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Peng Q, Liu X, Ai M, Huang L, Li L, Liu W, Zhao C, Hu C, Zhang L. Cerebral autoregulation-directed optimal blood pressure management reduced the risk of delirium in patients with septic shock. JOURNAL OF INTENSIVE MEDICINE 2024; 4:376-383. [PMID: 39035614 PMCID: PMC11258506 DOI: 10.1016/j.jointm.2023.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 12/05/2023] [Accepted: 12/08/2023] [Indexed: 07/23/2024]
Abstract
Background When resuscitating patients with septic shock, cerebrovascular reactivity parameters are calculated by monitoring regional cerebral oxygen saturation (rSO2) using near-infrared spectroscopy to determine the optimal blood pressure. Here, we aimed to analyze the impact of cerebral autoregulation-directed optimal blood pressure management on the incidence of delirium and the prognosis of patients with septic shock. Methods This prospective randomized controlled clinical study was conducted in the Xiangya Hospital of Central South University, China. Fifty-one patients with septic shock (December 2020-May 2022) were enrolled and randomly allocated to the experimental (n=26) or control group (n=25). Using the ICM+ software, we monitored the dynamic changes in rSO2 and mean arterial pressure (MAP) and calculated the cerebrovascular reactivity parameter tissue oxygen reactivity index to determine the optimal blood pressure to maintain normal cerebral autoregulation function during resuscitation in the experimental group. The control group was treated according to the Surviving Sepsis Campaign Guidelines. Differences in the incidence of delirium and 28-day mortality between the two groups were compared, and the risk factors were analyzed. Results The 51 patients, including 39 male and 12 female, had a mean age of (57.0±14.9) years. The incidence of delirium was 40.1% (23/51), and the 28-day mortality rate was 29.4% (15/51). The mean MAP during the first 24 h of intensive care unit (ICU) admission was higher ([84.5±12.2] mmHg vs. [77.4±11.8] mmHg, P=0.040), and the incidence of delirium was lower (30.8% vs. 60.0%, P=0.036) in the experimental group than in the control group. The use of cerebral autoregulation-directed optimal blood pressure (odds ratio [OR]=0.090, 95% confidence interval [CI]: 0.009 to 0.923, P=0.043) and length of ICU stay (OR=1.473, 95% CI: 1.093 to 1.985, P=0.011) were risk factors for delirium during septic shock. Vasoactive drug dose (OR=8.445, 95% CI: 1.26 to 56.576, P=0.028) and partial pressure of oxygen (PaO2) (OR=0.958, 95% CI: 0.921 to 0.996, P=0.032) were the risk factors for 28-day mortality. Conclusions The use of cerebral autoregulation-directed optimal blood pressure management during shock resuscitation reduces the incidence of delirium in patients with septic shock. Trial Registration ClinicalTrials.gov ldentifer: NCT03879317.
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Affiliation(s)
- Qianyi Peng
- Department of Critical Care Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Hunan Provincial Clinical Research Center for Critical Care Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Xia Liu
- Department of Critical Care Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Hunan Provincial Clinical Research Center for Critical Care Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Meilin Ai
- Department of Critical Care Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Hunan Provincial Clinical Research Center for Critical Care Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Li Huang
- Department of Critical Care Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Hunan Provincial Clinical Research Center for Critical Care Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Li Li
- Department of Critical Care Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Hunan Provincial Clinical Research Center for Critical Care Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Wei Liu
- Department of Critical Care Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Hunan Provincial Clinical Research Center for Critical Care Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Chunguang Zhao
- Department of Critical Care Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Hunan Provincial Clinical Research Center for Critical Care Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Chenghuan Hu
- Department of Critical Care Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Hunan Provincial Clinical Research Center for Critical Care Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Lina Zhang
- Department of Critical Care Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Hunan Provincial Clinical Research Center for Critical Care Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, China
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Kostoglou K, Bello-Robles F, Brassard P, Chacon M, Claassen JA, Czosnyka M, Elting JW, Hu K, Labrecque L, Liu J, Marmarelis VZ, Payne SJ, Shin DC, Simpson D, Smirl J, Panerai RB, Mitsis GD. Time-domain methods for quantifying dynamic cerebral blood flow autoregulation: Review and recommendations. A white paper from the Cerebrovascular Research Network (CARNet). J Cereb Blood Flow Metab 2024:271678X241249276. [PMID: 38688529 DOI: 10.1177/0271678x241249276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
Cerebral Autoregulation (CA) is an important physiological mechanism stabilizing cerebral blood flow (CBF) in response to changes in cerebral perfusion pressure (CPP). By maintaining an adequate, relatively constant supply of blood flow, CA plays a critical role in brain function. Quantifying CA under different physiological and pathological states is crucial for understanding its implications. This knowledge may serve as a foundation for informed clinical decision-making, particularly in cases where CA may become impaired. The quantification of CA functionality typically involves constructing models that capture the relationship between CPP (or arterial blood pressure) and experimental measures of CBF. Besides describing normal CA function, these models provide a means to detect possible deviations from the latter. In this context, a recent white paper from the Cerebrovascular Research Network focused on Transfer Function Analysis (TFA), which obtains frequency domain estimates of dynamic CA. In the present paper, we consider the use of time-domain techniques as an alternative approach. Due to their increased flexibility, time-domain methods enable the mitigation of measurement/physiological noise and the incorporation of nonlinearities and time variations in CA dynamics. Here, we provide practical recommendations and guidelines to support researchers and clinicians in effectively utilizing these techniques to study CA.
