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Carlson AP, Mayer AR, Cole C, van der Horn HJ, Marquez J, Stevenson TC, Shuttleworth CW. Cerebral autoregulation, spreading depolarization, and implications for targeted therapy in brain injury and ischemia. Rev Neurosci 2024; 0:revneuro-2024-0028. [PMID: 38581271 DOI: 10.1515/revneuro-2024-0028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Accepted: 03/25/2024] [Indexed: 04/08/2024]
Abstract
Cerebral autoregulation is an intrinsic myogenic response of cerebral vasculature that allows for preservation of stable cerebral blood flow levels in response to changing systemic blood pressure. It is effective across a broad range of blood pressure levels through precapillary vasoconstriction and dilation. Autoregulation is difficult to directly measure and methods to indirectly ascertain cerebral autoregulation status inherently require certain assumptions. Patients with impaired cerebral autoregulation may be at risk of brain ischemia. One of the central mechanisms of ischemia in patients with metabolically compromised states is likely the triggering of spreading depolarization (SD) events and ultimately, terminal (or anoxic) depolarization. Cerebral autoregulation and SD are therefore linked when considering the risk of ischemia. In this scoping review, we will discuss the range of methods to measure cerebral autoregulation, their theoretical strengths and weaknesses, and the available clinical evidence to support their utility. We will then discuss the emerging link between impaired cerebral autoregulation and the occurrence of SD events. Such an approach offers the opportunity to better understand an individual patient's physiology and provide targeted treatments.
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Affiliation(s)
- Andrew P Carlson
- Department of Neurosurgery, 12288 University of New Mexico School of Medicine , MSC10 5615, 1 UNM, Albuquerque, NM, 87131, USA
- Department of Neurosciences, 12288 University of New Mexico School of Medicine , 915 Camino de Salud NE, Albuquerque, NM, 87106, USA
| | - Andrew R Mayer
- 168528 Mind Research Network , 1101 Yale, Blvd, NE, Albuquerque, NM, 87106, USA
| | - Chad Cole
- Department of Neurosurgery, 12288 University of New Mexico School of Medicine , MSC10 5615, 1 UNM, Albuquerque, NM, 87131, USA
| | - Harm J van der Horn
- 168528 Mind Research Network , 1101 Yale, Blvd, NE, Albuquerque, NM, 87106, USA
| | - Joshua Marquez
- 12288 University of New Mexico School of Medicine , 915 Camino de Salud NE, Albuquerque, NM, 87106, USA
| | - Taylor C Stevenson
- Department of Neurosurgery, 12288 University of New Mexico School of Medicine , MSC10 5615, 1 UNM, Albuquerque, NM, 87131, USA
| | - C William Shuttleworth
- Department of Neurosciences, 12288 University of New Mexico School of Medicine , 915 Camino de Salud NE, Albuquerque, NM, 87106, USA
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Gomez A, Marquez I, Froese L, Bergmann T, Sainbhi AS, Vakitbilir N, Islam A, Stein KY, Ibrahim Y, Zeiler FA. Near-Infrared Spectroscopy Regional Oxygen Saturation Based Cerebrovascular Reactivity Assessments in Chronic Traumatic Neural Injury versus in Health: A Prospective Cohort Study. Bioengineering (Basel) 2024; 11:310. [PMID: 38671733 PMCID: PMC11047915 DOI: 10.3390/bioengineering11040310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 03/15/2024] [Accepted: 03/19/2024] [Indexed: 04/28/2024] Open
Abstract
Near-infrared spectroscopy (NIRS) regional cerebral oxygen saturation (rSO2)-based cerebrovascular reactivity (CVR) monitoring has enabled entirely non-invasive, continuous monitoring during both acute and long-term phases of care. To date, long-term post-injury CVR has not been properly characterized after acute traumatic neural injury, also known as traumatic brain injury (TBI). This study aims to compare CVR in those recovering from moderate-to-severe TBI with a healthy control group. A total of 101 heathy subjects were recruited for this study, along with 29 TBI patients. In the healthy cohort, the arterial blood pressure variant of the cerebral oxygen index (COx_a) was not statistically different between males and females or in the dominant and non-dominant hemispheres. In the TBI cohort, COx_a was not statistically different between the first and last available follow-up or by the side of cranial surgery. Surprisingly, CVR, as measured by COx_a, was statistically better in those recovering from TBI than those in the healthy cohort. In this prospective cohort study, CVR, as measured by NIRS-based methods, was found to be more active in those recovering from TBI than in the healthy cohort. This study may indicate that in individuals that survive TBI, CVR may be enhanced as a neuroprotective measure.
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Affiliation(s)
- Alwyn Gomez
- Section of Neurosurgery, Department of Surgery, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 0W2, Canada
- Department of Human Anatomy and Cell Science, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 0W2, Canada
| | - Izabella Marquez
- Department of Biosystems Engineering, Price Faculty of Engineering, University of Manitoba, Winnipeg, MB R3T 5V6, Canada
| | - Logan Froese
- Department of Biomedical Engineering, Price Faculty of Engineering, University of Manitoba, Winnipeg, MB R3T 5V6, Canada
| | - Tobias Bergmann
- Department of Biosystems Engineering, Price Faculty of Engineering, University of Manitoba, Winnipeg, MB R3T 5V6, Canada
| | - Amanjyot Singh Sainbhi
- Department of Biomedical Engineering, Price Faculty of Engineering, University of Manitoba, Winnipeg, MB R3T 5V6, Canada
| | - Nuray Vakitbilir
- Department of Biomedical Engineering, Price Faculty of Engineering, University of Manitoba, Winnipeg, MB R3T 5V6, Canada
| | - Abrar Islam
- Department of Biomedical Engineering, Price Faculty of Engineering, University of Manitoba, Winnipeg, MB R3T 5V6, Canada
| | - Kevin Y. Stein
- Department of Biomedical Engineering, Price Faculty of Engineering, University of Manitoba, Winnipeg, MB R3T 5V6, Canada
- Undergraduate Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 0W2, Canada
| | - Younis Ibrahim
- Department of Biomedical Engineering, Price Faculty of Engineering, University of Manitoba, Winnipeg, MB R3T 5V6, Canada
| | - Frederick A. Zeiler
- Section of Neurosurgery, Department of Surgery, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 0W2, Canada
- Department of Biomedical Engineering, Price Faculty of Engineering, University of Manitoba, Winnipeg, MB R3T 5V6, Canada
- Centre on Aging, Fort Garry Campus, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
- Division of Anaesthesia, Department of Medicine, Addenbrooke’s Hospital, University of Cambridge, Cambridge CB2 0QQ, UK
- Department of Clinical Neurosciences, Karolinksa Institutet, 171 77 Stockholm, Sweden
- Pan Am Clinic Foundation, Winnipeg, MB R3M 3E4, Canada
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Uryga A, Ziółkowski A, Kazimierska A, Pudełko A, Mataczyński C, Lang EW, Czosnyka M, Kasprowicz M. Analysis of intracranial pressure pulse waveform in traumatic brain injury patients: a CENTER-TBI study. J Neurosurg 2023; 139:201-211. [PMID: 36681948 DOI: 10.3171/2022.10.jns221523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 10/28/2022] [Indexed: 12/24/2022]
Abstract
OBJECTIVE Intracranial pressure (ICP) pulse waveform analysis may provide valuable information about cerebrospinal pressure-volume compensation in patients with traumatic brain injury (TBI). The authors applied spectral methods to analyze ICP waveforms in terms of the pulse amplitude of ICP (AMP), high frequency centroid (HFC), and higher harmonics centroid (HHC) and also used a morphological classification approach to assess changes in the shape of ICP pulse waveforms using the pulse shape index (PSI). METHODS The authors included 184 patients from the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) High-Resolution Sub-Study in the analysis. HFC was calculated as the average power-weighted frequency within the 4- to 15-Hz frequency range of the ICP power density spectrum. HHC was defined as the center of mass of the ICP pulse waveform harmonics from the 2nd to the 10th. PSI was defined as the weighted sum of artificial intelligence-based ICP pulse class numbers from 1 (normal pulse waveform) to 4 (pathological waveform). RESULTS AMP and PSI increased linearly with mean ICP. HFC increased proportionally to ICP until the upper breakpoint (average ICP of 31 mm Hg), whereas HHC slightly increased with ICP and then decreased significantly when ICP exceeded 25 mm Hg. AMP (p < 0.001), HFC (p = 0.003), and PSI (p < 0.001) were significantly greater in patients who died than in patients who survived. Among those patients with low ICP (< 15 mm Hg), AMP, PSI, and HFC were greater in those with poor outcome than in those with good outcome (all p < 0.001). CONCLUSIONS Whereas HFC, AMP, and PSI could be used as predictors of mortality, HHC may potentially serve as an early warning sign of intracranial hypertension. Elevated HFC, AMP, and PSI were associated with poor outcome in TBI patients with low ICP.
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Affiliation(s)
- Agnieszka Uryga
- 1Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wroclaw, Poland
| | - Arkadiusz Ziółkowski
- 1Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wroclaw, Poland
| | - Agnieszka Kazimierska
- 1Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wroclaw, Poland
| | - Agata Pudełko
- 1Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wroclaw, Poland
| | - Cyprian Mataczyński
- 2Department of Computer Engineering, Faculty of Information and Communication Technology, Wroclaw University of Science and Technology, Wroclaw, Poland
| | - Erhard W Lang
- 3Neurosurgical Associates, Red Cross Hospital, Kassel, Germany
- 4Department of Neurosurgery, Faculty of Medicine, Georg-August-Universität, Göttingen, Germany
| | - Marek Czosnyka
- 5Brain Physics Laboratory, Department of Clinical Neurosciences, Division of Neurosurgery, Addenbrooke's Hospital, University of Cambridge, Cambridge, United Kingdom; and
- 6Institute of Electronic Systems, Faculty of Electronics and Information Technology, Warsaw University of Technology, Warsaw, Poland
| | - Magdalena Kasprowicz
- 1Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wroclaw, Poland
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Shim Y, Kim J, Kim HS, Oh J, Lee S, Ha EJ. Intracranial Pressure Monitoring for Acute Brain Injured Patients: When, How, What Should We Monitor. Korean J Neurotrauma 2023; 19:149-161. [PMID: 37431379 PMCID: PMC10329885 DOI: 10.13004/kjnt.2023.19.e32] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 06/13/2023] [Accepted: 06/16/2023] [Indexed: 07/12/2023] Open
Abstract
While there is no level I recommendation for intracranial pressure (ICP) monitoring, it is typically indicated for patients with severe traumatic brain injury (TBI) with a Glasgow Coma Scale (GCS) score of 3-8 (class II). Even for moderate TBI patients with GCS 9-12, ICP monitoring should be considered for risk of increased ICP. The impact of ICP monitoring on patient outcomes is still not well-established, but recent studies reported a reduction of early mortality (class III) in TBI patients. There is no standard protocol for the application of ICP monitoring. In cases where cerebrospinal fluid drainage is required, an external ventricular drain is commonly used. In other cases, parenchymal ICP monitoring devices are generally employed. Subdural or non-invasive forms are not suitable for ICP monitoring. The mean value of ICP is the parameter recommended for observation in many guidelines. In TBI, values above 22 mmHg are associated with increased mortality. However, recent studies proposed various parameters including cumulative time with ICP above 20 mmHg (pressure-time dose), pressure reactivity index, ICP waveform characteristics (pulse amplitude of ICP, mean ICP wave amplitude), and the compensatory reserve of the brain (reserve-amplitude-pressure), which are useful in predicting patient outcomes and guiding treatment. Further research is required for validation of these parameters compared to simple ICP monitoring.
