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Clark A, Zelmanovich R, Vo Q, Martinez M, Nwafor DC, Lucke-Wold B. Inflammation and the role of infection: Complications and treatment options following neurotrauma. J Clin Neurosci 2022; 100:23-32. [PMID: 35381478 DOI: 10.1016/j.jocn.2022.03.043] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 02/14/2022] [Accepted: 03/29/2022] [Indexed: 02/08/2023]
Abstract
Traumatic brain injury can have devastating consequences for patients and extended hospital stays and recovery course. Recent data indicate that the initial insult causes profound changes to the immune system and leads to a pro-inflammatory state. This alteration in homeostasis predisposes patients to an increased risk of infection and underlying autoimmune conditions. Increased emphasis has been placed on understanding this process both in the clinical and preclinical literature. This review highlights the intrinsic inflammatory conditions that can occur within the initial hospital stay, discusses long-term immune consequences, highlights emerging treatment options, and delves into important pathways currently being investigated with preclinical models.
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Affiliation(s)
- Alec Clark
- University of Central Florida, College of Medicine, Orlando, USA
| | | | - Quan Vo
- Department of Neurosurgery, University of Florida, Gainesville, USA
| | - Melanie Martinez
- Department of Neurosurgery, University of Florida, Gainesville, USA
| | - Divine C Nwafor
- Department of Neurosurgery, West Virginia University, Morgantown, USA
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2
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Javaid MA, Selim M, Ortega-Gutierrez S, Lattanzi S, Zargar S, Alaouieh DA, Hong E, Divani AA. Potential application of intranasal insulin delivery for treatment of intracerebral hemorrhage: A review of the literature. J Stroke Cerebrovasc Dis 2022; 31:106489. [PMID: 35489182 DOI: 10.1016/j.jstrokecerebrovasdis.2022.106489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 03/04/2022] [Accepted: 04/03/2022] [Indexed: 12/01/2022] Open
Abstract
Intracerebral hemorrhage (ICH) is a devastating subtype of stroke associated with high morbidity and mortality that is considered a medical emergency, mainly managed with adequate blood pressure control and creating a favorable hemostatic condition. However, to date, none of the randomized clinical trials have led to an effective treatment for ICH. It is vital to better understand the mechanisms underlying brain injury to effectively decrease ICH-associated morbidity and mortality. It is well known that initial hematoma formation and its expansion have detrimental consequences. The literature has recently focused on other pathological processes, including oxidative stress, neuroinflammation, blood-brain barrier disruption, edema formation, and neurotoxicity, that constitute secondary brain injury. Since conventional management has failed to improve clinical outcomes significantly, various neuroprotective therapies are tested in preclinical and clinical settings. Unlike intravenous administration, intranasal insulin can reach a higher concentration in the cerebrospinal fluid without causing systemic side effects. Intranasal insulin delivery has been introduced as a novel neuroprotective agent for certain neurological diseases, including ischemic stroke, subarachnoid hemorrhage, and traumatic brain injury. Since there is an overlap of mechanisms causing neuroinflammation in these neurological diseases and ICH, we believe that preclinical studies testing the role of intranasal insulin therapy in ICH are warranted.
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Affiliation(s)
| | - Magdy Selim
- Stroke Division, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | | | - Simona Lattanzi
- Neurological Clinic, Department of Experimental and Clinical Medicine, Marche Polytechnic University, Ancona, Italy
| | - Shima Zargar
- Department of Neurology, University of New Mexico, Albuquerque, NM, USA
| | | | - Emily Hong
- School of Medicine, University of New Mexico, Albuquerque, NM, USA
| | - Afshin A Divani
- Department of Neurology, University of New Mexico, Albuquerque, NM, USA.
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3
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Sharma R, Shultz SR, Robinson MJ, Belli A, Hibbs ML, O'Brien TJ, Semple BD. Infections after a traumatic brain injury: The complex interplay between the immune and neurological systems. Brain Behav Immun 2019; 79:63-74. [PMID: 31029794 DOI: 10.1016/j.bbi.2019.04.034] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 03/29/2019] [Accepted: 04/24/2019] [Indexed: 12/21/2022] Open
Abstract
Traumatic brain injury (TBI) is a serious global health issue, being the leading cause of death and disability for individuals under the age of 45, and one of the largest causes of global neurological disability. In addition to the brain injury itself, it is increasingly appreciated that a TBI may also alter the systemic immune response in a way that renders TBI patients more vulnerable to infections in the acute post-injury period. Such infections pose an additional challenge to the patient, increasing rates of mortality and morbidity, and worsening neurological outcomes. Hospitalization, surgical interventions, and a state of immunosuppression induced by injury to the central nervous system (CNS), may all contribute to the high rate of infections seen in the population with TBI. Ongoing research to better understand the immunomodulators that underlie TBI-induced immunosuppression may aid in the development of effective therapeutic strategies to improve the recovery trajectory for patients. This review first describes the clinical scenario, posing the question of whether TBI patients are more susceptible to infections such as pneumonia, and if so, why? We then consider how cross-talk between the injured brain and the systemic immune system occurs, and further, how the additional immune challenge of an acquired infection can contribute to ongoing neuroinflammation and neurodegeneration after a TBI. Experimental models combining TBI with infection are discussed, as well as current treatment options available for this double-barreled insult. The aims of this review are to summarize current understanding of the bidirectional relationship between the CNS and the immune system when faced with a mechanical trauma combined with a concomitant infection, and to highlight key outstanding questions that remain in the field.