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Affiliation(s)
- Kyriaki Kostoglou
- Department of Electrical and Computer Engineering, McGill University, Montreal, QC, Canada
- Institute of Neural Engineering, Graz University of Technology, Graz, Austria
| | - Felipe Bello-Robles
- Departamento de Ingeniería Informática, Universidad de Santiago de Chile, Santiago, Chile
| | - Patrice Brassard
- Department of Kinesiology, Faculty of Medicine, Université Laval, Quebec, QC, Canada
- Research Center of the Institut universitaire de cardiologie et de pneumologie de Québec, Quebec, QC, Canada
| | - Max Chacon
- Departamento de Ingeniería Informática, Universidad de Santiago de Chile, Santiago, Chile
| | - Jurgen Ahr Claassen
- Department of Geriatrics, Radboud University Medical Center, Research Institute for Medical Innovation and Donders Institute, Nijmegen, The Netherlands
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM), Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
| | - Marek Czosnyka
- Department of Clinical Neurosciences, Neurosurgery Department, University of Cambridge, Cambridge, UK
| | - Jan-Willem Elting
- Department of Neurology and Clinical Neurophysiology, University Medical Center Groningen, Groningen, The Netherlands
| | - Kun Hu
- Medical Biodynamics Program, Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
- Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA
| | - Lawrence Labrecque
- Department of Kinesiology, Faculty of Medicine, Université Laval, Quebec, QC, Canada
- Research Center of the Institut universitaire de cardiologie et de pneumologie de Québec, Quebec, QC, Canada
| | - Jia Liu
- Laboratory for Engineering and Scientific Computing, Institute of Advanced Computing and Digital Engineering, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, China
| | - Vasilis Z Marmarelis
- Department Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA, USA
| | - Stephen J Payne
- Institute of Applied Mechanics, National Taiwan University, Taipei, Taiwan
| | - Dae Cheol Shin
- Department Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA, USA
| | - David Simpson
- Institute of Sound and Vibration Research, University of Southampton, Southampton, UK
| | - Jonathan Smirl
- Cerebrovascular Concussion Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
- Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| | - Ronney B Panerai
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM), Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
- NIHR Leicester Biomedical Research Centre, British Heart Foundation, Glenfield Hospital, Leicester, UK
| | - Georgios D Mitsis
- Department of Bioengineering, McGill University, Montreal, QC, Canada
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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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4
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Olsen MH, Riberholt C, Plovsing RR, Berg RMG, Møller K. Diagnostic and prognostic performance of Mxa and transfer function analysis-based dynamic cerebral autoregulation metrics. J Cereb Blood Flow Metab 2022; 42:2164-2172. [PMID: 36008917 PMCID: PMC9580178 DOI: 10.1177/0271678x221121841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 07/19/2022] [Accepted: 07/29/2022] [Indexed: 11/16/2022]
Abstract
Dynamic cerebral autoregulation is often assessed by continuously recorded arterial blood pressure (ABP) and transcranial Doppler-derived mean cerebral blood flow velocity followed by analysis in the time and frequency domain, respectively. Sequential correlation (in the time domain, yielding e.g., the measure mean flow index, Mxa) and transfer function analysis (TFA) (in the frequency domain, yielding, e.g., normalised and non-normalised gain as well as phase in the low frequency domain) are commonly used approaches. This study investigated the diagnostic and prognostic performance of these metrics. We included recordings from 48 healthy volunteers, 19 patients with sepsis, 36 with traumatic brain injury (TBI), and 14 patients admitted to a neurorehabilitation unit. The diagnostic (between healthy volunteers and patients) and prognostic performance (to predict death or poor functional outcome) of Mxa and the TFA measures were assessed by area under the receiver-operating characteristic (AUROC) curves. AUROC curves generally indicated that the measures were 'no better than chance' (AUROC ∼0.5) both for distinguishing between healthy volunteers and patient groups, and for predicting outcomes in our cohort. No metric emerged as superior for distinguishing between healthy volunteers and different patient groups, for assessing the effect of interventions, or for predicting mortality or functional outcome.
