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Liang Y, Gao ZZ, Chen HY, Gao HK, Qiang XP, Wang J. Assessment of Dynamic Cerebral Autoregulation During Long-Term Exposure to High Altitude in Normal Subjects by Ultrasonography. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2024; 43:1441-1448. [PMID: 38700100 DOI: 10.1002/jum.16467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2024] [Accepted: 03/30/2024] [Indexed: 05/05/2024]
Abstract
PURPOSE To evaluate changes in dynamic cerebral autoregulation (CA) during short-term and long-term exposure to high altitude with ultrasonography, and also study the sex differences in the response of CA to altitude. METHODS We assessed the differences in dynamic CA and measured with Doppler ultrasound of the bilateral internal carotid artery (ICA), vertebral artery (VA), and middle cerebral artery (MCA) and the values of basic information within 48 hours and at 2 years after arrival at Tibet in 65 healthy Han young Chinese volunteers, meanwhile, we compared the resistance index (RI) and pulsatility index (PI) of the right MCA at inhale oxygen 8 minutes when a newcomer with 2 years after arrival at Tibet. RESULTS With 2 years of altitude exposure, the SaO2 of all subjects was above 90%, the mean PEF, DAP, and HR values decreased, HGB increased compared within 48 hours in same-gender groups. Comparisons of cerebral hemodynamics between before 2 years and after 2 years within male and female groups, the mean RI and PI values of bilateral MCA after 2 years were significantly higher than before 2 years, at the same time, the mean RI and PI values of bilateral ICA were significant differences (P < .05) between male groups, with regard to female groups, showed that the mean RI and PI values of bilateral VA were significant differences (P < .05). Comparisons of Right MCA hemodynamics between after oxygen uptake 8 minutes and 2 years, the mean RI and PI values were no significant difference within male and female groups (P > .05). CONCLUSIONS Acute mountain sickness could result from an alteration of dynamic autoregulation of cerebral blood flow, but the impaired autoregulation may be corrected with the extension of time, furthermore, the response of CA to altitude in males and females are different.
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Affiliation(s)
- Yuan Liang
- Department of Ultrasonic Medicine, Tangdu Hospital, Air Force Medical University, Xi'an, China
| | - Zi Zhao Gao
- Department of Pathology, School of Basic Medicine and Xijing Hospital, Air Force Medical University, Xi'an, China
| | - Hong Yu Chen
- Department of Ultrasonic Medicine, Tangdu Hospital, Air Force Medical University, Xi'an, China
| | - Hong Kui Gao
- Department of Ultrasonic Medicine, Tangdu Hospital, Air Force Medical University, Xi'an, China
| | - Xiao Peng Qiang
- Department of Ultrasonic Medicine, Tangdu Hospital, Air Force Medical University, Xi'an, China
| | - Jia Wang
- Department of Ultrasonic Medicine, Tangdu Hospital, Air Force Medical University, Xi'an, China
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2
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Shali RK, Setarehdan SK, Seifi B. Functional near-infrared spectroscopy based blood pressure variations and hemodynamic activity of brain monitoring following postural changes: A systematic review. Physiol Behav 2024; 281:114574. [PMID: 38697274 DOI: 10.1016/j.physbeh.2024.114574] [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: 12/19/2023] [Revised: 04/03/2024] [Accepted: 04/26/2024] [Indexed: 05/04/2024]
Abstract
Postural change from supine or sitting to standing up leads to displacement of 300 to 1000 mL of blood from the central parts of the body to the lower limb, which causes a decrease in venous return to the heart, hence decrease in cardiac output, causing a drop in blood pressure. This may lead to falling down, syncope, and in general reducing the quality of daily activities, especially in the elderly and anyone suffering from nervous system disorders such as Parkinson's or orthostatic hypotension (OH). Among different modalities to study brain function, functional near-infrared spectroscopy (fNIRS) is a neuroimaging method that optically measures the hemodynamic response in brain tissue. Concentration changes in oxygenated hemoglobin (HbO2) and deoxygenated hemoglobin (HHb) are associated with brain neural activity. fNIRS is significantly more tolerant to motion artifacts compared to fMRI, PET, and EEG. At the same time, it is portable, has a simple structure and usage, is safer, and much more economical. In this article, we systematically reviewed the literature to examine the history of using fNIRS in monitoring brain oxygenation changes caused by sudden changes in body position and its relationship with the blood pressure changes. First, the theory behind brain hemodynamics monitoring using fNIRS and its advantages and disadvantages are presented. Then, a study of blood pressure variations as a result of postural changes using fNIRS is described. It is observed that only 58 % of the references concluded a positive correlation between brain oxygenation changes and blood pressure changes. At the same time, 3 % showed a negative correlation, and 39 % did not show any correlation between them.
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Affiliation(s)
- Roya Kheyrkhah Shali
- School of Electrical and Computer Engineering, College of Engineering, University of Tehran, Tehran, Iran.
| | - Seyed Kamaledin Setarehdan
- School of Electrical and Computer Engineering, College of Engineering, University of Tehran, Tehran, Iran
| | - Behjat Seifi
- Faculty of Medical Science, University of Tehran, Tehran, Iran
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3
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Mishra S, Grewal J, Wal P, Bhivshet GU, Tripathi AK, Walia V. Therapeutic potential of vasopressin in the treatment of neurological disorders. Peptides 2024; 174:171166. [PMID: 38309582 DOI: 10.1016/j.peptides.2024.171166] [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: 10/19/2023] [Revised: 01/18/2024] [Accepted: 01/29/2024] [Indexed: 02/05/2024]
Abstract
Vasopressin (VP) is a nonapeptide made of nine amino acids synthesized by the hypothalamus and released by the pituitary gland. VP acts as a neurohormone, neuropeptide and neuromodulator and plays an important role in the regulation of water balance, osmolarity, blood pressure, body temperature, stress response, emotional challenges, etc. Traditionally VP is known to regulate the osmolarity and tonicity. VP and its receptors are widely expressed in the various region of the brain including cortex, hippocampus, basal forebrain, amygdala, etc. VP has been shown to modulate the behavior, stress response, circadian rhythm, cerebral blood flow, learning and memory, etc. The potential role of VP in the regulation of these neurological functions have suggested the therapeutic importance of VP and its analogues in the management of neurological disorders. Further, different VP analogues have been developed across the world with different pharmacotherapeutic potential. In the present work authors highlighted the therapeutic potential of VP and its analogues in the treatment and management of various neurological disorders.
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Affiliation(s)
- Shweta Mishra
- SGT College of Pharmacy, SGT University, Gurugram, India
| | - Jyoti Grewal
- Maharisi Markandeshwar University, Sadopur, India
| | - Pranay Wal
- Pranveer Singh Institute of Pharmacy, Kanpur, India
| | | | | | - Vaibhav Walia
- SGT College of Pharmacy, SGT University, Gurugram, India.
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4
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Tymko MM. Unveiling the enigma from sick to beauty: Hungry to standardize metrics for dynamic cerebral autoregulation. Exp Physiol 2024; 109:472-473. [PMID: 38402582 PMCID: PMC10988677 DOI: 10.1113/ep091781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Accepted: 02/13/2024] [Indexed: 02/27/2024]
Affiliation(s)
- Michael M. Tymko
- Integrative Cerebrovascular and Environmental Physiology SB Laboratory, Department of Human Health and Nutritional Sciences, College of Biological ScienceUniversity of GuelphGuelphOntarioCanada
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5
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Thornton T, Mills D, Bliss E. The impact of lipopolysaccharide on cerebrovascular function and cognition resulting from obesity-induced gut dysbiosis. Life Sci 2024; 336:122337. [PMID: 38072189 DOI: 10.1016/j.lfs.2023.122337] [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: 09/20/2023] [Revised: 11/23/2023] [Accepted: 12/05/2023] [Indexed: 12/24/2023]
Abstract
Obesity is a worldwide epidemic coinciding with a concomitant increase in the incidence of neurodegenerative diseases, particularly dementia. Obesity is characterised by increased adiposity, chronic low-grade systemic inflammation, and oxidative stress, which promote endothelial dysfunction. Endothelial dysfunction reduces cerebrovascular function leading to reduced cerebral blood flow and, eventually, cognitive decline, thus predisposing to a neurodegenerative disease. Obesity is also characterised by gut dysbiosis and a subsequent increase in the lipopolysaccharide which increasingly activates toll-like receptor 4 (TLR4) and further promotes chronic low-grade systemic inflammation. This also disrupts the crosstalk within the gut-brain axis, thus influencing the functions of the central nervous system, including cognition. However, the mechanisms by which obesity-related increases in oxidative stress, inflammation and endothelial dysfunction are driven by, or associated with, increased systemic lipopolysaccharide leading to reduced cerebrovascular function and cognition, beyond normal ageing, have not been elucidated. Hence, this review examines how increased concentrations of lipopolysaccharide and the subsequent increased TLR4 activation observed in obesity exacerbate the development of obesity-induced reductions in cerebrovascular function and cognition.
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Affiliation(s)
- Tammy Thornton
- School of Health and Medical Sciences, University of Southern Queensland, Ipswich, QLD 4305, Australia; Respiratory and Exercise Physiology Research Group, School of Health and Medical Sciences, University of Southern Queensland, Ipswich, QLD 4305, Australia.
| | - Dean Mills
- School of Health and Medical Sciences, University of Southern Queensland, Ipswich, QLD 4305, Australia; Respiratory and Exercise Physiology Research Group, School of Health and Medical Sciences, University of Southern Queensland, Ipswich, QLD 4305, Australia; Centre for Health Research, Institute for Resilient Regions, University of Southern Queensland, Ipswich, QLD 4305, Australia; Molecular Biomarkers Research Group, University of Southern Queensland, Toowoomba, QLD 4350, Australia
| | - Edward Bliss
- School of Health and Medical Sciences, University of Southern Queensland, Ipswich, QLD 4305, Australia; Respiratory and Exercise Physiology Research Group, School of Health and Medical Sciences, University of Southern Queensland, Ipswich, QLD 4305, Australia; Centre for Health Research, Institute for Resilient Regions, University of Southern Queensland, Ipswich, QLD 4305, Australia; Molecular Biomarkers Research Group, University of Southern Queensland, Toowoomba, QLD 4350, Australia
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6
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Venkatraghavan L, Rosen C, McKetton L, Poublanc J, Sobczyk O, Duffin J, Tymianski M, Fisher JA, Mikulis DJ. Brain Stress Test for Assessing Risk for Hemodynamic Stroke. Can J Neurol Sci 2024; 51:57-63. [PMID: 36624923 DOI: 10.1017/cjn.2023.3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND In patients with intracranial steno-occlusive disease (SOD), the risk of hemodynamic stroke depends on the poststenotic vasodilatory reserve. Cerebrovascular reactivity (CVR) is a test for vasodilatory reserve. We tested for vasodilatory reserve by using PETCO2 as the stressor, and Blood Oxygen Level Dependent (BOLD) MRI as a surrogate of blood flow. We correlate the CVR to the incidence of stroke after a 1-year follow-up in patients with symptomatic intracranial SOD. METHODS In this retrospective study, 100 consecutive patients with symptomatic intracranial SOD that had undergone CVR testing were identified. CVR was measured as % BOLD MR signal intensity/mmHg PETCO2. All patients with normal CVR were treated with optimal medical therapy; those with abnormal CVR were offered revascularization where feasible. We determined the incidence of stroke at 1 year. RESULTS 83 patients were included in the study. CVR was normal in 14 patients and impaired in 69 patients ipsilateral to the lesion. Of these, 53 underwent surgical revascularization. CVR and symptoms improved in 86% of the latter. The overall incidence of stroke was 4.8 % (4/83). All strokes occurred in patients with impaired CVR (4/69; 2/53 in the surgical group, all in the nonrevascularized hemisphere), and none in patients with normal CVR (0/14). CONCLUSION Our study confirms that CO2-BOLD MRI CVR can be used as a brain stress test for the assessment of cerebrovascular reserve. Impaired CVR is associated with a higher incidence of stroke and normal CVR despite significant stenosis is associated with a low risk for stroke.
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Affiliation(s)
| | - Casey Rosen
- Division of Neuroradiology, Joint Department of Medical Imaging, University Health Network, Toronto, ON, Canada
| | - Larissa McKetton
- Division of Neuroradiology, Joint Department of Medical Imaging, University Health Network, Toronto, ON, Canada
| | - Julien Poublanc
- Division of Neuroradiology, Joint Department of Medical Imaging, University Health Network, Toronto, ON, Canada
| | - Olivia Sobczyk
- Division of Neuroradiology, Joint Department of Medical Imaging, University Health Network, Toronto, ON, Canada
| | - James Duffin
- Department of Physiology, The University of Toronto, Toronto, ON, Canada
| | - Michael Tymianski
- Division of Neurosurgery, University Health Network, University of Toronto, Toronto, ON, Canada
| | - Joseph A Fisher
- Department of Anaesthesia, University Health Network, Toronto, ON, Canada
| | - David J Mikulis
- Division of Neuroradiology, Joint Department of Medical Imaging, University Health Network, Toronto, ON, Canada
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7
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Andersen L, Appelblad M, Wiklund U, Sundström N, Svenmarker S. Our initial experience of monitoring the autoregulation of cerebral blood flow during cardiopulmonary bypass. THE JOURNAL OF EXTRA-CORPOREAL TECHNOLOGY 2023; 55:209-217. [PMID: 38099638 PMCID: PMC10723576 DOI: 10.1051/ject/2023032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 07/05/2023] [Indexed: 12/17/2023]
Abstract
BACKGROUND Cerebral blood flow (CBF) is believed to be relatively constant within an upper and lower blood pressure limit. Different methods are available to monitor CBF autoregulation during surgery. This study aims to critically analyze the application of the cerebral oxygenation index (COx), one of the commonly used techniques, using a reference to data from a series of clinical registrations. METHOD CBF was monitored using near-infrared spectroscopy, while cerebral blood pressure was estimated by recordings obtained from either the radial or femoral artery in 10 patients undergoing cardiopulmonary bypass. The association between CBF and blood pressure was calculated as a moving continuous correlation coefficient. A COx index > 0.4 was regarded as a sign of abnormal cerebral autoregulation (CA). Recordings were examined to discuss reliability measures and clinical feasibility of the measurements, followed by interpretation of individual results, identification of possible pitfalls, and suggestions of alternative methods. RESULTS AND CONCLUSION Monitoring of CA during cardiopulmonary bypass is intriguing and complex. A series of challenges and limitations should be considered before introducing this method into clinical practice.
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Affiliation(s)
- Leon Andersen
- Heart Centre, Department of Public Health and Clinical Medicine, Umeå University 901 87 Umeå Sweden
| | - Micael Appelblad
- Heart Centre, Department of Public Health and Clinical Medicine, Umeå University 901 87 Umeå Sweden
| | - Urban Wiklund
- Department of Radiation Sciences, Radiation Physics, Biomedical Engineering, Umeå University 901 87 Umeå Sweden
| | - Nina Sundström
- Department of Radiation Sciences, Radiation Physics, Biomedical Engineering, Umeå University 901 87 Umeå Sweden
| | - Staffan Svenmarker
- Heart Centre, Department of Public Health and Clinical Medicine, Umeå University 901 87 Umeå Sweden
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8
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Brassard P, Roy MA, Burma JS, Labrecque L, Smirl JD. Quantification of dynamic cerebral autoregulation: welcome to the jungle! Clin Auton Res 2023; 33:791-810. [PMID: 37758907 DOI: 10.1007/s10286-023-00986-2] [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: 08/01/2023] [Accepted: 09/11/2023] [Indexed: 09/29/2023]
Abstract
PURPOSE Patients with dysautonomia often experience symptoms such as dizziness, syncope, blurred vision and brain fog. Dynamic cerebral autoregulation, or the ability of the cerebrovasculature to react to transient changes in arterial blood pressure, could be associated with these symptoms. METHODS In this narrative review, we go beyond the classical view of cerebral autoregulation to discuss dynamic cerebral autoregulation, focusing on recent advances pitfalls and future directions. RESULTS Following some historical background, this narrative review provides a brief overview of the concept of cerebral autoregulation, with a focus on the quantification of dynamic cerebral autoregulation. We then discuss the main protocols and analytical approaches to assess dynamic cerebral autoregulation, including recent advances and important issues which need to be tackled. CONCLUSION The researcher or clinician new to this field needs an adequate comprehension of the toolbox they have to adequately assess, and interpret, the complex relationship between arterial blood pressure and cerebral blood flow in healthy individuals and clinical populations, including patients with autonomic disorders.
