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Zhou Y, Bai L, Tang W, Yang W, Sun L. Research progress in the pathogenesis of sepsis-associated encephalopathy. Heliyon 2024; 10:e33458. [PMID: 39027435 PMCID: PMC11254713 DOI: 10.1016/j.heliyon.2024.e33458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 06/18/2024] [Accepted: 06/21/2024] [Indexed: 07/20/2024] Open
Abstract
Sepsis is a syndrome that causes dysfunction of multiple organs due to the host's uncontrolled response to infection and is a significant contributor to morbidity and mortality in intensive care units worldwide. Surviving patients are often left with acute brain injury and long-term cognitive impairment, known as sepsis-associated encephalopathy (SAE). In recent years, researchers have directed their focus towards the pathogenesis of SAE. However, due to the complexity of its development, there remains a lack of effective treatment measures that arise as a serious issue affecting the prognosis of sepsis patients. Further research on the possible causes of SAE aims to provide clinicians with potential therapeutic targets and help develop targeted prevention strategies. This paper aims to review recent research on the pathogenesis of SAE, in order to enhance our understanding of this syndrome.
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Affiliation(s)
- Yue Zhou
- Teaching Department, First Hospital of Jilin University, Changchun, 130021, China
| | - Lu Bai
- Department of Medical Oncology, Dalian NO.3 People's Hospital, Dalian, 116091, China
| | - Wenjing Tang
- Department of Emergency Medicine, First Hospital of Jilin University, Changchun, 130021, China
| | - Weiying Yang
- Department of Emergency Medicine, First Hospital of Jilin University, Changchun, 130021, China
| | - Lichao Sun
- Department of Emergency Medicine, First Hospital of Jilin University, Changchun, 130021, China
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2
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Tian M, Zhan Y, Cao J, Gao J, Sun J, Zhang L. Targeting blood-brain barrier for sepsis-associated encephalopathy: Regulation of immune cells and ncRNAs. Brain Res Bull 2024; 209:110922. [PMID: 38458135 DOI: 10.1016/j.brainresbull.2024.110922] [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: 10/21/2023] [Revised: 02/14/2024] [Accepted: 03/05/2024] [Indexed: 03/10/2024]
Abstract
Sepsis causes significant morbidity and mortality worldwide, most surviving patients show acute or chronic mental disorders, which are known as sepsis-associated encephalopathy (SAE). SAE involves many pathological processes, including the blood-brain barrier (BBB) damage. The BBB is located at the interface between the central nervous system and the surrounding environment, which protects the central nervous system (CNS) from the invasion of exogenous molecules, harmful substances or microorganisms in the blood. Recently, a growing number of studies have indicated that the BBB destruction was involved in SAE and played an important role in SAE-induced brain injury. In the present review, we firstly reveal the pathological processes of SAE such as the neurotransmitter disorders, oxidative stress, immune dysfunction and BBB destruction. Moreover, we introduce the structure of BBB, and describe the immune cells including microglia and astrocytes that participate in the BBB destruction after SAE. Furthermore, in view of the current research on non-coding RNAs (ncRNAs), we explain the regulatory mechanism of ncRNAs including long noncoding RNAs (lncRNAs), microRNAs (miRNAs) and circular RNAs (circRNAs) on BBB in the processes of SAE. Finally, we propose some challenges and perspectives of regulating BBB functions in SAE. Hence, on the basis of these effects, both immune cells and ncRNAs may be developed as therapeutic targets to protect BBB for SAE patients.
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Affiliation(s)
- Mi Tian
- Department of Anesthesiology, Affiliated Zhongda Hospital of Southeast University, Nanjing, Jiangsu Province, China
| | - Yunliang Zhan
- Department of Anesthesiology and Perioperative Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Jinyuan Cao
- Department of Anesthesiology, Affiliated Zhongda Hospital of Southeast University, Nanjing, Jiangsu Province, China
| | - Jinqi Gao
- Department of Anesthesiology, Affiliated Zhongda Hospital of Southeast University, Nanjing, Jiangsu Province, China
| | - Jie Sun
- Department of Anesthesiology, Affiliated Zhongda Hospital of Southeast University, Nanjing, Jiangsu Province, China.
| | - Li Zhang
- Department of Neurosurgery, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, Jiangsu Province, China.
