钟内，对每个婴儿进行了三到八次测量。采用单因素方差分析来估计婴儿内部和婴儿之间的差异。中位胎龄为27.6周（23.9至33.0）。平均c-TOI（n = 253）为74.6±8.5%。重新放置光极时，婴儿内部差异为5.2%。相比之下，婴儿之间的差异为6.9%，而自发的2秒差异为2.9%。单次测量c-TOI的精度不佳。通过对每个受试者测量五次而非一次，可以认为平均值的精度与脉搏血氧饱和度测量相当。这对于临床应用可能过于繁琐，但可能会减少研究中的样本量。