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Affiliation(s)
- Markus Harboe Olsen
- Department of Neuroanaesthesiology, Neuroscience Centre, Copenhagen University Hospital – Rigshospitalet, Denmark
| | - Christian Riberholt
- Department of Neuroanaesthesiology, Neuroscience Centre, Copenhagen University Hospital – Rigshospitalet, Denmark
- Department of Neurorehabilitation/Traumatic Brain Injury, Copenhagen University Hospital – Rigshospitalet, Denmark
| | - Ronni R Plovsing
- Department of Anaesthesia, Hvidovre Hospital, University of Copenhagen, Copenhagen, Denmark
- Institute of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ronan MG Berg
- Department of Clinical Physiology, Nuclear Medicine & PET, Copenhagen University Hospital – Rigshospitalet, Denmark
- Centre for Physical Activity Research, Copenhagen University Hospital – Rigshospitalet, Denmark
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Pontypridd, UK
| | - Kirsten Møller
- Department of Neuroanaesthesiology, Neuroscience Centre, Copenhagen University Hospital – Rigshospitalet, Denmark
- Institute of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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5
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Relander FAJ, Ruesch A, Yang J, Acharya D, Scammon B, Schmitt S, Crane EC, Smith MA, Kainerstorfer JM. Using near-infrared spectroscopy and a random forest regressor to estimate intracranial pressure. NEUROPHOTONICS 2022; 9:045001. [PMID: 36247716 PMCID: PMC9552940 DOI: 10.1117/1.nph.9.4.045001] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 09/23/2022] [Indexed: 06/16/2023]
Abstract
SIGNIFICANCE Intracranial pressure (ICP) measurements are important for patient treatment but are invasive and prone to complications. Noninvasive ICP monitoring methods exist, but they suffer from poor accuracy, lack of generalizability, or high cost. AIM We previously showed that cerebral blood flow (CBF) cardiac waveforms measured with diffuse correlation spectroscopy can be used for noninvasive ICP monitoring. Here we extend the approach to cardiac waveforms measured with near-infrared spectroscopy (NIRS). APPROACH Changes in hemoglobin concentrations were measured in eight nonhuman primates, in addition to invasive ICP, arterial blood pressure, and CBF changes. Features of average cardiac waveforms in hemoglobin and CBF signals were used to train a random forest (RF) regressor. RESULTS The RF regressor achieves a cross-validated ICP estimation of 0.937 r 2 , 2.703 - mm Hg 2 mean squared error (MSE), and 95% confidence interval (CI) of [ - 3.064 3.160 ] mmHg on oxyhemoglobin concentration changes; 0.946 r 2 , 2.301 - mmHg 2 MSE, and 95% CI of [ - 2.841 2.866 ] mmHg on total hemoglobin concentration changes; and 0.963 r 2 , 1.688 mmHg 2 MSE, and 95% CI of [ - 2.450 2.397 ] mmHg on CBF changes. CONCLUSIONS This study provides a proof of concept for the use of NIRS in noninvasive ICP estimation.
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Affiliation(s)
- Filip A. J. Relander
- Carnegie Mellon University, Department of Biomedical Engineering, Pittsburgh, Pennsylvania, United States
| | - Alexander Ruesch
- Carnegie Mellon University, Department of Biomedical Engineering, Pittsburgh, Pennsylvania, United States
| | - Jason Yang
- Carnegie Mellon University, Department of Biomedical Engineering, Pittsburgh, Pennsylvania, United States
| | - Deepshikha Acharya
- Carnegie Mellon University, Department of Biomedical Engineering, Pittsburgh, Pennsylvania, United States
| | - Bradley Scammon
- Carnegie Mellon University, Department of Biomedical Engineering, Pittsburgh, Pennsylvania, United States
| | - Samantha Schmitt
- Carnegie Mellon University, Department of Biomedical Engineering, Pittsburgh, Pennsylvania, United States
- Carnegie Mellon University, Neuroscience Institute, Pittsburgh, Pennsylvania, United States
| | - Emily C. Crane
- Carnegie Mellon University, Department of Biomedical Engineering, Pittsburgh, Pennsylvania, United States
| | - Matthew A. Smith
- Carnegie Mellon University, Department of Biomedical Engineering, Pittsburgh, Pennsylvania, United States
- Carnegie Mellon University, Neuroscience Institute, Pittsburgh, Pennsylvania, United States
| | - Jana M. Kainerstorfer
- Carnegie Mellon University, Department of Biomedical Engineering, Pittsburgh, Pennsylvania, United States
- Carnegie Mellon University, Neuroscience Institute, Pittsburgh, Pennsylvania, United States
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6
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Simpson DM, Payne SJ, Panerai RB. The INfoMATAS project: Methods for assessing cerebral autoregulation in stroke. J Cereb Blood Flow Metab 2022; 42:411-429. [PMID: 34279146 PMCID: PMC8851676 DOI: 10.1177/0271678x211029049] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Cerebral autoregulation refers to the physiological mechanism that aims to maintain blood flow to the brain approximately constant when blood pressure changes. Impairment of this protective mechanism has been linked to a number of serious clinical conditions, including carotid stenosis, head trauma, subarachnoid haemorrhage and stroke. While the concept and experimental evidence is well established, methods for the assessment of autoregulation in individual patients remains an open challenge, with no gold-standard having emerged. In the current review paper, we will outline some of the basic concepts of autoregulation, as a foundation for experimental protocols and signal analysis methods used to extract indexes of cerebral autoregulation. Measurement methods for blood flow and pressure are discussed, followed by an outline of signal pre-processing steps. An outline of the data analysis methods is then provided, linking the different approaches through their underlying principles and rationale. The methods cover correlation based approaches (e.g. Mx) through Transfer Function Analysis to non-linear, multivariate and time-variant approaches. Challenges in choosing which method may be 'best' and some directions for ongoing and future research conclude this work.
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Affiliation(s)
- David M Simpson
- Institute of Sound and Vibration Research, University of Southampton, Southampton, UK
| | - Stephen J Payne
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford, UK
| | - Ronney B Panerai
- Department of Cardiovascular Sciences, Leicester Royal Infirmary, Leicester, UK
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7
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Olsen MH, Riberholt CG, Mehlsen J, Berg RM, Møller K. Reliability and validity of the mean flow index (Mx) for assessing cerebral autoregulation in humans: A systematic review of the methodology. J Cereb Blood Flow Metab 2022; 42:27-38. [PMID: 34617816 PMCID: PMC8721771 DOI: 10.1177/0271678x211052588] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Cerebral autoregulation is a complex mechanism that serves to keep cerebral blood flow relatively constant within a wide range of cerebral perfusion pressures. The mean flow index (Mx) is one of several methods to assess dynamic cerebral autoregulation, but its reliability and validity have never been assessed systematically. The purpose of the present systematic review was to evaluate the methodology, reliability and validity of Mx.Based on 128 studies, we found inconsistency in the pre-processing of the recordings and the methods for calculation of Mx. The reliability in terms of repeatability and reproducibility ranged from poor to excellent, with optimal repeatability when comparing overlapping recordings. The discriminatory ability varied depending on the patient populations; in general, those with acute brain injury exhibited a higher Mx than healthy volunteers. The prognostic ability in terms of functional outcome and mortality ranged from chance result to moderate accuracy.Since the methodology was inconsistent between studies, resulting in varying reliability and validity estimates, the results were difficult to compare. The optimal method for deriving Mx is currently unknown.