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Affiliation(s)
- Youngbo Shim
- Department of Critical Care Medicine, Kangbuk Samsung Hospital, Seoul, Korea
| | - Jungook Kim
- Gachon University Gil Hospital Regional Trauma Center, Gachon, Korea
| | - Hye Seon Kim
- Department of Neurosurgery, Incheon St. Mary’s Hospital, College of Medicine, The Catholic University, Incheon, Korea
| | - Jiwoong Oh
- Departments of Neurological Surgery and Critical Care Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Seungioo Lee
- Departments of Neurological Surgery and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Eun Jin Ha
- Department of Critical Care Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
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Hassett CE, Uysal SP, Butler R, Moore NZ, Cardim D, Gomes JA. Assessment of Cerebral Autoregulation Using Invasive and Noninvasive Methods of Intracranial Pressure Monitoring. Neurocrit Care 2023; 38:591-599. [PMID: 36050535 DOI: 10.1007/s12028-022-01585-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Accepted: 08/05/2022] [Indexed: 10/14/2022]
Abstract
BACKGROUND Pulse amplitude index (PAx), a descriptor of cerebrovascular reactivity, correlates the changes of the pulse amplitude of the intracranial pressure (ICP) waveform (AMP) with changes in mean arterial pressure (MAP). AMP relies on cerebrovascular compliance, which is modulated by the state of the cerebrovascular reactivity. PAx can aid in prognostication after acute brain injuries as a tool for the assessment of cerebral autoregulation and could potentially tailor individual management; however, invasive measurements are required for its calculation. Our aim was to evaluate the relationship between noninvasive PAx (nPAx) derived from a novel noninvasive device for ICP monitoring and PAx derived from gold standard invasive methods. METHODS We retrospectively analyzed invasive ICP (external ventricular drain) and non-invasive ICP (nICP), via mechanical extensometer (Brain4Care Corp.). Invasive and non-invasive ICP waveform morphology data was collected in adult patients with brain injury with arterial blood pressure monitoring. The time series from all signals were first treated to remove movement artifacts. PAx and nPAx were calculated as the moving correlation coefficients of 10-s averages of AMP or non-invasive AMP (nAMP) and MAP. AMP/nAMP was determined by calculating the fundamental frequency amplitude of the ICP/nICP signal over a 10-s window, updated every 10-s. We then evaluated the relationship between invasive PAx and noninvasive nPAx using the methods of repeated-measures analysis to generate an estimate of the correlation coefficient and its 95% confidence interval (CI). The agreement between the two methods was assessed using the Bland-Altman test. RESULTS Twenty-four patients were identified. The median age was 53.5 years (interquartile range 40-70), and intracranial hemorrhage (84%) was the most common etiology. Twenty-one (87.5%) patients underwent mechanical ventilation, and 60% were sedated with a median Glasgow Coma Scale score of 8 (7-15). Mean PAx was 0.0296 ± 0.331, and nPAx was 0.0171 ± 0.332. The correlation between PAx and nPAx was strong (R = 0.70, p < 0.0005, 95% CI 0.687-0.717). Bland-Altman analysis showed excellent agreement, with a bias of - 0.018 (95% CI - 0.026 to - 0.01) and a localized regression trend line that did not deviate from 0. CONCLUSIONS PAx can be calculated by conventional and noninvasive ICP monitoring in a statistically significant evaluation with strong agreement. Further study of the applications of this clinical tool is warranted, with the goal of early therapeutic intervention to improve neurologic outcomes following acute brain injuries.
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Affiliation(s)
- Catherine E Hassett
- Cerebrovascular Center, Neurologic Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44102, USA.
| | - S Pinar Uysal
- Department of Neurology, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Robert Butler
- Department of Quantitative Health Sciences, Cleveland Clinic, Cleveland, OH, USA
| | - Nina Z Moore
- Cerebrovascular Center, Neurologic Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44102, USA
- Department of Neurosurgery, Cleveland Clinic, Cleveland, OH, USA
| | - Danilo Cardim
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, TX, USA
| | - Joao A Gomes
- Cerebrovascular Center, Neurologic Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44102, USA
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Batson C, Froese L, Sekhon MS, Griesdale DE, Gomez A, Thelin EP, Raj R, Aries M, Gallagher CN, Bernard F, Kramer AH, Zeiler FA. Impact of Chronological Age and Biological Sex on Cerebrovascular Reactivity in Moderate/Severe Traumatic Brain Injury: A CAnadian High-Resolution TBI (CAHR-TBI) Study. J Neurotrauma 2022. [PMID: 36047825 DOI: 10.1089/neu.2022.0293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Impaired cerebrovascular reactivity has emerged as an important associate with poor long-term outcome after moderate/severe traumatic brain injury (TBI). However, our understanding of what drives or modulates the degree of impaired cerebrovascular function remains poor. Age and biological sex remain important modifiers of cerebrovascular function in health and disease, yet their impact on cerebrovascular reactivity after TBI remains unclear. The aim of this study was to explore subgroup responses based on age and biological sex on cerebral physiology. Data from 283 TBI patients from the CAnadian High Resolution TBI (CAHR-TBI) Research Collaborative were evaluated. Cerebrovascular reactivity was determined using high-frequency cerebral physiology for the derivation of three intracranial pressure (ICP) based indices: (1). PRx - correlation between ICP and mean arterial pressure (MAP), (2). PAx - correlation between pulse amplitude of ICP (AMP) and MAP and (3). RAC - correlation between AMP and cerebral perfusion pressure (CPP). Insult burden (% time above clinically defined thresholds) were calculated for these indices. These cerebral physiology indices were studied for their relationship with age via linear regression, age trichotomization (< 40, 40 - 60, > 60) and decades of age (< 30, 30 - 39, 40 - 49, 50 - 59, 60 - 69, > 69) schemes. Similarly, differences based on biological sex were assessed. A statistically significant positive linear correlation was found between PAx, RAC and age. In corollary, a statistically significant relationship was found between increasing age on trichotomized and decades of age analysis with PAx and RAC measures. PRx failed to demonstrate such relationships to advancing age. There was no clear difference in cerebrovascular reactivity profiles between biological sex categories. These findings suggest that AMP-based cerebrovascular reactivity indices may be better positioned to detect impairment in TBI patients with advancing age. Further investigation into the utility of PAx and RAC is required, as they may prove useful for certain subgroups of patients.
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Affiliation(s)
| | - Logan Froese
- University of Manitoba Faculty of Engineering, Biomedical Engineering, SP-422 EITC, 75 Chancellor`s Circle, Winnipeg, Manitoba, Canada, R3T 5V6;
| | - Mypinder Singh Sekhon
- University of British Columbia, Critical Care Medicine, 899 West 12th Avenue, Vancouver, British Columbia, Canada, V5Z 1M9;
| | - Donald E Griesdale
- University of British Columbia, Anesthesiology, Pharmacology and Therapeutics, Vancouver, British Columbia, Canada;
| | - Alwyn Gomez
- University of Manitoba Faculty of Health Sciences, Surgery, GF231, Health Sciences Centre, Winnipeg, Manitoba, Canada, R3A1R9;
| | - Eric Peter Thelin
- Karolinska Institutet, Department of Clinical Neuroscience, Neurosurgical Research Laboratory, Building R2:02, Karolinska University Hospital, Stockholm, Sweden, 171 76;
| | - Rahul Raj
- HUS, Topeliuksenkatu 5, Helsinki, Finland, 00029 HUS;
| | - Marcel Aries
- University of Maastricht Medical Center, Department of Intensive Care, Maastricht, Netherlands;
| | - Clare N Gallagher
- University of Calgary, Department of Clinical Neurosciences, Calgary, Alberta, Canada;
| | - Francis Bernard
- Hôpital du Sacré-Coeur de Montreal, Intensive Care Unit, 5400 Boul Gouin O, Montreal, Quebec, Canada, H4J1C5;
| | - Andreas H Kramer
- University of Calgary, Departments of Critical Care Medicine and Clinical Neurosciences, 3132 Hospital Drive NW, Calgary, Calgary, Alberta, Canada, T2N 2T9;
| | - Frederick Adam Zeiler
- Health Sciences Centre, Section of Neurosurgery, GB-1 820 Sherbrook Street, Winnipeg, Manitoba, Canada, R3A1R9;
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Batson C, Stein KY, Gomez A, Sainbhi AS, Froese L, Alizadeh A, Mathieu F, Zeiler FA. Intracranial Pressure–Derived Cerebrovascular Reactivity Indices, Chronological Age, and Biological Sex in Traumatic Brain Injury: A Scoping Review. Neurotrauma Rep 2022; 3:44-56. [PMID: 35112107 PMCID: PMC8804238 DOI: 10.1089/neur.2021.0054] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
To date, there has been limited literature exploring the association between age and sex with cerebrovascular reactivity (CVR) in moderate/severe traumatic brain injury (TBI). Given the known link between age, sex, and cerebrovascular function, knowledge of the impacts on continuously assessed CVR is critical for the development of future therapeutics. We conducted a scoping review of the literature for studies that had a direct statistical interrogation of the relationship between age, sex, and continuous intracranial pressure (ICP)-based indices of CVR in moderate/severe TBI. The ICP-based indices researched included: pressure reactivity index (PRx), pulse amplitude index (PAx), and RAC. MEDLINE, BIOSIS, EMBASE, SCOPUS, Global Health, and the Cochrane library were searched from inception to June 2021 for relevant articles. A total of 10 original studies fulfilled our inclusion criteria. Nine of the articles documented a correlation between advanced age and worse CVR, with eight using PRx (2192 total patients), three using PAx (978 total patients), and one using RAC (358 total patients), p < 0.05; R ranging from 0.17 to 0.495 for all indices across all studies. Three articles (1256 total patients) displayed a correlation between biological sex and PRx, with females trending towards higher PRx values (p < 0.05) in the limited available literature. However, no literature exists comparing PAx or RAC with biological sex. Findings showed that aging was associated with impaired CVR. We observed a trend between female sex and worse PRx values, but the literature was limited and statistical significance was borderline. The identified studies were few in number, carried significant population heterogeneity, and utilized grand averaging of large epochs of physiology during statistical comparisons with age and biological sex. Because of the heterogeneous nature of TBI populations and limited focus on the effects of age and sex on outcomes in TBI, it is challenging to highlight the differences between the indices and patient age groups and sex. The largest study showing an association between PRx and age was done by Zeiler and colleagues, where 165 patients were studied noting that patients with a mean PRx value above zero had a mean age above 51.4 years versus a mean age of 41.4 years for those with a mean PRx value below zero (p = 0.0007). The largest study showing an association between PRx and sex was done by Czosnyka and colleagues, where 469 patients were studied noting that for patients <50 years of age, PRx was worse in females (0.11 ± 0.047) compared to males (0.044 ± 0.031), p < 0.05. The findings from these 10 studies provide preliminary data, but are insufficient to definitively characterize the impact of age and sex on CVR in moderate/severe TBI. Future work in the field should focus on the impact of age and sex on multi-modal cerebral physiological monitoring.