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Affiliation(s)
- Rishabh Sharma
- Department of Neuroscience, Central Clinical School at the Alfred Hospital, Monash University, Melbourne, VIC, Australia
| | - Sandy R Shultz
- Department of Neuroscience, Central Clinical School at the Alfred Hospital, Monash University, Melbourne, VIC, Australia; Department of Medicine (Royal Melbourne Hospital), Melbourne Medical School, The University of Melbourne, Parkville, VIC, Australia
| | - Marcus J Robinson
- Department of Immunology and Pathology, Central Clinical School at the Alfred Hospital, Monash University, Melbourne, VIC, Australia
| | - Antonio Belli
- Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Margaret L Hibbs
- Department of Immunology and Pathology, Central Clinical School at the Alfred Hospital, Monash University, Melbourne, VIC, Australia
| | - Terence J O'Brien
- Department of Neuroscience, Central Clinical School at the Alfred Hospital, Monash University, Melbourne, VIC, Australia; Department of Medicine (Royal Melbourne Hospital), Melbourne Medical School, The University of Melbourne, Parkville, VIC, Australia
| | - Bridgette D Semple
- Department of Neuroscience, Central Clinical School at the Alfred Hospital, Monash University, Melbourne, VIC, Australia; Department of Medicine (Royal Melbourne Hospital), Melbourne Medical School, The University of Melbourne, Parkville, VIC, Australia.
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4
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Kim S, Mortera M, Hu X, Krishnan S, Hoffecker L, Herrold A, Terhorst L, King L, Machtinger J, Zumsteg JM, Negm A, Heyn P. Overview of pharmacological interventions after traumatic brain injuries: impact on selected outcomes. Brain Inj 2019; 33:442-455. [DOI: 10.1080/02699052.2019.1565896] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Sonya Kim
- Department of Neurology and Department of Rehabilitation Medicine, NYU School of Medicine, New York, USA
| | - Marianne Mortera
- NYU Steinhardt, Department of Occupational Therapy, New York University, New York, USA
| | - Xiaolei Hu
- Department of Community Medicine and Rehabilitation, Umeå University, Sweden
| | - Shilpa Krishnan
- Department of Rehabilitation Medicine, Division of Physical Therapy, Emory University, Atlanta, Georgia, USA
| | - Lilian Hoffecker
- Health Sciences Library, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Amy Herrold
- Center of Innovation for Complex Chronic Healthcare, Edward Hines Jr., VA Hospital, Hines, Illinois, USA
| | - Lauren Terhorst
- Department of Occupational Therapy, School of Health and Rehabilitation Services, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Laurie King
- Neurology, Oregon Health & Science University, Portland, Oregon, USA
| | - Joseph Machtinger
- Department of Neurology, Division of Multiple Sclerosis, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Jennifer M. Zumsteg
- Department of Rehabilitation Medicine, University of Washington, Seattle, Washington, USA
| | - Ahmed Negm
- School of Rehabilitation Sciences, McMaster University, Hamilton, Ontario, USA
| | - Patricia Heyn
- Department of Physical Medicine and Rehabilitation, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
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Zhu C, Chen J, Pan J, Qiu Z, Xu T. Therapeutic effect of intensive glycemic control therapy in patients with traumatic brain injury: A systematic review and meta-analysis of randomized controlled trials. Medicine (Baltimore) 2018; 97:e11671. [PMID: 30045323 PMCID: PMC6078679 DOI: 10.1097/md.0000000000011671] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Hyperglycemia is associated with dismal outcomes in patients with traumatic brain injury (TBI), which is frequently treated with insulin therapy. In this study, a systematic review and meta-analysis of the published randomized controlled trials (RCTs) was performed to assess the safety and efficacy of intensive glycemic control (IGC) versus conventional glycemic control (CGC) for patients following TBI. METHODS Databases, including PubMed, Embase, and the Cochran database, were retrieved up to January 2018. The outcomes evaluated in this study included mortality, neurological outcome, infection rate, hypoglycemia episode, and length of stay (LOS) in intensive care unit (ICU). The enrolled trials were analyzed using the Review Manager 5.3 software. RESULTS A total of 7 randomized controlled trials (RCTs) involving 1013 cases were enrolled in this study, and the results indicated no significant difference in 6-month mortality (risk ratio [RR], 0.92; 95% confidence interval [CI] 0.76-1.10; P = .34). Subsequently, IGC was associated with a better neurological outcome (RR, 1.22; 95% CI 1.05-1.43; P = .01), lower infection rate (RR, 0.65; 95% CI 0.51-0.82; P = .0003) and shorter LOS in ICU (mean difference [MD] = -1.37; 95%CI = -2.11, -0.63; P = .0003). In addition, IGC would also increase the risk of hypoglycemia episode (RR, 4.53; 95% CI 2.18-9.42; P < .001). CONCLUSIONS IGC plays a protective role in improving neurological outcome, decreasing infection rate and reducing the LOS in ICU. However, IGC therapy can also remarkably increase the risk of hypoglycemia, but it will not affect the mortality in TBI patients.