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Affiliation(s)
- Markus Harboe Olsen
- Department of Neuroanaesthesiology, 53146Rigshospitalet, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Christian Gunge Riberholt
- Department of Neuroanaesthesiology, 53146Rigshospitalet, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.,Department of Neurorehabilitation/Traumatic Brain Injury Unit, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Jesper Mehlsen
- Surgical Pathophysiology Unit, 53146Rigshospitalet, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Ronan Mg Berg
- Department of Clinical Physiology, Nuclear Medicine & PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.,Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.,Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Pontypridd, UK
| | - Kirsten Møller
- Department of Neuroanaesthesiology, 53146Rigshospitalet, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.,Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Gomez A, Batson C, Froese L, Sainbhi AS, Zeiler FA. Utility of Transcranial Doppler in Moderate and Severe Traumatic Brain Injury: A Narrative Review of Cerebral Physiologic Metrics. J Neurotrauma 2021; 38:2206-2220. [PMID: 33554739 PMCID: PMC8328046 DOI: 10.1089/neu.2020.7523] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Since its creation in the 1980s, transcranial Doppler (TCD) has provided a method of non-invasively monitoring cerebral physiology and has become an invaluable tool in neurocritical care. In this narrative review, we examine the role TCD has in the management of the moderate and severe traumatic brain injury (TBI) patient. We examine the principles of TCD and the ways in which it has been applied to gain insight into cerebral physiology following TBI, as well as explore the clinical evidence supporting these applications. Its usefulness as a tool to non-invasively determine intracranial pressure, detect post-traumatic vasospasm, predict patient outcome, and assess the state of cerebral autoregulation are all explored.
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Affiliation(s)
- Alwyn Gomez
- Department of Surgery, University of Manitoba, Winnipeg, Canada
- Department of Anatomy and Cell Science, University of Manitoba, Winnipeg, Canada
| | - Carleen Batson
- Department of Anatomy and Cell Science, University of Manitoba, Winnipeg, Canada
| | - Logan Froese
- Department of Biomedical Engineering, University of Manitoba, Winnipeg, Canada
| | | | - Frederick Adam Zeiler
- Department of Surgery, University of Manitoba, Winnipeg, Canada
- Department of Anatomy and Cell Science, University of Manitoba, Winnipeg, Canada
- Department of Biomedical Engineering, University of Manitoba, Winnipeg, Canada
- Center on Aging, University of Manitoba, Winnipeg, Canada
- Department of Medicine, Addenbrooke's Hospital, University of Cambridge, Cambridge, United Kingdom
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9
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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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Lalou AD, Czosnyka M, Placek MM, Smielewski P, Nabbanja E, Czosnyka Z. CSF Dynamics for Shunt Prognostication and Revision in Normal Pressure Hydrocephalus. J Clin Med 2021; 10:jcm10081711. [PMID: 33921142 PMCID: PMC8071572 DOI: 10.3390/jcm10081711] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 04/09/2021] [Accepted: 04/12/2021] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Despite the quantitative information derived from testing of the CSF circulation, there is still no consensus on what the best approach could be in defining criteria for shunting and predicting response to CSF diversion in normal pressure hydrocephalus (NPH). OBJECTIVE We aimed to review the lessons learned from assessment of CSF dynamics in our center and summarize our findings to date. We have focused on reporting the objective perspective of CSF dynamics testing, without further inferences to individual patient management. DISCUSSION No single parameter from the CSF infusion study has so far been able to serve as an unquestionable outcome predictor. Resistance to CSF outflow (Rout) is an important biological marker of CSF circulation. It should not, however, be used as a single predictor for improvement after shunting. Testing of CSF dynamics provides information on hydrodynamic properties of the cerebrospinal compartment: the system which is being modified by a shunt. Our experience of nearly 30 years of studying CSF dynamics in patients requiring shunting and/or shunt revision, combined with all the recent progress made in producing evidence on the clinical utility of CSF dynamics, has led to reconsidering the relationship between CSF circulation testing and clinical improvement. CONCLUSIONS Despite many open questions and limitations, testing of CSF dynamics provides unique perspectives for the clinician. We have found value in understanding shunt function and potentially shunt response through shunt testing in vivo. In the absence of infusion tests, further methods that provide a clear description of the pre and post-shunting CSF circulation, and potentially cerebral blood flow, should be developed and adapted to the bed-space.
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Affiliation(s)
- Afroditi Despina Lalou
- Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0QQ, UK; (M.C.); (M.M.P.); (P.S.); (E.N.); (Z.C.)
- Correspondence: ; Tel.: +44-774-3567-585
| | - Marek Czosnyka
- Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0QQ, UK; (M.C.); (M.M.P.); (P.S.); (E.N.); (Z.C.)