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Affiliation(s)
- Carleen Batson
- Department of Human Anatomy and Cell Science, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Kevin Y. Stein
- Section of Neurosurgery, Department of Surgery, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Alwyn Gomez
- Department of Human Anatomy and Cell Science, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
- Section of Neurosurgery, Department of Surgery, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Amanjyot Singh Sainbhi
- Biomedical Engineering, Faculty of Engineering, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Logan Froese
- Biomedical Engineering, Faculty of Engineering, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Arsalan Alizadeh
- Section of Neurosurgery, Department of Surgery, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Francois Mathieu
- Interdepartmental Division of Critical Care, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Frederick A. Zeiler
- Department of Human Anatomy and Cell Science, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
- Section of Neurosurgery, Department of Surgery, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
- Biomedical Engineering, Faculty of Engineering, University of Manitoba, Winnipeg, Manitoba, Canada
- Centre on Aging, University of Manitoba, Winnipeg, Manitoba, Canada
- Division of Anaesthesia, Department of Medicine, Addenbrooke's Hospital, University of Cambridge, Cambridge, United Kingdom
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Gomez A, Froese L, Sainbhi AS, Batson C, Zeiler FA. Transcranial Doppler Based Cerebrovascular Reactivity Indices in Adult Traumatic Brain Injury: A Scoping Review of Associations With Patient Oriented Outcomes. Front Pharmacol 2021; 12:690921. [PMID: 34295251 PMCID: PMC8290494 DOI: 10.3389/fphar.2021.690921] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Accepted: 06/25/2021] [Indexed: 12/30/2022] Open
Abstract
Background: Disruption in cerebrovascular reactivity following traumatic brain injury (TBI) is a known phenomenon that may hold prognostic value and clinical relevance. Ultimately, improved knowledge of this process and more robust means of continuous assessment may lead to advances in precision medicine following TBI. One such method is transcranial Doppler (TCD), which has been employed to evaluate cerebrovascular reactivity following injury utilizing a continuous time-series approach. Objective: The present study undertakes a scoping review of the literature on the association of continuous time-domain TCD based indices of cerebrovascular reactivity, with global functional outcomes, cerebral physiologic correlates, and imaging evidence of lesion change. Design: Multiple databases were searched from inception to November 2020 for articles relevant to the association of continuous time-domain TCD based indices of cerebrovascular reactivity with global functional outcomes, cerebral physiologic correlates, and imaging evidence of lesion change. Results: Thirty-six relevant articles were identified. There was significant evidence supporting an association with continuous time-domain TCD based indices and functional outcomes following TBI. Indices based on mean flow velocity, as measured by TCD, were most numerous while more recent studies point to systolic flow velocity-based indices encoding more prognostic utility. Physiologic parameters such as intracranial pressure, cerebral perfusion pressure, Carbon Dioxide (CO2) reactivity as well as more established indices of cerebrovascular reactivity have all been associated with these TCD based indices. The literature has been concentrated in a few centres and is further limited by the lack of multivariate analysis. Conclusions: This systematic scoping review of the literature identifies that there is a substantial body of evidence that cerebrovascular reactivity as measured by time-domain TCD based indices have prognostic utility following TBI. Indices based on mean flow velocities have the largest body of literature for their support. However, recent studies indicate that indices based on systolic flow velocities may contain the most prognostic utility and more closely follow more established measures of cerebrovascular reactivity. To a lesser extent, the literature supports some associations between these indices and cerebral physiologic parameters. These indices provide a more complete picture of the patient’s physiome following TBI and may ultimately lead to personalized and precise clinical care. Further validation in multi-institution studies is required before these indices can be widely adopted clinically.
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Affiliation(s)
- Alwyn Gomez
- Section of Neurosurgery, Department of Surgery, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada.,Department of Human Anatomy and Cell Science, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Logan Froese
- Biomedical Engineering, Faculty of Engineering, University of Manitoba, Winnipeg, MB, Canada
| | - Amanjyot Singh Sainbhi
- Biomedical Engineering, Faculty of Engineering, University of Manitoba, Winnipeg, MB, Canada
| | - Carleen Batson
- Department of Human Anatomy and Cell Science, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Frederick A Zeiler
- Section of Neurosurgery, Department of Surgery, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada.,Department of Human Anatomy and Cell Science, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada.,Biomedical Engineering, Faculty of Engineering, University of Manitoba, Winnipeg, MB, Canada.,Centre on Aging, University of Manitoba, Winnipeg, MB, Canada.,Division of Anaesthesia, Department of Medicine, Addenbrooke's Hospital, University of Cambridge, Cambridge, United Kingdom
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Lilja-Cyron A, Zeiler FA, Beqiri E, Cabeleira M, Smielewski P, Czosnyka M. Optimal Cerebral Perfusion Pressure Based on Intracranial Pressure-Derived Indices of Cerebrovascular Reactivity: Which One Is Better for Outcome Prediction in Moderate/Severe Traumatic Brain Injury? ACTA NEUROCHIRURGICA. SUPPLEMENT 2021; 131:173-179. [PMID: 33839841 DOI: 10.1007/978-3-030-59436-7_35] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/07/2023]
Abstract
Intracranial pressure (ICP)-derived indices of cerebrovascular reactivity (e.g., PRx, PAx, and RAC) have been developed to improve understanding of brain status from available neuromonitoring variables. These indices are moving correlation coefficients between slow-wave vasogenic fluctuations in ICP and arterial blood pressure. In this retrospective analysis of neuromonitoring data from 200 patients admitted with moderate/severe traumatic brain injury (TBI), we evaluate the predictive value of CPPopt based on these ICP-derived indices of cerebrovascular reactivity. Valid CPPopt values were obtained in 92.3% (PRx), 86.7% (PAX), and 84.6% (RAC) of the monitoring periods, respectively. In multivariate logistic analysis, a baseline model that includes age, sex, and admission Glasgow Coma Score had an area under the receiver operating curve of 0.762 (P < 0.0001) for dichotomous outcome prediction (dead vs. good recovery). When adding time/dose of CPP below CPPopt, all multivariate models (based on PRx, PAx, and RAC) predicted the dichotomous outcome measure, but additional value of the prediction was only significantly added by the PRx-based calculations of time spent with CPP below CPPopt and dose of CPP below CPPopt.
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Affiliation(s)
- Alexander Lilja-Cyron
- Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK. .,Department of Neurosurgery, Rigshospitalet, Copenhagen, Denmark.
| | - Frederick A Zeiler
- Division of Anaesthesia, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK.,Rady Faculty of Health Sciences, Department of Surgery, University of Manitoba, Winnipeg, Canada.,Clinician Investigator Program, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada
| | - Erta Beqiri
- Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK.,Department of Pathophysiology and Transplantation, University of Milan, Milano, Italy
| | - Manuel Cabeleira
- Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK
| | - Peter Smielewski
- Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK
| | - Marek Czosnyka
- Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK.,Institute of Electronic Systems, Warsaw University of Technology, Warsaw, Poland
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10
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Cerebral autoregulation assessed by near-infrared spectroscopy: validation using transcranial Doppler in patients with controlled hypertension, cognitive impairment and controls. Eur J Appl Physiol 2021; 121:2165-2176. [PMID: 33860383 PMCID: PMC8260523 DOI: 10.1007/s00421-021-04681-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 04/02/2021] [Indexed: 01/05/2023]
Abstract
PURPOSE Cerebral autoregulation (CA) aims to attenuate the effects of blood pressure variation on cerebral blood flow. This study assessed the criterion validity of CA derived from near-infrared spectroscopy (NIRS) as an alternative for Transcranial Doppler (TCD). METHODS Measurements of continuous blood pressure (BP), oxygenated hemoglobin (O2Hb) using NIRS and cerebral blood flow velocity (CBFV) using TCD (gold standard) were performed in 82 controls, 27 patients with hypertension and 94 cognitively impaired patients during supine rest (all individuals) and repeated sit to stand transitions (cognitively impaired patients). The BP-CBFV and BP-O2Hb transfer function phase shifts (TFφ) were computed as CA measures. Spearman correlations (ρ) and Bland Altman limits of agreement (BAloa) between NIRS- and TCD-derived CA measures were computed. BAloa separation < 50° was considered a high absolute agreement. RESULTS NIRS- and TCD-derived CA estimates were significantly correlated during supine rest (ρ = 0.22-0.30, N = 111-120) and repeated sit-to-stand transitions (ρ = 0.46-0.61, N = 19-32). BAloa separation ranged between 87° and 112° (supine rest) and 65°-77° (repeated sit to stand transitions). CONCLUSION Criterion validity of NIRS-derived CA measures allows for comparison between groups but was insufficient for clinical application in individuals.
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11
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Reehal N, Cummings S, Mullen MT, Baker WB, Kung D, Tackett W, Favilla CG. Differentiating Dynamic Cerebral Autoregulation Across Vascular Territories. Front Neurol 2021; 12:653167. [PMID: 33833734 PMCID: PMC8021764 DOI: 10.3389/fneur.2021.653167] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 02/25/2021] [Indexed: 11/13/2022] Open
Abstract
Objective: Transcranial Doppler is commonly used to calculate cerebral autoregulation, but measurements are typically restricted to a single cerebral artery. In exploring topographic heterogeneity, this study reports the first thorough comparison of autoregulation in all major cerebral vessels. Methods: In forty healthy adults, flow velocity was monitored in the anterior, middle, and posterior cerebral arteries, and synchronized with arterial blood pressure. A transfer function analysis provided characteristics of autoregulation by quantifying the relationship between blood pressure and cerebral blood flow velocity. Results: Phase, which quantifies the time course of autoregulation, was similar in all vessels. Gain, which quantifies the magnitude of hemodynamic regulation, was lower in posterior cerebral artery, indicative of tighter regulation. However, after adjusting for baseline flow differences in each vascular territory, normalized gain was similar in all vessels. Conclusions: Discriminating dynamic cerebral autoregulation between cerebrovascular territories is feasible with a transcranial doppler based approach. In the posterior cerebral artery of healthy volunteers, absolute flow is more tightly regulated, but relative flow regulation is consistent across cerebrovascular territories. Significance: The methodology can be applied to focal disease states such as stroke or posterior reversible encephalopathy syndrome, in which the topographic distribution of autoregulation may be particularly critical.
