评估受损大脑的状态：脑血管储备（CVR）与诱导性脑血管反应性（iCVRx）和诱导压力反应性（iPRx）在定义临界脑灌注压（CPP）方面并不等同。

Evaluating the Status of the Injured Brain: Cerebrovascular Reserve (CVR) Is Not Equivalent to Induced Cerebrovascular Reactivity (iCVRx) and Induced Pressure Reactivity (iPRx) in Defining the Critical Cerebral Perfusion Pressure (CPP).

机构信息

Department of Neurology, University of New Mexico, Albuquerque, NM, USA.

Lovelace Biomedical Research Institute, Albuquerque, NM, USA.

出版信息

Adv Exp Med Biol. 2024;1463:85-89. doi: 10.1007/978-3-031-67458-7_15.

DOI:10.1007/978-3-031-67458-7_15

PMID:39400805

Abstract

Methods evaluating the status of the injured brain have evolved over the past 63 years since Lundberg first reported clinical measurement of intracranial pressure (ICP) to evaluate the status of the injured brain (Lundberg, Acta Psychiatr Scand Suppl. 36:1-193, 1960). Subsequent evaluation involved measurement of the autoregulatory capacity of the brain by measuring cerebral blood flow (CBF) with decreasing mean arterial pressure (MAP) to define the critical CPP where the vasodilatory capacity of the cerebral circulation is exceeded and CBF begins to fall (CPP of 50 mmHg). A seminal advance was made by Marmarou (Marmarou et al., J Neurosurg. 48:332-344, 1978) who measured brain compliance by injecting a bolus of saline into the intracranial catheter while measuring the rise in intracranial pressure (ICP) otherwise known as induced pressure reactivity (iPRx). Seeking to utilise continuous measurement of iPRx in traumatic brain injury (TBI) patients with continuous monitoring of ICP, the ICP response to arterial pulsations was developed to evaluate the optimal CPP patients with raised ICP by the arterial pulsations-based iPRx. A similar approach was made with Doppler measurement of CBF with arterial pulsations for iCVRx to guide optimal CPP (CPPopt). Both iPRx and iCVRx are associated with microvascular shunts (MVS) and can accurately measure the critical CPP, whereas the CBF autoregulation curve by decreasing MAP does not. Sophisticated continuous multimodal monitoring established with ICM+ algorithms successfully identifies CPPopt for ICP control and identifies CBF dysregulation as related to outcome, but does not provide insights into the mechanisms involved in the loss of CBF autoregulation as related to increased ICP and potentially effective treatments (Froese et al., Neurocrit Care. 34:325-335, 2021).

摘要

自 Lundberg 首次报告临床测量颅内压（ICP）以评估受伤大脑的状态（Lundberg，Acta Psychiatr Scand Suppl. 36：1-193，1960）以来，过去 63 年来，评估受伤大脑状态的方法一直在不断发展。随后的评估涉及通过测量脑血流量（CBF）来评估大脑的自动调节能力，方法是降低平均动脉压（MAP）以定义脑血管扩张能力超过的临界 CPP，从而导致 CBF 开始下降（CPP 为 50mmHg）。Marmarou（Marmarou 等人，J Neurosurg. 48：332-344，1978）通过在颅内导管中注入盐水来测量脑顺应性取得了重大进展，同时测量颅内压（ICP）的升高，即所谓的诱导压力反应性（iPRx）。为了在创伤性脑损伤（TBI）患者中利用 iPRx 的连续测量，并对 ICP 进行连续监测，开发了 ICP 对动脉搏动的反应，以评估存在升高 ICP 的患者的最佳 CPP，该方法基于动脉搏动的 iPRx。对于 iCVRx，也采用了类似的方法，使用动脉搏动测量 CBF，以指导最佳 CPP（CPPopt）。iPRx 和 iCVRx 都与微血管分流（MVS）有关，可以准确测量临界 CPP，而通过降低 MAP 测量的 CBF 自动调节曲线则不能。利用 ICM+算法建立的复杂连续多模态监测成功确定了 ICP 控制的 CPPopt，并确定了与预后相关的 CBF 失调，但无法深入了解与 ICP 升高相关的 CBF 自动调节丧失的机制以及潜在的有效治疗方法（Froese 等人，Neurocrit Care. 34：325-335，2021）。