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Affiliation(s)
- Patrice Brassard
- Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, Canada.
- Research center of the Institut Universitaire de Cardiologie et de Pneumologie de Québec, Québec, Canada.
| | - Marc-Antoine Roy
- Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, Canada
- Research center of the Institut Universitaire de Cardiologie et de Pneumologie de Québec, Québec, Canada
| | - Joel S Burma
- Cerebrovascular Concussion Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
- Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
- Integrated Concussion Research Program, University of Calgary, Calgary, AB, Canada
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
- Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
| | - Lawrence Labrecque
- Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, Canada
- Research center of the Institut Universitaire de Cardiologie et de Pneumologie de Québec, Québec, Canada
| | - Jonathan D Smirl
- Cerebrovascular Concussion Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
- Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
- Integrated Concussion Research Program, University of Calgary, Calgary, AB, Canada
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
- Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
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9
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Zdun M, Melnyk OP, Melnyk OO, Nabzdyk M. Blood supply to the cranial cavity in the patagonian mara (Dolichotis patagonum). Vet Res Commun 2023; 47:2199-2205. [PMID: 36976443 DOI: 10.1007/s11259-023-10113-1] [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: 12/30/2022] [Accepted: 03/20/2023] [Indexed: 03/29/2023]
Abstract
Rodents are the most numerous order of mammals. The literature presents information on the arterial circle of the brain in capybara, the guinea pig of the family Caviidae and many other not so closely related rodent species. Information on the blood supply to the brain is often incomplete and focuses on one pathway in a broader comparative aspect. The supply of oxygen and nutrients to the brain is very important for its proper functioning. The aim of this study is to describe the pathways supplying blood to the cranial cavity and to describe the arterial circle of the brain in the Patagonian mara. The study was conducted on 46 specimens using two methods. The first of them used a stained solution of the chemo-setting acrylic material. The second one, the colored liquid LBS 3060 latex. The arterial circle of the brain is a heart-shaped structure. It is formed by rostral cerebral arteries, caudal communicating arteries and the basilar artery. Blood supplies the arterial circle of the brain in three ways. First one is the basilar artery, which originates from the vertebral arteries. The second one is the internal carotid artery which joins a branch from the external ophthalmic artery. The third is the internal ophthalmic artery, which branches from the external ophthalmic artery.
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Affiliation(s)
- Maciej Zdun
- Department of Animal Anatomy, Poznan University of Life Sciences, Wojska Polskiego 71C, Poznań, 60-625, Poland.
- Department of Basic and Preclinical Sciences, Nicolaus Copernicus University, Lwowska 1, Toruń, 87-100, Poland.
- Department of Animal Anatomy, Histology and Pathomorphology, National University of Life and Environmental Sciences of Ukraine, Heroiv Oborony Str.15, Kyiv, 03041, Ukraine.
| | - Oleg P Melnyk
- Department of Animal Anatomy, Histology and Pathomorphology, National University of Life and Environmental Sciences of Ukraine, Heroiv Oborony Str.15, Kyiv, 03041, Ukraine
| | - Oleksii O Melnyk
- Department of Animal Anatomy, Histology and Pathomorphology, National University of Life and Environmental Sciences of Ukraine, Heroiv Oborony Str.15, Kyiv, 03041, Ukraine
| | - Maria Nabzdyk
- Department of Animal Anatomy, Poznan University of Life Sciences, Wojska Polskiego 71C, Poznań, 60-625, Poland
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Gavish B, Gottschalk A, Hogue CW, Steppan J. Additional predictors of the lower limit of cerebral autoregulation during cardiac surgery. J Hypertens 2023; 41:1844-1852. [PMID: 37702558 PMCID: PMC10552816 DOI: 10.1097/hjh.0000000000003556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 05/31/2023] [Accepted: 08/22/2023] [Indexed: 09/14/2023]
Abstract
OBJECTIVES The lower limit of autoregulation (LLA) of cerebral blood flow was previously shown to vary directly with the Ambulatory Arterial Stiffness Index (AASI) redefined as 1-regression slope of DBP-versus-SBP readings invasively measured from the radial artery before the bypass. We aimed expanding the predictive capacity of the LLA with AASI by combining it with additional predictors and provide new indications whether mean arterial pressure (MAP) is above/below the LLA. DESIGN AND METHOD In 181 patients undergoing cardiac surgery, mean (SD) age 71 (8) years), we identified from the demographic, preoperative and intraoperative characteristics independent and statistically significant 'single predictors' of the LLA (including AASI). This was achieved using multivariate linear regression with a backward-elimination technique. The single predictors combined with 1-AASI generated new multiplicative and additive composite predictors of the LLA. Indicators for the MAP-to-LLA difference (DIF) were determined using DIF-versus-predictor plots. The odds ratio (OR) for the DIF sign (Outcome = 1 for DIF≤0) and predictor-minus-median sign (Exposure = 1 for Predictor ≤ Median) were calculated using logistic regression. RESULTS BMI, 1-AASI and systolic coefficient of variation were identified single predictors that correlated similarly with the LLA ( r = -0.26 to -0.27, P < 0.001). The multiplicative and additive composite predictors displayed higher correlation with LLA ( r = -0.41 and r = -0.43, respectively, P < 0.001) and improved LLA estimation. The adjusted OR for the composite predictors was nearly twice that of the single predictors. CONCLUSION The novel composite predictors may enhance the LLA estimation and the ability to maintain MAP in the cerebral autoregulatory range during cardiac surgery.
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Affiliation(s)
| | - Allan Gottschalk
- Johns Hopkins University, Department of Anesthesiology and Critical Care Medicine, Baltimore, Maryland
| | - Charles W Hogue
- Northwestern University Feinberg, Department of Anesthesiology, Chicago, Illinois, USA
| | - Jochen Steppan
- Johns Hopkins University, Department of Anesthesiology and Critical Care Medicine, Baltimore, Maryland
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11
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Moris JM, Cardona A, Hinckley B, Mendez A, Blades A, Paidisetty VK, Chang CJ, Curtis R, Allen K, Koh Y. A framework of transient hypercapnia to achieve an increased cerebral blood flow induced by nasal breathing during aerobic exercise. CEREBRAL CIRCULATION - COGNITION AND BEHAVIOR 2023; 5:100183. [PMID: 37745894 PMCID: PMC10514094 DOI: 10.1016/j.cccb.2023.100183] [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: 04/21/2023] [Revised: 08/30/2023] [Accepted: 09/11/2023] [Indexed: 09/26/2023]
Abstract
During exercise, cerebral blood flow (CBF) is expected to only increase to a maximal volume up to a moderate intensity aerobic effort, suggesting that CBF is expected to decline past 70 % of a maximal aerobic effort. Increasing CBF during exercise permits an increased cerebral metabolic activity that stimulates neuroplasticity and other key processes of cerebral adaptations that ultimately improve cognitive health. Recent work has focused on utilizing gas-induced exposure to intermittent hypoxia during aerobic exercise to maximize the improvements in cognitive function compared to those seen under normoxic conditions. However, it is postulated that exercising by isolating breathing only to the nasal route may provide a similar effect by stimulating a transient hypercapnic condition that is non-gas dependent. Because nasal breathing prevents hyperventilation during exercise, it promotes an increase in the partial arterial pressure of CO2. The rise in systemic CO2 stimulates hypercapnia and permits the upregulation of hypoxia-related genes. In addition, the rise in systemic CO2 stimulates cerebral vasodilation, promoting a greater increase in CBF than seen during normoxic conditions. While more research is warranted, nasal breathing might also promote benefits related to improved sleep, greater immunity, and body fat loss. Altogether, this narrative review presents a theoretical framework by which exercise-induced hypercapnia by utilizing nasal breathing during moderate-intensity aerobic exercise may promote greater health adaptations and cognitive improvements than utilizing oronasal breathing.
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Affiliation(s)
- Jose M. Moris
- Department of Health, Human Performance, and Recreation, Baylor University, One Bear Place #97313, 1312 S. 5th St., Waco, TX 76798, United States
| | - Arturo Cardona
- Department of Health, Human Performance, and Recreation, Baylor University, One Bear Place #97313, 1312 S. 5th St., Waco, TX 76798, United States
| | - Brendan Hinckley
- Department of Health, Human Performance, and Recreation, Baylor University, One Bear Place #97313, 1312 S. 5th St., Waco, TX 76798, United States
| | - Armando Mendez
- Department of Health, Human Performance, and Recreation, Baylor University, One Bear Place #97313, 1312 S. 5th St., Waco, TX 76798, United States
| | - Alexandra Blades
- Department of Health, Human Performance, and Recreation, Baylor University, One Bear Place #97313, 1312 S. 5th St., Waco, TX 76798, United States
| | - Vineet K. Paidisetty
- Department of Health, Human Performance, and Recreation, Baylor University, One Bear Place #97313, 1312 S. 5th St., Waco, TX 76798, United States
| | - Christian J. Chang
- Department of Health, Human Performance, and Recreation, Baylor University, One Bear Place #97313, 1312 S. 5th St., Waco, TX 76798, United States
| | - Ryan Curtis
- Department of Health, Human Performance, and Recreation, Baylor University, One Bear Place #97313, 1312 S. 5th St., Waco, TX 76798, United States
| | - Kylie Allen
- Department of Health, Human Performance, and Recreation, Baylor University, One Bear Place #97313, 1312 S. 5th St., Waco, TX 76798, United States
| | - Yunsuk Koh
- Department of Health, Human Performance, and Recreation, Baylor University, One Bear Place #97313, 1312 S. 5th St., Waco, TX 76798, United States
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Duan W, Zhou CM, Yang JJ, Zhang Y, Li ZP, Ma DQ, Yang JJ. A long duration of intraoperative hypotension is associated with postoperative delirium occurrence following thoracic and orthopedic surgery in elderly. J Clin Anesth 2023; 88:111125. [PMID: 37084642 DOI: 10.1016/j.jclinane.2023.111125] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 04/07/2023] [Accepted: 04/12/2023] [Indexed: 04/23/2023]
Abstract
BACKGROUND Postoperative delirium (POD) is a common surgical complication associated with increased morbidity and mortality in elderly. Although the underlying mechanisms remain elusive, perioperative risk factors were reported to be closely related to its development. This study was designed to investigate the association between the duration of intraoperative hypotension and POD incidence following thoracic and orthopedic surgery in elderly. METHOD The perioperative data from 605 elderly undergoing thoracic and orthopedic surgery from January 2021 to July 2022 were analyzed. The primary exposure was a cumulative duration of mean arterial pressure (MAP) ≤ 65 mmHg. The primary end-point was the POD incidence assessed with confusion assessment method (CAM) or CAM-ICU for three days after surgery. Restricted cubic spline (RCS) was conducted to examine the continuous relationship between the duration of intraoperative hypotension and POD incidence adjusted with patients' demographics and surgery related factors. Then the duration of intraoperative hypotension was categorized into three groups: no hypotension, short (< 5 mins) or long duration (≥ 5 mins) of hypotension for further analysis. RESULT The incidence of POD was 14.7% (89 cases out of 605) within three days after surgery. The duration of hypotension presented a non-linear and "inverted L-shaped" effect on POD development. Compared to no hypotension, long duration (adjusted OR 3.93; 95% CI: 2.07-7.45; P < 0.001) rather than short duration of MAP ≤65 mmHg (adjusted OR 1.18; 95% CI: 0.56-2.50; P = 0.671) was closely related to the POD incidence. CONCLUSION Intraoperative hypotension (MAP ≤65 mmHg) for ≥5 mins was associated with an increased incidence of POD after thoracic and orthopedic surgery in elderly.
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Affiliation(s)
- Wen Duan
- Department of Anesthesiology, Pain and Perioperative Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Cheng-Mao Zhou
- Department of Anesthesiology, Pain and Perioperative Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Jin-Jin Yang
- Department of Anesthesiology, Pain and Perioperative Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Yue Zhang
- Department of Anesthesiology, Pain and Perioperative Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Ze-Ping Li
- Department of Anesthesiology, Pain and Perioperative Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Da-Qing Ma
- Division of Anaesthetics, Pain Medicine & Intensive Care, Department of Surgery & Cancer, Faculty of Medicine, Imperial College London, Chelsea & Westminster Hospital, London, UK
| | - Jian-Jun Yang
- Department of Anesthesiology, Pain and Perioperative Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.
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13
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Thudium M, Moestl S, Hoffmann F, Hoff A, Kornilov E, Heusser K, Tank J, Soehle M. Cerebral blood flow autoregulation assessment by correlation analysis between mean arterial blood pressure and transcranial doppler sonography or near infrared spectroscopy is different: A pilot study. PLoS One 2023; 18:e0287578. [PMID: 37347763 PMCID: PMC10286962 DOI: 10.1371/journal.pone.0287578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 05/26/2023] [Indexed: 06/24/2023] Open
Abstract
PURPOSE Recently, cerebral autoregulation indices based on moving correlation indices between mean arterial pressure (MAP) and cerebral oximetry (NIRS, ORx) or transcranial Doppler (TCD)-derived middle cerebral artery flow velocity (Mx) have been introduced to clinical practice. In a pilot study, we aimed to evaluate the validity of these indices using incremental lower body negative pressure (LBNP) until presyncope representing beginning cerebral hypoperfusion as well as lower body positive pressure (LBPP) with added mild hypoxia to induce cerebral hyperperfusion in healthy subjects. METHODS Five male subjects received continuous hemodynamic, TCD and NIRS monitoring. Decreasing levels of LBNP were applied in 5-minute steps until subjects reached presyncope. Increasing levels of LBPP were applied stepwise up to 20 or 25 mmHg. Normobaric hypoxia was added until an oxygen saturation of 84% was reached. This was continued for 10 minutes. ORx and Mx indices were calculated using previously described methods. RESULTS Both Indices showed an increase > 0.3 indicating impaired cerebral autoregulation during presyncope. However, there was no significant difference in Mx at presyncope compared to baseline (p = 0.168). Mean arterial pressure and cardiac output decreased only in presyncope, while stroke volume was decreased at the last pressure level. Neither Mx nor ORx showed significant changes during LBPP or hypoxia. Agreement between Mx and ORx was poor during the LBNP and LBPP experiments (R2 = 0.001, p = 0.3339). CONCLUSION Mx and ORx represent impaired cerebral autoregulation, but in Mx this may not be distinguished sufficiently from baseline. LBPP and hypoxia are insufficient to reach the upper limit of cerebral autoregulation as indicated by Mx and ORx.