- Institute of Electronic Systems, Faculty of Electronics and Information Sciences, Warsaw University of Technology, 00-661 Warsaw, Poland
| | - Michal M. Placek
- Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0QQ, UK; (M.C.); (M.M.P.); (P.S.); (E.N.); (Z.C.)
| | - Peter Smielewski
- Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0QQ, UK; (M.C.); (M.M.P.); (P.S.); (E.N.); (Z.C.)
| | - Eva Nabbanja
- Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0QQ, UK; (M.C.); (M.M.P.); (P.S.); (E.N.); (Z.C.)
| | - Zofia Czosnyka
- Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0QQ, UK; (M.C.); (M.M.P.); (P.S.); (E.N.); (Z.C.)
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11
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Papaioannou VE, Budohoski KP, Placek MM, Czosnyka Z, Smielewski P, Czosnyka M. Association of transcranial Doppler blood flow velocity slow waves with delayed cerebral ischemia in patients suffering from subarachnoid hemorrhage: a retrospective study. Intensive Care Med Exp 2021; 9:11. [PMID: 33768351 PMCID: PMC7994457 DOI: 10.1186/s40635-021-00378-8] [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: 11/04/2020] [Accepted: 02/17/2021] [Indexed: 11/25/2022] Open
Abstract
Background Cerebral vasospasm (VS) and delayed cerebral ischemia (DCI) constitute major complications following subarachnoid hemorrhage (SAH). A few studies have examined the relationship between different indices of cerebrovascular dynamics with the occurrence of VS. However, their potential association with the development of DCI remains elusive. In this study, we investigated the pattern of changes of different transcranial Doppler (TCD)-derived indices of cerebrovascular dynamics during vasospasm in patients suffering from subarachnoid hemorrhage, dichotomized by the presence of delayed cerebral ischemia. Methods A retrospective analysis was performed using recordings from 32 SAH patients, diagnosed with VS. Patients were divided in two groups, depending on development of DCI. Magnitude of slow waves (SWs) of cerebral blood flow velocity (CBFV) was measured. Cerebral autoregulation was estimated using the moving correlation coefficient Mxa. Cerebral arterial time constant (tau) was expressed as the product of resistance and compliance. Complexity of CBFV was estimated through measurement of sample entropy (SampEn). Results In the whole population (N = 32), magnitude of SWs of ipsilateral to VS side CBFV was higher during vasospasm (4.15 ± 1.55 vs before: 2.86 ± 1.21 cm/s, p < 0.001). Ipsilateral SWs of CBFV before VS had higher magnitude in DCI group (N = 19, p < 0.001) and were strongly predictive of DCI, with area under the curve (AUC) = 0.745 (p = 0.02). Vasospasm caused a non-significant shortening of ipsilateral values of tau and increase in SampEn in all patients related to pre-VS measurements, as well as an insignificant increase of Mxa in DCI related to non-DCI group (N = 13). Conclusions In patients suffering from subarachnoid hemorrhage, TCD-detected VS was associated with higher ipsilateral CBFV SWs, related to pre-VS measurements. Higher CBFV SWs before VS were significantly predictive of delayed cerebral ischemia.
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Affiliation(s)
- Vasilios E Papaioannou
- Department of Intensive Care Medicine, Alexandroupolis Hospital, Democritus University of Thrace, 68100, Alexandoupolis, Greece. .,Academic Neurosurgery Unit, Brain Physics Lab, Addenbrooke's Hospital, Box 167, Cambridge, CB20QQ, UK.
| | - Karol P Budohoski
- Academic Neurosurgery Unit, Brain Physics Lab, Addenbrooke's Hospital, Box 167, Cambridge, CB20QQ, UK.,Department of Neurosurgery, Cambridge University Hospitals, Cambridge, CB20QQ, UK
| | - Michal M Placek
- Academic Neurosurgery Unit, Brain Physics Lab, Addenbrooke's Hospital, Box 167, Cambridge, CB20QQ, UK.,Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, 50-370, Wrocław, Poland
| | - Zofia Czosnyka
- Academic Neurosurgery Unit, Brain Physics Lab, Addenbrooke's Hospital, Box 167, Cambridge, CB20QQ, UK
| | - Peter Smielewski
- Academic Neurosurgery Unit, Brain Physics Lab, Addenbrooke's Hospital, Box 167, Cambridge, CB20QQ, UK
| | - Marek Czosnyka
- Academic Neurosurgery Unit, Brain Physics Lab, Addenbrooke's Hospital, Box 167, Cambridge, CB20QQ, UK
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Ruesch A, Yang J, Schmitt S, Acharya D, Smith MA, Kainerstorfer JM. Estimating intracranial pressure using pulsatile cerebral blood flow measured with diffuse correlation spectroscopy. BIOMEDICAL OPTICS EXPRESS 2020; 11:1462-1476. [PMID: 32206422 PMCID: PMC7075623 DOI: 10.1364/boe.386612] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 02/11/2020] [Accepted: 02/12/2020] [Indexed: 05/08/2023]
Abstract
Measuring intracranial pressure (ICP) is necessary for the treatment of severe head injury but measurement systems are highly invasive and introduce risk of infection and complications. We developed a non-invasive alternative for quantifying ICP using measurements of cerebral blood flow (CBF) by diffuse correlation spectroscopy. The recorded cardiac pulsation waveform in CBF undergoes morphological changes in response to ICP changes. We used the pulse shape to train a randomized regression forest to estimate the underlying ICP and demonstrate in five non-human primates that DCS-based estimation can explain over 90% of the variance in invasively measured ICP.