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Affiliation(s)
- Navpreet Reehal
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
| | - Stephanie Cummings
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
| | - Michael T Mullen
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
| | - Wesley B Baker
- Department of Neurology, Children's Hospital of Philadelphia, Philadelphia, PA, United States
| | - David Kung
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA, United States
| | - William Tackett
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
| | - Christopher G Favilla
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
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12
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Hasen M, Gomez A, Froese L, Dian J, Raj R, Thelin EP, Zeiler FA. Alternative continuous intracranial pressure-derived cerebrovascular reactivity metrics in traumatic brain injury: a scoping overview. Acta Neurochir (Wien) 2020; 162:1647-1662. [PMID: 32385635 DOI: 10.1007/s00701-020-04378-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 04/25/2020] [Indexed: 12/20/2022]
Abstract
BACKGROUND Pressure reactivity index (PRx) has emerged as a means to continuously monitor cerebrovascular reactivity in traumatic brain injury (TBI). However, other intracranial pressure (ICP)-based continuous metrics exist, and may have advantages over PRx. The goal of this study was to perform a scoping overview of the literature on non-PRx ICP-based continuous cerebrovascular reactivity metrics in adult TBI. METHODS We searched MEDLINE, BIOSIS, EMBASE, Global Health, SCOPUS, and Cochrane Library from inception to December 2019. Using a two-stage filtering of title/abstract, and then full manuscript, we identified pertinent articles. Data was abstracted to tables and each technique summarized, including pulse amplitude index (PAx), correlation between pulse amplitude of ICP and cerebral perfusion pressure (RAC), PRx55-15, and low-resolution metrics LAx and L-PRx. RESULTS A total of 23 articles met the inclusion criteria, with the vast majority being retrospective in nature and based out of European centers. Sixteen articles focused on high-resolution metrics PAx, RAC, and PRx55-15, with 6 articles focusing on LAx and L-PRx. PAx may have a role in low ICP situations, where it appears to perform superior to PRx. RAC displays similar behavior to PRx, with a trend to stronger associations with favorable/unfavorable outcome at 6 months, and stronger parabolic relationship with CPP. PRx55-15 provides a focused assessment on the vasogenic frequency range associated with cerebral autoregulation, with preliminary data supporting a strong association with outcome in TBI. LAx and L-PRx display varying associations with 6-month outcome in TBI, depending on the window length of calculation, with shorter windows demonstrating stronger correlations with classical PRx. CONCLUSIONS Non-PRx continuous ICP-based cerebrovascular reactivity metrics can be split into high-resolution and low-resolution measures. High-resolution indices include PAx, RAC, and PRx55-15, while low-resolution indices include L-PRx and LAx. The true role for these metrics beyond classic PRx remains unclear. Each displays situations where it may prove superior over PRx, given limitations with this currently widely accepted measure. Much future investigation into each of these alternative metrics is required prior to adoption into the clinical monitoring armamentarium in adult TBI.
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Affiliation(s)
- Mohammed Hasen
- Section of Neurosurgery, Division of Surgery, Rady Faculty of Health Science, University of Manitoba, Winnipeg, Canada
- Department of Neurosurgery, King Fahad University Hospital, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Alwyn Gomez
- Section of Neurosurgery, Division of Surgery, Rady Faculty of Health Science, University of Manitoba, Winnipeg, Canada
| | - Logan Froese
- Biomedical Engineering, Faculty of Engineering, University of Manitoba, Winnipeg, Canada
| | - Joshua Dian
- Section of Neurosurgery, Division of Surgery, Rady Faculty of Health Science, University of Manitoba, Winnipeg, Canada
| | - Rahul Raj
- Department of Neurosurgery, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Eric P Thelin
- Department of Neurology, Karolinska University Hospital, Stockholm, Sweden
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Frederick A Zeiler
- Section of Neurosurgery, Division of Surgery, Rady Faculty of Health Science, University of Manitoba, Winnipeg, Canada.
- Centre on Aging, University of Manitoba, Winnipeg, Canada.
- Biomedical Engineering, Faculty of Engineering, University of Manitoba, Winnipeg, Canada.
- Department of Human Anatomy and Cell Sciences, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada.
- Department of Medicine, Division of Anaesthesia, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK.
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13
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Liu X, Czosnyka M, Donnelly J, Cardim D, Cabeleira M, Lalou DA, Hu X, Hutchinson PJ, Smielewski P. Assessment of cerebral autoregulation indices - a modelling perspective. Sci Rep 2020; 10:9600. [PMID: 32541858 PMCID: PMC7295753 DOI: 10.1038/s41598-020-66346-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 05/13/2020] [Indexed: 11/09/2022] Open
Abstract
Various methodologies to assess cerebral autoregulation (CA) have been developed, including model - based methods (e.g. autoregulation index, ARI), correlation coefficient - based methods (e.g. mean flow index, Mx), and frequency domain - based methods (e.g. transfer function analysis, TF). Our understanding of relationships among CA indices remains limited, partly due to disagreement of different studies by using real physiological signals, which introduce confounding factors. The influence of exogenous noise on CA parameters needs further investigation. Using a set of artificial cerebral blood flow velocities (CBFV) generated from a well-known CA model, this study aims to cross-validate the relationship among CA indices in a more controlled environment. Real arterial blood pressure (ABP) measurements from 34 traumatic brain injury patients were applied to create artificial CBFVs. Each ABP recording was used to create 10 CBFVs corresponding to 10 CA levels (ARI from 0 to 9). Mx, TF phase, gain and coherence in low frequency (LF) and very low frequency (VLF) were calculated. The influence of exogenous noise was investigated by adding three levels of colored noise to the artificial CBFVs. The result showed a significant negative relationship between Mx and ARI (r = −0.95, p < 0.001), and it became almost purely linear when ARI is between 3 to 6. For transfer function parameters, ARI positively related with phase (r = 0.99 at VLF and 0.93 at LF, p < 0.001) and negatively related with gain_VLF(r = −0.98, p < 0.001). Exogenous noise changed the actual values of the CA parameters and increased the standard deviation. Our results show that different methods can lead to poor correlation between some of the autoregulation parameters even under well controlled situations, undisturbed by unknown confounding factors. They also highlighted the importance of exogenous noise, showing that even the same CA value might correspond to different CA levels under different ‘noise’ conditions.
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Affiliation(s)
- Xiuyun Liu
- Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK. .,Department of Anesthesiology & Critical Care Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD, USA.
| | - Marek Czosnyka
- Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK.,Institute of Electronic Systems, Warsaw University of Technology, Warszawa, Poland
| | - Joseph Donnelly
- Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK.,Department of Anaesthesiology, University of Auckland, Auckland, New Zealand
| | - Danilo Cardim
- Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK.,Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, USA
| | - Manuel Cabeleira
- Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK
| | - Despina Aphroditi Lalou
- Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK
| | - Xiao Hu
- School of Nursing, Duke University, Durham, NC, USA
| | - Peter J Hutchinson
- Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK
| | - Peter Smielewski
- Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK
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Zeiler FA, Cabeleira M, Hutchinson PJ, Stocchetti N, Czosnyka M, Smielewski P, Ercole A. Evaluation of the relationship between slow-waves of intracranial pressure, mean arterial pressure and brain tissue oxygen in TBI: a CENTER-TBI exploratory analysis. J Clin Monit Comput 2020; 35:711-722. [PMID: 32418148 PMCID: PMC8286934 DOI: 10.1007/s10877-020-00527-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 05/08/2020] [Indexed: 01/17/2023]
Abstract
Brain tissue oxygen (PbtO2) monitoring in traumatic brain injury (TBI) has demonstrated strong associations with global outcome. Additionally, PbtO2 signals have been used to derive indices thought to be associated with cerebrovascular reactivity in TBI. However, their true relationship to slow-wave vasogenic fluctuations associated with cerebral autoregulation remains unclear. The goal of this study was to investigate the relationship between slow-wave fluctuations of intracranial pressure (ICP), mean arterial pressure (MAP) and PbtO2 over time. Using the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) high resolution ICU sub-study cohort, we evaluated those patients with recorded high-frequency digital intra-parenchymal ICP and PbtO2 monitoring data of a minimum of 6 h in duration. Digital physiologic signals were processed for ICP, MAP, and PbtO2 slow-waves using a moving average filter to decimate the high-frequency signal. The first 5 days of recording were analyzed. The relationship between ICP, MAP and PbtO2 slow-waves over time were assessed using autoregressive integrative moving average (ARIMA) and vector autoregressive integrative moving average (VARIMA) modelling, as well as Granger causality testing. A total of 47 patients were included. The ARIMA structure of ICP and MAP were similar in time, where PbtO2 displayed different optimal structure. VARIMA modelling and IRF plots confirmed the strong directional relationship between MAP and ICP, demonstrating an ICP response to MAP impulse. PbtO2 slow-waves, however, failed to demonstrate a definite response to ICP and MAP slow-wave impulses. These results raise questions as to the utility of PbtO2 in the derivation of cerebrovascular reactivity measures in TBI. There is a reproducible relationship between slow-wave fluctuations of ICP and MAP, as demonstrated across various time-series analytic techniques. PbtO2 does not appear to reliably respond in time to slow-wave fluctuations in MAP, as demonstrated on various VARIMA models across all patients. These findings suggest that PbtO2 should not be utilized in the derivation of cerebrovascular reactivity metrics in TBI, as it does not appear to be responsive to changes in MAP in the slow-waves. These findings corroborate previous results regarding PbtO2 based cerebrovascular reactivity indices.
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Affiliation(s)
- Frederick A Zeiler
- Division of Anaesthesia, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK. .,Department of Surgery, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, R3A 1R9, Canada. .,Department of Human Anatomy and Cell Science, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada. .,Biomedical Engineering, Faculty of Engineering, University of Manitoba, Winnipeg, Canada. .,Centre on Aging, University of Manitoba, Winnipeg, Canada.
| | - Manuel Cabeleira
- Brain Physics Laboratory, Division of Neurosurgery, Dept of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Peter J Hutchinson
- Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Nino Stocchetti
- Neuro ICU Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Italy.,Department of Physiopathology and Transplantation, Milan University, Milan, Italy
| | - Marek Czosnyka
- Brain Physics Laboratory, Division of Neurosurgery, Dept of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, CB2 0QQ, UK.,Institute of Electronic Systems, Warsaw University of Technology, Warsaw, Poland
| | - Peter Smielewski
- Brain Physics Laboratory, Division of Neurosurgery, Dept of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Ari Ercole
- Division of Anaesthesia, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK
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15
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Hüser M, Kündig A, Karlen W, De Luca V, Jaggi M. Forecasting intracranial hypertension using multi-scale waveform metrics. Physiol Meas 2020; 41:014001. [PMID: 31851948 DOI: 10.1088/1361-6579/ab6360] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
OBJECTIVE Acute intracranial hypertension is an important risk factor of secondary brain damage after traumatic brain injury. Hypertensive episodes are often diagnosed reactively, leading to late detection and lost time for intervention planning. A pro-active approach that predicts critical events several hours ahead of time could assist in directing attention to patients at risk. APPROACH We developed a prediction framework that forecasts onsets of acute intracranial hypertension in the next 8 h. It jointly uses cerebral auto-regulation indices, spectral energies and morphological pulse metrics to describe the neurological state of the patient. One-minute base windows were compressed by computing signal metrics, and then stored in a multi-scale history, from which physiological features were derived. MAIN RESULTS Our model predicted events up to 8 h in advance with an alarm recall rate of 90% at a precision of 30% in the MIMIC-III waveform database, improving upon two baselines from the literature. We found that features derived from high-frequency waveforms substantially improved the prediction performance over simple statistical summaries of low-frequency time series, and each of the three feature classes contributed to the performance gain. The inclusion of long-term history up to 8 h was especially important. SIGNIFICANCE Our results highlight the importance of information contained in high-frequency waveforms in the neurological intensive care unit. They could motivate future studies on pre-hypertensive patterns and the design of new alarm algorithms for critical events in the injured brain.