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Affiliation(s)
- Marcus Thudium
- Department of Anesthesiology and Intensive Care Medicine, University Hospital Bonn, Venusberg Campus 1, Bonn, Germany
| | - Stefan Moestl
- Institute of Aerospace Medicine, German Aerospace Center, Linder Hoehe, Cologne, Germany
| | - Fabian Hoffmann
- Institute of Aerospace Medicine, German Aerospace Center, Linder Hoehe, Cologne, Germany
- Department of Cardiology, University Hospital Cologne, Cologne, Germany
| | - Alex Hoff
- Institute of Aerospace Medicine, German Aerospace Center, Linder Hoehe, Cologne, Germany
| | - Evgeniya Kornilov
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Karsten Heusser
- Institute of Aerospace Medicine, German Aerospace Center, Linder Hoehe, Cologne, Germany
| | - Jens Tank
- Institute of Aerospace Medicine, German Aerospace Center, Linder Hoehe, Cologne, Germany
| | - Martin Soehle
- Department of Anesthesiology and Intensive Care Medicine, University Hospital Bonn, Venusberg Campus 1, Bonn, Germany
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14
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Abadjiev DS, Toschi-Dias E, Salinet ASM, Gaykova NN, Lo MT, Nogueira RC, Hu K. Daily rhythm of dynamic cerebral autoregulation in patients after stroke. J Cereb Blood Flow Metab 2023; 43:989-998. [PMID: 36722135 PMCID: PMC10196745 DOI: 10.1177/0271678x231153750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 12/02/2022] [Accepted: 01/02/2022] [Indexed: 02/02/2023]
Abstract
Dynamic cerebral autoregulation (dCA) in healthy young adults displays a daily variation. Whether the rhythm exists in patients with stroke is unknown. We studied 28 stroke patients (age: 26-83 years, 7 females) within 48 hours after thrombolysis. dCA was assessed 54 times in these patients during supine rest (twice in 26 and once in 2 patients): 9 assessments between 0-9AM, 12 between 9AM-2PM, 20 between 2-7PM, and 13 between 7PM-12AM. To estimate dCA, phase shifts between spontaneous oscillations of cerebral blood flow velocity (CBFV) in the middle cerebral artery and arterial blood pressure (BP) were obtained in four frequency bands: <0.05 Hz, 0.05-0.1 Hz, 0.1-0.2 Hz, and >0.2 Hz. CBFV-BP phase shifts at <0.05 Hz were significantly larger between 2-7PM, suggesting better dCA, than those at other times (p < 0.0001), and the daily rhythm was consistent for stroke and non-stroke sides. No significant rhythms were observed at higher frequencies (all p > 0.2). All results were independent of age, sex, stroke type and severity, and other cardiovascular conditions. dCA after stroke showed a daily rhythm, leading to a better regulation of CBFV at <0.05 Hz during the afternoon. The finding may have implications for daily activity management of stroke patients.
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Affiliation(s)
- Daniel S Abadjiev
- Medical Biodynamics Program,
Division of Sleep and Circadian Disorders, Brigham and Women’s Hospital, Harvard
Medical School, Boston, MA, USA
| | - Edgar Toschi-Dias
- Neurology Department, School of
Medicine, Hospital das Clinicas, University of São Paulo, São Paulo ,
Brazil
| | - Angela SM Salinet
- Neurology Department, School of
Medicine, Hospital das Clinicas, University of São Paulo, São Paulo ,
Brazil
| | - Nicole N Gaykova
- Medical Biodynamics Program,
Division of Sleep and Circadian Disorders, Brigham and Women’s Hospital, Harvard
Medical School, Boston, MA, USA
| | - Men-Tzung Lo
- Institute of Translational and
Interdisciplinary Medicine and Department of Biomedical Sciences and
Engineering, National Central University, Taoyuan
| | - Ricardo C Nogueira
- Neurology Department, School of
Medicine, Hospital das Clinicas, University of São Paulo, São Paulo ,
Brazil
- Neurology Department, Hospital
Sirio Libanes, São Paulo, Brazil
| | - 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
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15
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Thornton T, Mills D, Bliss E. Capsaicin: A Potential Treatment to Improve Cerebrovascular Function and Cognition in Obesity and Ageing. Nutrients 2023; 15:nu15061537. [PMID: 36986266 PMCID: PMC10057869 DOI: 10.3390/nu15061537] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 03/17/2023] [Accepted: 03/21/2023] [Indexed: 03/30/2023] Open
Abstract
Impaired cognition is the primary symptom of dementia, which can lead to functional disability and reduced quality of life among an increasingly ageing population. Ageing is associated with increased oxidative stress, chronic low-grade systemic inflammation, and endothelial dysfunction, which reduces cerebrovascular function leading to cognitive decline. Chronic low-grade systemic inflammatory conditions, such as obesity, exacerbate this decline beyond normal ageing and predispose individuals to neurodegenerative diseases, such as dementia. Capsaicin, the major pungent molecule of chilli, has recently demonstrated improvements in cognition in animal models via activation of the transient receptor potential vanilloid channel 1 (TRPV1). Capsaicin-induced TRPV1 activation reduces adiposity, chronic low-grade systemic inflammation, and oxidative stress, as well as improves endothelial function, all of which are associated with cerebrovascular function and cognition. This review examines the current literature on capsaicin and Capsimax, a capsaicin supplement associated with reduced gastrointestinal irritation compared to capsaicin. Acute and chronic capsaicin treatment can improve cognition in animals. However, studies adequately assessing the effects of capsaicin on cerebrovascular function, and cognition in humans do not exist. Capsimax may be a potentially safe therapeutic intervention for future clinical trials testing the effects of capsaicin on cerebrovascular function and cognition.
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Affiliation(s)
- Tammy Thornton
- School of Health and Medical Sciences, University of Southern Queensland, Ipswich, QLD 4305, Australia
| | - Dean Mills
- School of Health and Medical Sciences, University of Southern Queensland, Ipswich, QLD 4305, Australia
- Respiratory and Exercise Physiology Research Group, School of Health and Medical Sciences, University of Southern Queensland, Ipswich, QLD 4305, Australia
- Centre for Health Research, Institute for Resilient Regions, University of Southern Queensland, Ipswich, QLD 4305, Australia
- Molecular Biomarkers Research Group, University of Southern Queensland, Toowoomba, QLD 4350, Australia
| | - Edward Bliss
- School of Health and Medical Sciences, University of Southern Queensland, Ipswich, QLD 4305, Australia
- Respiratory and Exercise Physiology Research Group, School of Health and Medical Sciences, University of Southern Queensland, Ipswich, QLD 4305, Australia
- Centre for Health Research, Institute for Resilient Regions, University of Southern Queensland, Ipswich, QLD 4305, Australia
- Molecular Biomarkers Research Group, University of Southern Queensland, Toowoomba, QLD 4350, Australia
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16
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Mattersberger C, Baik-Schneditz N, Schwaberger B, Schmölzer GM, Mileder L, Urlesberger B, Pichler G. Acid-base and metabolic parameters and cerebral oxygenation during the immediate transition after birth-A two-center observational study. PLoS One 2023; 18:e0283278. [PMID: 37196035 DOI: 10.1371/journal.pone.0283278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 03/06/2023] [Indexed: 05/19/2023] Open
Abstract
OBJECTIVE The association between blood glucose level and cerebral oxygenation (cerebral regional oxygen saturation [crSO2] and cerebral fractional tissue oxygen extraction [FTOE]) in neonates has already been described. Aim of the present study was to investigate if acid-base and other metabolic parameters have an impact on cerebral oxygenation immediately after birth in preterm and term neonates. STUDY DESIGN Post-hoc analyses of secondary outcome parameters of two prospective observational studies were performed. Preterm and term neonates born by caesarean section were included, in whom i) cerebral near-infrared spectroscopy (NIRS) measurements were performed during the first 15 minutes after birth and ii) a capillary blood gas analysis was performed between 10 and 20 minutes after birth. Vital signs were routinely monitored with pulse oximetry (arterial oxygen saturation [SpO2] and heart rate [HR]). Correlation analyses were performed to investigate potential associations between acid-base and metabolic parameters (lactate [LAC], pH-value [pH], base-excess [BE] and bicarbonate [HCO3]) from capillary blood and NIRS-derived crSO2 and FTOE at 15 minutes after birth. RESULTS One-hundred-fifty-seven neonates, 42 preterm neonates (median gestational age [IQR] 34.0 weeks [3.3], median birth weight 1845g [592]) and 115 term neonates (median gestational age [IQR] 38.9 weeks [1.0], median birth weight 3230g [570]) were included in the study. Median crSO2 [IQR] values at 15 minutes after birth were 82% [16] in preterm neonates and 83% [12] in term neonates. Median FTOE [IQR] values at 15 minutes after birth were 0.13 [0.15] in preterm neonates and 0.14 [0.14] in term neonates. In preterm neonates, higher LAC and lower pH and BE were associated with lower crSO2 and higher FTOE. In term neonates, higher HCO3 was associated with higher FTOE. CONCLUSION There were significant associations between several acid-base and metabolic parameters and cerebral oxygenation in preterm neonates, while in term neonates only HCO3 correlated positively with FTOE.
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Affiliation(s)
- Christian Mattersberger
- Department of Paediatrics and Adolescent Medicine, Division of Neonatology, Medical University of Graz, Graz, Styria, Austria
| | - Nariae Baik-Schneditz
- Department of Paediatrics and Adolescent Medicine, Division of Neonatology, Medical University of Graz, Graz, Styria, Austria
- Research Unit for Neonatal Micro- and Macrocircultation, Department of Paediatrics and Adolescent Medicine, Medical University of Graz, Graz, Styria, Austria
| | - Bernhard Schwaberger
- Department of Paediatrics and Adolescent Medicine, Division of Neonatology, Medical University of Graz, Graz, Styria, Austria
- Research Unit for Neonatal Micro- and Macrocircultation, Department of Paediatrics and Adolescent Medicine, Medical University of Graz, Graz, Styria, Austria
| | - Georg M Schmölzer
- Centre for the Studies of Asphyxia and Resuscitation, Royal Alexandra Hospital, Edmonton, Canada
- Department of Paediatrics, University of Alberta, Edmonton, Canada
| | - Lukas Mileder
- Department of Paediatrics and Adolescent Medicine, Division of Neonatology, Medical University of Graz, Graz, Styria, Austria
- Research Unit for Neonatal Micro- and Macrocircultation, Department of Paediatrics and Adolescent Medicine, Medical University of Graz, Graz, Styria, Austria
| | - Berndt Urlesberger
- Department of Paediatrics and Adolescent Medicine, Division of Neonatology, Medical University of Graz, Graz, Styria, Austria
- Research Unit for Neonatal Micro- and Macrocircultation, Department of Paediatrics and Adolescent Medicine, Medical University of Graz, Graz, Styria, Austria
| | - Gerhard Pichler
- Department of Paediatrics and Adolescent Medicine, Division of Neonatology, Medical University of Graz, Graz, Styria, Austria
- Research Unit for Neonatal Micro- and Macrocircultation, Department of Paediatrics and Adolescent Medicine, Medical University of Graz, Graz, Styria, Austria
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17
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Huang S, Luo Y, Liang L, Guo N, Duan X, Zhou Q, Ge L. The baseline and repeated measurements of DBP to assess in-hospital mortality risk among critically ill patients with acute myocardial infarction: A retrospective cohort study. Medicine (Baltimore) 2022; 101:e30980. [PMID: 36221379 PMCID: PMC9543008 DOI: 10.1097/md.0000000000030980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Changes in diastolic blood pressure (DBP) are common in patients with acute myocardial infarction (AMI). The relationship between the dynamic change of DBP and in-hospital mortality among patients with AMI remains unclear. This study aimed to explore the importance of DBP during disease development among patients with AMI. We performed a retrospective cohort study involving patients from the Medical Information Mart for Intensive Care III database, which included > 40,000 patients admitted to the intensive care unit (ICU). Overall, 3209 adult AMI admissions were identified. We extracted the clinical and laboratory information in the patients with AMI. Cox proportional hazards models were used to evaluate the prognostic values of baseline DBP. We used the generalized additive mixed model (GAMM) to compare trends in DBP over time among survivors and non-survivors, after adjusting for potential confounders. During the ICU stay, 189 patients died (mortality rate, 6.36%). The age of each non-survivor together with the variations in DBP over time from admission to the time of death is of great importance to the scientific community. Cox multivariable regression analysis displayed that after adjusting for confounding factors, ascended baseline DBP was an important hazard factor for hospital deaths (hazard ratio, 1.02; 95% confidence interval, 1.01-1.03; P = .003). Based on GAMM, DBP in the death group was markedly lower than that of the surviving group. Moreover, the difference between the two groups showed an increasing trend within 3 days after ICU admission. After adjusting for various variables, the results were stable. DBP significantly contributed to in-hospital mortality among patients with AMI. There was a nonlinear correlation between baseline DBP and in-hospital mortality among patients with AMI, and the DBP of the non-survivors decreased within the first 3 days after ICU admission. However, the causality cannot be deduced from our data.
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Affiliation(s)
- Sulan Huang
- Cardiovascular Medicine Department, The First People’s Hospital of Changde City, Changde City, Hunan Province, People’s Republic of China
| | - Yanlan Luo
- Cardiovascular Medicine Department, The First People’s Hospital of Changde City, Changde City, Hunan Province, People’s Republic of China
| | - Li Liang
- Cardiovascular Medicine Department, The First People’s Hospital of Changde City, Changde City, Hunan Province, People’s Republic of China
| | - Ning Guo
- Cardiovascular Medicine Department, The First People’s Hospital of Changde City, Changde City, Hunan Province, People’s Republic of China
| | - Xiangjie Duan
- Infectious Disease Department, The First People’s Hospital of Changde, Changde City, Hunan Province, People’s Republic of China
| | - Quan Zhou
- Department of Science and Education Section, The First People’s Hospital of Changde, Changde City, Hunan Province, 415000, People’s Republic of China
| | - Liangqing Ge
- Cardiovascular Medicine Department, The First People’s Hospital of Changde City, Changde City, Hunan Province, People’s Republic of China
- *Correspondence: Liangqing Ge, Cardiovascular Medicine Department, The First People’s Hospital of Changde City, Changde City, Hunan Province, 415000, People’s Republic of China (e-mail: )
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18
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Abstract
PURPOSE OF REVIEW The scope of procedures conducted by neurointerventionalists is expanding quickly, with lacking consensus over the best anesthesia modality. Although the procedures involve all age groups, the interventions may be complex and lengthy and may be provided in hospitals currently not yet familiar with the field. Here we review current literature addressing elective outpatient neurointerventional procedures and aim to provide an update on the management of intervention-specific crises, address special patient populations, and provide key learning points for everyday use in the neurointerventional radiology suite. RECENT FINDINGS Various studies have compared the use of different anesthesia modalities and preinterventional and postinterventional care. Monitored anesthesia care is generally recommended for elderly patients, whereas children are preferably treated with general anesthesia. Additional local anesthesia is beneficial for procedures, such as percutaneous kyphoplasty and vascular access. SUMMARY Combining different anesthetic modalities is a valuable approach in the neurointerventional radiology suite. More interventional and patient population-specific studies are needed to improve evidence-based perioperative management.
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19
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Association of 24-hour blood pressure parameters post-thrombectomy with functional outcomes according to collateral status. J Neurol Sci 2022; 441:120369. [DOI: 10.1016/j.jns.2022.120369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Revised: 07/07/2022] [Accepted: 07/27/2022] [Indexed: 11/17/2022]
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20
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Use of real-time phase-contrast MRI to quantify the effect of spontaneous breathing on the cerebral arteries. Neuroimage 2022; 258:119361. [PMID: 35688317 DOI: 10.1016/j.neuroimage.2022.119361] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 05/05/2022] [Accepted: 06/06/2022] [Indexed: 11/22/2022] Open
Abstract
Quantification of the effect of breathing on the cerebral circulation provides a better mechanistic understanding of the brain's circulatory system and is important in the early diagnosis of certain neurological diseases. However, conventional cine phase-contrast (CINE-PC) MRI cannot be used in this field of study because it only provides an average cardiac cycle flow curve reconstructed from multiple cardiac cycles. Unlike CINE-PC, phase-contrast echo-planar imaging (EPI-PC) can be used to quantify the blood flow rate in "real-time" and thus assess the effect of breathing on blood flow. Here, we first used post-processing software (developed in-house) to determine the feasibility of quantifying cerebral arterial blood flow with EPI-PC (relative to CINE-PC) in 16 participants. In a second step, we developed a new time-domain method for quantifying the intensity and the phase shift of the effects of breathing on the mean flow rate, stroke volume, cardiac period and amplitude of cerebral blood flow (in 10 participants). Our results showed that EPI-PC can quantify cerebral arterial blood flow rate with much the same degree of accuracy as CINE-PC but is more strongly influenced by differences in magnetic susceptibility. We found that breathing affected the mean flow rate, stroke volume and cardiac period of cerebral arterial blood flow.