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Affiliation(s)
- Chunran Zhu
- Department of Neurosurgery, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine
| | - Jinjing Chen
- Department of Neurosurgery, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine
| | - Junchen Pan
- Department of Neurosurgery, BenQ Medical Center, The Affiliated BenQ Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Zhichao Qiu
- Department of Neurosurgery, BenQ Medical Center, The Affiliated BenQ Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Tao Xu
- Department of Neurosurgery, BenQ Medical Center, The Affiliated BenQ Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
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Núñez-Patiño RA, Zorrilla-Vaca A, Rivera-Lara L. Comparison of intensive versus conventional insulin therapy in traumatic brain injury: a meta-analysis of randomized controlled trials. Brain Inj 2018; 32:693-703. [PMID: 29580096 DOI: 10.1080/02699052.2018.1457181] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVE To compare intensive insulin therapy (IIT) and conventional insulin therapy (CIT) on clinical outcomes of patients with traumatic brain injury (TBI). METHODS MEDLINE, EMBASE, Google Scholar, ISI Web of Science, and Cochrane Library were systematically searched for randomized controlled trials (RCTs) comparing IIT to CIT in patients with TBI. Study-level characteristics, intensive care unit (ICU) events, and long-term functional outcomes were extracted from the articles. Meta-analysis was performed with random-effect models. RESULTS Seven RCTs comprising 1070 patients were included. Although IIT was associated with better neurologic outcome (GOS > 3) (RR=0.87, 95% CI=0.78-0.97; P=0.01; I2=0%), sensitivity analysis revealed that one study influenced this overall estimate (RR=0.90, 95% CI=0.80-1.01, P=0.07; I2=0%). IIT was strongly associated with higher risk of hypoglycaemia (RR=5.79, 95% CI=3.27-10.26, P<0.01; I2=38%). IIT and CIT did not differ in terms of early or late mortality (RR=0.96, 95% CI=0.79-1.17, P=0.7; I2=0%), infection rate (RR=0.82, 95% CI=0.59-1.14, P=0.23; I2=68%), or ICU length of stay (SMD= -0.14, 95% CI=-0.35 to 0.07, P=0.18; I2=45%0.) Conclusions: IIT did not improve long-term neurologic outcome, mortality, or infection rate and was associated with increased risk of hypoglycaemia. Additional well-designed RCTs with defined TBI subgroups should be performed to generate more powerful conclusions.
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Affiliation(s)
- Rafael A Núñez-Patiño
- a Faculty of Health Sciences. School of Medicine , Pontificia Universidad Javeriana , Cali , Colombia
| | - Andres Zorrilla-Vaca
- b Department of Anesthesiology and Critical Care Medicine , The Johns Hopkins Hospital , Baltimore , Maryland , USA.,c Faculty of Health , Universidad del Valle, Hospital Universitario del Valle , Cali , Colombia
| | - Lucia Rivera-Lara
- b Department of Anesthesiology and Critical Care Medicine , The Johns Hopkins Hospital , Baltimore , Maryland , USA.,d Department of Neurology , Johns Hopkins University , Baltimore , Maryland , USA
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Hermanides J, Plummer MP, Finnis M, Deane AM, Coles JP, Menon DK. Glycaemic control targets after traumatic brain injury: a systematic review and meta-analysis. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2018; 22:11. [PMID: 29351760 PMCID: PMC5775599 DOI: 10.1186/s13054-017-1883-y] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2017] [Accepted: 10/31/2017] [Indexed: 01/04/2023]
Abstract
Background Optimal glycaemic targets in traumatic brain injury (TBI) remain unclear. We performed a systematic review and meta-analysis of randomised controlled trials (RCTs) comparing intensive with conventional glycaemic control in TBI requiring admission to an intensive care unit (ICU). Methods We systematically searched MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials to November 2016. Outcomes of interest included ICU and in-hospital mortality, poor neurological outcome, the incidence of hypoglycaemia and infective complications. Data were analysed by pairwise random effects models with secondary analysis of differing levels of conventional glycaemic control. Results Ten RCTs, involving 1066 TBI patients were included. Three studies were