Descriptive analysis of low versus elevated intracranial pressure on cerebral physiology in adult traumatic brain injury: a CENTER-TBI exploratory study

Center-Tbi High Resolution (Hr Icu) Sub-Study Participants And Investigators ,Frederick A Zeiler,Ari Ercole,Manuel Cabeleira,Nino Stocchetti,Peter Smielewski,Peter J Hutchinson,Marek Czosnyka

doi:10.1007/s00701-020-04485-5

Abstract

BackgroundTo date, the cerebral physiologic consequences of persistently elevated intracranial pressure (ICP) have been based on either low-resolution physiologic data or retrospective high-frequency data from single centers. The goal of this study was to provide a descriptive multi-center analysis of the cerebral physiologic consequences of ICP, comparing those with normal ICP to those with elevated ICP.MethodsThe Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) High-Resolution Intensive Care Unit (HR-ICU) sub-study cohort was utilized. The first 3 days of physiologic recording were analyzed, evaluating and comparing those patients with mean ICP < 15 mmHg versus those with mean ICP > 20 mmHg. Various cerebral physiologic parameters were derived and evaluated, including ICP, brain tissue oxygen (PbtO2), cerebral perfusion pressure (CPP), pulse amplitude of ICP (AMP), cerebrovascular reactivity, and cerebral compensatory reserve. The percentage time and dose above/below thresholds were also assessed. Basic descriptive statistics were employed in comparing the two cohorts.Results185 patients were included, with 157 displaying a mean ICP below 15 mmHg and 28 having a mean ICP above 20 mmHg. For admission demographics, only admission Marshall and Rotterdam CT scores were statistically different between groups (p = 0.017 and p = 0.030, respectively). The high ICP group displayed statistically worse CPP, PbtO2, cerebrovascular reactivity, and compensatory reserve. The high ICP group displayed worse 6-month mortality (p < 0.0001) and poor outcome (p = 0.014), based on the Extended Glasgow Outcome Score.ConclusionsLow versus high ICP during the first 72 h after moderate/severe TBI is associated with significant disparities in CPP, AMP, cerebrovascular reactivity, cerebral compensatory reserve, and brain tissue oxygenation metrics. Such ICP extremes appear to be strongly related to 6-month patient outcomes, in keeping with previous literature. This work provides multi-center validation for previously described single-center retrospective results.

Highlights

Intracranial pressure (ICP) has long been the focus of the critical care management in moderate/severe traumatic brain injury (TBI) patients
Various retrospective studies over the past few decades have sought to describe cerebral physiologic phenomena of elevations in intracranial pressure (ICP) [1, 3, 8, 9, 11, 14]. Data from such preliminary work supports the association between persistently elevated ICP and mortality at 6 months post-TBI. [6, 14, 24] persistent ICP elevations have been shown to be potentially linked to lower cerebral perfusion pressure (CPP) values, [6] worse compensatory reserve, [5, 34] impaired cerebrovascular reactivity, [1, 10, 14] lower PbtO2 values, [16, 22] and autonomic dysfunction, [15, 26] in those rare data sets with high-frequency digital physiology
The group with ICP above 20 mmHg had a median age of 54 years (IQR 35.3 to 68.3 years), median admission GCS of 7 (IQR 3 to 8), and 19 males (67.9%)

Summary

Introduction

Intracranial pressure (ICP) has long been the focus of the critical care management in moderate/severe traumatic brain injury (TBI) patients. Various retrospective studies over the past few decades have sought to describe cerebral physiologic phenomena of elevations in ICP [1, 3, 8, 9, 11, 14]. Data from such preliminary work supports the association between persistently elevated ICP and mortality at 6 months post-TBI. The cerebral physiologic consequences of persistently elevated intracranial pressure (ICP) have been based on either low-resolution physiologic data or retrospective high-frequency data from single centers. The goal of this study was to provide a descriptive multi-center analysis of the cerebral physiologic consequences of ICP, comparing those with normal ICP to those with elevated ICP

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