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21
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Moncion K, Allison EY, Al-Khazraji BK, MacDonald MJ, Roig M, Tang A. What are the effects of acute exercise and exercise training on cerebrovascular hemodynamics following stroke? A systematic review and meta-analysis. J Appl Physiol (1985) 2022; 132:1379-1393. [PMID: 35482325 DOI: 10.1152/japplphysiol.00872.2021] [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: 11/22/2022] Open
Abstract
INTRODUCTION Limited data exist regarding the effects of acute exercise and exercise training on cerebrovascular hemodynamic variables post-stroke. PURPOSE This systematic review and meta-analysis 1) examined the effects of acute exercise and exercise training on cerebrovascular hemodynamic variables reported in the stroke exercise literature; and 2) synthesized the peak middle cerebral artery blood velocity (MCAv) achieved during an acute bout of moderate-intensity exercise in individuals post-stroke. METHODS Six databases (MEDLINE, EMBASE, Web of Science, CINAHL, PsycINFO, AMED) were searched from inception to December 1st 2021, for studies that examined the effect of acute exercise or exercise training on cerebrovascular hemodynamics in adults post-stroke. Two reviewers conducted title and abstract screening, full-text evaluation, data extraction, and quality appraisal. Random effects models were used in meta-analysis. RESULTS Nine studies, including 4 acute exercise (n=61) and 5 exercise training studies (n=193), were included. Meta-analyses were not statistically feasible for several cerebrovascular hemodynamic variables. Descriptive analysis reveals that exercise training may increase cerebral blood flow and cerebrovascular reactivity to carbon dioxide among individuals post-stroke. Meta-analysis of three acute exercise studies revealed no significant changes in MCAv during acute moderate intensity exercise (n=48 participants, mean difference = 5.2 cm/s, 95% CI [-0.6, 11.0], P=0.08) compared to resting MCAv values. CONCLUSION This review suggests that individuals post-stroke may have attenuated cerebrovascular hemodynamics as measured by the MCAv during acute moderate-intensity exercise. Higher quality research utilizing agreed upon hemodynamic variables are needed to synthesize the effects of exercise training on cerebrovascular hemodynamics post-stroke.
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Affiliation(s)
- Kevin Moncion
- School of Rehabilitation Sciences, Faculty of Health Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Elric Y Allison
- Department of Kinesiology, Faculty of Science, McMaster University, Hamilton, Ontario, Canada
| | - Baraa K Al-Khazraji
- Department of Kinesiology, Faculty of Science, McMaster University, Hamilton, Ontario, Canada
| | - Maureen J MacDonald
- Department of Kinesiology, Faculty of Science, McMaster University, Hamilton, Ontario, Canada
| | - Marc Roig
- School of Physical and Occupational Therapy, Faculty of Medicine, McGill University, Montreal, Québec, Canada
| | - Ada Tang
- School of Rehabilitation Sciences, Faculty of Health Sciences, McMaster University, Hamilton, Ontario, Canada
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22
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Hemodynamic Imaging in Cerebral Diffuse Glioma-Part A: Concept, Differential Diagnosis and Tumor Grading. Cancers (Basel) 2022; 14:cancers14061432. [PMID: 35326580 PMCID: PMC8946242 DOI: 10.3390/cancers14061432] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 03/01/2022] [Accepted: 03/08/2022] [Indexed: 11/17/2022] Open
Abstract
Diffuse gliomas are the most common primary malignant intracranial neoplasms. Aside from the challenges pertaining to their treatment-glioblastomas, in particular, have a dismal prognosis and are currently incurable-their pre-operative assessment using standard neuroimaging has several drawbacks, including broad differentials diagnosis, imprecise characterization of tumor subtype and definition of its infiltration in the surrounding brain parenchyma for accurate resection planning. As the pathophysiological alterations of tumor tissue are tightly linked to an aberrant vascularization, advanced hemodynamic imaging, in addition to other innovative approaches, has attracted considerable interest as a means to improve diffuse glioma characterization. In the present part A of our two-review series, the fundamental concepts, techniques and parameters of hemodynamic imaging are discussed in conjunction with their potential role in the differential diagnosis and grading of diffuse gliomas. In particular, recent evidence on dynamic susceptibility contrast, dynamic contrast-enhanced and arterial spin labeling magnetic resonance imaging are reviewed together with perfusion-computed tomography. While these techniques have provided encouraging results in terms of their sensitivity and specificity, the limitations deriving from a lack of standardized acquisition and processing have prevented their widespread clinical adoption, with current efforts aimed at overcoming the existing barriers.
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23
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Miller GD, Maxwell JD, Thompson A, Cable NT, Low DA, George KP, Jones H. The effects of exercise training in the cold on cerebral blood flow and cerebrovascular function in young healthy individuals. Auton Neurosci 2022; 238:102945. [PMID: 35176639 DOI: 10.1016/j.autneu.2022.102945] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 11/09/2021] [Accepted: 01/16/2022] [Indexed: 11/17/2022]
Abstract
Exercise elicits acute increases in cerebral blood flow velocity (CBFv) and provokes long-term beneficial effects on CBFv, thereby reducing cerebrovascular risk. Acute exposure to a cold stimulus also increases CBFv. We compared the impact of exercise training in cold and thermoneutral environments on CFBv, cerebrovascular function and peripheral endothelial function. Twenty-one (16 males, 22 ± 5 years) individuals were randomly allocated to either a cold (5 °C) or thermoneutral (15 °C) exercise intervention. Exercise consisted of 50-min cycling at 70% heart rate max, three times per week for eight weeks. Transcranial Doppler was used to determine pre and post intervention CBFv, dynamic cerebral autoregulation (dCA) and cerebrovascular reactivity (CVRCO2). Conduit endothelial function, microvascular function and cardiorespiratory fitness were also assessed. Cardiorespiratory fitness improved (2.91 ml.min.kg-1, 95%CI 0.49, 5.3; P = 0.02), regardless of exercise setting. Neither intervention had an impact on CBFv, CVRCO2, FMD or microvascular function (P > 0.05). There was a significant interaction between time and condition for dCA normalised gain with evidence of a decrease by 0.192%cm.s-1.%mmHg-1 (95%CI -0.318, -0.065) following training in the cold and increase (0.129%cm.s-1.%mmHg-1, 95%CI 0.011, 0.248) following training in the thermoneutral environment (P = 0.001). This was also evident for dCA phase with evidence of an increase by 0.072 rad (95%CI -0.007, 0.152) following training in the cold and decrease by 0.065 (95%CI -0.144, 0.014) radians following training in the thermoneutral environment (P = 0.02). Both training interventions improved fitness but CBFv, CVRCO2 and peripheral endothelial function were unaltered. Exercise training in the cold improved dCA whereas thermoneutral negated dCA.
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Affiliation(s)
- G D Miller
- Research Institute of Sport and Exercise Science, Liverpool John Moores University, Liverpool, UK
| | - J D Maxwell
- Manchester University NHS Foundation Trust, Manchester, UK
| | - A Thompson
- Wolfson Centre for Personalised Medicine, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - N T Cable
- The Institute of Sport, Manchester Metropolitan University, Manchester, UK
| | - D A Low
- Research Institute of Sport and Exercise Science, Liverpool John Moores University, Liverpool, UK
| | - K P George
- Research Institute of Sport and Exercise Science, Liverpool John Moores University, Liverpool, UK
| | - H Jones
- Research Institute of Sport and Exercise Science, Liverpool John Moores University, Liverpool, UK.
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Fan JL, Nogueira RC, Brassard P, Rickards CA, Page M, Nasr N, Tzeng YC. Integrative physiological assessment of cerebral hemodynamics and metabolism in acute ischemic stroke. J Cereb Blood Flow Metab 2022; 42:454-470. [PMID: 34304623 PMCID: PMC8985442 DOI: 10.1177/0271678x211033732] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Restoring perfusion to ischemic tissue is the primary goal of acute ischemic stroke care, yet only a small portion of patients receive reperfusion treatment. Since blood pressure (BP) is an important determinant of cerebral perfusion, effective BP management could facilitate reperfusion. But how BP should be managed in very early phase of ischemic stroke remains a contentious issue, due to the lack of clear evidence. Given the complex relationship between BP and cerebral blood flow (CBF)-termed cerebral autoregulation (CA)-bedside monitoring of cerebral perfusion and oxygenation could help guide BP management, thereby improve stroke patient outcome. The aim of INFOMATAS is to 'identify novel therapeutic targets for treatment and management in acute ischemic stroke'. In this review, we identify novel physiological parameters which could be used to guide BP management in acute stroke, and explore methodologies for monitoring them at the bedside. We outline the challenges in translating these potential prognostic markers into clinical use.
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Affiliation(s)
- Jui-Lin Fan
- Manaaki Mānawa - The Centre for Heart Research, Department of Physiology, Faculty of Medical & Health Sciences, University of Auckland, Auckland, New Zealand
| | - Ricardo C Nogueira
- Neurology Department, School of Medicine, Hospital das Clinicas, University of São Paulo, São Paulo, Brazil.,Neurology Department, Hospital Nove de Julho, São Paulo, Brazil
| | - Patrice Brassard
- Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, Canada.,Research Center of the Institut Universitaire de Cardiologie et de Pneumologie de Québec, Québec, Canada
| | - Caroline A Rickards
- Department of Physiology & Anatomy, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Matthew Page
- Department of Radiology, Wellington Regional Hospital, Wellington, New Zealand
| | - Nathalie Nasr
- Department of Neurology, Toulouse University Hospital, NSERM UMR 1297, Toulouse, France
| | - Yu-Chieh Tzeng
- Wellington Medical Technology Group, Department of Surgery & Anaesthesia, University of Otago, Wellington, New Zealand.,Centre for Translational Physiology, Department of Surgery & Anaesthesia, University of Otago, Wellington, New Zealand
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25
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Horiuchi M, Rossetti GM, Oliver SJ. Dietary nitrate supplementation effect on dynamic cerebral autoregulation in normoxia and acute hypoxia. J Cereb Blood Flow Metab 2022; 42:486-494. [PMID: 32151227 PMCID: PMC8985441 DOI: 10.1177/0271678x20910053] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
We tested the hypothesis that increasing the nitric oxide (NO) bioavailability by dietary nitrate would recover the hypoxia-induced reduction in dynamic cerebral autoregulation (CA). Twelve healthy males (age 21 ± 2 years) completed four days of dietary supplementation with a placebo or inorganic nitrate drink (140-ml beetroot juice per day) followed by 60-min of normoxia or hypoxia (fraction of inspired oxygen [FiO2] = 13%). Duplex ultrasonography was used to perform volumetric change-based assessment of dynamic CA in the internal carotid artery (ICA). Dynamic CA was assessed by rate of regulation (RoR) of vascular conductance using the thigh-cuff method. Four days of beetroot supplementation increased circulating nitrate by 208 [171,245] μM (mean difference [95% confidence interval]) compared with placebo. Dynamic CA was lower in hypoxia than normoxia (RoR Δ-0.085 [-0.116, -0.054]). Compared with placebo, nitrate did not alter dynamic CA in normoxia (RoR Δ-0.022 [-0.060, 0.016]) or hypoxia (RoR Δ0.017 [-0.019, 0.053]). Further, nitrate did not affect ICA vessel diameter, blood velocity or flow in either normoxia or hypoxia. Increased bioavailability of NO through dietary nitrate supplementation did not recover the hypoxia-induced reduction in dynamic CA. This suggests the mechanism of hypoxia-induced reduction in dynamic CA does not relate to the availability of NO.
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Affiliation(s)
- Masahiro Horiuchi
- Division of Human Environmental Science, Mt. Fuji Research Institute, Fujiyoshida, Japan
| | - Gabriella Mk Rossetti
- Extremes Research Group, College of Human Sciences, Bangor University, Bangor, Wales
| | - Samuel J Oliver
- Extremes Research Group, College of Human Sciences, Bangor University, Bangor, Wales
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26
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Roy MA, Labrecque L, Perry BG, Korad S, Smirl JD, Brassard P. Directional sensitivity of the cerebral pressure-flow relationship in young healthy individuals trained in endurance and resistance exercise. Exp Physiol 2022; 107:299-311. [PMID: 35213765 DOI: 10.1113/ep090159] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 02/08/2022] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? Does habitual exercise modality affect the directionality of the cerebral pressure-flow relationship? What is the main finding and its importance? These data suggest the hysteresis-like pattern of dynamic cerebral autoregulation appears present in long-term sedentary and endurance-trained individuals, but absent in resistance-trained individuals. This is the first study to expand knowledge on the directional sensitivity of the cerebral pressure-flow relationship to trained populations. ABSTRACT Evidence suggests the cerebrovasculature may be more efficient at dampening cerebral blood flow (CBF) variations when mean arterial pressure (MAP) transiently increases, compared to when it decreases. Despite divergent MAP and CBF responses to acute endurance and resistance training, the long-term impact of habitual exercise modality on the directionality of dynamic cerebral autoregulation (dCA) is currently unknown. Thirty-six young healthy participants [sedentary (n = 12), endurance-trained (n = 12) and resistance-trained (n = 12)] undertook a 5-min repeated squat-stand protocol at two forced MAP oscillation frequencies (0.05 Hz and 0.10 Hz). Middle cerebral artery mean blood velocity (MCAv) and MAP were continuously monitored. We calculated absolute (ΔMCAvT /ΔMAPT ) and relative (%MCAvT /%MAPT ) changes in MCAv and MAP with respect to the transition time intervals of both variables to compute a time-adjusted ratio in each MAP direction, averaged over the 5-min repeated squat-stand protocols. At 0.10 Hz repeated squat-stands, ΔMCAvT /ΔMAPT and %MCAvT /%MAPT were lower when MAP increased compared with when MAP decreased for sedentary (ΔMCAvT /ΔMAPT : p = 0.032; %MCAvT /%MAPT : p = 0.040) and endurance-trained individuals (ΔMCAvT /ΔMAPT : p = 0.012; %MCAvT /%MAPT : p = 0.007), but not in the resistance-trained (ΔMCAvT /ΔMAPT : p = 0.512; %MCAvT /%MAPT : p = 0.666). At 0.05 Hz repeated squat-stands, time-adjusted ratios were similar for all groups (all p>0.605). These findings suggest exercise training modality does influence the directionality of the cerebral pressure-flow relationship and support the presence of a hysteresis-like pattern during 0.10 Hz repeated squat-stands in sedentary and endurance-trained participants, but not in resistance-trained individuals. In future studies, assessment of elite endurance and resistance training habits may further elucidate modality-dependent discrepancies on directional dCA measurements. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Marc-Antoine Roy
- Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, Canada.,Research center of the Institut universitaire de cardiologie et de pneumologie de Québec, Québec, Canada
| | - Lawrence Labrecque
- Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, Canada.,Research center of the Institut universitaire de cardiologie et de pneumologie de Québec, Québec, Canada
| | - Blake G Perry
- School of Health Sciences, Massey University, Wellington, New Zealand.,School of Sport, Exercise and Nutrition, Massey University, Wellington, New Zealand
| | - Stephanie Korad
- School of Health Sciences, Massey University, Wellington, New Zealand.,School of Sport, Exercise and Nutrition, Massey University, Wellington, New Zealand
| | - Jonathan D 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.,Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.,Integrated Concussion Research Program, University of Calgary, Calgary, AB, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada.,Libin Cardiovascular Institute of Alberta, University of Calgary, Alberta, Canada.,Concussion Research Laboratory, Faculty of Health and Exercise Science, University of British Columbia, Kelowna, BC, Canada
| | - Patrice Brassard
- Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, Canada.,Research center of the Institut universitaire de cardiologie et de pneumologie de Québec, Québec, Canada
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27
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Change in the optic nerve sheath diameter after deflation of a pneumatic tourniquet: a prospective observational study. Sci Rep 2022; 12:521. [PMID: 35017581 PMCID: PMC8752803 DOI: 10.1038/s41598-021-04457-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 12/17/2021] [Indexed: 11/22/2022] Open
Abstract
Applying a pneumatic tourniquet provides surgeons with a bloodless surgical field. However, application of the tourniquet induces various physiological changes. We evaluated the effect of tourniquet deflation on the intracranial pressure by using ultrasonography to measure the optic nerve sheath diameter (ONSD) in patients undergoing lower limb surgery. The ONSD was measured in 20 patients at five time points: after anesthetic induction (T0) and immediately before (T1), immediately after (T2), 5 min after (T3), and 10 min after tourniquet deflation (T4). Hemodynamic and respiratory variables were recorded. The ONSD showed significant differences at each point (P < 0.001). The ONSDs at T2 and T3 were significantly greater than that at T1 (P = 0.0007 and < 0.0001, respectively). The change in the end-tidal carbon dioxide partial pressure (EtCO2) was similar to the change in the ONSD. The change in the ONSD was significantly correlated with the change in the EtCO2 after tourniquet deflation (r = 0.484, P = 0.030). In conclusion, the ONSD, as an indicator of intracranial pressure, increased after tourniquet deflation in patients undergoing lower limb surgery. This was correlated with an increased EtCO2 and arterial carbon dioxide partial pressure. Trial registration: ClinicalTrials.gov (NCT03782077).