conducted exclusively in a TBI population, whereas in seven trials, the TBI population was a sub-cohort of a mixed neurocritical or general ICU population. Glycaemic targets with intensive control ranged from 4.4 to 6.7 mmol/L, while conventional targets aimed to keep glucose levels below thresholds of 8.4–12 mmol/L. Conventional versus intensive control showed no association with ICU or hospital mortality (relative risk (RR) (95% CI) 0.93 (0.68–1.27), P = 0.64 and 1.07 (0.84–1.36), P = 0.62, respectively). The risk of a poor neurological outcome was higher with conventional control (RR (95% CI) = 1.10 (1.001–1.24), P = 0.047). However, severe hypoglycaemia occurred less frequently with conventional control (RR (95% CI) = 0.22 (0.09–0.52), P = 0.001). Conclusions This meta-analysis of intensive glycaemic control shows no association with reduced mortality in TBI. Intensive glucose control showed a borderline significant reduction in the risk of poor neurological outcome, but markedly increased the risk of hypoglycaemia. These contradictory findings should motivate further research. Electronic supplementary material The online version of this article (10.1186/s13054-017-1883-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jeroen Hermanides
- Division of Anaesthesia, Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK. .,Department of Anesthesiology, Academic Medical Centre, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
| | - Mark P Plummer
- Neurosciences Critical Care Unit, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK
| | - Mark Finnis
- Intensive Care Unit, Royal Adelaide Hospital, Adelaide, 5000, Australia
| | - Adam M Deane
- Intensive Care Unit, Royal Melbourne Hospital, Melbourne, 3050, Australia
| | - Jonathan P Coles
- Division of Anaesthesia, Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK
| | - David K Menon
- Division of Anaesthesia, Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK
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8
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Tu TW, Ibrahim WG, Jikaria N, Munasinghe JP, Witko JA, Hammoud DA, Frank JA. On the detection of cerebral metabolic depression in experimental traumatic brain injury using Chemical Exchange Saturation Transfer (CEST)-weighted MRI. Sci Rep 2018; 8:669. [PMID: 29330386 PMCID: PMC5766554 DOI: 10.1038/s41598-017-19094-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Accepted: 12/21/2017] [Indexed: 12/13/2022] Open
Abstract
Metabolic abnormalities are commonly observed in traumatic brain injury (TBI) patients exhibiting long-term neurological deficits. This study investigated the feasibility and reproducibility of using chemical exchange saturation transfer (CEST) MRI to detect cerebral metabolic depression in experimental TBI. Phantom and in vivo CEST experiments were conducted at 9.4 Tesla to optimize the selective saturation for enhancing the endogenous contrast-weighting of the proton exchanges over the range of glucose proton chemical shifts (glucoCEST) in the resting rat brain. The optimized glucoCEST-weighted imaging was performed on a closed-head model of diffuse TBI in rats with 2-deoxy-D-[14C]-glucose (2DG) autoradiography validation. The results demonstrated that saturation duration of 1‒2 seconds at pulse powers 1.5‒2µT resulted in an improved contrast-to-noise ratio between the gray and white matter comparable to 2DG autoradiographs. The intrasubject (n = 4) and intersubject (n = 3) coefficient of variations for repeated glucoCEST acquisitions (n = 4) ranged between 8‒16%. Optimization for the TBI study revealed that glucoCEST-weighted images with 1.5μT power and 1 s saturation duration revealed the greatest changes in contrast before and after TBI, and positively correlated with 2DG autoradiograph (r = 0.78, p < 0.01, n = 6) observations. These results demonstrate that glucoCEST-weighted imaging may be useful in detecting metabolic abnormalities following TBI.
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Affiliation(s)
- Tsang-Wei Tu
- Frank Laboratory, Radiology & Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, United States. .,Center for Neuroscience and Regenerative Medicine, Henry Jackson Foundation, Bethesda, MD, United States. .,Molecular Imaging Laboratory, Department of Radiology, Howard University, Washington, DC, United States.
