Easley Ronald B, Marino Bradley S, Jennings Jacky, Cassedy Amy E, Kibler Kathleen K, Brady Ken M, Andropoulos Dean B, Brunetti Marissa, Hogue Charles W, Heitmiller Eugenie S, Lee Jennifer K, Spaeth James, Everett Allen D
1Texas Children's Hospital,Houston,Texas,United Sates of America.
2Northwestern University Feinberg School of Medicine,Chicago,Illinois,United Sates of America.
Cardiol Young. 2018 Jan;28(1):55-65. doi: 10.1017/S1047951117001573. Epub 2017 Aug 24.
Cerebrovascular reactivity monitoring has been used to identify the lower limit of pressure autoregulation in adult patients with brain injury. We hypothesise that impaired cerebrovascular reactivity and time spent below the lower limit of autoregulation during cardiopulmonary bypass will result in hypoperfusion injuries to the brain detectable by elevation in serum glial fibrillary acidic protein level.
We designed a multicentre observational pilot study combining concurrent cerebrovascular reactivity and biomarker monitoring during cardiopulmonary bypass. All children undergoing bypass for CHD were eligible. Autoregulation was monitored with the haemoglobin volume index, a moving correlation coefficient between the mean arterial blood pressure and the near-infrared spectroscopy-based trend of cerebral blood volume. Both haemoglobin volume index and glial fibrillary acidic protein data were analysed by phases of bypass. Each patient's autoregulation curve was analysed to identify the lower limit of autoregulation and optimal arterial blood pressure.
A total of 57 children had autoregulation and biomarker data for all phases of bypass. The mean baseline haemoglobin volume index was 0.084. Haemoglobin volume index increased with lowering of pressure with 82% demonstrating a lower limit of autoregulation (41±9 mmHg), whereas 100% demonstrated optimal blood pressure (48±11 mmHg). There was a significant association between an individual's peak autoregulation and biomarker values (p=0.01).
Individual, dynamic non-invasive cerebrovascular reactivity monitoring demonstrated transient periods of impairment related to possible silent brain injury. The association between an impaired autoregulation burden and elevation in the serum brain biomarker may identify brain perfusion risk that could result in injury.
脑血管反应性监测已被用于确定成年脑损伤患者压力自动调节的下限。我们假设，在体外循环期间脑血管反应性受损以及处于自动调节下限以下的时间会导致脑灌注不足损伤，这可通过血清胶质纤维酸性蛋白水平升高来检测。
我们设计了一项多中心观察性试点研究，在体外循环期间同时进行脑血管反应性和生物标志物监测。所有接受先天性心脏病体外循环的儿童均符合条件。使用血红蛋白容积指数监测自动调节，血红蛋白容积指数是平均动脉血压与基于近红外光谱的脑血容量趋势之间的移动相关系数。血红蛋白容积指数和胶质纤维酸性蛋白数据均按体外循环阶段进行分析。分析每位患者的自动调节曲线以确定自动调节下限和最佳动脉血压。
共有57名儿童获得了体外循环各阶段的自动调节和生物标志物数据。平均基线血红蛋白容积指数为0.084。血红蛋白容积指数随压力降低而增加，82% 的患者显示自动调节下限（41±9 mmHg），而100% 的患者显示最佳血压（48±11 mmHg）。个体的峰值自动调节与生物标志物值之间存在显著关联（p=0.01）。
个体动态非侵入性脑血管反应性监测显示出与可能的无症状脑损伤相关的短暂受损期。自动调节负担受损与血清脑生物标志物升高之间的关联可能识别出可能导致损伤的脑灌注风险。
