Department of Medical Sciences, Section of Neurosurgery, Uppsala University, Uppsala, Sweden.
J Neurotrauma. 2023 Nov;40(21-22):2341-2352. doi: 10.1089/neu.2023.0017. Epub 2023 Jun 22.
The aim of this study was to investigate if the absolute pressure reactivity index (PRx) value influenced the association between cerebral perfusion pressure (CPP) and outcome and if the optimal CPP (CPPopt) curve shape influenced the association between deviation from CPPopt and outcome in traumatic brain injury (TBI). We included 383 TBI patients treated at the neurointensive care in Uppsala between 2008 and 2018 with at least 24 h of CPP data. To determine the influence of absolute PRx values on the association between absolute CPP and outcome, the percentage of monitoring time for combinations of CPP and PRx were correlated with outcome (Extended Glasgow Outcome Scale [GOS-E]) in a heatmap. To determine the association between CPP and the relatively best PRx (CPPopt), the percentage of monitoring time of ΔCPPopt (actual CPP-CPPopt) ±5 mm Hg was analyzed in relation to GOS-E. To determine the association between CPP and the relatively best PRx within a certain absolute PRx range (curve shape), both the percentage of ΔCPPopt within the absolute limits of reactivity (PRx <0.00, < 0.15, etc.) and within certain confidence intervals of PRx-deterioration (+0.025, +0.05 etc.) from CPPopt were analyzed in relation to GOS-E. The heatmap of PRx and absolute CPP versus outcome indicated that the CPP range (55-75 mm Hg) associated with favorable outcome was wider when PRx was below 0, whereas the upper CPP-threshold decreased as PRx increased. CPPopt could be calculated during 53% of the monitoring time. Higher percentage of monitoring time with ΔCPPopt ±5 mm Hg, ΔCPPopt within the reactivity-thresholds (PRx <0.30), and ΔCPPopt within the PRx-confidence interval +0.025 were all independently associated with favorable outcome in separate logistic regressions. These regressions had similar area under receiver operating curve and were not superior to a similar regression when the CPPopt-target was replaced by the percentage of monitoring time within the traditional fixed CPP-targets 60 to 70 mm Hg. Individualized CPPopt-targets exhibited a comparable outcome association as traditional CPP targets and different definitions of the best CPPopt range based on the PRx value had a limited effect on the association between deviation from CPPopt and outcome. Since CPPopt could only be calculated during half of the time, an alternative approach would be to assess the absolute PRx to anticipate a safe CPP range.
本研究旨在探讨绝对压力反应指数 (PRx) 值是否会影响脑灌注压 (CPP) 与结局之间的关联，以及最佳 CPP (CPPopt) 曲线形状是否会影响创伤性脑损伤 (TBI) 中偏离 CPPopt 与结局之间的关联。我们纳入了 2008 年至 2018 年在乌普萨拉神经重症监护病房接受治疗的 383 例 TBI 患者，这些患者至少有 24 小时的 CPP 数据。为了确定绝对 PRx 值对 CPP 与结局之间关联的影响，我们通过热图分析了 CPP 和 PRx 监测时间组合与结局（扩展格拉斯哥预后评分 [GOS-E]）之间的相关性。为了确定 CPP 与相对最佳 PRx（CPPopt）之间的关联，我们分析了 CPPopt ±5mmHg 时 ΔCPPopt（实际 CPP-CPPopt）的监测时间百分比与 GOS-E 的关系。为了确定 CPP 与特定绝对 PRx 范围内（曲线形状）的相对最佳 PRx 之间的关联，我们分析了绝对反应性范围内的 ΔCPPopt 百分比（PRx <0.00、<0.15 等）以及 CPPopt 时 PRx 恶化的特定置信区间（+0.025、+0.05 等）与 GOS-E 的关系。PRx 和绝对 CPP 与结局的热图表明，当 PRx 低于 0 时，与良好结局相关的 CPP 范围（55-75mmHg）较宽，而随着 PRx 的增加，上 CPP 阈值降低。CPPopt 可在 53%的监测时间内计算。ΔCPPopt ±5mmHg、PRx <0.30 时的 ΔCPPopt 反应性阈值内和 PRx 置信区间内 +0.025 的 ΔCPPopt 监测时间百分比越高，在单独的逻辑回归中与良好结局独立相关。这些回归的接收者操作曲线下面积相似，并且当 CPPopt 目标被替换为传统固定 CPP 目标 60 至 70mmHg 范围内的监测时间百分比时，并不优于类似的回归。个性化 CPPopt 目标与传统 CPP 目标具有相似的结局关联，基于 PRx 值的最佳 CPPopt 范围的不同定义对偏离 CPPopt 与结局之间的关联影响有限。由于 CPPopt 只能在一半的时间内计算，因此另一种方法是评估绝对 PRx，以预测安全的 CPP 范围。