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3
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Yan X, Yang K, Xiao Q, Hou R, Pan X, Zhu X. Central role of microglia in sepsis-associated encephalopathy: From mechanism to therapy. Front Immunol 2022; 13:929316. [PMID: 35958583 PMCID: PMC9361477 DOI: 10.3389/fimmu.2022.929316] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 06/22/2022] [Indexed: 11/20/2022] Open
Abstract
Sepsis-associated encephalopathy (SAE) is a cognitive impairment associated with sepsis that occurs in the absence of direct infection in the central nervous system or structural brain damage. Microglia are thought to be macrophages of the central nervous system, devouring bits of neuronal cells and dead cells in the brain. They are activated in various ways, and microglia-mediated neuroinflammation is characteristic of central nervous system diseases, including SAE. Here, we systematically described the pathogenesis of SAE and demonstrated that microglia are closely related to the occurrence and development of SAE. Furthermore, we comprehensively discussed the function and phenotype of microglia and summarized their activation mechanism and role in SAE pathogenesis. Finally, this review summarizes recent studies on treating cognitive impairment in SAE by blocking microglial activation and toxic factors produced after activation. We suggest that targeting microglial activation may be a putative treatment for SAE.
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Affiliation(s)
- Xiaoqian Yan
- Department of Critical Care Medicine, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Kaiying Yang
- Department of Neurology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Qi Xiao
- Department of Neurology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Rongyao Hou
- Department of Neurology, The Affiliated Hiser Hospital of Qingdao University, Qingdao, China
- *Correspondence: Rongyao Hou, ; Xudong Pan, ; Xiaoyan Zhu,
| | - Xudong Pan
- Department of Neurology, The Affiliated Hospital of Qingdao University, Qingdao, China
- *Correspondence: Rongyao Hou, ; Xudong Pan, ; Xiaoyan Zhu,
| | - Xiaoyan Zhu
- Department of Critical Care Medicine, The Affiliated Hospital of Qingdao University, Qingdao, China
- *Correspondence: Rongyao Hou, ; Xudong Pan, ; Xiaoyan Zhu,
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4
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Sepsis-Associated Brain Dysfunction: A Review of Current Literature. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17165852. [PMID: 32806705 PMCID: PMC7460246 DOI: 10.3390/ijerph17165852] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 08/02/2020] [Accepted: 08/04/2020] [Indexed: 12/18/2022]
Abstract
Sepsis-associated brain dysfunction (SABD) may be the most common type of encephalopathy in critically ill patients. SABD develops in up to 70% of septic patients and represents the most frequent organ insufficiency associated with sepsis. It presents with a plethora of acute neurological features and may have several serious long-term psychiatric consequences. SABD might cause various pathological changes in the brain through numerous mechanisms. Clinical neurological examination is the basic screening method for SABD, although it may be challenging in subjects receiving with opioids and sedative agents. As electrographic seizures and periodic discharges might be present in 20% of septic patients, screening with electroencephalography (EEG) might be useful. Several imaging techniques have been suggested for non-invasive assessment of structure and function of the brain in SABD patients; however, their usefulness is rather limited. Although several experimental therapies have been postulated, at the moment, no specific treatment exists. Clinicians should focus on preventive measures and optimal management of sepsis. This review discusses epidemiology, clinical presentation, pathology, pathophysiology, diagnosis, management, and prevention of SABD.
