Division of Neonatology, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
Neonatology. 2013;103(4):308-14. doi: 10.1159/000346383. Epub 2013 Mar 26.
Preterm infants with signs of poor perfusion are often treated with volume expansion, although evidence regarding its effect on cerebral perfusion is lacking. Moreover, the effect is questionable in preterm infants with an adequate cerebrovascular autoregulation (CAR). A useful measure to assess perfusion is cerebral fractional tissue oxygen extraction (cFTOE).
To assess the effect of volume expansion on cFTOE in preterm infants with signs of poor perfusion.
In this observational study, we assessed cFTOE using near-infrared spectroscopy in preterm infants with signs of poor perfusion before, during and 1 h after volume expansion treatment. Simultaneously, we measured mean arterial blood pressure (MABP). We tested the effect of volume expansion on both cFTOE and MABP, using multi-level analyses. We intended to define a subgroup that responded to volume expansion with an increase in blood pressure and a decrease in cFTOE, suggesting absent CAR.
In 14 preterm infants, with a median gestational age of 26.7 weeks (25.0-28.7 weeks) and a median birth weight of 836 g (615-1,290 g), we found a small increase in MABP during (1.4 ± 1.4 mm Hg, p = 0.003) and after (1.8 ± 1.7 mm Hg, p = 0.001) volume expansion, but no change in cFTOE during (-0.19 ± 0.1% p = 0.44) or after (-0.53 ± 0.1% p = 0.34) volume expansion. We were unable to define a subgroup lacking CAR.
Cerebral perfusion, as assessed by cFTOE, does not improve in preterm infants with signs of poor perfusion following volume expansion. In these infants, either CAR is present or volume expansion is inadequate to affect cFTOE.
有灌注不良表现的早产儿常接受扩容治疗，但目前尚缺乏扩容治疗对脑灌注影响的证据。而且，对于脑血管自动调节功能（Cerebrovascular Autoregulation，CAR）正常的早产儿，扩容的效果也值得怀疑。评估灌注的一个有用指标是脑氧摄取分数（Cerebral Fractional Tissue Oxygen Extraction，cFTOE）。
评估扩容治疗对有灌注不良表现的早产儿 cFTOE 的影响。
本观察性研究采用近红外光谱技术（Near-Infrared Spectroscopy，NIRS），在扩容治疗前、扩容治疗中及扩容治疗后 1 小时评估有灌注不良表现的早产儿的 cFTOE，并同步测量平均动脉压（Mean Arterial Blood Pressure，MABP）。我们采用多水平分析方法，评估扩容对 cFTOE 和 MABP 的影响。我们计划定义一个亚组，即扩容治疗后血压升高而 cFTOE 降低的患儿，提示其 CAR 缺失。
本研究共纳入 14 名胎龄中位数为 26.7 周（25.0-28.7 周）、出生体重中位数为 836 g（615-1290 g）的早产儿。扩容治疗期间和治疗后，MABP 分别升高 1.4 ± 1.4 mm Hg（p = 0.003）和 1.8 ± 1.7 mm Hg（p = 0.001），但 cFTOE 在扩容治疗期间（-0.19 ± 0.1%，p = 0.44）和治疗后（-0.53 ± 0.1%，p = 0.34）均无变化。我们未能定义 CAR 缺失的亚组。
有灌注不良表现的早产儿接受扩容治疗后，cFTOE 评估的脑灌注并未改善。在这些患儿中，要么 CAR 存在，要么扩容治疗不足以影响 cFTOE。
