Biomedical Engineering, Faculty of Engineering, University of Manitoba, Winnipeg, Canada.
Department of Surgery, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada.
Acta Neurochir (Wien). 2021 May;163(5):1383-1389. doi: 10.1007/s00701-020-04662-6. Epub 2021 Jan 6.
Impaired cerebrovascular reactivity appears to be linked to worse global outcome in adult traumatic brain injury (TBI). Literature suggests that current treatments administered in TBI care, in the intensive care unit (ICU), fail to greatly impact recorded cerebrovascular reactivity measures. In particular, the impact of sedation on cerebrovascular reactivity in traumatic brain injury (TBI) remains unclear in vivo. The goal of this study was to preliminarily assess the relationship between objectively measured depth of sedation and cerebrovascular reactivity in TBI.
Within, we describe a case series of 5 adult TBI patients with TBI, during which objective high-frequency physiology for sedation depth, using bispectral index (BIS), and both intracranial pressure (ICP) and arterial blood pressure (ABP) were recorded. Pressure reactivity index (PRx) and RAP (a metric of cerebral compensatory reserve) were derived. Relationships between cerebrovascular reactivity and compensatory reserve monitoring with BIS metrics were explored using descriptive plots.
A total of 5 cases in our prospectively maintained database with high-frequency physiology for ICP, ABP, and BIS. Through error bar plotting, it can be seen that each patient displays a parabolic relationship between BIS and PRx. This suggests a potential "optimal" depth of sedation where cerebrovascular reactivity is the most intact.
This small series highlights the potential impact of depth of sedation on cerebrovascular reactivity in TBI. It suggests that there may be an individual optimal depth of sedation, so as to optimize cerebrovascular reactivity. Further study of objective depth of sedation and its impact on cerebrovascular physiology in TBI is required.
脑血管反应性受损似乎与成人创伤性脑损伤 (TBI) 的整体预后较差有关。文献表明，目前在 TBI 护理中、在重症监护病房 (ICU) 中使用的治疗方法并没有对记录的脑血管反应性测量值产生重大影响。特别是，镇静对创伤性脑损伤 (TBI) 中脑血管反应性的影响在体内尚不清楚。本研究的目的是初步评估 TBI 患者中客观测量的镇静深度与脑血管反应性之间的关系。
我们描述了 5 例成人 TBI 患者的病例系列，在此期间，使用双频谱指数 (BIS) 记录了客观的高频生理学用于镇静深度，同时记录了颅内压 (ICP) 和动脉血压 (ABP)。推导了压力反应性指数 (PRx) 和 RAP（大脑代偿储备的指标）。使用描述性图探索了 BIS 指标与脑血管反应性和代偿储备监测之间的关系。
在我们前瞻性维护的具有 ICP、ABP 和 BIS 高频生理学的数据库中共有 5 例病例。通过误差条绘图，可以看出每个患者的 BIS 和 PRx 之间呈现出抛物线关系。这表明在脑血管反应性最完整的情况下，存在潜在的“最佳”镇静深度。
这个小系列强调了镇静深度对 TBI 中脑血管反应性的潜在影响。这表明可能存在个体最佳镇静深度，以优化脑血管反应性。需要进一步研究 TBI 中客观镇静深度及其对脑血管生理学的影响。
