Pressure autoregulation monitoring and cerebral perfusion pressure target recommendation in patients with severe traumatic brain injury based on minute-by-minute monitoring data Clinical article
Pressure autoregulation monitoring and cerebral perfusion pressure target recommendation in patients with severe traumatic brain injury based on minute-by-minute monitoring data Clinical article
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DOI：
10.3171/2014.3.jns131500
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发表时间：
2014-06-01
影响因子：
4.1
通讯作者：
Meyfroidt, Geert
中科院分区：
文献类型：
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作者：
Depreitere, Bart;Gueiza, Fabian;Meyfroidt, Geert
object.在严重创伤性脑损伤中，脑灌注压（CPP）的通用目标已被放弃。到目前为止，根据患者的脑血管自动调节能力来确定动态CPP目标的尝试是有希望的。床旁监测的压力自动调节能力已成为可能的方法，Czosnyka的压力反应性指数（PRx）是最常用的。PRx计算为颅内压（ICP）和平均动脉压（MABP）值的40个连续5秒平均值之间的移动相关系数。绘制PRx对CPP的曲线在大约三分之二的监测时间内产生U形曲线，该曲线的底部代表与最佳自动调节能力（CPPopt）对应的CPP范围。在回顾性系列中，保持CPP接近CPPopt对应于更好的结局。PRx的监测需要高频信号处理。本研究的目的是调查如何处理脑血管压力反应性的信息，可以从常规的分分钟ICP和MABP数据可以得到增强，使CPPopt的建议，不从PRx方法获得的不同，显示相同的关联与结果，并可以在超过三分之二的监测时间产生。低频自动调节指数（LAx）定义为在3至120分钟的时间间隔内计算的移动分钟ICP/MABP相关系数。CPPopt计算基于LAx-CPP图，并针对1 - 24小时的时间窗和每种LAx类型进行。然后以加权方式对所得的CPPopt矩阵进行平均，其中权重基于U形的拟合优度，并且LAx的较低值对应于U形底，以产生最终的CPPopt推荐。在多中心脑监测信息技术研究组（BrainIT）数据库（n = 180）中评估了实际CPP/CPPopt与结局之间的关联。在Leuven-Tubingen数据库中（60 Hz波形数据，n = 21），比较了基于LAx和PRx的CPPopts。在BrainIT数据库中，CPPopt建议在95%的监测时间内生成。实际CPP接近基于LAx的CPPopt与生存率增加相关。在一个多变量模型中，使用严重脑损伤后皮质类固醇随机化（CRASH）模型作为协变量，实际CPP和CPPopt之间的平均绝对差异与死亡率增加独立相关。在高频数据集中，基于PRx和基于LAx的CPPopts之间未观察到显著差异。新方法在97%的监测时间内发布了CPPopt建议，而基于PRx的CPPopt仅为44%。每分钟的ICP/MABP数据包含自动调节监测的相关信息。在这项研究中，作者基于逐分钟数据分辨率的新方法允许在几乎整个监测时间内计算CPPopt。这将有助于在所有ICU中使用压力反应监测。
Object. In severe traumatic brain injury, a universal target for cerebral perfusion pressure (CPP) has been abandoned. Attempts to identify a dynamic CPP target based on the patient's cerebrovascular autoregulatory capacity have been promising so far. Bedside monitoring of pressure autoregulatory capacity has become possible by a number of methods, Czosnyka's pressure reactivity index (PRx) being the most frequently used. The PRx is calculated as the moving correlation coefficient between 40 consecutive 5-second averages of intracranial pressure (ICP) and mean arterial blood pressure (MABP) values. Plotting PRx against CPP produces a U-shaped curve in roughly two-thirds of monitoring time, with the bottom of this curve representing a CPP range corresponding with optimal autoregulatory capacity (CPPopt). In retrospective series, keeping CPP close to CPPopt corresponded with better outcomes. Monitoring of PRx requires high-frequency signal processing. The aim of the present study is to investigate how the processing of the information on cerebrovascular pressure reactivity that can be obtained from routine minute-by-minute ICP and MABP data can be enhanced to enable CPPopt recommendations that do not differ from those obtained by the PRx method, show the same associations with outcome, and can be generated in more than two-thirds of monitoring time.Methods. The low-frequency autoregulation index (LAx) was defined as the moving minute-by-minute ICP/MABP correlation coefficient calculated over time intervals varying from 3 to 120 minutes. The CPPopt calculation was based on LAx-CPP plots and done for time windows between 1 and 24 hours and for each LAx type. The resulting matrix of CPPopts were then averaged in a weighted manner, with the weight based on the goodness of fit of a U-shape and the lower value of the LAx corresponding to the U-bottom, to result in a final CPPopt recommendation. The association between actual CPP/CPPopt and outcome was assessed in the multicenter Brain Monitoring with Information Technology Research Group (BrainIT) database (n = 180). In the Leuven-Tubingen database (60-Hz waveform data, n = 21), LAx- and PRx-based CPPopts were compared.Results. In the BrainIT database, CPPopt recommendations were generated in 95% of monitoring time. Actual CPP being close to LAx-based CPPopt was associated with increased survival. In a multivariate model using the Corticosteroid Randomization After Significant Head Injury (CRASH) model as covariates, the average absolute difference between actual CPP and CPPopt was independently associated with increased mortality. In the high-frequency data set no significant difference was observed between PRx-based and LAx-based CPPopts. The new method issued a CPPopt recommendation in 97% of monitoring time, as opposed to 44% for PRx-based CPPopt.Conclusions. Minute-by-minute ICP/MABP data contain relevant information for autoregulation monitoring. In this study, the authors' new method based on minute-by-minute data resolution allowed for CPPopt calculation in nearly the entire monitoring time. This will facilitate the use of pressure reactivity monitoring in all ICUs.