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28
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Effects of circulatory arrest and cardiopulmonary bypass on cerebral autoregulation in neonatal swine. Pediatr Res 2022; 91:1374-1382. [PMID: 33947997 PMCID: PMC8566324 DOI: 10.1038/s41390-021-01525-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 02/02/2021] [Accepted: 03/18/2021] [Indexed: 02/03/2023]
Abstract
BACKGROUND Cerebral autoregulation mechanisms help maintain adequate cerebral blood flow (CBF) despite changes in cerebral perfusion pressure. Impairment of cerebral autoregulation, during and after cardiopulmonary bypass (CPB), may increase risk of neurologic injury in neonates undergoing surgery. In this study, alterations of cerebral autoregulation were assessed in a neonatal swine model probing four perfusion strategies. METHODS Neonatal swine (n = 25) were randomized to continuous deep hypothermic cardiopulmonary bypass (DH-CPB, n = 7), deep hypothermic circulatory arrest (DHCA, n = 7), selective cerebral perfusion (SCP, n = 7) at deep hypothermia, or normothermic cardiopulmonary bypass (control, n = 4). The correlation coefficient (LDx) between laser Doppler measurements of CBF and mean arterial blood pressure was computed at initiation and conclusion of CPB. Alterations in cerebral autoregulation were assessed by the change between initial and final LDx measurements. RESULTS Cerebral autoregulation became more impaired (LDx increased) in piglets that underwent DH-CPB (initial LDx: median 0.15, IQR [0.03, 0.26]; final: 0.45, [0.27, 0.74]; p = 0.02). LDx was not altered in those undergoing DHCA (p > 0.99) or SCP (p = 0.13). These differences were not explained by other risk factors. CONCLUSIONS In a validated swine model of cardiac surgery, DH-CPB had a significant effect on cerebral autoregulation, whereas DHCA and SCP did not. IMPACT Approximately half of the patients who survive neonatal heart surgery with cardiopulmonary bypass (CPB) experience neurodevelopmental delays. This preclinical investigation takes steps to elucidate and isolate potential perioperative risk factors of neurologic injury, such as impairment of cerebral autoregulation, associated with cardiac surgical procedures involving CPB. We demonstrate a method to characterize cerebral autoregulation during CPB pump flow changes in a neonatal swine model of cardiac surgery. Cerebral autoregulation was not altered in piglets that underwent deep hypothermic circulatory arrest (DHCA) or selective cerebral perfusion (SCP), but it was altered in piglets that underwent deep hypothermic CBP.
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29
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Klein SP, De Sloovere V, Meyfroidt G, Depreitere B. Differential Hemodynamic Response of Pial Arterioles Contributes to a Quadriphasic Cerebral Autoregulation Physiology. J Am Heart Assoc 2021; 11:e022943. [PMID: 34935426 PMCID: PMC9075199 DOI: 10.1161/jaha.121.022943] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Background Cerebrovascular autoregulation (CA) regulates cerebral vascular tone to maintain near-constant cerebral blood flow during fluctuations in cerebral perfusion pressure (CPP). Preclinical and clinical research has challenged the classic triphasic pressure-flow relationship, leaving the normal pressure-flow relationship unclear. Methods and Results We used in vivo imaging of the hemodynamic response in pial arterioles to study CA in a porcine closed cranial window model during nonpharmacological blood pressure manipulation. Red blood cell flux was determined in 52 pial arterioles during 10 hypotension and 10 hypertension experiments to describe the pressure-flow relationship. We found a quadriphasic pressure-flow relationship with 4 distinct physiological phases. Smaller arterioles demonstrated greater vasodilation during low CPP when compared with large arterioles (P<0.01), whereas vasoconstrictive capacity during high CPP was not significantly different between arterioles (P>0.9). The upper limit of CA was defined by 2 breakpoints. Increases in CPP lead to a point of maximal vasoconstriction of the smallest pial arterioles (upper limit of autoregulation [ULA] 1). Beyond ULA1, only larger arterioles maintain a limited additional vasoconstrictive capacity, extending the buffer for high CPP. Beyond ULA2, vasoconstrictive capacity is exhausted, and all pial arterioles passively dilate. There was substantial intersubject variability, with ranges of 29.2, 47.3, and 50.9 mm Hg for the lower limit, ULA1, and ULA2, respectively. Conclusions We provide new insights into the quadriphasic physiology of CA, differentiating between truly active CA and an extended capacity to buffer increased CPP with progressive failure of CA. In this experimental model, the limits of CA widely varied between subjects.
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Affiliation(s)
- Samuel P Klein
- Department of Neurosurgery University Hospitals Leuven Leuven Belgium
| | | | - Geert Meyfroidt
- Department of Intensive Care Medicine University Hospitals Leuven Leuven Belgium
| | - Bart Depreitere
- Department of Neurosurgery University Hospitals Leuven Leuven Belgium
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30
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Skow RJ, Labrecque L, Rosenberger JA, Brassard P, Steinback CD, Davenport MH. Prenatal exercise and cardiovascular health (PEACH) study: impact of acute and chronic exercise on cerebrovascular hemodynamics and dynamic cerebral autoregulation. J Appl Physiol (1985) 2021; 132:247-260. [PMID: 34818074 DOI: 10.1152/japplphysiol.00446.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We performed a randomised controlled trial measuring dynamic cerebral autoregulation (dCA) using a sit-to-stand maneuver before (SS1) and following (SS2) an acute exercise test at 16-20 weeks gestation (trimester 2; TM2) and then again at 34-37 weeks gestation (third trimester; TM3). Following the first assessment, women were randomised into exercise training or control (standard care) groups; women in the exercise training group were prescribed moderate intensity aerobic exercise for 25-40 minutes on 3-4 days per week for 14±1weeks. Resting seated mean blood velocity in the middle cerebral artery (MCAvmean) was lower in TM3 compared to TM2 but not impacted by exercise training intervention. dCA was not impacted by gestational age, or exercise training during SS1. During SS2, dCA was altered such that there were greater absolute and relative decreases in mean arterial blood pressure (MAP) and MCAvmean, but this was not impacted by the intervention. There was also no difference in the relationship between the decrease in MCAvmean compared to the decrease in MAP (%/%), or the onset of the regulatory response with respect to acute exercise, gestational age, or intervention; however, rate of regulation was faster in women in the exercise group following acute exercise (interaction effect, p=0.048). These data highlight the resilience of the cerebral circulation in that dCA was well maintained or improved in healthy pregnant women between TM2 and TM3. However, future work addressing the impact of acute and chronic exercise on dCA in women who are at risk for cardiovascular complications during pregnancy is needed.
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Affiliation(s)
- Rachel J Skow
- Program for Pregnancy and Postpartum Health, Neurovascular Health Laboratory, Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Alberta, Canada
| | - Lawrence Labrecque
- Department of Kinesiology and Research center of the Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Québec, Canada
| | - Jade A Rosenberger
- Program for Pregnancy and Postpartum Health, Neurovascular Health Laboratory, Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Alberta, Canada
| | - Patrice Brassard
- Department of Kinesiology and Research center of the Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Québec, Canada
| | - Craig D Steinback
- Program for Pregnancy and Postpartum Health, Neurovascular Health Laboratory, Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Alberta, Canada
| | - Margie H Davenport
- Program for Pregnancy and Postpartum Health, Neurovascular Health Laboratory, Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Alberta, Canada
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31
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Carter SE, Draijer R, Stewart CE, Moss AD, Thijssen DHJ, Hopkins ND. Are acute sitting-induced changes in inflammation and cerebrovascular function related to impaired mood and cognition? SPORT SCIENCES FOR HEALTH 2021; 17:753-762. [PMID: 34721696 PMCID: PMC8550027 DOI: 10.1007/s11332-021-00753-8] [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: 09/11/2020] [Accepted: 03/27/2021] [Indexed: 11/29/2022]
Abstract
Purpose Sedentary behaviour is negatively associated with mood and cognition, yet how acute sitting contributes to these overall associations is unknown. Since sitting heightens inflammation and impairs cerebrovascular function, this study investigated the hypothesis that these sitting-induced changes are related to impaired mood and cognition. Methods Twenty-five healthy desk workers (18 male, 28.3 ± 7.5 years, BMI: 24.2 ± 3.3 kg∙m-2) were recruited. During laboratory visit one, participants were familiarised with cognitive performance tests measuring executive function, attention and working memory. During laboratory visit two, participants completed 6 h of continuous, uninterrupted sitting. At baseline and after 6 h, serum markers of inflammation, middle cerebral artery blood flow velocity (MCAv), cerebrovascular carbon dioxide reactivity (CVR), dynamic cerebral autoregulation (CA), cognitive performance and mood (positive and negative affect, alert, contented and calm) were assessed. Data were analysed using paired-samples t tests and correlation analyses. Results Following sitting, C-reactive protein (∆-1.0 µg/ml) and tissue plasminogen activator (∆-360.4 pg/ml) decreased (p < 0.05), MCAv reduced (∆-2.9 cm∙s-1, p = 0.012) and normalised gain increased in the very low frequency range, indicating impaired CA (∆ + 0.22%·mmHg-1, p = 0.016). Positive affect (∆-4.6, p < 0.001), and alert (∆-10.6 p = 0.002) and contented (∆-7.4, p = 0.006) mood states also decreased following sitting. No significant changes in interleukin-6, tumour necrosis factor-alpha, von Willebrand factor, CVR or cognitive performance were observed (p > 0.05). The observed changes in inflammation and cerebrovascular function were not related to changes in mood (p > 0.05). Conclusion Alterations in inflammation or cerebrovascular function following six hours of prolonged, uninterrupted sitting are not related to the observed reductions in mood, indicating other mechanisms underlie the relationship between acute sitting and mood disturbances.
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Affiliation(s)
- Sophie E Carter
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK.,School of Science, Technology and Health, York St John University, Nestlé Rowntree Park Sports Campus, Haxby Road, York, YO31 8TA UK
| | - Richard Draijer
- Unilever Foods Innovation Centre, Wageningen, The Netherlands
| | - Claire E Stewart
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | - Andy D Moss
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | - Dick H J Thijssen
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK.,Radboud Institute for Health Sciences, Department of Physiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Nicola D Hopkins
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
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32
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Crippa IA, Vincent JL, Zama Cavicchi F, Pozzebon S, Annoni F, Cotoia A, Njimi H, Gaspard N, Creteur J, Taccone FS. Cerebral autoregulation in anoxic brain injury patients treated with targeted temperature management. J Intensive Care 2021; 9:67. [PMID: 34702372 PMCID: PMC8547304 DOI: 10.1186/s40560-021-00579-z] [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: 06/28/2021] [Accepted: 10/12/2021] [Indexed: 01/02/2023] Open
Abstract
Background Little is known about the prevalence of altered CAR in anoxic brain injury and the association with patients’ outcome. We aimed at investigating CAR in cardiac arrest survivors treated by targeted temperature management and its association to outcome.
Methods Retrospective analysis of prospectively collected data. Inclusion criteria: adult cardiac arrest survivors treated by targeted temperature management (TTM). Exclusion criteria: trauma; sepsis, intoxication; acute intra-cranial disease; history of supra-aortic vascular disease; severe hemodynamic instability; cardiac output mechanical support; arterial carbon dioxide partial pressure (PaCO2) > 60 mmHg; arrhythmias; lack of acoustic window. Middle cerebral artery flow velocitiy (FV) was assessed by transcranial Doppler (TCD) once during hypothermia (HT) and once during normothermia (NT). FV and blood pressure (BP) were recorded simultaneously and Mxa calculated (MATLAB). Mxa is the Pearson correlation coefficient between FV and BP. Mxa > 0.3 defined altered CAR. Survival was assessed at hospital discharge. Cerebral Performance Category (CPC) 3–5 assessed 3 months after CA defined unfavorable neurological outcome (UO). Results We included 50 patients (Jan 2015–Dec 2018). All patients had out-of-hospital cardiac arrest, 24 (48%) had initial shockable rhythm. Time to return of spontaneous circulation was 20 [10–35] min. HT (core body temperature 33.7 [33.2–34] °C) lasted for 24 [23–28] h, followed by rewarming and NT (core body temperature: 36.9 [36.6–37.4] °C). Thirty-one (62%) patients did not survive at hospital discharge and 36 (72%) had UO. Mxa was lower during HT than during NT (0.33 [0.11–0.58] vs. 0.58 [0.30–0.83]; p = 0.03). During HT, Mxa did not differ between outcome groups. During NT, Mxa was higher in patients with UO than others (0.63 [0.43–0.83] vs. 0.31 [− 0.01–0.67]; p = 0.03). Mxa differed among CPC values at NT (p = 0.03). Specifically, CPC 2 group had lower Mxa than CPC 3 and 5 groups. At multivariate analysis, initial non-shockable rhythm, high Mxa during NT and highly malignant electroencephalography pattern (HMp) were associated with in-hospital mortality; high Mxa during NT and HMp were associated with UO. Conclusions CAR is frequently altered in cardiac arrest survivors treated by TTM. Altered CAR during normothermia was independently associated with poor outcome. Supplementary Information The online version contains supplementary material available at 10.1186/s40560-021-00579-z.