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Atterton B, Paulino MC, Povoa P, Martin-Loeches I. Sepsis Associated Delirium. ACTA ACUST UNITED AC 2020; 56:medicina56050240. [PMID: 32443606 PMCID: PMC7279289 DOI: 10.3390/medicina56050240] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 05/13/2020] [Accepted: 05/14/2020] [Indexed: 01/04/2023]
Abstract
Sepsis is a potentially life-threatening condition caused by a systemic dysregulated host response to infection. The brain is particularly susceptible to the effects of sepsis with clinical manifestations ranging from mild confusion to a deep comatose state. Sepsis-associated delirium (SAD) is a cerebral manifestation commonly occurring in patients with sepsis and is thought to occur due to a combination of neuroinflammation and disturbances in cerebral perfusion, the blood brain barrier (BBB) and neurotransmission. The neurological impairment associated with SAD can persist for months or even longer, after the initial septic episode has subsided which may impair the rehabilitation potential of sepsis survivors. Early identification and treatment of the underlying sepsis is key in the management of SAD as once present it can be difficult to control. Through the regular use of validated screening tools for delirium, cases of SAD can be identified early; this allows potentially aggravating factors to be addressed promptly. The usefulness of biomarkers, neuroimaging and electroencephalopathy (EEG) in the diagnosis of SAD remains controversial. The Society of Critical Care Medicine (SCCM) guidelines advise against the use of medications to treat delirium unless distressing symptoms are present or it is hindering the patient’s ability to wean from organ support.
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Affiliation(s)
- Ben Atterton
- Department of Intensive Care Medicine, Multidisciplinary Intensive Care Research Organization (MICRO), St. James’s Hospital, St. James Street, Dublin 8, Dublin, D08 NHY1, Ireland;
| | - Maria Carolina Paulino
- Polyvalent Intensive Care Unit, São Francisco Xavier Hospital, Centro Hospitalar de Lisboa Ocidental, 1449-005 Lisbon, Portugal; (M.C.P.); (P.P.)
| | - Pedro Povoa
- Polyvalent Intensive Care Unit, São Francisco Xavier Hospital, Centro Hospitalar de Lisboa Ocidental, 1449-005 Lisbon, Portugal; (M.C.P.); (P.P.)
- NOVA Medical School, CHRC, New University of Lisbon, 1099-085 Lisbon, Portugal
- Center for Clinical Epidemiology and Research Unit of Clinical Epidemiology, OUH Odense University Hospital, 5000 Odense, Denmark
| | - Ignacio Martin-Loeches
- Department of Intensive Care Medicine, Multidisciplinary Intensive Care Research Organization (MICRO), St. James’s Hospital, St. James Street, Dublin 8, Dublin, D08 NHY1, Ireland;
- Hospital Clinic, IDIBAPS, Universidad de Barcelona, Ciberes, 08036 Barcelona, Spain
- Correspondence:
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Dahl RH, Berg RMG, Taudorf S, Bailey DM, Lundby C, Christensen M, Larsen FS, Møller K. Transcerebral exchange kinetics of large neutral amino acids during acute inspiratory hypoxia in humans. Scandinavian Journal of Clinical and Laboratory Investigation 2019; 79:595-600. [PMID: 31657241 DOI: 10.1080/00365513.2019.1683762] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Hypoxaemia is present in many critically ill patients, and may contribute to encephalopathy. Changes in the passage of large neutral amino acids (LNAAs) across the blood-brain barrier (BBB) with an increased cerebral influx of aromatic amino acids into the brain may concurrently be present and also contribute to encephalopathy, but it has not been established whether hypoxaemia per se may trigger such changes. We measured cerebral blood flow (CBF) in 11 healthy men using the Kety-Schmidt technique and obtained paired arterial and jugular-venous blood samples for the determination of LNAAs by high performance liquid chromatography at baseline and after 9 hours of poikilocapnic normobaric hypoxia (12% O2). Transcerebral net exchange was determined by the Fick principle, and transport of LNAAs across the BBB was determined mathematically. Hypoxia increased both the systemic and corresponding cerebral delivery of the aromatic amino acid phenylalanine, and the branched-chain amino acids leucine and isoleucine. Despite this, the transcerebral net exchange values and mathematically derived brain extracellular concentrations for all LNAAs were unaffected. In conclusion, the observed changes in circulating LNAAs triggered by hypoxaemia do not affect the transcerebral exchange kinetics of LNAAs to such an extent that their brain extracellular concentrations are affected.