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Affiliation(s)
- Alexander Ruesch
- Department of Biomedical Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213, USA
| | - Jason Yang
- Department of Biomedical Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213, USA
| | - Samantha Schmitt
- Department of Biomedical Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213, USA
- Neuroscience Institute, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213, USA
- Department of Ophthalmology, University of Pittsburgh, 203 Lothrop Street, Pittsburgh, PA 15213, USA
| | - Deepshikha Acharya
- Department of Biomedical Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213, USA
| | - Matthew A. Smith
- Department of Biomedical Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213, USA
- Neuroscience Institute, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213, USA
- Department of Ophthalmology, University of Pittsburgh, 203 Lothrop Street, Pittsburgh, PA 15213, USA
| | - Jana M. Kainerstorfer
- Department of Biomedical Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213, USA
- Neuroscience Institute, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213, USA
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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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14
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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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15
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The Correlation Between Intracranial Pressure and Cerebral Blood Flow Velocity During ICP Plateau Waves. ACTA NEUROCHIRURGICA. SUPPLEMENT 2016; 122:81-3. [PMID: 27165882 DOI: 10.1007/978-3-319-22533-3_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
We previously showed that the flow-ICP index (Fix), a moving correlation coefficient between intracranial pressure (ICP) and cerebral blood flow velocity (CBFV), had marginally greater prognostic value for patients with traumatic brain injury (TBI) than an index of cerebral autoregulation (mean index, Mx). The aim of this study was to further examine the clinical and physiological relevance of Fix by studying its behaviour during ICP plateau waves in patients with TBI. Twenty-nine recordings of CBFV made during ICP plateau waves were analysed. Both Mx and Fix at baseline and peak ICP were significantly different, although the magnitude of Fix change was slightly greater. The correlation between Fix and cerebral perfusion pressure (CPP) was stronger than that between Mx and CPP. Unlike in our previous study, plotting Fix against CPP revealed a peak value in the range of "optimal" CPP, as indicated by the Mx versus CPP plot. The findings suggest that during periods of reduced CPP caused by plateau waves, the dynamic behaviour of Fix is similar to that of a measure of cerebral autoregulation. This conclusion needs to be verified against similar results obtained during episodes of supranormal CPP.
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16
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Liu X, Czosnyka M, Donnelly J, Budohoski KP, Varsos GV, Nasr N, Brady KM, Reinhard M, Hutchinson PJ, Smielewski P. Comparison of frequency and time domain methods of assessment of cerebral autoregulation in traumatic brain injury. J Cereb Blood Flow Metab 2015; 35:248-56. [PMID: 25407266 PMCID: PMC4426741 DOI: 10.1038/jcbfm.2014.192] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 09/29/2014] [Accepted: 10/14/2014] [Indexed: 01/31/2023]
Abstract
The impulse response (IR)-based autoregulation index (ARI) allows for continuous monitoring of cerebral autoregulation using spontaneous fluctuations of arterial blood pressure (ABP) and cerebral flow velocity (FV). We compared three methods of autoregulation assessment in 288 traumatic brain injury (TBI) patients managed in the Neurocritical Care Unit: (1) IR-based ARI; (2) transfer function (TF) phase, gain, and coherence; and (3) mean flow index (Mx). Autoregulation index was calculated using the TF estimation (Welch method) and classified according to the original Tiecks' model. Mx was calculated as a correlation coefficient between 10-second averages of ABP and FV using a moving 300-second data window. Transfer function phase, gain, and coherence were extracted in the very low frequency (VLF, 0 to 0.05 Hz) and low frequency (LF, 0.05 to 0.15 Hz) bandwidths. We studied the relationship between these parameters and also compared them with patients' Glasgow outcome score. The calculations were performed using both cerebral perfusion pressure (CPP; suffix 'c') as input and ABP (suffix 'a'). The result showed a significant relationship between ARI and Mx when using either ABP (r=-0.38, P<0.001) or CPP (r=-0.404, P<0.001) as input. Transfer function phase and coherence_a were significantly correlated with ARI_a and ARI_c (P<0.05). Only ARI_a, ARI_c, Mx_a, Mx_c, and phase_c were significantly correlated with patients' outcome, with Mx_c showing the strongest association.
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Affiliation(s)
- Xiuyun Liu
- Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK
| | - Marek Czosnyka
- 1] Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK [2] Institute of Electronic Systems, Warsaw University of Technology, Warsaw, Poland
| | - Joseph Donnelly
- Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK
| | - Karol P Budohoski
- Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK
| | - Georgios V Varsos
- Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK
| | - Nathalie Nasr
- 1] Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK [2] Service de Neurologie Vasculaire, Hôpital Rangueil, INSERM U1048 - Team 11 (I2MC-Toulouse), Université de Toulouse III, Toulouse, France
| | - Ken M Brady
- Baylor College of Medicine, Texas Children's Hospital, Houston, Texas, USA
| | - Matthias Reinhard
- Department of Neurology, University Hospital, University of Freiburg, Freiburg, Germany
| | - Peter J Hutchinson
- Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK
| | - Peter Smielewski
- Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK
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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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18
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Blaine Easley R, Kibler KK, Brady KM, Joshi B, Ono M, Brown C, Hogue CW. Continuous cerebrovascular reactivity monitoring and autoregulation monitoring identify similar lower limits of autoregulation in patients undergoing cardiopulmonary bypass. Neurol Res 2013; 35:344-54. [PMID: 23540403 DOI: 10.1179/1743132812y.0000000145] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
OBJECTIVES Cerebrovascular autoregulation can be monitored with a moving linear correlation of blood pressure to cerebral blood flow velocity (mean velocity index, Mx) during cardiopulmonary bypass (CPB). Vascular reactivity can be monitored with a moving linear correlation of blood pressure to cerebral blood volume trended with near-infrared spectroscopy (hemoglobin volume index, HVx). We hypothesized that the lower limits of autoregulation (LLA) and the optimal blood pressure (ABPopt) associated with the most active autoregulation could be determined by HVx in patients undergoing CPB. METHODS Adult patients (n = 109) who underwent CPB for cardiac surgery had monitoring of both autoregulation (Mx) and vascular reactivity (HVx). Individual curves of Mx and HVx were constructed by placing each in 5 mmHg bins. The LLA and ABPopt for each subject were then identified by both methods and compared for agreement by correlation analysis and Bland-Altman. RESULTS The average LLA defined by Mx compared to HVx were comparable (66±13 and 66±12 mmHg). Correlation between the LLA defined by Mx and HVx was significant (Pearson r = 0.2867; P = 0.0068). The average ABPopt with the most robust autoregulation by Mx was comparable to HVx (75±11 and 74±13 mmHg) with significant correlation (Pearson r = 0.5915; P < or =0.0001). DISCUSSION Autoregulation and vascular reactivity monitoring are expected to be distinct, as flow and volume have different phasic relationships to pressure when cerebrovascular autoregulation is active. However, the two metrics have good agreement when identifying the LLA and optimal blood pressure in patients during CPB.