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Affiliation(s)
- Ilaria Alice Crippa
- Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles (ULB), Route de Lennik 808, 1070, Bruxelles, Belgium.
| | - Jean-Louis Vincent
- Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles (ULB), Route de Lennik 808, 1070, Bruxelles, Belgium
| | - Federica Zama Cavicchi
- Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles (ULB), Route de Lennik 808, 1070, Bruxelles, Belgium
| | - Selene Pozzebon
- Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles (ULB), Route de Lennik 808, 1070, Bruxelles, Belgium
| | - Filippo Annoni
- Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles (ULB), Route de Lennik 808, 1070, Bruxelles, Belgium
| | - Antonella Cotoia
- Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles (ULB), Route de Lennik 808, 1070, Bruxelles, Belgium.,Department of Anesthesia and Intensive Care, University Hospital of Foggia, Viale Luigi Pinto 1, 71122, Foggia, Italy
| | - Hassane Njimi
- Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles (ULB), Route de Lennik 808, 1070, Bruxelles, Belgium
| | - Nicolas Gaspard
- Department of Neurology, Erasme Hospital, Université Libre de Bruxelles (ULB), Route de Lennik 808, 1070, Bruxelles, Belgium
| | - Jacques Creteur
- Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles (ULB), Route de Lennik 808, 1070, Bruxelles, Belgium
| | - Fabio Silvio Taccone
- Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles (ULB), Route de Lennik 808, 1070, Bruxelles, Belgium
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Brassard P, Labrecque L, Smirl JD, Tymko MM, Caldwell HG, Hoiland RL, Lucas SJE, Denault AY, Couture EJ, Ainslie PN. Losing the dogmatic view of cerebral autoregulation. Physiol Rep 2021; 9:e14982. [PMID: 34323023 PMCID: PMC8319534 DOI: 10.14814/phy2.14982] [Citation(s) in RCA: 74] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 07/04/2021] [Indexed: 02/07/2023] Open
Abstract
In 1959, Niels Lassen illustrated the cerebral autoregulation curve in the classic review article entitled Cerebral Blood Flow and Oxygen Consumption in Man. This concept suggested a relatively broad mean arterial pressure range (~60-150 mmHg) wherein cerebral blood flow remains constant. However, the assumption that this wide cerebral autoregulation plateau could be applied on a within-individual basis is incorrect and greatly variable between individuals. Indeed, each data point on the autoregulatory curve originated from independent samples of participants and patients and represented interindividual relationships between cerebral blood flow and mean arterial pressure. Nonetheless, this influential concept remains commonly cited and illustrated in various high-impact publications and medical textbooks, and is frequently taught in medical and science education without appropriate nuances and caveats. Herein, we provide the rationale and additional experimental data supporting the notion we need to lose this dogmatic view of cerebral autoregulation.
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Affiliation(s)
- Patrice Brassard
- Department of KinesiologyFaculty of MedicineUniversité LavalQuébecQCCanada
- Research center of the Institut universitaire de cardiologie et de pneumologie de QuébecQuébecQCCanada
| | - Lawrence Labrecque
- Department of KinesiologyFaculty of MedicineUniversité LavalQuébecQCCanada
- Research center of the Institut universitaire de cardiologie et de pneumologie de QuébecQuébecQCCanada
| | - Jonathan D. Smirl
- Sport Injury Prevention Research CentreFaculty of KinesiologyUniversity of CalgaryCalgaryABCanada
- Cerebrovascular Concussion LaboratoryFaculty of KinesiologyUniversity of CalgaryCalgaryABCanada
- Human Performance LaboratoryFaculty of KinesiologyUniversity of CalgaryCalgaryABCanada
- Hotchkiss Brain InstituteUniversity of CalgaryCalgaryABCanada
- Integrated Concussion Research ProgramUniversity of CalgaryCalgaryABCanada
- Alberta Children’s Hospital Research InstituteUniversity of CalgaryCalgaryABCanada
- Libin Cardiovascular Institute of AlbertaUniversity of CalgaryABCanada
| | - Michael M. Tymko
- Neurovascular Health LaboratoryUniversity of AlbertaEdmontonABCanada
| | - Hannah G. Caldwell
- Center for Heart, Lung and Vascular HealthSchool of Health and Exercise SciencesUniversity of British Columbia – OkanaganKelownaBCCanada
| | - Ryan L. Hoiland
- Department of Cellular and Physiological SciencesFaculty of MedicineUniversity of British ColumbiaVancouverBCCanada
- Department of Anesthesiology, Pharmacology and TherapeuticsUniversity of British ColumbiaVancouverBCCanada
| | - Samuel J. E. Lucas
- School of Sport, Exercise and Rehabilitation SciencesCollege of Life and Environmental SciencesUniversity of BirminghamBirminghamUnited Kingdom
- Centre for Human Brain HealthUniversity of BirminghamBirminghamUnited Kingdom
| | - André Y. Denault
- Department of Anesthesiology and Critical Care DivisionMontreal Heart InstituteMontrealQCCanada
- Division of Critical Care MedicineCentre Hospitalier de l’Université de MontréalMontrealQCCanada
| | - Etienne J. Couture
- Research center of the Institut universitaire de cardiologie et de pneumologie de QuébecQuébecQCCanada
| | - Philip N. Ainslie
- Center for Heart, Lung and Vascular HealthSchool of Health and Exercise SciencesUniversity of British Columbia – OkanaganKelownaBCCanada
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Mazumder D, Wu MM, Ozana N, Tamborini D, Franceschini MA, Carp SA. Optimization of time domain diffuse correlation spectroscopy parameters for measuring brain blood flow. NEUROPHOTONICS 2021; 8:035005. [PMID: 34395719 PMCID: PMC8358828 DOI: 10.1117/1.nph.8.3.035005] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 07/15/2021] [Indexed: 05/05/2023]
Abstract
Significance: Time domain diffuse correlation spectroscopy (TD-DCS) can offer increased sensitivity to cerebral hemodynamics and reduced contamination from extracerebral layers by differentiating photons based on their travel time in tissue. We have developed rigorous simulation and evaluation procedures to determine the optimal time gate parameters for monitoring cerebral perfusion considering instrumentation characteristics and realistic measurement noise. Aim: We simulate TD-DCS cerebral perfusion monitoring performance for different instrument response functions (IRFs) in the presence of realistic experimental noise and evaluate metrics of sensitivity to brain blood flow, signal-to-noise ratio (SNR), and ability to reject the influence of extracerebral blood flow across a variety of time gates to determine optimal operating parameters. Approach: Light propagation was modeled on an MRI-derived human head geometry using Monte Carlo simulations for 765- and 1064-nm excitation wavelengths. We use a virtual probe with a source-detector separation of 1 cm placed in the pre-frontal region. Performance metrics described above were evaluated to determine optimal time gate(s) for different IRFs. Validation of simulation noise estimates was done with experiments conducted on an intralipid-based liquid phantom. Results: We find that TD-DCS performance strongly depends on the system IRF. Among Gaussian pulse shapes, ∼ 300 ps pulse length appears to offer the best performance, at wide gates (500 ps and larger) with start times 400 and 600 ps after the peak of the TPSF at 765 and 1064 nm, respectively, for a 1-s integration time at photon detection rates seen experimentally (600 kcps at 765 nm and 4 Mcps at 1064 nm). Conclusions: Our work shows that optimal time gates satisfy competing requirements for sufficient sensitivity and sufficient SNR. The achievable performance is further impacted by system IRF with ∼ 300 ps quasi-Gaussian pulse obtained using electro-optic laser shaping providing the best results.
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Affiliation(s)
- Dibbyan Mazumder
- Harvard Medical School, Massachusetts General Hospital, Optics at Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Charlestown, Massachusetts, United States
- Address all correspondence to Dibbyan Mazumder,
| | - Melissa M. Wu
- Harvard Medical School, Massachusetts General Hospital, Optics at Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Charlestown, Massachusetts, United States
| | - Nisan Ozana
- Harvard Medical School, Massachusetts General Hospital, Optics at Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Charlestown, Massachusetts, United States
| | - Davide Tamborini
- Harvard Medical School, Massachusetts General Hospital, Optics at Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Charlestown, Massachusetts, United States
| | - Maria Angela Franceschini
- Harvard Medical School, Massachusetts General Hospital, Optics at Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Charlestown, Massachusetts, United States
| | - Stefan A. Carp
- Harvard Medical School, Massachusetts General Hospital, Optics at Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Charlestown, Massachusetts, United States
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Liming Z, Weiliang S, Jia J, Hao L, Yang L, Ludtka C, Jahromi BR, Goehre F, Zemmar A, Tianxiao L, Hernesniemi J, Andrade-Barazarte H, Chaoyue L. Impact of blood pressure changes in cerebral blood perfusion of patients with ischemic Moyamoya disease evaluated by SPECT. J Cereb Blood Flow Metab 2021; 41:1472-1480. [PMID: 33153375 PMCID: PMC8142135 DOI: 10.1177/0271678x20967458] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Our aim was to determine the impact of targeted blood pressure modifications on cerebral blood flow in ischemic moyamoya disease patients assessed by single-photon emission computed tomography (SPECT). From March to September 2018, we prospectively collected data of 154 moyamoya disease patients and selected 40 patients with ischemic moyamoya disease. All patients underwent in-hospital blood pressure monitoring to determine the mean arterial pressure baseline values. The study cohort was subdivided into two subgroups: (1) Group A or relative high blood pressure (RHBP) with an induced mean arterial pressure 10-20% higher than baseline and (2) Group B or relative low blood pressure (RLBP) including patients with mean arterial pressure 10-20% lower than baseline. All patients underwent initial SPECT study on admission-day, and on the following day, every subgroup underwent a second SPECT study under their respective targeted blood pressure values. In general, RHBP patients showed an increment in perfusion of 10.13% (SD 2.94%), whereas RLBP patients showed a reduction of perfusion of 12.19% (SD 2.68%). Cerebral blood flow of moyamoya disease patients is susceptible to small blood pressure changes, and cerebral autoregulation might be affected due to short dynamic blood pressure modifications.
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Affiliation(s)
- Zhao Liming
- Department of Neurosurgery, Cerebrovascular Disease Hospital, Henan Provincial People's Hospital; Zhengzhou University, Zhengzhou, China
| | - Sun Weiliang
- Department of Neurosurgery, Cerebrovascular Disease Hospital, Henan Provincial People's Hospital; Zhengzhou University, Zhengzhou, China
| | - Jia Jia
- Department of Anesthesiology and Perioperative medicine, Henan Provincial People's Hospital; Zhengzhou; Zhengzhou, China
| | - Liang Hao
- Department of Neurosurgery, Cerebrovascular Disease Hospital, Henan Provincial People's Hospital; Zhengzhou University, Zhengzhou, China
| | - Liu Yang
- Department of Neurosurgery, Cerebrovascular Disease Hospital, Henan Provincial People's Hospital; Zhengzhou University, Zhengzhou, China
| | - Christopher Ludtka
- "Juha Hernesniemi" International Center for Neurosurgery, Henan Provincial People's Hospital, Zhengzhou University, Zhengzhou, China
| | - Behnam Rezai Jahromi
- Department of Neurosurgery, Cerebrovascular Disease Hospital, Henan Provincial People's Hospital; Zhengzhou University, Zhengzhou, China
| | - Felix Goehre
- Department of Neurosurgery, BG Klinikum Bergmannstrost Halle, Halle, Germany
| | - Ajmal Zemmar
- Department of Neurosurgery, Cerebrovascular Disease Hospital, Henan Provincial People's Hospital; Zhengzhou University, Zhengzhou, China.,"Juha Hernesniemi" International Center for Neurosurgery, Henan Provincial People's Hospital, Zhengzhou University, Zhengzhou, China
| | - Li Tianxiao
- Department of Neurosurgery, Cerebrovascular Disease Hospital, Henan Provincial People's Hospital; Zhengzhou University, Zhengzhou, China
| | - Juha Hernesniemi
- Department of Neurosurgery, Cerebrovascular Disease Hospital, Henan Provincial People's Hospital; Zhengzhou University, Zhengzhou, China.,"Juha Hernesniemi" International Center for Neurosurgery, Henan Provincial People's Hospital, Zhengzhou University, Zhengzhou, China
| | - Hugo Andrade-Barazarte
- Department of Neurosurgery, Cerebrovascular Disease Hospital, Henan Provincial People's Hospital; Zhengzhou University, Zhengzhou, China.,"Juha Hernesniemi" International Center for Neurosurgery, Henan Provincial People's Hospital, Zhengzhou University, Zhengzhou, China
| | - Li Chaoyue
- Department of Neurosurgery, Cerebrovascular Disease Hospital, Henan Provincial People's Hospital; Zhengzhou University, Zhengzhou, China
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Perry BG, Lucas SJE. The Acute Cardiorespiratory and Cerebrovascular Response to Resistance Exercise. SPORTS MEDICINE-OPEN 2021; 7:36. [PMID: 34046740 PMCID: PMC8160070 DOI: 10.1186/s40798-021-00314-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 03/07/2021] [Indexed: 12/18/2022]
Abstract
Resistance exercise (RE) is a popular modality for the general population and athletes alike, due to the numerous benefits of regular participation. The acute response to dynamic RE is characterised by temporary and bidirectional physiological extremes, not typically seen in continuous aerobic exercise (e.g. cycling) and headlined by phasic perturbations in blood pressure that challenge cerebral blood flow (CBF) regulation. Cerebral autoregulation has been heavily scrutinised over the last decade with new data challenging the effectiveness of this intrinsic flow regulating mechanism, particularly to abrupt changes in blood pressure over the course of seconds (i.e. dynamic cerebral autoregulation), like those observed during RE. Acutely, RE can challenge CBF regulation, resulting in adverse responses (e.g. syncope). Compared with aerobic exercise, RE is relatively understudied, particularly high-intensity dynamic RE with a concurrent Valsalva manoeuvre (VM). However, the VM alone challenges CBF regulation and generates additional complexity when trying to dissociate the mechanisms underpinning the circulatory response to RE. Given the disparate circulatory response between aerobic and RE, primarily the blood pressure profiles, regulation of CBF is ostensibly different. In this review, we summarise current literature and highlight the acute physiological responses to RE, with a focus on the cerebral circulation.
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Affiliation(s)
- Blake G Perry
- School of Health Sciences, Massey University, Wellington, New Zealand.
| | - Samuel J E Lucas
- School of Sport, Exercise and Rehabilitation Sciences & Centre for Human Brain Health, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
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Larson S, Anderson L, Thomson S. Effect of phenylephrine on cerebral oxygen saturation and cardiac output in adults when used to treat intraoperative hypotension: a systematic review. JBI Evid Synth 2021; 19:34-58. [PMID: 32941358 DOI: 10.11124/jbisrir-d-19-00352] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
OBJECTIVE The objective of this review was to examine the effect of phenylephrine on cerebral oxygen saturation, cardiac output, and middle cerebral artery blood flow velocity when used to treat intraoperative hypotension. INTRODUCTION While the etiology of postoperative cognitive dysfunction in adults following surgery is likely multifactorial, intraoperative cerebral hypoperfusion is a commonly proposed mechanism. Research evidence and expert opinion are emerging that suggest phenylephrine adversely affects cerebral oxygen saturation and may also adversely affect cerebral perfusion via a reduction in cardiac output or cerebral vascular vasoconstriction. The administration of phenylephrine to treat intraoperative hypotension is common anesthesia practice, despite a lack of evidence to show it improves cerebral perfusion. Therefore, a systematic review of the effect of phenylephrine on cerebral hemodynamics has significant implications for anesthesia practice and future research. INCLUSION CRITERIA Studies of adults 18 years and over undergoing elective, non-neurosurgical procedures involving anesthesia were included. In these studies, participants received phenylephrine to treat intraoperative hypotension. The effect of phenylephrine on cerebral oxygen saturation, cardiac output, or middle cerebral artery blood flow velocity was measured. METHODS Key information sources searched included MEDLINE (Ovid), Embase, CINAHL (EBSCO), and Google Scholar. The scope of the search was limited to English-language studies published from 1999 through 2017. The recommended JBI approach to critical appraisal, study selection, data extraction, and data synthesis were used. RESULTS This systematic review found that phenylephrine consistently decreased cerebral oxygen saturation values despite simultaneously increasing mean arterial pressure to normal range. Results also found that ephedrine and dopamine were superior to phenylephrine in maintaining or increasing values. Phenylephrine was found to be similar to vasopressin in the extent to which both decreased cerebral oxygen saturation values. Results also showed that phenylephrine resulted in statistically significant declines in cardiac output, or failed to improve abnormally low preintervention values. The effect of phenylephrine on middle cerebral artery blood flow velocity was only measured in one study and showed that phenylephrine increased flow velocity by about 20%. Statistical pooling of the study results was not possible due to the gross variation in how the intervention was administered and how effect was measured. CONCLUSIONS This review found that phenylephrine administration resulted in declines in cerebral oxygen saturation and cardiac output. However, the research studies were ineffective in informing phenylephrine's mechanism of action or its impact on postoperative cognitive function. SYSTEMATIC REVIEW REGISTRATION NUMBER PROSPERO (CRD42018100740).