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Affiliation(s)
- Matthias Hüser
- Biomedical Informatics Group, Institute of Machine Learning, Department of Computer Science, ETH Zürich, 8092 Zürich, Switzerland
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16
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Ortega-Gutierrez S, Samaniego EA, Reccius A, Huang A, Zheng-Lin B, Masukar A, Marshall RS, Petersen NH. Changes on Dynamic Cerebral Autoregulation Are Associated with Delayed Cerebral Ischemia in Patients with Aneurysmal Subarachnoid Hemorrhage. ACTA NEUROCHIRURGICA. SUPPLEMENT 2020; 127:149-153. [PMID: 31407076 DOI: 10.1007/978-3-030-04615-6_22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND Early identification of vasospasm prior to symptom onset would allow prevention of delayed cerebral ischemia (DCI) in aneurysmal subarachnoid hemorrhage (aSAH). Dynamic cerebral autoregulation (DCA) is a noninvasive means of assessing cerebral blood flow regulation by determining independence of low-frequency temporal oscillations of systemic blood pressure (BP) and cerebral blood flow velocities (CBFV). METHODS Eight SAH patients underwent prospectively a median of 7 DCA assessments consisting of continuous measurements of BCFV and BP. Transfer function analysis was applied to calculate average phase shift (PS) in low (0.07-0.2 Hz) frequency range for each hemisphere as continuous measure of DCA. Lower PS indicated poorer regulatory response. DCI was defined as a 2-point decrease in Glasgow Coma Score and/or infarction on CT. RESULTS Three subjects developed symptomatic vasospasm with median time-to-DCI of 9 days. DCI was significantly associated with lower PS over the entire recording period (Wald = 4.28; p = 0.039). Additionally, there was a significant change in PS over different recording periods after adjusting for DCI (Wald = 15.66; p = 0.001); particularly, a significantly lower mean PS day 3-5 after bleed (14.22 vs 27.51; p = 0.05). CONCLUSIONS DCA might be useful for early detection of symptomatic vasospasm. A larger cohort study of SAH patients is currently underway.
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Affiliation(s)
- S Ortega-Gutierrez
- Stroke Division, Neurointerventional Surgery Section, Departments of Neurology, Neurosurgery and Radiology, University of Iowa Hospitals and Clinics, Iowa, IA, USA.
| | - E A Samaniego
- Stroke Division, Neurointerventional Surgery Section, Departments of Neurology, Neurosurgery and Radiology, University of Iowa Hospitals and Clinics, Iowa, IA, USA
| | - A Reccius
- Department of Critical Care, Clinica Alemana, Universidad del Desarrollo, Santiago, Chile
| | - A Huang
- Department of Neurology, Columbia University, New York, NY, USA
| | - B Zheng-Lin
- Stroke Division, Neurointerventional Surgery Section, Departments of Neurology, Neurosurgery and Radiology, University of Iowa Hospitals and Clinics, Iowa, IA, USA
| | - A Masukar
- Department of Neurology, Columbia University, New York, NY, USA
| | - R S Marshall
- Department of Neurology, Columbia University, New York, NY, USA
| | - N H Petersen
- Division of Neurocritical Care and Emergency Neurology, Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
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18
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Kim H, Lee HJ, Kim YT, Son Y, Smielewski P, Czosnyka M, Kim DJ. Novel index for predicting mortality during the first 24 hours after traumatic brain injury. J Neurosurg 2018; 131:1887-1895. [PMID: 30579283 DOI: 10.3171/2018.7.jns18995] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 07/31/2018] [Indexed: 01/22/2023]
Abstract
OBJECTIVE Failure of cerebral autoregulation and subsequent hypoperfusion is common during the acute phase of traumatic brain injury (TBI). The cerebrovascular pressure-reactivity index (PRx) indirectly reflects cerebral autoregulation and has been used to derive optimal cerebral perfusion pressure (CPP). This study provides a method for the use of a combination of PRx, CPP, and intracranial pressure (ICP) to better evaluate the extent of cerebral hypoperfusion during the first 24 hours after TBI, allowing for a more accurate prediction of mortality risk. METHODS Continuous ICP and arterial blood pressure (ABP) signals acquired from 295 TBI patients during the first 24 hours after admission were retrospectively analyzed. The CPP at the lowest PRx was determined as the optimal CPP (CPPopt). The duration of a severe hypoperfusion event (dHP) was defined as the cumulative time that the PRx was > 0.2 and the CPP was < 70 mm Hg with the addition of intracranial hypertension (ICP > 20 or > 22 mm Hg). The outcome was determined as 6-month mortality. RESULTS The cumulative duration of PRx > 0.2 and CPP < 70 mm Hg exhibited a significant association with mortality (p < 0.001). When utilized with basic clinical information available during the first 24 hours after admission (i.e., Glasgow Coma Scale score, age, and mean ICP), a dHP > 25 minutes yielded a significant predictive capacity for mortality (p < 0.05, area under the curve [AUC] = 0.75). The parameter was particularly predictive of mortality for patients with a mean ICP > 20 or > 22 mm Hg (AUC = 0.81 and 0.87, respectively). CONCLUSIONS A short duration (25 minutes) of severe hypoperfusion, evaluated as lowered CPP during worsened cerebrovascular reactivity during the 1st day after TBI, is highly indicative of mortality.
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Affiliation(s)
- Hakseung Kim
- 1Department of Brain and Cognitive Engineering, Korea University, Seoul
| | - Hack-Jin Lee
- 1Department of Brain and Cognitive Engineering, Korea University, Seoul
| | - Young-Tak Kim
- 1Department of Brain and Cognitive Engineering, Korea University, Seoul
| | - Yunsik Son
- 2Department of Computer Engineering, Dongguk University, Seoul, South Korea
| | - Peter Smielewski
- 3Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, United Kingdom; and
| | - Marek Czosnyka
- 3Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, United Kingdom; and
- 4Institute of Electronic Systems, Warsaw University of Technology, Warsaw, Poland
| | - Dong-Joo Kim
- 1Department of Brain and Cognitive Engineering, Korea University, Seoul
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Zeiler FA, Lee JK, Smielewski P, Czosnyka M, Brady K. Validation of Intracranial Pressure-Derived Cerebrovascular Reactivity Indices against the Lower Limit of Autoregulation, Part II: Experimental Model of Arterial Hypotension. J Neurotrauma 2018; 35:2812-2819. [PMID: 29808745 DOI: 10.1089/neu.2017.5604] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The aim of this work was to explore the relationship between intracranial pressure (ICP)-derived indices of cerebrovascular reactivity and the lower limit of autoregulation (LLA) during arterial hypotension. We retrospectively reviewed recorded physiological data from piglets that underwent controlled hypotension. Hypotension was induced by inflation of a balloon catheter in the inferior vena cava. ICP, cortical laser Doppler flowmetry (LDF), and arterial blood pressure (ABP) monitoring was conducted. ICP-derived indices were calculated: pressure reactivity index (PRx; correlation between ICP and mean arterial pressure [MAP]); pulse amplitude index (PAx; correlation between pulse amplitude of ICP [AMP] and MAP); and RAC (correlation between AMP and cerebral perfusion pressure [CPP]). LLA was estimated by piece-wise linear regression of CPP versus LDF. We produced error bar plots for PRx, PAx, and RAC against 5-mm Hg bins of CPP, displaying the relationship with the LLA. We compared CPP values at clinically relevant thresholds of PRx, PAx, and RAC to CPP measured at the LLA. Receiver operating curve (ROC) analysis was performed for each index across the LLA using 5-mm Hg bins for CPP. Mean LLA was 36.2 ± 10.5 mm Hg. Error bar plots demonstrated that PRx, PAx, and RAC increased, with CPP decreasing below the LLA. CPP at clinically relevant thresholds for PRx, PAx, and RAC displayed weak associations with the LLA, indicating that thresholds defined in TBI may not apply to a model of arterial hypotension. ROC analysis indicated that PRx, PAx, and RAC predicted the LLA, with AUCs of: 0.806 (95% confidence interval [CI], 0.750-0.863; p < 0.0001), 0.726 (95% CI, 0.664-0.789; p < 0.0001), and 0.710 (95% CI, 0.646-0.775; p < 0.0001), respectively. Three ICP-derived continuous indices of cerebrovascular reactivity, PRx, PAx, and RAC, were validated against the LLA within this experimental model of arterial hypotension, with PRx being superior.
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Affiliation(s)
- Frederick A Zeiler
- 2 Division of Anaesthesia, Addenbrooke's Hospital, University of Cambridge , Cambridge, United Kingdom .,3 Section of Surgery, Rady Faculty of Health Sciences, University of Manitoba , Winnipeg, Manitoba, Canada .,4 Clinician Investigator Program, Rady Faculty of Health Science, University of Manitoba , Winnipeg, Manitoba, Canada
| | - Jennifer K Lee
- 1 Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University , Baltimore, Maryland
| | - Peter Smielewski
- 5 Section of Brain Physics, Division of Neurosurgery, Addenbrooke's Hospital, University of Cambridge , Cambridge, United Kingdom
| | - Marek Czosnyka
- 5 Section of Brain Physics, Division of Neurosurgery, Addenbrooke's Hospital, University of Cambridge , Cambridge, United Kingdom .,6 Institute of Electronic Systems, Warsaw University of Technology , Warsaw, Poland
| | - Ken Brady
- 7 Pediatric Cardiology, Texas Children's Hospital , Baylor College of Medicine, Houston, Texas
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Shin SS, Huisman TAGM, Hwang M. Ultrasound Imaging for Traumatic Brain Injury. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2018; 37:1857-1867. [PMID: 29388231 DOI: 10.1002/jum.14547] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 10/17/2017] [Accepted: 10/30/2017] [Indexed: 06/07/2023]
Abstract
Traumatic brain injury (TBI) is challenging to assess even with recent advancements in computed tomography and magnetic resonance imaging. Ultrasound (US) imaging has previously been less utilized in TBI compared to conventional imaging because of limited resolution in the intracranial space. However, there have been substantial improvements in contrast-enhanced US and development of novel techniques such as intravascular US. Also, continued research provides further insight into cerebrovascular parameters from transcranial Doppler imaging. These advancements in US imaging provides the community of TBI imaging researchers and clinicians new opportunities in clinically monitoring and understanding the pathologic mechanisms of TBI.
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Affiliation(s)
- Samuel S Shin
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Thierry A G M Huisman
- Division of Pediatric Radiology and Pediatric Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Misun Hwang
- Division of Pediatric Radiology and Pediatric Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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de-Lima-Oliveira M, Salinet ASM, Nogueira RC, de Azevedo DS, Paiva WS, Teixeira MJ, Bor-Seng-Shu E. Intracranial Hypertension and Cerebral Autoregulation: A Systematic Review and Meta-Analysis. World Neurosurg 2018; 113:110-124. [PMID: 29421451 DOI: 10.1016/j.wneu.2018.01.194] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 01/23/2018] [Accepted: 01/24/2018] [Indexed: 01/20/2023]
Abstract
OBJECTIVE To present a systematic review and meta-analysis to establish the relation between cerebral autoregulation (CA) and intracranial hypertension. METHODS An electronic search using the term "Cerebral autoregulation and intracranial hypertension" was designed to identify studies that analyzed cerebral blood flow autoregulation in patients undergoing intracranial pressure (ICP) monitoring. The data were used in meta-analyses and sensitivity analyses. RESULTS A static CA technique was applied in 10 studies (26.3%), a dynamic technique was applied in 25 studies (65.8%), and both techniques were used in 3 studies (7.9%). Static CA studies using the cerebral blood flow technique revealed impaired CA in patients with an ICP ≥20 (standardized mean difference [SMD] 5.44%, 95% confidence interval [CI] 0.25-10.65, P = 0.04); static CA studies with transcranial Doppler revealed a tendency toward impaired CA in patients with ICP ≥20 (SMD -7.83%, 95% CI -17.52 to 1.85, P = 0.11). Moving correlation studies reported impaired CA in patients with ICP ≥20 (SMD 0.06, 95% CI 0.07-0.14, P < 0.00001). A comparison of CA values and mean ICP revealed a correlation between greater ICP and impaired CA (SMD 5.47, 95% CI 1.39-10.1, P = 0.01). Patients with ICP ≥20 had an elevated risk of impaired CA (OR 2.27, 95% CI 1.20-4.31, P = 0.01). CONCLUSIONS A clear tendency toward CA impairment was observed in patients with increased ICP.