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Affiliation(s)
- R Blaine Easley
- Baylor College of Medicine, Texas Children's Hospital, Houston, TX 77030, USA.
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19
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Critical Thresholds for Transcranial Doppler Indices of Cerebral Autoregulation in Traumatic Brain Injury. Neurocrit Care 2010; 14:188-93. [DOI: 10.1007/s12028-010-9492-5] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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20
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Zweifel C, Castellani G, Czosnyka M, Carrera E, Brady KM, Kirkpatrick PJ, Pickard JD, Smielewski P. Continuous assessment of cerebral autoregulation with near-infrared spectroscopy in adults after subarachnoid hemorrhage. Stroke 2010; 41:1963-8. [PMID: 20651272 DOI: 10.1161/strokeaha.109.577320] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE In patients with subarachnoid hemorrhage, the assessment of cerebral autoregulation aids in prognosis as well as detection of vasospasm. Mx is a validated index of cerebral autoregulation based on measures of cerebral perfusion pressure and mean flow velocity on transcranial Doppler but is impractical for longer-term monitoring. Near-infrared spectroscopy is noninvasive and suitable for continuous monitoring of cerebral tissue oxygenation using the Tissue Oxygenation Index. In this study, we compared near-infrared spectroscopy-based indices of cerebral autoregulation (TOx) with Mx in patients with subarachnoid hemorrhage. METHODS Arterial blood pressure, intracranial pressure, mean flow velocity, and Tissue Oxygenation Index were recorded. Mx and TOx were calculated as moving correlation coefficients between 10-second averaged values of cerebral perfusion pressure and mean flow velocity and between cerebral perfusion pressure and Tissue Oxygenation Index. We also calculated TOxA, the moving correlation coefficient between arterial blood pressure and Tissue Oxygenation Index. RESULTS Fifty-one recording sessions were performed in 27 patients with subarachnoid hemorrhage with a total duration of 62.5 hours. Correlations of Mx and TOx over time varied markedly among individual recordings. However, time-averaging over the entire recording interval in each of the 51 recordings, we found correlations between Mx and TOx and between Mx and TOxA were highly significant. This correlation was even stronger after correction for multiple sampling for each patient, reaching r=0.81 for Mx and TOx and r=0.72 for Mx and TOxA. CONCLUSIONS Near-infrared spectroscopy can be used to continuously assess cerebral autoregulation in adults after subarachnoid hemorrhage.
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Affiliation(s)
- Christian Zweifel
- Academic Neurosurgical Unit, University of Cambridge Clinical School, Cambridge, UK.
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21
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Noninvasive autoregulation monitoring with and without intracranial pressure in the naive piglet brain. Anesth Analg 2010; 111:191-5. [PMID: 20519421 DOI: 10.1213/ane.0b013e3181e054ba] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Cerebrovascular autoregulation monitoring is often desirable for critically ill patients in whom intracranial pressure (ICP) is not measured directly. Without ICP, arterial blood pressure (ABP) is a substitute for cerebral perfusion pressure (CPP) to gauge the constraint of cerebral blood flow across pressure changes. We compared the use of ABP versus CPP to measure autoregulation in a piglet model of arterial hypotension. METHODS Our database of neonatal piglet (5-7 days old) experiments was queried for animals with naïve ICP that were made lethally hypotensive to determine the lower limit of autoregulation (LLA). Twenty-five piglets were identified, each with continuous recordings of ICP, regional cerebral oximetry (rSo2), and cortical red cell flux (laser Doppler). Autoregulation was assessed with the cerebral oximetry index (COx) in 2 ways: linear correlation between ABP and rSo2 (COx(ABP)) and between CPP and rSo2 (COx(CPP)). The lower limits of autoregulation were determined from plots of red cell flux versus ABP. Averaged values of COx(ABP) and COx(CPP) from 5 mm Hg ABP bins were used to show receiver operating characteristics for the 2 methods. RESULTS COx(ABP) and COx(CPP) yielded identical receiver operating characteristic curve areas of 0.91 (95% confidence interval [CI], 0.88-0.95) for determining the LLA. However, the thresholds for the 2 methods differed: a threshold COx(ABP) of 0.5 was 89% sensitive (95% CI, 81%-94%) and 81% specific (95% CI, 73%-88%) for detecting ABP below the LLA. A threshold COx(CPP) of 0.42 gave the same 89% sensitivity (95% CI, 81%-94%) with 77% specificity (95% CI, 69%-84%). CONCLUSIONS The use of ABP instead of CPP for autoregulation monitoring in the naïve brain with COx results in a higher threshold value to discriminate ABP above from ABP below the LLA. However, accuracy was similar with the 2 methods. These findings support and refine the use of near-infrared spectroscopy to monitor autoregulation in patients without ICP monitors.