| | - Wael G Ibrahim
- Center for Infectious Disease Imaging, Radiology & Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, United States
| | - Neekita Jikaria
- Frank Laboratory, Radiology & Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, United States.,Center for Neuroscience and Regenerative Medicine, Henry Jackson Foundation, Bethesda, MD, United States.,Acute Stroke Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
| | - Jeeva P Munasinghe
- Mouse Imaging Facility, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
| | - Jaclyn A Witko
- Frank Laboratory, Radiology & Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, United States.,Center for Neuroscience and Regenerative Medicine, Henry Jackson Foundation, Bethesda, MD, United States
| | - Dima A Hammoud
- Center for Infectious Disease Imaging, Radiology & Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, United States
| | - Joseph A Frank
- Frank Laboratory, Radiology & Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, United States.,National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, United States
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Figaji AA, Graham Fieggen A, Mankahla N, Enslin N, Rohlwink UK. Targeted treatment in severe traumatic brain injury in the age of precision medicine. Childs Nerv Syst 2017; 33:1651-1661. [PMID: 28808845 DOI: 10.1007/s00381-017-3562-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Accepted: 07/27/2017] [Indexed: 11/28/2022]
Abstract
In recent years, much progress has been made in our understanding of traumatic brain injury (TBI). Clinical outcomes have progressively improved, but evidence-based guidelines for how we manage patients remain surprisingly weak. The problem is that the many interventions and strategies that have been investigated in randomized controlled trials have all disappointed. These include many concepts that had become standard care in TBI. And that is just for adult TBI; in children, the situation is even worse. Not only is pediatric care more difficult than adult care because physiological norms change with age, but also there is less evidence for clinical practice. In this article, we discuss the heterogeneity inherent in TBI and why so many clinical trials have failed. We submit that a key goal for the future is to appreciate important clinical differences between patients in their pathophysiology and their responses to treatment. The challenge that faces us is how to rationally apply therapies based on the specific needs of an individual patient. In doing so, we may be able to apply the principles of precision medicine approaches to the patients we treat.
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Affiliation(s)
- Anthony A Figaji
- Division of Neurosurgery and Neuroscience Institute, University of Cape Town, Cape Town, South Africa.
| | - A Graham Fieggen
- Division of Neurosurgery and Neuroscience Institute, University of Cape Town, Cape Town, South Africa
| | - Ncedile Mankahla
- Division of Neurosurgery, University of Cape Town, Cape Town, South Africa
| | - Nico Enslin
- Division of Neurosurgery, University of Cape Town, Cape Town, South Africa
| | - Ursula K Rohlwink
- Division of Neurosurgery and Neuroscience Institute, University of Cape Town, Cape Town, South Africa
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10
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Nord CL, Valton V, Wood J, Roiser JP. Power-up: A Reanalysis of 'Power Failure' in Neuroscience Using Mixture Modeling. J Neurosci 2017; 37:8051-8061. [PMID: 28706080 PMCID: PMC5566862 DOI: 10.1523/jneurosci.3592-16.2017] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 06/06/2017] [Accepted: 06/17/2017] [Indexed: 11/25/2022] Open
Abstract
Recently, evidence for endemically low statistical power has cast neuroscience findings into doubt. If low statistical power plagues neuroscience, then this reduces confidence in the reported effects. However, if statistical power is not uniformly low, then such blanket mistrust might not be warranted. Here, we provide a different perspective on this issue, analyzing data from an influential study reporting a median power of 21% across 49 meta-analyses (Button et al., 2013). We demonstrate, using Gaussian mixture modeling, that the sample of 730 studies included in that analysis comprises several subcomponents so the use of a single summary statistic is insufficient to characterize the nature of the distribution. We find that statistical power is extremely low for studies included in meta-analyses that reported a null result and that it varies substantially across subfields of neuroscience, with particularly low power in candidate gene association studies. Therefore, whereas power in neuroscience remains a critical issue, the notion that studies are systematically underpowered is not the full story: low power is far from a universal problem.SIGNIFICANCE STATEMENT Recently, researchers across the biomedical and psychological sciences have become concerned with the reliability of results. One marker for reliability is statistical power: the probability of finding a statistically significant result given that the effect exists. Previous evidence suggests that statistical power is low across the field of neuroscience. Our results present a more comprehensive picture of statistical power in neuroscience: on average, studies are indeed underpowered-some very seriously so-but many studies show acceptable or even exemplary statistical power. We show that this heterogeneity in statistical power is common across most subfields in neuroscience. This new, more nuanced picture of statistical power in neuroscience could affect not only scientific understanding, but potentially policy and funding decisions for neuroscience research.
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Affiliation(s)
- Camilla L Nord
- Institute of Cognitive Neuroscience, University College London, London, WC1N 3AZ, United Kingdom, and
| | - Vincent Valton
- Institute of Cognitive Neuroscience, University College London, London, WC1N 3AZ, United Kingdom, and
| | - John Wood
- Research Department of Primary Care and Population Health, University College London Medical School, London NW3 2PF, United Kingdom
| | - Jonathan P Roiser
- Institute of Cognitive Neuroscience, University College London, London, WC1N 3AZ, United Kingdom, and
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11
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Chowdhury T, Kowalski S, Arabi Y, Dash HH. General intensive care for patients with traumatic brain injury: An update. Saudi J Anaesth 2014; 8:256-63. [PMID: 24843343 PMCID: PMC4024687 DOI: 10.4103/1658-354x.130742] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Background: Traumatic brain injury (TBI) is a growing epidemic throughout the world and may present as major global burden in 2020. Some intensive care units throughout the world still have no access to specialized monitoring methods, equipments and other technologies related to intensive care management of these patients; therefore, this review is meant for providing generalized supportive measurement to this subgroup of patients so that evidence based management could minimize or prevent the secondary brain injury. Methods: Therefore, we have included the PubMed search for the relevant clinical trials and reviews (from 1 January 2007 to 31 March 2013), which specifically discussed about the topic. Results: General supportive measures are equally important to prevent and minimize the effects of secondary brain injury and therefore, have a substantial impact on the outcome in patients with TBI. The important considerations for general supportive intensive care unit care remain the prompt reorganization and treatment of hypoxemia, hypotension and hypercarbia. Evidences are found to be either against or weak regarding the use of routine hyperventilation therapy, tight control blood sugar regime, use of colloids and late as well as parenteral nutrition therapy in patients with severe TBI. Conclusion: There is also a need to develop some evidence based protocols for the health-care sectors, in which there is still lack of specific management related to monitoring methods, equipments and other technical resources. Optimization of physiological parameters, understanding of basic neurocritical care knowledge as well as incorporation of newer guidelines would certainly improve the outcome of the TBI patients.