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Affiliation(s)
- Sandra Larson
- Rosalind Franklin University of Medicine and Science: A JBI Affiliated Group, Chicago, IL, USA
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Carr JMJR, Caldwell HG, Ainslie PN. Cerebral blood flow, cerebrovascular reactivity and their influence on ventilatory sensitivity. Exp Physiol 2021; 106:1425-1448. [PMID: 33932955 DOI: 10.1113/ep089446] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Accepted: 04/26/2021] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the topic of this review? Cerebrovascular reactivity to CO2 , which is a principal factor in determining ventilatory responses to CO2 through the role reactivity plays in determining cerebral extra- and intracellular pH. What advances does it highlight? Recent animal evidence suggests central chemoreceptor vasculature may demonstrate regionally heterogeneous cerebrovascular reactivity to CO2 , potentially as a protective mechanism against excessive CO2 washout from the central chemoreceptors, thereby allowing ventilation to reflect the systemic acid-base balance needs (respiratory changes in P aC O 2 ) rather than solely the cerebral needs. Ventilation per se does not influence cerebrovascular reactivity independent of changes in P aC O 2 . ABSTRACT Alveolar ventilation and cerebral blood flow are both predominantly regulated by arterial blood gases, especially arterial P C O 2 , and so are intricately entwined. In this review, the fundamental mechanisms underlying cerebrovascular reactivity and central chemoreceptor control of breathing are covered. We discuss the interaction of cerebral blood flow and its reactivity with the control of ventilation and ventilatory responsiveness to changes in P C O 2 , as well as the lack of influence of ventilation itself on cerebrovascular reactivity. We briefly summarize the effects of arterial hypoxaemia on the relationship between ventilatory and cerebrovascular response to both P C O 2 and P O 2 . We then highlight key methodological considerations regarding the interaction of reactivity and ventilatory sensitivity, including the following: regional heterogeneity of cerebrovascular reactivity; a pharmacological approach for the reduction of cerebral blood flow; reactivity assessment techniques; the influence of mean arterial blood pressure; and sex-related differences. Finally, we discuss ventilatory and cerebrovascular control in the context of high altitude and congestive heart failure. Future research directions and pertinent questions of interest are highlighted throughout.
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Affiliation(s)
- Jay M J R Carr
- Centre for Heart, Lung and Vascular Health, University of British Columbia - Okanagan Campus, British Columbia, Canada
| | - Hannah G Caldwell
- Centre for Heart, Lung and Vascular Health, University of British Columbia - Okanagan Campus, British Columbia, Canada
| | - Philip N Ainslie
- Centre for Heart, Lung and Vascular Health, University of British Columbia - Okanagan Campus, British Columbia, Canada
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Hogan WJ, Moon-Grady AJ, Zhao Y, Cresalia NM, Nawaytou H, Quezada E, Brook M, McQuillen P, Peyvandi S. Fetal cerebrovascular response to maternal hyperoxygenation in congenital heart disease: effect of cardiac physiology. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2021; 57:769-775. [PMID: 32202689 PMCID: PMC7673795 DOI: 10.1002/uog.22024] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 02/23/2020] [Accepted: 03/13/2020] [Indexed: 06/10/2023]
Abstract
OBJECTIVE Fetal cerebrovascular resistance is influenced by several factors in the setting of intact autoregulation to allow for normal cerebral blood flow and oxygenation. Maternal hyperoxygenation (MH) allows for acute alterations in fetal physiology and can be a tool to test cerebrovascular reactivity in late-gestation fetuses. In this study, we utilized MH to evaluate cerebrovascular reactivity in fetuses with specific congenital heart disease (CHD). METHODS This was a cross-sectional study of fetuses with complex CHD compared to controls without CHD. CHD cases were grouped according to physiology into: left-sided obstructive lesion (LSOL), right-sided obstructive lesion (RSOL) or dextro-transposition of the great arteries (d-TGA). Subjects underwent MH testing during the third-trimester fetal echocardiogram. The pulsatility index (PI) was calculated for the fetal middle cerebral artery (MCA), umbilical artery (UA) and branch pulmonary artery (PA). The change in PI from baseline to during MH was compared between each CHD group and controls. RESULTS Sixty pregnant women were enrolled (CHD, n = 43; control, n = 17). In the CHD group, there were 27 fetuses with LSOL, seven with RSOL and nine with d-TGA. Mean gestational age was 33.9 (95% CI, 33.6-34.2) weeks. At baseline, MCA-PI Z-score was lowest in the LSOL group (-1.8 (95% CI, -2.4 to -1.2)) compared with the control group (-0.8 (95% CI, -1.3 to -0.3)) (P = 0.01). In response to MH, MCA-PI Z-score increased significantly in the control and d-TGA groups but did not change significantly in the LSOL and RSOL groups. The change in MCA-PI Z-score was significantly higher in the control group than in the LSOL group (0.9 (95% CI, 0.42-1.4) vs 0.12 (95% CI, -0.21 to 0.45); P = 0.03). This difference was more pronounced in the LSOL subgroup with retrograde aortic arch flow. Branch PA-PI decreased significantly in response to MH in all groups, with no difference in the change from baseline to MH between the groups, while UA-PI was unchanged during MH compared with at baseline. CONCLUSIONS The fetal cerebrovascular response to MH varies based on the underlying CHD diagnosis, suggesting that cardiovascular physiology may influence the autoregulatory capacity of the fetal brain. Further studies are needed to determine the clinical implications of these findings on long-term neurodevelopment in these at-risk children. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.
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Affiliation(s)
- W J Hogan
- Division of Pediatric Cardiology, Department of Pediatrics, The University of California San Francisco, San Francisco, CA, USA
| | - A J Moon-Grady
- Division of Pediatric Cardiology, Department of Pediatrics, The University of California San Francisco, San Francisco, CA, USA
| | - Y Zhao
- Division of Pediatric Cardiology, Department of Pediatrics, The University of California San Francisco, San Francisco, CA, USA
| | - N M Cresalia
- Division of Pediatric Cardiology, Department of Pediatrics, The University of California San Francisco, San Francisco, CA, USA
| | - H Nawaytou
- Division of Pediatric Cardiology, Department of Pediatrics, The University of California San Francisco, San Francisco, CA, USA
| | - E Quezada
- Division of Pediatric Cardiology, Department of Pediatrics, The University of California San Francisco, San Francisco, CA, USA
| | - M Brook
- Division of Pediatric Cardiology, Department of Pediatrics, The University of California San Francisco, San Francisco, CA, USA
| | - P McQuillen
- Division of Critical Care, Department of Pediatrics, The University of California San Francisco, San Francisco, CA, USA
| | - S Peyvandi
- Division of Pediatric Cardiology, Department of Pediatrics, The University of California San Francisco, San Francisco, CA, USA
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Effects on cerebral blood flow of position changes, hyperoxia, CO2 partial pressure variations and the Valsalva manoeuvre: A study in healthy volunteers. Eur J Anaesthesiol 2021; 38:49-57. [PMID: 33074942 DOI: 10.1097/eja.0000000000001356] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Maintaining adequate blood pressure to ensure proper cerebral blood flow (CBF) during surgery is challenging. Induced mild hypotension, sitting position or unavoidable intra-operative circumstances such as haemorrhage, added to variations in carbon dioxide and oxygen tensions, may influence perfusion. Several of these circumstances may coincide and it is unclear how these may affect CBF. OBJECTIVE To describe the variation in transcranial Doppler and regional cerebral oxygen saturation (rSO2), as a surrogate of CBF, after cardiac preload and gravitational positional changes. DESIGN Observational study. SETTING Operating room at Hospital Clínic de Barcelona. VOLUNTEERS Ten healthy volunteers, white, both sexes. INTERVENTIONS Measurements were performed in the supine, sitting and standing positions during hyperoxia, hypocapnia and hypercapnia protocols and after a Valsalva manoeuvre. MAIN OUTCOME MEASURES Cardiac index (CI), haemodynamic and respiratory variables, maximal and mean velocities (Vmax, Vmean) (transcranial Doppler) and rSO2 were acquired. Results were analysed using a generalised estimating equation technique. RESULTS CI increases more than 16% after a preload challenge were not accompanied by differences in rSO2 or Vmax - Vmean. With positional changes, Vmean decreased more than 7% (P = 0.042) from the supine to the seated position. Hyperoxia induced a cerebral rSO2 increase more than 6% (P = 0.0001) with decreases in Vmax, Vmean and CI values more than 3% (P = 0.001, 0.022 and 0.001) in the supine and standing position. During hypocapnia, CI rose more than 20% from supine to seated and standing (P = 0.0001) with a 4.5% decrease in cerebral rSO2 (P = 0.001) and a decrease of Vmax - Vmean more than 24% in all positions (P = 0.001). Hypercapnia increased cerebral rSO2 more than 17% (P = 0.001), Vmax - Vmean more than 30% (P = 0.001) with no changes in CI. After a Valsalva manoeuvre, rSO2 decreased more than 3% in the right hemisphere in the upright position (P = 0.001). Vmax - Vmean decreased more than 10% (P = 0.001) with no changes in CI. CONCLUSION CBF changes in response to cerebral vasoconstriction and vasodilatation were detected with rSO2 and transcranial Doppler in healthy volunteers during cardiac preload and in different body positions. Acute hypercapnia had a greater effect on recorded brain parameters than hypocapnia.
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Bliss ES, Wong RHX, Howe PRC, Mills DE. Benefits of exercise training on cerebrovascular and cognitive function in ageing. J Cereb Blood Flow Metab 2021; 41:447-470. [PMID: 32954902 PMCID: PMC7907999 DOI: 10.1177/0271678x20957807] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Derangements in cerebrovascular structure and function can impair cognitive performance throughout ageing and in cardiometabolic disease states, thus increasing dementia risk. Modifiable lifestyle factors that cause a decline in cardiometabolic health, such as physical inactivity, exacerbate these changes beyond those that are associated with normal ageing. The purpose of this review was to examine cerebrovascular, cognitive and neuroanatomical adaptations to ageing and the potential benefits of exercise training on these outcomes in adults 50 years or older. We systematically searched for cross-sectional or intervention studies that included exercise (aerobic, resistance or multimodal) and its effect on cerebrovascular function, cognition and neuroanatomical adaptations in this age demographic. The included studies were tabulated and described narratively. Aerobic exercise training was the predominant focus of the studies identified; there were limited studies exploring the effects of resistance exercise training and multimodal training on cerebrovascular function and cognition. Collectively, the evidence indicated that exercise can improve cerebrovascular function, cognition and neuroplasticity through areas of the brain associated with executive function and memory in adults 50 years or older, irrespective of their health status. However, more research is required to ascertain the mechanisms of action.
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Affiliation(s)
- Edward S Bliss
- Respiratory and Exercise Physiology Research Group, School of
Health and Wellbeing, University of Southern Queensland, Ipswich, Queensland,
Australia
- Edward S Bliss, School of Health and
Wellbeing, University of Southern Queensland, Toowoomba Campus, West St,
Toowoomba QLD 4350, Australia.
| | - Rachel HX Wong
- Centre for Health, Informatics, and Economic Research, Institute
for Resilient Regions, University of Southern Queensland, Ipswich, Queensland,
Australia
- School of Biomedical Sciences and Pharmacy, Clinical Nutrition
Research Centre, University of Newcastle, Callaghan, New South Wales,
Australia
| | - Peter RC Howe
- Centre for Health, Informatics, and Economic Research, Institute
for Resilient Regions, University of Southern Queensland, Ipswich, Queensland,
Australia
- School of Biomedical Sciences and Pharmacy, Clinical Nutrition
Research Centre, University of Newcastle, Callaghan, New South Wales,
Australia
- Allied Health and Human Performance, University of South
Australia, Adelaide, South Australia, Australia
| | - Dean E Mills
- Respiratory and Exercise Physiology Research Group, School of
Health and Wellbeing, University of Southern Queensland, Ipswich, Queensland,
Australia
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Duffin J, Mikulis DJ, Fisher JA. Control of Cerebral Blood Flow by Blood Gases. Front Physiol 2021; 12:640075. [PMID: 33679453 PMCID: PMC7930328 DOI: 10.3389/fphys.2021.640075] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 01/25/2021] [Indexed: 12/19/2022] Open
Abstract
Cerebrovascular reactivity can be measured as the cerebrovascular flow response to a hypercapnic challenge. The many faceted responses of cerebral blood flow to combinations of blood gas challenges are mediated by its vasculature's smooth muscle and can be comprehensively described by a simple mathematical model. The model accounts for the blood flow during hypoxia, anemia, hypocapnia, and hypercapnia. The main hypothetical basis of the model is that these various challenges, singly or in combination, act via a common regulatory pathway: the regulation of intracellular hydrogen ion concentration. This regulation is achieved by membrane transport of strongly dissociated ions to control their intracellular concentrations. The model assumes that smooth muscle vasoconstriction and vasodilation and hence cerebral blood flow, are proportional to the intracellular hydrogen ion concentration. Model predictions of the cerebral blood flow responses to hypoxia, anemia, hypocapnia, and hypercapnia match the form of observed responses, providing some confidence that the theories on which the model is based have some merit.
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Affiliation(s)
- James Duffin
- Department of Anesthesia and Pain Management, University of Toronto, Toronto, ON, Canada
- Department of Physiology, University of Toronto, Toronto, ON, Canada
- Thornhill Research Inc., Toronto, ON, Canada
- University Health Network, Toronto, ON, Canada
| | - David J. Mikulis
- Division of Neuroradiology Imaging, Joint Department of Medical Imaging, University Health Network, Toronto, ON, Canada
| | - Joseph A. Fisher
- Department of Anesthesia and Pain Management, University of Toronto, Toronto, ON, Canada
- Department of Physiology, University of Toronto, Toronto, ON, Canada
- Thornhill Research Inc., Toronto, ON, Canada
- University Health Network, Toronto, ON, Canada
- Faculty of Medicine, Institute of Medical Science, University of Toronto, Toronto, ON, Canada
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43
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Slessarev M, Mahmoud O, McIntyre CW, Ellis CG. Cerebral Blood Flow Deviations in Critically Ill Patients: Potential Insult Contributing to Ischemic and Hyperemic Injury. Front Med (Lausanne) 2021; 7:615318. [PMID: 33553208 PMCID: PMC7854569 DOI: 10.3389/fmed.2020.615318] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 12/14/2020] [Indexed: 11/27/2022] Open
Abstract
Background: Ischemic and hyperemic injury have emerged as biologic mechanisms that contribute to cognitive impairment in critically ill patients. Spontaneous deviations in cerebral blood flow (CBF) beyond ischemic and hyperemic thresholds may represent an insult that contributes to this brain injury, especially if they accumulate over time and coincide with impaired autoregulation. Methods: We used transcranial Doppler to measure the proportion of time that CBF velocity (CBFv) deviated beyond previously reported ischemic and hyperemic thresholds in a cohort of critically ill patients with respiratory failure and/or shock within 48 h of ICU admission. We also assessed whether these CBFv deviations were more common during periods of impaired dynamic autoregulation, and whether they are explained by concurrent variations in mean arterial pressure (MAP) and end-tidal PCO2 (PetCO2). Results: We enrolled 12 consecutive patients (three females) who were monitored for a mean duration of 462.6 ± 39.8 min. Across patients, CBFv deviated by more than 20–30% from its baseline for 17–24% of the analysis time. These CBFv deviations occurred equally during periods of preserved and impaired autoregulation, while concurrent variations in MAP and PetCO2 explained only 13–21% of these CBFv deviations. Conclusion: CBFv deviations beyond ischemic and hyperemic thresholds are common in critically ill patients with respiratory failure or shock. These deviations occur irrespective of the state of dynamic autoregulation and are not explained by changes in MAP and CO2. Future studies should explore mechanisms responsible for these CBFv deviations and establish whether their cumulative burden predicts poor neurocognitive outcomes.