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Affiliation(s)
- Marcelo de-Lima-Oliveira
- Division of Neurosurgery, Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, Brazil
| | - Angela S M Salinet
- Division of Neurosurgery, Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, Brazil
| | - Ricardo C Nogueira
- Division of Neurosurgery, Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, Brazil
| | - Daniel S de Azevedo
- Division of Neurosurgery, Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, Brazil
| | - Wellingson S Paiva
- Division of Neurosurgery, Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, Brazil
| | - Manoel J Teixeira
- Division of Neurosurgery, Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, Brazil
| | - Edson Bor-Seng-Shu
- Division of Neurosurgery, Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, Brazil.
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Zeiler FA, Donnelly J, Calviello L, Menon DK, Smielewski P, Czosnyka M. Pressure Autoregulation Measurement Techniques in Adult Traumatic Brain Injury, Part I: A Scoping Review of Intermittent/Semi-Intermittent Methods. J Neurotrauma 2017. [PMID: 28648106 DOI: 10.1089/neu.2017.5085] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The purpose of this study was to perform a systematic, scoping review of commonly described intermittent/semi-intermittent autoregulation measurement techniques in adult traumatic brain injury (TBI). Nine separate systematic reviews were conducted for each intermittent technique: computed tomographic perfusion (CTP)/Xenon-CT (Xe-CT), positron emission tomography (PET), magnetic resonance imaging (MRI), arteriovenous difference in oxygen (AVDO2) technique, thigh cuff deflation technique (TCDT), transient hyperemic response test (THRT), orthostatic hypotension test (OHT), mean flow index (Mx), and transfer function autoregulation index (TF-ARI). MEDLINE®, BIOSIS, EMBASE, Global Health, Scopus, Cochrane Library (inception to December 2016), and reference lists of relevant articles were searched. A two tier filter of references was conducted. The total number of articles utilizing each of the nine searched techniques for intermittent/semi-intermittent autoregulation techniques in adult TBI were: CTP/Xe-CT (10), PET (6), MRI (0), AVDO2 (10), ARI-based TCDT (9), THRT (6), OHT (3), Mx (17), and TF-ARI (6). The premise behind all of the intermittent techniques is manipulation of systemic blood pressure/blood volume via either chemical (such as vasopressors) or mechanical (such as thigh cuffs or carotid compression) means. Exceptionally, Mx and TF-ARI are based on spontaneous fluctuations of cerebral perfusion pressure (CPP) or mean arterial pressure (MAP). The method for assessing the cerebral circulation during these manipulations varies, with both imaging-based techniques and TCD utilized. Despite the limited literature for intermittent/semi-intermittent techniques in adult TBI (minus Mx), it is important to acknowledge the availability of such tests. They have provided fundamental insight into human autoregulatory capacity, leading to the development of continuous and more commonly applied techniques in the intensive care unit (ICU). Numerous methods of intermittent/semi-intermittent pressure autoregulation assessment in adult TBI exist, including: CTP/Xe-CT, PET, AVDO2 technique, TCDT-based ARI, THRT, OHT, Mx, and TF-ARI. MRI-based techniques in adult TBI are yet to be described, with the main focus of MRI techniques on metabolic-based cerebrovascular reactivity (CVR) and not pressure-based autoregulation.
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Affiliation(s)
- Frederick A Zeiler
- 1 Division of Anaesthesia, University of Cambridge , Cambridge, United Kingdom .,2 Clinician Investigator Program, University of Manitoba , Winnipeg, Canada .,3 Section of Neurosurgery, Department of Surgery, University of Manitoba , Winnipeg, Canada
| | - Joseph Donnelly
- 4 Section of Brain Physics, Division of Neurosurgery, Addenbrooke's Hospital, University of Cambridge , Cambridge, United Kingdom
| | - Leanne Calviello
- 4 Section of Brain Physics, Division of Neurosurgery, Addenbrooke's Hospital, University of Cambridge , Cambridge, United Kingdom
| | - David K Menon
- 1 Division of Anaesthesia, University of Cambridge , Cambridge, United Kingdom
| | - Peter Smielewski
- 4 Section of Brain Physics, Division of Neurosurgery, Addenbrooke's Hospital, University of Cambridge , Cambridge, United Kingdom
| | - Marek Czosnyka
- 4 Section of Brain Physics, Division of Neurosurgery, Addenbrooke's Hospital, University of Cambridge , Cambridge, United Kingdom
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Predictors of Outcome With Cerebral Autoregulation Monitoring: A Systematic Review and Meta-Analysis. Crit Care Med 2017; 45:695-704. [PMID: 28291094 DOI: 10.1097/ccm.0000000000002251] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To compare cerebral autoregulation indices as predictors of patient outcome and their dependence on duration of monitoring. DATA SOURCES Systematic literature search and meta-analysis using PubMed, EMBASE, and the Cochrane Library from January 1990 to October 2015. STUDY SELECTION We chose articles that assessed the association between cerebral autoregulation indices and dichotomized or continuous outcomes reported as standardized mean differences or correlation coefficients (R), respectively. Animal and validation studies were excluded. DATA EXTRACTION Two authors collected and assessed the data independently. The studies were grouped into two sets according to the type of analysis used to assess the relationship between cerebral autoregulation indices and predictors of outcome (standardized mean differences or R). DATA SYNTHESIS Thirty-three studies compared cerebral autoregulation indices and patient outcomes using standardized mean differences, and 20 used Rs. The only data available for meta-analysis were from patients with traumatic brain injury or subarachnoid hemorrhage. Based on z score analysis, the best three cerebral autoregulation index predictors of mortality or Glasgow Outcome Scale for patients with traumatic brain injury were the pressure reactivity index, transcranial Doppler-derived mean velocity index based on cerebral perfusion pressure, and autoregulation reactivity index (z scores: 8.97, 6.01, 3.94, respectively). Mean velocity index based on arterial blood pressure did not reach statistical significance for predicting outcome measured as a continuous variable (p = 0.07) for patients with traumatic brain injury. For patients with subarachnoid hemorrhage, autoregulation reactivity index was the only cerebral autoregulation index that predicted patient outcome measured with the Glasgow Outcome Scale as a continuous outcome (R = 0.82; p = 0.001; z score, 3.39). We found a significant correlation between the duration of monitoring and predictive value for mortality (R = 0.78; p < 0.001). CONCLUSIONS Three cerebral autoregulation indices, pressure reactivity index, mean velocity index based on cerebral perfusion pressure, and autoregulation reactivity index were the best outcome predictors for patients with traumatic brain injury. For patients with subarachnoid hemorrhage, autoregulation reactivity index was the only cerebral autoregulation index predictor of Glasgow Outcome Scale. Continuous assessment of cerebral autoregulation predicted outcome better than intermittent monitoring.
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Czosnyka M, Pickard J, Steiner L. Principles of intracranial pressure monitoring and treatment. HANDBOOK OF CLINICAL NEUROLOGY 2017; 140:67-89. [DOI: 10.1016/b978-0-444-63600-3.00005-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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The best marker for guiding the clinical management of patients with raised intracranial pressure-the RAP index or the mean pulse amplitude? Acta Neurochir (Wien) 2016; 158:1997-2009. [PMID: 27567609 PMCID: PMC5025501 DOI: 10.1007/s00701-016-2932-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 08/08/2016] [Indexed: 01/30/2023]
Abstract
Raised intracranial pressure is a common problem in a variety of neurosurgical conditions including traumatic brain injury, hydrocephalus and intracranial haemorrhage. The clinical management of these patients is guided by a variety of haemodynamic, biochemical and clinical factors. However to date there is no single parameter that is used to guide clinical management of patients with raised intracranial pressure (ICP). However, the role of ICP indices, specifically the mean pulse amplitude (AMP) and RAP index [correlation coefficient (R) between AMP amplitude (A) and mean ICP pressure (P); index of compensatory reserve], as an indicator of true ICP has been investigated. Whilst the RAP index has been used both as a descriptor of neurological deterioration in TBI patients and as a way of characterising the compensatory reserve in hydrocephalus, more recent studies have highlighted the limitation of the RAP index due to the influence that baseline effect errors have on the mean ICP, which is used in the calculation of the RAP index. These studies have suggested that the ICP mean pulse amplitude may be a more accurate marker of true intracranial pressure due to the fact that it is uninfluenced by the mean ICP and, therefore, the AMP may be a more reliable marker than the RAP index for guiding the clinical management of patients with raised ICP. Although further investigation needs to be undertaken in order to fully assess the role of ICP indices in guiding the clinical management of patients with raised ICP, the studies undertaken to date provide an insight into the potential role of ICP indices to treat raised ICP proactively rather than reactively and therefore help prevent or minimise secondary brain injury.
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Abstract
Assessing intracranial pressure (ICP) remains a cornerstone in neurosurgical care. Invasive techniques for monitoring ICP remain the gold standard. The need for a reliable, safe and reproducible technique to non-invasively assess ICP in the context of early screening and in the neurocritical care environment is obvious. Numerous techniques have been described with several novel advances. While none of the currently available techniques appear independently accurate enough to quantify raised ICP, there is some promising work being undertaken.
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27
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Needham E, McFadyen C, Newcombe V, Synnot AJ, Czosnyka M, Menon D. Cerebral Perfusion Pressure Targets Individualized to Pressure-Reactivity Index in Moderate to Severe Traumatic Brain Injury: A Systematic Review. J Neurotrauma 2016; 34:963-970. [PMID: 27246184 DOI: 10.1089/neu.2016.4450] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Traumatic brain injury (TBI) frequently triggers a disruption of cerebral autoregulation. The cerebral perfusion pressure (CPP) at which autoregulation is optimal ("CPPopt") varies between individuals, and can be calculated based on fluctuations between arterial blood pressure and intracranial pressure. This review assesses the effect of individualizing CPP targets to pressure reactivity index (a measure of autoregulation) in patients with TBI. Cochrane Central Register of Controlled Trials, MEDLINE®, Embase, and Cumulative Index of Nursing and Allied Health Literature were searched in March 2015 for studies assessing the effect of targeting CPPopt in TBI. We included all studies that assessed the impact of targeting CPPopt on outcomes including mortality, neurological outcome, and physiological changes. Risk of bias was assessed using the RTI Item Bank and evidence quality was considered using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) criteria. Eight cohort studies (based on six distinct data sets) assessing the association between CPPopt and mortality, Glasgow Outcome Scale and physiological measures in TBI were included. The quality of evidence was deemed very low based on the GRADE criteria. Although the data suggest an association between variation from CPPopt and poor clinical outcome at 6 months, the quality of evidence prevents firm conclusions, particularly regarding causality, from being drawn. Available data suggest that targeting CPPopt might represent a technique to improve outcomes following TBI, but currently there is insufficient high-quality data to support a recommendation for use in clinical practice. Further prospective, randomized controlled studies should be undertaken to clarify its role in the acute management of TBI.