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Affiliation(s)
- Tumul Chowdhury
- Department of Anesthesiology and Perioperative Medicine, Section of Critical Care, University of Manitoba, Winnipeg, Canada
| | - Stephen Kowalski
- Department of Anesthesiology and Perioperative Medicine, Section of Critical Care, University of Manitoba, Winnipeg, Canada
| | - Yaseen Arabi
- Department of Intensive Care, King Abdul-Aziz Medical City, Riyadh, Kingdom of Saudi Arabia
| | - Hari Hara Dash
- Department of Anesthesia and Perioperative Medicine, Fortis Memorial Research Institute, Gurgaon, Haryana, India
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12
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Bouzat P, Sala N, Payen JF, Oddo M. Beyond intracranial pressure: optimization of cerebral blood flow, oxygen, and substrate delivery after traumatic brain injury. Ann Intensive Care 2013; 3:23. [PMID: 23837598 PMCID: PMC3716965 DOI: 10.1186/2110-5820-3-23] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Accepted: 06/25/2013] [Indexed: 02/17/2023] Open
Abstract
Monitoring and management of intracranial pressure (ICP) and cerebral perfusion pressure (CPP) is a standard of care after traumatic brain injury (TBI). However, the pathophysiology of so-called secondary brain injury, i.e., the cascade of potentially deleterious events that occur in the early phase following initial cerebral insult—after TBI, is complex, involving a subtle interplay between cerebral blood flow (CBF), oxygen delivery and utilization, and supply of main cerebral energy substrates (glucose) to the injured brain. Regulation of this interplay depends on the type of injury and may vary individually and over time. In this setting, patient management can be a challenging task, where standard ICP/CPP monitoring may become insufficient to prevent secondary brain injury. Growing clinical evidence demonstrates that so-called multimodal brain monitoring, including brain tissue oxygen (PbtO2), cerebral microdialysis and transcranial Doppler among others, might help to optimize CBF and the delivery of oxygen/energy substrate at the bedside, thereby improving the management of secondary brain injury. Looking beyond ICP and CPP, and applying a multimodal therapeutic approach for the optimization of CBF, oxygen delivery, and brain energy supply may eventually improve overall care of patients with head injury. This review summarizes some of the important pathophysiological determinants of secondary cerebral damage after TBI and discusses novel approaches to optimize CBF and provide adequate oxygen and energy supply to the injured brain using multimodal brain monitoring.
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Affiliation(s)
- Pierre Bouzat
- Department of Intensive Care Medicine, CHUV-University Hospital, Rue du Bugnon 46, BH 08,623, CH-1011 Lausanne, Switzerland.
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Lei J, Gao G, Jiang J. Acute traumatic brain injury: is current management evidence based? An empirical analysis of systematic reviews. J Neurotrauma 2013; 30:529-37. [PMID: 23151044 DOI: 10.1089/neu.2012.2548] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Traumatic brain injury (TBI) is a major health and socioeconomic problem worldwide with a high rate of death and long-term disability. Previous studies have summarized evidence from large-scale randomized trials, finding no intervention showing convincing efficacy for acute TBI management. The present empirical study set out to assess another crucial component of evidence base-systematic review, which contributes a lot to evidence-based health care, in terms of clinical issues, methodological aspects, and implication for practice and research. A total of 44 systematic reviews pertaining to therapeutic interventions for acute TBI were identified through electronic database searching, clinical guideline retrieval, and expert consultation, of which 21 were published in Cochrane Library and 23 in peer-reviewed journals. Their methodological quality was generally satisfactory, with the median Overview Quality Assessment Questionnaire score of 5.5 (interquartile range 2-7). Cochrane reviews are of better quality than regular journal reviews. Twenty-nine high-quality reviews provided no conclusive evidence for the investigated 22 interventions except for an adverse effect of corticosteroids. Less than one-third of the component trials were reported with adequate allocation concealment. Additionally other methodological flaws in design-for example, ignoring heterogeneity among the TBI population-also contributed to the failure of past clinical research. Based on the above findings, evidence from both systematic reviews and clinical trials does not fully support current management of acute TBI. Translating from laboratory success to clinical effect remains an unique challenge. Accordingly it may be the time to rethink the way in future practice and clinical research in TBI.