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Affiliation(s)
- Marat Slessarev
- Department of Medicine, Western University, London, ON, Canada.,Department of Medical Biophysics, Western University, London, ON, Canada.,Brain & Mind Institute, Western University, London, ON, Canada
| | - Ossama Mahmoud
- Department of Computer Science, Western University, London, ON, Canada
| | - Christopher W McIntyre
- Department of Medicine, Western University, London, ON, Canada.,Department of Medical Biophysics, Western University, London, ON, Canada
| | - Christopher G Ellis
- Department of Medical Biophysics, Western University, London, ON, Canada.,Robarts Research Institute, Western University, London, ON, Canada
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44
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Beishon L, Clough RH, Kadicheeni M, Chithiramohan T, Panerai RB, Haunton VJ, Minhas JS, Robinson TG. Vascular and haemodynamic issues of brain ageing. Pflugers Arch 2021; 473:735-751. [PMID: 33439324 PMCID: PMC8076154 DOI: 10.1007/s00424-020-02508-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 12/14/2020] [Accepted: 12/16/2020] [Indexed: 01/17/2023]
Abstract
The population is ageing worldwide, thus increasing the burden of common age-related disorders to the individual, society and economy. Cerebrovascular diseases (stroke, dementia) contribute a significant proportion of this burden and are associated with high morbidity and mortality. Thus, understanding and promoting healthy vascular brain ageing are becoming an increasing priority for healthcare systems. In this review, we consider the effects of normal ageing on two major physiological processes responsible for vascular brain function: Cerebral autoregulation (CA) and neurovascular coupling (NVC). CA is the process by which the brain regulates cerebral blood flow (CBF) and protects against falls and surges in cerebral perfusion pressure, which risk hypoxic brain injury and pressure damage, respectively. In contrast, NVC is the process by which CBF is matched to cerebral metabolic activity, ensuring adequate local oxygenation and nutrient delivery for increased neuronal activity. Healthy ageing is associated with a number of key physiological adaptations in these processes to mitigate age-related functional and structural declines. Through multiple different paradigms assessing CA in healthy younger and older humans, generating conflicting findings, carbon dioxide studies in CA have provided the greatest understanding of intrinsic vascular anatomical factors that may mediate healthy ageing responses. In NVC, studies have found mixed results, with reduced, equivalent and increased activation of vascular responses to cognitive stimulation. In summary, vascular and haemodynamic changes occur in response to ageing and are important in distinguishing “normal” ageing from disease states and may help to develop effective therapeutic strategies to promote healthy brain ageing.
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Affiliation(s)
- Lucy Beishon
- Department of Cardiovascular Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester, LE2 7LX, UK.
| | - Rebecca H Clough
- Department of Cardiovascular Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester, LE2 7LX, UK
| | - Meeriam Kadicheeni
- Department of Cardiovascular Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester, LE2 7LX, UK
| | - Tamara Chithiramohan
- Department of Cardiovascular Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester, LE2 7LX, UK
| | - Ronney B Panerai
- Department of Cardiovascular Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester, LE2 7LX, UK.,NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, UK
| | - Victoria J Haunton
- Department of Cardiovascular Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester, LE2 7LX, UK.,NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, UK
| | - Jatinder S Minhas
- Department of Cardiovascular Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester, LE2 7LX, UK.,NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, UK
| | - Thompson G Robinson
- Department of Cardiovascular Sciences, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester, LE2 7LX, UK.,NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, UK
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45
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Horiuchi M, Rossetti GMK, Oliver SJ. The role of dietary nitrate supplementation in neurovascular function. Neural Regen Res 2021; 16:1419-1420. [PMID: 33318435 PMCID: PMC8284290 DOI: 10.4103/1673-5374.300993] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Affiliation(s)
- Masahiro Horiuchi
- Division of Human Environmental Science, Mount Fuji Research Institute, Yamanashi, Japan
| | - Gabriella M K Rossetti
- School of Sport, Health and Exercise Sciences, College of Human Sciences, Bangor University, Bangor, UK
| | - Samuel J Oliver
- School of Sport, Health and Exercise Sciences, College of Human Sciences, Bangor University, Bangor, UK
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46
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Ma Y, Tully PJ, Hofman A, Tzourio C. Blood Pressure Variability and Dementia: A State-of-the-Art Review. Am J Hypertens 2020; 33:1059-1066. [PMID: 32710605 DOI: 10.1093/ajh/hpaa119] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 07/17/2020] [Accepted: 07/21/2020] [Indexed: 12/30/2022] Open
Abstract
Accumulating evidence demonstrates that blood pressure variability (BPV) may contribute to target organ damage, causing coronary heart disease, stroke, and renal disease independent of the level of blood pressure (BP). Several lines of evidence have also linked increased BPV to a higher risk of cognitive decline and incident dementia. The estimated number of dementia cases worldwide is nearly 50 million, and this number continues to grow with increasing life expectancy. Because there is no effective treatment to modify the course of dementia, targeting modifiable vascular factors continues as a top priority for dementia prevention. A clear understanding of the role of BPV in dementia may shed light on the etiology, early prevention, and novel therapeutic targets of dementia, and has therefore gained substantial attention from researchers and clinicians. This review summarizes state-of-art evidence on the relationship between BPV and dementia, with a specific focus on the epidemiological evidence, the underlying mechanisms, and potential intervention strategies. We also discuss challenges and opportunities for future research to facilitate optimal BP management and the clinical translation of BPV for the risk assessment and prevention of dementia.
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Affiliation(s)
- Yuan Ma
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Phillip J Tully
- School of Medicine, The University of Adelaide, Adelaide, Australia
| | - Albert Hofman
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Christophe Tzourio
- Univ. Bordeaux, Inserm, Bordeaux Population Health Research Center, UMR 1219, CHU Bordeaux, Bordeaux, France
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47
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Andalib S, Lattanzi S, Di Napoli M, Petersen A, Biller J, Kulik T, Macri E, Girotra T, Torbey MT, Divani AA. Blood Pressure Variability: A New Predicting Factor for Clinical Outcomes of Intracerebral Hemorrhage. J Stroke Cerebrovasc Dis 2020; 29:105340. [DOI: 10.1016/j.jstrokecerebrovasdis.2020.105340] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 09/10/2020] [Accepted: 09/18/2020] [Indexed: 02/06/2023] Open
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48
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Busch DR, Baker WB, Mavroudis CD, Ko TS, Lynch JM, McCarthy AL, DuPont-Thibodeau G, Buckley EM, Jacobwitz M, Boorady TW, Mensah-Brown K, Connelly JT, Yodh AG, Kilbaugh TJ, Licht DJ. Noninvasive optical measurement of microvascular cerebral hemodynamics and autoregulation in the neonatal ECMO patient. Pediatr Res 2020; 88:925-933. [PMID: 32172282 PMCID: PMC7492409 DOI: 10.1038/s41390-020-0841-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 02/12/2020] [Accepted: 02/19/2020] [Indexed: 01/14/2023]
Abstract
BACKGROUND Extra-corporeal membrane oxygenation (ECMO) is a life-saving intervention for severe respiratory and cardiac diseases. However, 50% of survivors have abnormal neurologic exams. Current ECMO management is guided by systemic metrics, which may poorly predict cerebral perfusion. Continuous optical monitoring of cerebral hemodynamics during ECMO holds potential to detect risk factors of brain injury such as impaired cerebrovascular autoregulation (CA). METHODS We conducted daily measurements of microvascular cerebral blood flow (CBF), oxygen saturation, and total hemoglobin concentration using diffuse correlation spectroscopy (DCS) and frequency-domain diffuse optical spectroscopy in nine neonates. We characterize CA utilizing the correlation coefficient (DCSx) between CBF and mean arterial blood pressure (MAP) during ECMO pump flow changes. RESULTS Average MAP and pump flow levels were weakly correlated with CBF and were not correlated with cerebral oxygen saturation. CA integrity varied between individuals and with time. Systemic measurements of MAP, pulse pressure, and left cardiac dysfunction were not predictive of impaired CA. CONCLUSIONS Our pilot results suggest that systemic measures alone cannot distinguish impaired CA from intact CA during ECMO. Furthermore, optical neuromonitoring could help determine patient-specific ECMO pump flows for optimal CA integrity, thereby reducing risk of secondary brain injury. IMPACT Cerebral blood flow and oxygenation are not well predicted by systemic proxies such as ECMO pump flow or blood pressure. Continuous, quantitative, bedside monitoring of cerebral blood flow and oxygenation with optical tools enables new insight into the adequacy of cerebral perfusion during ECMO. A demonstration of hybrid diffuse optical and correlation spectroscopies to continuously measure cerebral blood oxygen saturation and flow in patients on ECMO, enabling assessment of cerebral autoregulation. An observation of poor correlation of cerebral blood flow and oxygenation with systemic mean arterial pressure and ECMO pump flow, suggesting that clinical decision making guided by target values for these surrogates may not be neuroprotective. ~50% of ECMO survivors have long-term neurological deficiencies; continuous monitoring of brain health throughout therapy may reduce these tragically common sequelae through brain-focused adjustment of ECMO parameters.
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Affiliation(s)
- David R Busch
- Departments of Anesthesiology & Pain Management and Neurology & Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Wesley B Baker
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Constantine D Mavroudis
- Division of Cardiovascular Surgery, Department of Surgery, Hospital of the University of Pennsylvania, Philadelphia, PA, USA
| | - Tiffany S Ko
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, USA
| | - Jennifer M Lynch
- Department of Anesthesiology, Hospital of the University of Pennsylvania, Philadelphia, PA, USA
| | - Ann L McCarthy
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | | | - Erin M Buckley
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
- Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA, USA
| | - Marin Jacobwitz
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Timothy W Boorady
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Kobina Mensah-Brown
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - James T Connelly
- ECMO Center, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Arjun G Yodh
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, USA
| | - Todd J Kilbaugh
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Daniel J Licht
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA.
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49
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Hsu PC, Lee WH, Chiu CA, Chen YC, Chang CT, Tsai WC, Chu CY, Lin TH, Voon WC, Lai WT, Sheu SH, Su HM. Usefulness of ankle-brachial index calculated using diastolic blood pressure for prediction of mortality in patients with acute myocardial infarction. J Clin Hypertens (Greenwich) 2020; 22:2044-2050. [PMID: 33086427 DOI: 10.1111/jch.14032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 08/17/2020] [Accepted: 08/24/2020] [Indexed: 11/29/2022]
Abstract
A low ankle-brachial index (ABI) calculated using systolic blood pressure (SBP) (ABIsbp) is associated with poor cardiovascular outcome in patients with acute myocardial infarction (AMI). ABI is always calculated using SBP clinically. However, there was no study investigating ABI calculated using mean artery pressure (MAP)(ABImap) and diastolic blood pressure (DBP)(ABIdbp) for mortality prediction in AMI patients. Therefore, our study was aimed to investigate the issue. 199 AMI patients were enrolled. Different ABIs were measured by an ABI-form device. The median follow-up to mortality was 64 months. There were 40 cardiovascular and 137 all-cause mortality. The best cutoff values of ABImbp and ABIdbp for mortality prediction were 0.91 and 0.78, respectively. After multivariate analysis, only ABIdbp and ABIdbp < 0.78 could predict cardiovascular mortality (P ≤ .047). However, all of six ABI parameters, including ABIsbp, ABImap, ABIdbp, ABIsbp < 0.90, ABImap < 0.91, and ABIdbp < 0.78, could predict all-cause mortality (P ≤ .048). In a direct comparison of six ABI models for prediction of all-cause mortality, basic model + ABIdbp <0.78 had the highest predictive value (P ≤ .025). In conclusion, only ABIdbp and ABIdbp < 0.78 could predict cardiovascular and all-cause mortality after multivariate analysis in our study. Furthermore, when adding into a basic model, ABIdbp < 0.78 had the highest additively predictive value for all-cause mortality in the six ABI parameters. Hence, calculation of ABI using DBP except SBP might provide an extra benefit in prediction of cardiovascular and all-cause mortality in AMI patients.
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Affiliation(s)
- Po-Chao Hsu
- Division of Cardiology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.,Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Wen-Hsien Lee
- Division of Cardiology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.,Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.,Department of Internal Medicine, Kaohsiung Municipal Siaogang Hospital, Kaohsiung, Taiwan
| | - Cheng-An Chiu
- Division of Cardiology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
| | - Ying-Chih Chen
- Division of Cardiology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.,Department of Internal Medicine, Kaohsiung Municipal Siaogang Hospital, Kaohsiung, Taiwan
| | - Ching-Tang Chang
- Division of Cardiology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
| | - Wei-Chung Tsai
- Division of Cardiology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.,Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Chun-Yuan Chu
- Division of Cardiology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.,Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Tsung-Hsien Lin
- Division of Cardiology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.,Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Wen-Chol Voon
- Division of Cardiology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.,Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Wen-Ter Lai
- Division of Cardiology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.,Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Sheng-Hsiung Sheu
- Division of Cardiology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.,Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Ho-Ming Su
- Division of Cardiology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.,Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.,Department of Internal Medicine, Kaohsiung Municipal Siaogang Hospital, Kaohsiung, Taiwan
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50
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Too Aggressive Drop in Blood Pressure in a Hypertensive Male Leading to "Man-in-the-Barrel Syndrome". Case Rep Neurol Med 2020; 2020:8855574. [PMID: 33029439 PMCID: PMC7532409 DOI: 10.1155/2020/8855574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 09/13/2020] [Accepted: 09/16/2020] [Indexed: 11/17/2022] Open
Abstract
Introduction "Man-in-the-barrel syndrome" is a neurological phenotype with brachial diplegia, normal sensation, and preserved motor function of the lower limb. It has been described in various neuropathological conditions affecting the cerebral hemispheres, pons, upper spinal cord, and peripheral neurons. Severe hypotension leading to watershed infarctions leading to this phenotype has been reported. We describe the first case of "man-in-the-barrel syndrome" in a patient with a precipitous drop in blood pressure following oral antihypertensive medications. Case Presentation. A 75-year-old Sri Lankan male presented following a generalized tonic-clonic seizure to a tertiary care hospital. Upon recovery, he was noted to have severe brachia diplegia affecting shoulder movements with preserved hand muscle power and motor functions of the lower limb. The previous day, he was newly diagnosed with markedly elevated blood pressure without acute end organ involvement. Treatment with three antihypertensives had been initiated. Noncontrast CT of the brain revealed watershed infarctions affecting both cerebral hemispheres. Conclusion It is generally unwise to lower blood pressure very rapidly, as ischemic damage can occur in vascular beds that are habituated to high levels of blood pressure in the brain. Ischemic damage caused by rapid lowering of blood pressure may rarely result in "man-in-the-barrel syndrome" leading to severe functional disability.
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