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Zweifel C, Czosnyka M, Lavinio A, Castellani G, Kim DJ, Carrera E, Pickard JD, Kirkpatrick PJ, Smielewski P. A comparison study of cerebral autoregulation assessed with transcranial Doppler and cortical laser Doppler flowmetry. Neurol Res 2009; 32:425-8. [PMID: 19703359 DOI: 10.1179/174313209x459165] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
OBJECTIVES We compared autoregulation monitored with cortical laser Doppler flowmetry (LDF) and autoregulation monitored with transcranial Doppler (TCD) in the middle cerebral artery (MCA) to verify the hypothesis that, following brain trauma, cortical vessel autoregulation to intracranial hypertension is different than assessed in the MCA. METHODS Data collected from 29 head injured patients were analysed retrospectively. Arterial blood pressure (ABP), intracranial pressure (ICP), flow velocity (FV) of the MCA and cortical flux (LDF) were monitored. Indices of cortical autoregulation (Lx) and autoregulation of cerebral blood flow in the MCA (Mx) were calculated as a moving correlation coefficient between slow waves of LDF and cerebral perfusion pressure (CPP) (Lx) or FV and CPP (Mx), respectively. Intact autoregulation was indicated by negative values for Lx and Mx; disturbed autoregulation was reflected by positive values. RESULTS FV and LDF showed a high coherence in the slow wave spectrum of 1-4 cycles/min (mean: 0.79 +/- 0.12), indicating that similar information regarding autoregulation is carried by both signals. Mx and Lx correlated in all patients (R=0.43, p=0.02). On average, Lx was significantly higher than Mx; the mean difference was 0.13 +/- 0.38 (p=0.032), potentially due to severe intracranial hypertension above 40 mmHg, driving CPP values below 60 mmHg. CONCLUSION After traumatic brain injury, cortical autoregulation appears to be worse than autoregulation assessed in the MCA during rising ICP and falling CPP. When CPP is above 60 mmHg, cortical assessed autoregulation is similar to autoregulation assessed in the MCA.
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Affiliation(s)
- Christian Zweifel
- Academic Neurosurgical Unit, University of Cambridge Clinical School, Cambridge, UK.
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Monitoring of cerebrovascular autoregulation: facts, myths, and missing links. Neurocrit Care 2009; 10:373-86. [PMID: 19127448 DOI: 10.1007/s12028-008-9175-7] [Citation(s) in RCA: 227] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2008] [Accepted: 12/02/2008] [Indexed: 12/16/2022]
Abstract
UNLABELLED The methods for continuous assessment of cerebral autoregulation using correlation, phase shift, or transmission (either in time- or frequency-domain) were introduced a decade ago. They express dynamic relationships between slow waves of transcranial Doppler (TCD), blood flow velocity (FV) and cerebral perfusion pressure (CPP), or arterial pressure (ABP). We review a methodology and clinical application of indices useful for monitoring cerebral autoregulation and pressure-reactivity in various scenarios of neuro-critical care. FACTS Poor autoregulation and loss of pressure-reactivity are independent predictors of fatal outcome following head injury. Autoregulation is impaired by too low or too high CPP when compared to autoregulation with normal CPP (usually between 60 and 85 mmHg; and these limits are highly individual). Hemispheric asymmetry of the bi-laterally assessed autoregulation has been associated with asymmetry of CT scan findings: autoregulation was found to be worse ipsilateral to contusion or lateralized edema causing midline shift. The pressure-reactivity (PRx index) correlated with a state of low CBF and CMRO2 revealed using PET studies. The PRx is easier to monitor over prolonged periods of time than the TCD-based indices as it does not require fixation of external probes. Continuous monitoring with the PRx can be used to direct CPP-oriented therapy by determining the optimal CPP for pressure-reactivity. Autoregulation indices are able to reflect transient changes of autoregulation, as seen during plateau waves of ICP. However, minute-to-minute assessment of autoregulation has a poor signal-to-noise ratio. Averaging across time (30 min) or by combining with other relevant parameters improves the accuracy. MYTHS: It is debatable whether the TCD-based indices in head injured patients can be calculated using ABP instead of CPP. Thresholds for functional and disturbed autoregulation dramatically depends on arterial tension of CO2--therefore, comparison between patients cannot be performed without comparing their PaCO2. The TCD pulsatility index cannot accurately detect the lower limit of autoregulation. MISSING LINKS: We still do not know whether autoregulation-oriented therapy can be understood as a consensus between CPP-directed protocols and the Lund-concept. What are the links between endothelial function and autoregulation indices? Can autoregulation after head injury be improved with statins or EPO, as in subarachnoid hemorrhage? In conclusion, monitoring cerebral autoregulation can be used in a variety of clinical scenarios and may be helpful in delineating optimal therapeutic strategies.
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Bergui M, Bradac GB. Hypertonic Saline. J Neurosurg 2008; 108:632; author reply 632-3. [DOI: 10.3171/jns/2008/108/3/0632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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