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Affiliation(s)
- Jin Lei
- Department of Neurosurgery, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
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Button KS, Ioannidis JPA, Mokrysz C, Nosek BA, Flint J, Robinson ESJ, Munafò MR. Power failure: why small sample size undermines the reliability of neuroscience. Nat Rev Neurosci 2013; 14:365-76. [PMID: 23571845 DOI: 10.1038/nrn3475] [Citation(s) in RCA: 3937] [Impact Index Per Article: 357.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A study with low statistical power has a reduced chance of detecting a true effect, but it is less well appreciated that low power also reduces the likelihood that a statistically significant result reflects a true effect. Here, we show that the average statistical power of studies in the neurosciences is very low. The consequences of this include overestimates of effect size and low reproducibility of results. There are also ethical dimensions to this problem, as unreliable research is inefficient and wasteful. Improving reproducibility in neuroscience is a key priority and requires attention to well-established but often ignored methodological principles.
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Kuppinger D, Hartl WH. In search of the perfect glucose concentration for hospitalized patients: a brief review of the meta-analyses. Nutrition 2013; 29:708-12. [PMID: 23422535 DOI: 10.1016/j.nut.2012.11.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Revised: 10/31/2012] [Accepted: 11/23/2012] [Indexed: 11/25/2022]
Abstract
In hospitalized patients, the optimal target blood glucose concentration is controversial. Numerous studies have examined clinical use of glucose control in various patient populations. In the present review, we briefly discuss corresponding meta-analyses. We electronically searched MEDLINE, EMBASE and CINAHL for meta-analyses relevant to the subject. Fifteen meta-analyses were identified that analyzed effects of a targeted glucose control. Twelve meta-analyses examined studies performed in critically ill patients. Included studies in this review varied in terms of the type of nutritional support, the efficacy of glucose control, the kind of glucose measurement, clinical end points (hospital or intensive care unit mortality, or 28-, 90- or 180-d mortality, or mortality 30 d after discharge), and the intensity of glucose control (moderate, tight, very tight). Four meta-analyses also including studies with a less stringent glucose control (glucose target <200 mg/dL) showed a beneficial effect on mortality. This effect disappeared when analyzing studies with a tighter glucose control (glucose target <150 mg/dL or <110/120 mg/dL, n = 5), with a very tight glucose control (glucose target <110/120 mg/dL, n = 2), or with a more precise definition of clinical endpoints (28-d mortality, n = 2). Eight meta-analyses showed that, despite the intensity of glucose control, the frequency of hypoglycemic episodes increased. The residual heterogeneity of individual studies incorporated into the various meta-analyses prevents a valid conclusion regarding potential benefits of a specific glucose target. A glucose concentration <200 mg/dL appears preferable.
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Affiliation(s)
- David Kuppinger
- Department of Surgery, University School of Medicine, Grosshadern Campus, Ludwig-Maximilian University, Munich, Germany
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Bilotta F, Rosa G. Optimal glycemic control in neurocritical care patients. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2012; 16:163. [PMID: 23106972 PMCID: PMC3682264 DOI: 10.1186/cc11521] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Currently, the major issue in glycemic control in neurocritical care patients is that tight glycemic control (target range of 80 to 110 mg/dL) using intensive insulin therapy is associated with higher rates of hypoglycemia without an improvement in survival rate. The review by Kramer and colleagues in this issue of Critical Care confirms these data but provides solid evidence about the relationship between hyperglycemia and worsened neurological outcome after acute brain injury. In accordance with the conclusions of Kramer and colleagues, we recommend that a glucose control goal in neurocritical care patients be in the 'moderate' target range (110 to 180 mg/dL). In addition, we recommend adequate nutrition before and during insulin infusion, avoidance of insulin as a bolus, and the use of continuous insulin infusion, beginning with low doses with titration to individual sensitivity. Careful and accurate glycemic monitoring is especially important when insulin is infused.