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Affiliation(s)
- Edward Needham
- 1 Department of Neurology, Addenbrookes Hospital, University of Cambridge , Cambridge, United Kingdom
| | - Charles McFadyen
- 2 Division of Anaesthesia, Addenbrookes Hospital, University of Cambridge , Cambridge, United Kingdom
| | - Virginia Newcombe
- 2 Division of Anaesthesia, Addenbrookes Hospital, University of Cambridge , Cambridge, United Kingdom
| | - Anneliese J Synnot
- 3 Australian & New Zealand Intensive Care Research Centre (ANZIC-RC) , School of Public Health and Preventive Medicine, Monash University, Melbourne Victoria, Australia; Cochrane Consumers and Communication Review Group, Centre for Health Communication and Participation, School of Psychology and Public Health, La Trobe University, Melbourne, Australia; National Trauma Research Institute, Melborne, Australia
| | - Marek Czosnyka
- 4 Brain Physics Lab, Division of Neurosurgery, Addenbrookes Hospital, University of Cambridge , Cambridge, United Kingdom
| | - David Menon
- 2 Division of Anaesthesia, Addenbrookes Hospital, University of Cambridge , Cambridge, United Kingdom
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Makarenko S, Griesdale DE, Gooderham P, Sekhon MS. Multimodal neuromonitoring for traumatic brain injury: A shift towards individualized therapy. J Clin Neurosci 2016; 26:8-13. [PMID: 26755455 DOI: 10.1016/j.jocn.2015.05.065] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Accepted: 05/30/2015] [Indexed: 01/08/2023]
Abstract
Multimodal neuromonitoring in the management of traumatic brain injury (TBI) enables clinicians to make individualized management decisions to prevent secondary ischemic brain injury. Traditionally, neuromonitoring in TBI patients has consisted of a combination of clinical examination, neuroimaging and intracranial pressure monitoring. Unfortunately, each of these modalities has its limitations and although pragmatic, this simplistic approach has failed to demonstrate improved outcomes, likely owing to an inability to consider the underlying heterogeneity of various injury patterns. As neurocritical care has evolved, so has our understanding of underlying disease pathophysiology and patient specific considerations. Recent additions to the multimodal neuromonitoring platform include measures of cerebrovascular autoregulation, brain tissue oxygenation, microdialysis and continuous electroencephalography. The implementation of neurocritical care teams to manage patients with advanced brain injury has led to improved outcomes. Herein, we present a narrative review of the recent advances in multimodal neuromonitoring and highlight the utility of dedicated neurocritical care.
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Affiliation(s)
- Serge Makarenko
- Division of Neurosurgery, Department of Surgery, Vancouver General Hospital, University of British Columbia, Vancouver, BC, Canada
| | - Donald E Griesdale
- Department of Anaesthesiology, Pharmacology and Therapeutics, Vancouver General Hospital, University of British Columbia, Vancouver, BC, Canada; Centre for Clinical Epidemiology and Evaluation, Vancouver Coastal Health Research Institute, University of British Columbia, Vancouver, BC, Canada; Division of Critical Care Medicine, Department of Medicine, Vancouver General Hospital, Room 2438, Jim Pattison Pavilion, 2nd Floor, 899 West 12th Avenue, University of British Columbia, Vancouver, BC V5Z 1M9, Canada
| | - Peter Gooderham
- Division of Neurosurgery, Department of Surgery, Vancouver General Hospital, University of British Columbia, Vancouver, BC, Canada
| | - Mypinder S Sekhon
- Division of Critical Care Medicine, Department of Medicine, Vancouver General Hospital, Room 2438, Jim Pattison Pavilion, 2nd Floor, 899 West 12th Avenue, University of British Columbia, Vancouver, BC V5Z 1M9, Canada.
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29
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Abstract
Pressure autoregulation is an important hemodynamic mechanism that protects the brain against inappropriate fluctuations in cerebral blood flow in the face of changing cerebral perfusion pressure (CPP). Static autoregulation represents how far cerebrovascular resistance changes when CPP varies, and dynamic autoregulation represents how fast these changes happen. Both have been monitored in the setting of neurocritical care to aid prognostication and contribute to individualizing CPP targets in patients. Failure of autoregulation is associated with a worse outcome in various acute neurological diseases. Several studies have used transcranial Doppler ultrasound, intracranial pressure (ICP with vascular reactivity as surrogate measure of autoregulation), and near-infrared spectroscopy to continuously monitor the impact of spontaneous fluctuations in CPP on cerebrovascular physiology and to calculate derived variables of autoregulatory efficiency. Many patients who undergo such monitoring demonstrate a range of CPP in which autoregulatory efficiency is optimal. Management of patients at or near this optimal level of CPP is associated with better outcomes in traumatic brain injury. Many of these studies have utilized the concept of the pressure reactivity index, a correlation coefficient between ICP and mean arterial pressure. While further studies are needed, these data suggest that monitoring of autoregulation could aid prognostication and may help identify optimal CPP levels in individual patients.
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Affiliation(s)
- Marek Czosnyka
- Department of Clinical Neurosciences, Division of Neurosurgery, University of Cambridge, Addenbrooke's Hospital, Box 167, Cambridge, CB2 2QQ, UK,
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Reis C, Wang Y, Akyol O, Ho WM, Ii RA, Stier G, Martin R, Zhang JH. What's New in Traumatic Brain Injury: Update on Tracking, Monitoring and Treatment. Int J Mol Sci 2015; 16:11903-65. [PMID: 26016501 PMCID: PMC4490422 DOI: 10.3390/ijms160611903] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 05/04/2015] [Accepted: 05/06/2015] [Indexed: 12/11/2022] Open
Abstract
Traumatic brain injury (TBI), defined as an alteration in brain functions caused by an external force, is responsible for high morbidity and mortality around the world. It is important to identify and treat TBI victims as early as possible. Tracking and monitoring TBI with neuroimaging technologies, including functional magnetic resonance imaging (fMRI), diffusion tensor imaging (DTI), positron emission tomography (PET), and high definition fiber tracking (HDFT) show increasing sensitivity and specificity. Classical electrophysiological monitoring, together with newly established brain-on-chip, cerebral microdialysis techniques, both benefit TBI. First generation molecular biomarkers, based on genomic and proteomic changes following TBI, have proven effective and economical. It is conceivable that TBI-specific biomarkers will be developed with the combination of systems biology and bioinformation strategies. Advances in treatment of TBI include stem cell-based and nanotechnology-based therapy, physical and pharmaceutical interventions and also new use in TBI for approved drugs which all present favorable promise in preventing and reversing TBI.
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Affiliation(s)
- Cesar Reis
- Department of Anesthesiology, Loma Linda University Medical Center, Loma Linda, CA 92354, USA.
| | - Yuechun Wang
- Department of Physiology and Pharmacology, Loma Linda University School of Medicine, 11041 Campus Street, Risley Hall, Room 219, Loma Linda, CA 92354, USA.
- Department of Physiology, School of Medicine, University of Jinan, Guangzhou 250012, China.
| | - Onat Akyol
- Department of Physiology and Pharmacology, Loma Linda University School of Medicine, 11041 Campus Street, Risley Hall, Room 219, Loma Linda, CA 92354, USA.
| | - Wing Mann Ho
- Department of Physiology and Pharmacology, Loma Linda University School of Medicine, 11041 Campus Street, Risley Hall, Room 219, Loma Linda, CA 92354, USA.
- Department of Neurosurgery, University Hospital Innsbruck, Tyrol 6020, Austria.
| | - Richard Applegate Ii
- Department of Anesthesiology, Loma Linda University Medical Center, Loma Linda, CA 92354, USA.
| | - Gary Stier
- Department of Anesthesiology, Loma Linda University Medical Center, Loma Linda, CA 92354, USA.
| | - Robert Martin
- Department of Anesthesiology, Loma Linda University Medical Center, Loma Linda, CA 92354, USA.
| | - John H Zhang
- Department of Anesthesiology, Loma Linda University Medical Center, Loma Linda, CA 92354, USA.
- Department of Physiology and Pharmacology, Loma Linda University School of Medicine, 11041 Campus Street, Risley Hall, Room 219, Loma Linda, CA 92354, USA.
- Department of Neurosurgery, Loma Linda University School of Medicine, Loma Linda, CA 92354, USA.
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Varsos GV, Kasprowicz M, Smielewski P, Czosnyka M. Model-based indices describing cerebrovascular dynamics. Neurocrit Care 2015; 20:142-57. [PMID: 24091657 DOI: 10.1007/s12028-013-9868-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Understanding the dynamic relationship between cerebral blood flow (CBF) and the circulation of cerebrospinal fluid (CSF) can facilitate management of cerebral pathologies. For this reason, various hydrodynamic models have been introduced in order to simulate the phenomena governing the interaction between CBF and CSF. The identification of hydrodynamic models requires an array of signals as input, with the most common of them being arterial blood pressure, intracranial pressure, and cerebral blood flow velocity; monitoring all of them is considered as a standard practice in neurointensive care. Based on these signals, physiological parameters like cerebrovascular resistance, compliances of cerebrovascular bed, and CSF space could then be estimated. Various secondary model-based indices describing cerebrovascular dynamics have been introduced, like the cerebral arterial time constant or critical closing pressure. This review presents model-derived indices that describe cerebrovascular phenomena, the nature of which is both physiological (carbon dioxide reactivity and arterial hypotension) and pathological (cerebral artery stenosis, intracranial hypertension, and cerebral vasospasm). In a neurointensive environment, real-time monitoring of a patient with these indices may be able to provide a detection of the onset of a cerebrovascular phenomenon, which could have otherwise been missed. This potentially "early warning" indicator may then prove to be important for the therapeutic management of the patient.
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Affiliation(s)
- Georgios V Varsos
- Neurosurgical Unit, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK,
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32
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KOIZUMI H, SUEHIRO E, FUJIYAMA Y, SUGIMOTO K, INOUE T, SUZUKI M. Update on intensive neuromonitoring for patients with traumatic brain injury: a review of the literature and the current situation. Neurol Med Chir (Tokyo) 2014; 54:870-7. [PMID: 25367587 PMCID: PMC4533348 DOI: 10.2176/nmc.ra.2014-0168] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 06/28/2014] [Indexed: 11/20/2022] Open
Abstract
Intracranial pressure (ICP) measurements are fundamental in the present protocols for intensive care of patients during the acute stage of severe traumatic brain injury. However, the latest report of a large scale randomized clinical trial indicated no association of ICP monitoring with any significant improvement in neurological outcome in severely head injured patients. Aggressive treatment of patients with therapeutic hypothermia during the acute stage of traumatic brain injury also failed to show any significant beneficial effects on clinical outcome. This lack of significant results in clinical trials has limited the therapeutic strategies available for treatment of severe traumatic brain injury. However, combined application of different types of neuromonitoring, including ICP measurement, may have potential benefits for understanding the pathophysiology of damaged brains. The combination of monitoring techniques is expected to increase the precision of the data and aid in prevention of secondary brain damage, as well as assist in determining appropriate time periods for therapeutic interventions. In this study, we have characterized the techniques used to monitor patients during the acute severe traumatic brain injury stage, in order to establish the beneficial effects on outcome observed in clinical studies conducted in the past and to follow up any valuable clues that point to additional strategies for aggressive management of these patients.
