使用非侵入性方法探索脑脊液代偿区

Exploring Cerebrospinal Compensatory Zones Using a Noninvasive Approach.

作者信息

Brasil Sérgio, Czosnyka Marek, Paiva Wellingson S, Frigieri Gustavo

机构信息

Division of Neurosurgery, Department of Neurology, University of São Paulo Medical School, São Paulo, Brazil.

University of Cambridge, Cambridge, UK.

出版信息

Neurocrit Care. 2025 Jul 14. doi: 10.1007/s12028-025-02320-2.

DOI:10.1007/s12028-025-02320-2

PMID:40659917

Abstract

BACKGROUND

Intracranial compliance (ICC) reflects the balance among intracranial volume components. Recent technological advances enable continuous, noninvasive assessment of ICC in neurocritical care settings. In this study, we aimed to correlate noninvasive ICC parameters derived from intracranial pressure (ICP) waveform morphology with the established amplitude-pressure index (RAP index), which is calculated using invasive ICP monitoring.

METHODS

Patients with traumatic brain injury underwent ventricular ICP monitoring. Simultaneously, ICP values and waveform characteristics were recorded using an external skull microdynamics sensor (brain4care) that provides surrogate waveform parameters, including the P2/P1 ratio and time-to-peak (TTP). The RAP index was calculated using dedicated software based on ICP values and pulse amplitude and was used to categorize patients into three groups: (1) adequate ICC, (2) compromised ICC, and (3) exhausted ICC. Noninvasive parameters (P2/P1 ratio and TTP) were then analyzed in relation to RAP index groupings.

RESULTS

A total of 61 patients were included. Group 1 (adequate ICC) had a median ICP of 12.3 ± 5.4 mm Hg, a P2/P1 ratio of 1.06 ± 0.3, and a TTP of 0.18 ± 0.09 s. Group 2 (compromised ICC) had a median ICP of 13 ± 6.4 mm Hg, a P2/P1 ratio of 1.15 ± 0.32, and a TTP of 0.23 ± 0.07 s. Group 3 (exhausted ICC) had a median ICP of 19.45 ± 5.9 mm Hg, a P2/P1 ratio of 1.31 ± 0.26, and a TTP of 0.25 ± 0.05 s. Regression analysis revealed a statistically significant association between the noninvasive parameters and RAP index-based ICC classification (p < 0.0001).

CONCLUSIONS

This study demonstrates a significant correlation between the RAP index and noninvasive ICP waveform-derived parameters, such as the P2/P1 ratio and TTP. These findings suggest that such noninvasive measures may serve as reliable indicators of ICC status. The critical ICP cut-off per RAP was 19.45 mmHg, below the current threshold for therapy escalation according to TBI guidelines. Although further prospective validation is required, this approach has the potential to facilitate earlier intervention before ICC deterioration and enable noninvasive monitoring, possibly improving outcomes in neurocritical care.

TRIAL REGISTRATION

NCT03144219. Registered 15 June 2017, http://www.

CLINICALTRIALS

gov/NCT03144219 .

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03144219.

摘要

背景

颅内顺应性（ICC）反映了颅内各容积成分之间的平衡。最近的技术进步使得在神经重症监护环境中能够对ICC进行连续、无创评估。在本研究中，我们旨在将源自颅内压（ICP）波形形态的无创ICC参数与使用有创ICP监测计算得出的既定振幅-压力指数（RAP指数）相关联。

方法

创伤性脑损伤患者接受了脑室ICP监测。同时，使用外部颅骨微动力学传感器（brain4care）记录ICP值和波形特征，该传感器可提供替代波形参数，包括P2/P1比值和峰值时间（TTP）。基于ICP值和脉搏振幅，使用专用软件计算RAP指数，并将患者分为三组：（1）ICC正常，（2）ICC受损，（3）ICC耗竭。然后分析无创参数（P2/P1比值和TTP）与RAP指数分组的关系。

结果

共纳入61例患者。第1组（ICC正常）的ICP中位数为12.3±5.4 mmHg，P2/P1比值为1.06±0.3，TTP为0.18±0.09秒。第2组（ICC受损）的ICP中位数为13±6.4 mmHg，P2/P1比值为1.15±0.32，TTP为0.23±0.07秒。第3组（ICC耗竭）的ICP中位数为19.45±5.9 mmHg，P2/P1比值为1.31±0.26，TTP为0.25±0.05秒。回归分析显示，无创参数与基于RAP指数的ICC分类之间存在统计学显著关联（p<0.0001）。

结论

本研究表明RAP指数与源自无创ICP波形的参数（如P2/P1比值和TTP）之间存在显著相关性。这些发现表明，此类无创测量可能作为ICC状态的可靠指标。根据RAP得出的关键ICP临界值为19.45 mmHg，低于目前根据创伤性脑损伤指南进行治疗升级的阈值。尽管需要进一步的前瞻性验证，但这种方法有可能在ICC恶化之前促进更早的干预，并实现无创监测，可能改善神经重症监护的结局。