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Kramer AH, Roberts DJ, Zygun DA. Optimal glycemic control in neurocritical care patients: a systematic review and meta-analysis. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2012; 16:R203. [PMID: 23082798 PMCID: PMC3682305 DOI: 10.1186/cc11812] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Accepted: 08/29/2012] [Indexed: 02/07/2023]
Abstract
INTRODUCTION Hyper- and hypoglycemia are strongly associated with adverse outcomes in critical care. Neurologically injured patients are a unique subgroup, where optimal glycemic targets may differ, such that the findings of clinical trials involving heterogeneous critically ill patients may not apply. METHODS We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) comparing intensive insulin therapy with conventional glycemic control among patients with traumatic brain injury, ischemic or hemorrhagic stroke, anoxic encephalopathy, central nervous system infections or spinal cord injury. RESULTS Sixteen RCTs, involving 1248 neurocritical care patients, were included. Glycemic targets with intensive insulin ranged from 70-140 mg/dl (3.9-7.8 mmol/L), while conventional protocols aimed to keep glucose levels below 144-300 mg/dl (8.0-16.7 mmol/L). Tight glycemic control had no impact on mortality (RR 0.99; 95% CI 0.83-1.17; p = 0.88), but did result in fewer unfavorable neurological outcomes (RR 0.91; 95% CI 0.84-1.00; p = 0.04). However, improved outcomes were only observed when glucose levels in the conventional glycemic control group were permitted to be relatively high [threshold for insulin administration > 200 mg/dl (> 11.1 mmol/L)], but not with more intermediate glycemic targets [threshold for insulin administration 140-180 mg/dl (7.8-10.0 mmol/L)]. Hypoglycemia was far more common with intensive therapy (RR 3.10; 95% CI 1.54-6.23; p = 0.002), but there was a large degree of heterogeneity in the results of individual trials (Q = 47.9; p<0.0001; I2 = 75%). Mortality was non-significantly higher with intensive insulin in studies where the proportion of patients developing hypoglycemia was large (> 33%) (RR 1.17; 95% CI 0.79-1.75; p = 0.44). CONCLUSIONS Intensive insulin therapy significantly increases the risk of hypoglycemia and does not influence mortality among neurocritical care patients. Very loose glucose control is associated with worse neurological recovery and should be avoided. These results suggest that intermediate glycemic goals may be most appropriate.
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Bilotta F, Rosa G. Glycemia management in critical care patients. World J Diabetes 2012; 3:130-4. [PMID: 22816025 PMCID: PMC3399911 DOI: 10.4239/wjd.v3.i7.130] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Revised: 05/22/2012] [Accepted: 06/10/2012] [Indexed: 02/05/2023] Open
Abstract
Over the last decade, the approach to clinical management of blood glucose concentration (BGC) in critical care patients has dramatically changed. In this editorial, the risks related to hypo, hyperglycemia and high BGC variability, optimal BGC target range and BGC monitoring devices for patients in the intensive care unit (ICU) will be discussed. Hypoglycemia has an increased risk of death, even after the occurrence of a single episode of mild hypoglycemia (BGC < 80 mg/dL), and it is also associated with an increase in the ICU length of stay, the major determinant of ICU costs. Hyperglycemia (with a threshold value of 180 mg/dL) is associated with an increased risk of death, longer length of stay and higher infective morbidity in ICU patients. In ICU patients, insulin infusion aimed at maintaining BGC within a 140-180 mg/dL target range (NICE-SUGAR protocol) is considered to be the state-of-the-art. Recent evidence suggests that a lower BGC target range (129-145 mg/dL) is safe and associated with lower mortality. In trauma patients without traumatic brain injury, tight BGC (target < 110 mg/dL) might be associated with lower mortality. Safe BGC targeting and estimation of optimal insulin dose titration should include an adequate nutrition protocol, the length of insulin infusion and the change in insulin sensitivity over time. Continuous glucose monitoring devices that provide accurate measurement can contribute to minimizing the risk of hypoglycemia and improve insulin titration. In conclusion, in ICU patients, safe and effective glycemia management is based on accurate glycemia monitoring and achievement of the optimal BGC target range by using insulin titration, along with an adequate nutritional protocol.
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Affiliation(s)
- Federico Bilotta
- Federico Bilotta, Giovanni Rosa, Department of Anesthesiology, Critical Care and Pain Medicine, Section of Neuroanesthesia and Neurocritical Care, "Sapienza" University of Rome, 00199 Rome, Italy
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Haddad SH, Arabi YM. Critical care management of severe traumatic brain injury in adults. Scand J Trauma Resusc Emerg Med 2012; 20:12. [PMID: 22304785 PMCID: PMC3298793 DOI: 10.1186/1757-7241-20-12] [Citation(s) in RCA: 163] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2011] [Accepted: 02/03/2012] [Indexed: 01/29/2023] Open
Abstract
Traumatic brain injury (TBI) is a major medical and socio-economic problem, and is the leading cause of death in children and young adults. The critical care management of severe TBI is largely derived from the "Guidelines for the Management of Severe Traumatic Brain Injury" that have been published by the Brain Trauma Foundation. The main objectives are prevention and treatment of intracranial hypertension and secondary brain insults, preservation of cerebral perfusion pressure (CPP), and optimization of cerebral oxygenation. In this review, the critical care management of severe TBI will be discussed with focus on monitoring, avoidance and minimization of secondary brain insults, and optimization of cerebral oxygenation and CPP.
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Affiliation(s)
- Samir H Haddad
- Intensive Care Department, King Abdulaziz Medical City, Riyadh, Kingdom of Saudi Arabia.
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