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Affiliation(s)
- Hiroyasu KOIZUMI
- Department of Neurosurgery, Yamaguchi University School of Medicine, Ube, Yamaguchi
| | - Eiichi SUEHIRO
- Department of Neurosurgery, Yamaguchi University School of Medicine, Ube, Yamaguchi
| | - Yuichi FUJIYAMA
- Department of Neurosurgery, Yamaguchi University School of Medicine, Ube, Yamaguchi
| | - Kazutaka SUGIMOTO
- Department of Neurosurgery, Yamaguchi University School of Medicine, Ube, Yamaguchi
| | - Takao INOUE
- Department of Neurosurgery, Yamaguchi University School of Medicine, Ube, Yamaguchi
| | - Michiyasu SUZUKI
- Department of Neurosurgery, Yamaguchi University School of Medicine, Ube, Yamaguchi
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Sekhon MS, Griesdale DE, Robba C, McGlashan N, Needham E, Walland K, Shook AC, Smielewski P, Czosnyka M, Gupta AK, Menon DK. Optic nerve sheath diameter on computed tomography is correlated with simultaneously measured intracranial pressure in patients with severe traumatic brain injury. Intensive Care Med 2014; 40:1267-74. [DOI: 10.1007/s00134-014-3392-7] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 07/01/2014] [Indexed: 10/25/2022]
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Zweifel C, Dias C, Smielewski P, Czosnyka M. Continuous time-domain monitoring of cerebral autoregulation in neurocritical care. Med Eng Phys 2014; 36:638-45. [DOI: 10.1016/j.medengphy.2014.03.002] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Revised: 02/24/2014] [Accepted: 03/10/2014] [Indexed: 12/26/2022]
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Gong X, Liu J, Dong P, Zhang P, Li N, Zhao X, Wang Y. Assessment of dynamic cerebral autoregulation in patients with basilar artery stenosis. PLoS One 2013; 8:e77802. [PMID: 24124620 PMCID: PMC3790759 DOI: 10.1371/journal.pone.0077802] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Accepted: 09/04/2013] [Indexed: 11/20/2022] Open
Abstract
Background and Aims Previous studies have shown impaired cerebral autoregulation (CA) in carotid and middle cerebral artery (MCA) stenosis/occlusion. Little is known about CA in patients with basilar artery (BA) stenosis. We therefore investigated dynamic CA patterns in BA stenosis using transfer function analysis (TFA). Methods We measured spontaneous oscillations of blood flow velocity (CBFV) in the right posterior cerebral artery (PCA), and left MCA and mean arterial pressure (ABP) continuously in 25 patients with BA stenosis (moderate n=16 with 50-69% occlusion and severe n=9 with ≥70% occlusion) and 22 healthy volunteers in supine position during 6 circles per minute deep breath. Analysis was based on the ‘black-box’ model of transfer function deriving phase and gain in both PCA and MCA. Results Though changes of phase shift and gain between the patients and healthy controls were observed in MCA, the differences are however not significant. Phase shift in PCA was significantly decreased in severe stenosis when comparing with healthy controls and moderate stenosis (4.2±34.2° VS 41.1±40.4°, 4.2±34.2° VS 34.2±27.2°, both p<0.05), whilst the gain in PCA is increased for moderate BA stenosis and decreased for severe BA stenosis. Furthermore, we found that phase shift were almost abolished in patients with ischemic stroke who developed unfavorable clinical outcome (mRs>2) on the 90 days after stroke onset. Conclusion Dynamic CA in PCA reduces in patients with severe BA stenosis and those with ischemic stroke who present poor outcome in 90 days after stroke onset. Phase shift might be a sensitive index prompting impaired CA in posterior circulation.
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Affiliation(s)
- Xiping Gong
- Department of Neurology, Beijing Tiantan Hospital, affiliated to Capital Medical University, Beijing, China
| | - Jia Liu
- Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
- * E-mail: (JL); (YW)
| | - Pei Dong
- Department of Neurology, Beijing Tiantan Hospital, affiliated to Capital Medical University, Beijing, China
| | - Pandeng Zhang
- Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Na Li
- Department of Neurology, Beijing Tiantan Hospital, affiliated to Capital Medical University, Beijing, China
| | - Xingquan Zhao
- Department of Neurology, Beijing Tiantan Hospital, affiliated to Capital Medical University, Beijing, China
| | - Yongjun Wang
- Department of Neurology, Beijing Tiantan Hospital, affiliated to Capital Medical University, Beijing, China
- * E-mail: (JL); (YW)
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Ortega-Gutierrez S, Petersen N, Masurkar A, Reccius A, Huang A, Li M, Choi JH, Marshall RS. Reliability, asymmetry, and age influence on dynamic cerebral autoregulation measured by spontaneous fluctuations of blood pressure and cerebral blood flow velocities in healthy individuals. J Neuroimaging 2013; 24:379-86. [PMID: 23607680 DOI: 10.1111/jon.12019] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Revised: 01/03/2013] [Accepted: 02/03/2013] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Cerebral autoregulation (CA) enables the brain to maintain stable cerebral blood flow (CBF). CA can be assessed noninvasively by determining correlations between CBF velocity (CBFV) and spontaneous changes in blood pressure. Postrecording signal analysis methods have included both frequency- and time-domain methods. However, the test-retest reliability, cross-validation, and determination of normal values have not been adequately established. METHODS In 53 healthy volunteers, a transfer function analysis was applied to calculate phase shift (PS) and gain in the low frequency range (.06-.12 Hz) where CA is most apparent. Correlation analysis was used to derive mean velocity index (Mx). Intraclass correlation and bivariate correlation coefficients were applied to assess asymmetry, cross-validity, and test-retest results: The bihemispheric average PS, gain, and Mx means were 45.99+/-14.24°, .62+/-.38 cm/second/mmHg, and .41+/-.13, respectively. Gain exhibited a difference by age (P = .03). PS, gain, and Mx values showed excellent interhemispheric correlation (r > .8; P < .001). PS and gain showed good reliability (R ICC = .632, L ICC = .576; P < .001). PS and Mx showed fair correlation (r = -.37; P < .001). CONCLUSIONS CA parameters obtained by time- and frequency-domain methods correlate well, and show good interhemispheric and test-retest reliability. Group means from healthy controls may provide adequate norms for determining abnormal CA in cerebrovascular patients.
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Lazaridis C, Smielewski P, Steiner LA, Brady KM, Hutchinson P, Pickard JD, Czosnyka M. Optimal cerebral perfusion pressure: are we ready for it? Neurol Res 2013; 35:138-148. [DOI: 10.1179/1743132812y.0000000150] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
Affiliation(s)
- Christos Lazaridis
- Academic Neurosurgical UnitUniversity of Cambridge Clinical School, Cambridge, UK
- Neurosciences Intensive Care UnitMedical University of South Carolina, Charleston, SC, USA
| | - Piotr Smielewski
- Academic Neurosurgical UnitUniversity of Cambridge Clinical School, Cambridge, UK
| | - Luzius A Steiner
- Academic Neurosurgical UnitUniversity of Cambridge Clinical School, Cambridge, UK
- Department of AnesthesiaLausanne University Hospital, Lausanne, Switzerland
| | - Ken M Brady
- Academic Neurosurgical UnitUniversity of Cambridge Clinical School, Cambridge, UK
- Department of Anesthesiology and Pediatrics, Texas Children’s Hospital, Houston, TX, USA
| | - Peter Hutchinson
- Academic Neurosurgical UnitUniversity of Cambridge Clinical School, Cambridge, UK
| | - John D Pickard
- Academic Neurosurgical UnitUniversity of Cambridge Clinical School, Cambridge, UK
| | - Marek Czosnyka
- Academic Neurosurgical UnitUniversity of Cambridge Clinical School, Cambridge, UK
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Continuous monitoring of cerebrovascular reactivity using pulse waveform of intracranial pressure. Neurocrit Care 2012; 17:67-76. [PMID: 22477613 DOI: 10.1007/s12028-012-9687-z] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
BACKGROUND Guidelines for the management of traumatic brain injury (TBI) call for the development of accurate methods for assessment of the relationship between cerebral perfusion pressure (CPP) and cerebral autoregulation and to determine the influence of quantitative indices of pressure autoregulation on outcome. We investigated the relationship between slow fluctuations of arterial blood pressure (ABP) and intracranial pressure (ICP) pulse amplitude (an index called PAx) using a moving correlation technique to reflect the state of cerebral vasoreactivity and compared it to the index of pressure reactivity (PRx) as a moving correlation coefficient between averaged values of ABP and ICP. METHODS A retrospective analysis of prospective 327 TBI patients (admitted on neurocritical care unit of a university hospital in the period 2003-2009) with continuous ABP and ICP monitoring. RESULTS PAx was worse in patients who died compared to those who survived (-0.04 ± 0.15 vs. -0.16 ± 0.15, χ2 = 28, p < 0.001). In contrast to PRx, PAx was able to differentiate between fatal and non-fatal outcome in a group of 120 patients with ICP levels below 15 mmHg (-0.04 ± 0.16 vs. -0.14 ± 0.16, χ2 = 6, p = 0.01). CONCLUSIONS PAx is a new modified index of cerebrovascular reactivity which performs equally well as established PRx in long-term monitoring in severe TBI patients, but importantly is potentially more robust at lower values of ICP. In view of establishing an autoregulation-oriented CPP therapy, continuous determination of PAx is feasible but its value has to be evaluated in a prospective controlled trail.
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Hu X, Gonzalez N, Bergsneider M. Steady-state indicators of the intracranial pressure dynamic system using geodesic distance of the ICP pulse waveform. Physiol Meas 2012; 33:2017-31. [PMID: 23151442 DOI: 10.1088/0967-3334/33/12/2017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Normal functioning of the brain depends on the homeostasis (∼ steady state) of its various physiological sub-systems, one of which is the intracranial pressure (ICP) dynamic system. The ICP dynamic system of an injured brain is susceptible to various acute changes that should ideally be detected by ICP monitoring even for comatose patients. However, the status quo of ICP monitoring solely targets mean ICP. We aimed to demonstrate a novel approach to detect acute deviation from steady state of an ICP dynamic system in an absence of significant mean ICP changes. We hypothesized that steady state of ICP dynamic systems is reflected as ICP pulses of similar mean ICP levels resembling each other for a given subject. A general framework was used to derive such a steady-state indicator that can accommodate different metrics of inter-pulse distance and different statistics of the distance histograms. In addition to conventional Euclidean distance and Pearson correlation, geodesic distance between pulses was introduced as a novel metric. These different ways of calculating steady-state indicators under the proposed framework were evaluated on three types of continuous ICP recordings: (1) those between two consecutive brain imaging studies that demonstrated acute ventricular enlargement for slit ventricle syndrome (SVS) patients undergoing a trial of shunt externalization and clamping (SVS+); (2) those between consecutive brain imaging studies from the SVS patients under the same trial but without ventricular enlargement (SVS-); (3) overnight recordings from normal pressure hydrocephalus (NPH) patients. It was observed that only the standard deviation of geodesic distance correctly differentiated between SVS+ and SVS- and between SVS+ and NPH while avoiding discriminating between SVS- and NPH. It was also found that 45% SVS+ cases had a multimodal geodesic distance histogram while none of SVS- and 3.8% of NPH cases had such a multimodal histogram. Pulses with a large number of distant pulses for the five multimodal-histogram SVS+ cases fell in short time windows indicating that acute ventricular changes may have occurred in these confined time windows during which no significant changes of mean ICP were observed. In contrast, the pulses with a large number of distant pulses for the two multimodal-histogram NPH cases did not cluster temporally. In conclusion, the geodesic inter-pulse distance is a promising metric to quantify distance intrinsic to the underneath geometric structure of ICP signals and hence is a more suitable way to derive a steady-state indicator of an ICP dynamic system.
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Affiliation(s)
- Xiao Hu
- Neural Systems and Dynamics Laboratory, Department of Neurosurgery, David Geffen School of Medicine, University of California, Los Angeles, CA, USA.
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