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Affiliation(s)
- Rasmus H Dahl
- Department of Neuroanaesthesiology, Rigshospitalet, Copenhagen, Denmark
| | - Ronan M G Berg
- Department of Clinical Physiology, Nuclear Medicine & PET, Rigshospitalet, Copenhagen, Denmark.,Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Pontyprid, UK
| | - Sarah Taudorf
- Department of Neurology 2082, University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Damian M Bailey
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Pontyprid, UK
| | - Carsten Lundby
- Centre for Physical Activity Research, Rigshospitalet, Copenhagen, Denmark
| | - Mette Christensen
- Department of Clinical Genetics, Rigshospitalet, Copenhagen, Denmark
| | - Fin S Larsen
- Department of Hepatology, Rigshospitalet, Copenhagen, Denmark
| | - Kirsten Møller
- Department of Neuroanaesthesiology, Rigshospitalet, Copenhagen, Denmark
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Abstract
PURPOSE OF THE REVIEW To discuss the diagnostic approach to patients with septic encephalopathy as well as the need for specific neuro-monitoring and the perspectives on future therapeutic approaches in this setting. RECENT FINDINGS Most of data-concern experimental studies evaluating the pathophysiology of septic encephalopathy. A combination of neurodegenerative pathways with neurovascular injury is the cornerstone for the development of such complication and the long-term neurological sequelae among survivors. Septic encephalopathy is a common complication in septic patients. Clinical presentation may range from mild confusion and disorientation to convulsions and deep coma. The diagnosis of septic encephalopathy is made difficult by the lack of any specific clinical and non-clinical feature, in particular among sedated patients in whom neurological examination is unreliable. In spite of the high mortality rate associated with this condition, there is no prophylactic or targeted therapy to reduce or minimize brain damage in septic patients and clinical management is limited to the treatment of the underlying infection.
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Berg RMG, Taudorf S, Bailey DM, Dahl RH, Lundby C, Møller K. Transcerebral net exchange of vasoactive peptides and catecholamines during lipopolysaccharide-induced systemic inflammation in healthy humans. Can J Physiol Pharmacol 2017; 96:313-316. [PMID: 28898586 DOI: 10.1139/cjpp-2017-0266] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The systemic inflammatory response triggered by lipopolysaccharide (LPS) is associated with cerebral vasoconstriction, but the underlying mechanisms are unknown. We therefore examined whether a 4-hour intravenous LPS infusion (0.3 ng·kg-1) induces any changes in the transcerebral net exchange of the vasoactive peptides endothelin-1 (ET-1) and calcitonin-gene related peptide (CGRP) and catecholamines in human volunteers. Cerebral blood flow was measured by the Kety-Schmidt technique, and paired arterial-to-jugular venous blood samples were obtained for estimating the transcerebral exchange of ET-1, CGRP, and catecholamines by the Fick principle in 12 volunteers before and after LPS infusion. The cerebrovascular release of ET-1 was enhanced, whereas the transcerebral net exchange of CGRP and catecholamines was unaffected. Our findings thus point towards locally produced ET-1 within the cerebrovasculature as a contributor to cerebral vasoconstriction after LPS infusion.
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Affiliation(s)
- Ronan M G Berg
- a Centre of Inflammation & Metabolism, University Hospital Rigshospitalet, Copenhagen, Denmark.,b Department of Clinical Physiology & Nuclear Medicine, Bispebjerg and Frederiksberg Hospitals, Copenhagen, Denmark
| | - Sarah Taudorf
- a Centre of Inflammation & Metabolism, University Hospital Rigshospitalet, Copenhagen, Denmark.,c Department of Neurology 2082, University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Damian M Bailey
- d Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Pontypridd, UK
| | - Rasmus H Dahl
- e Department of Neuroanaesthesiology, University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Carsten Lundby
- f Zürich Center for Integrative Human Physiology (ZIHP), University of Zürich, Zürich, Switzerland
| | - Kirsten Møller
- a Centre of Inflammation & Metabolism, University Hospital Rigshospitalet, Copenhagen, Denmark.,e Department of Neuroanaesthesiology, University Hospital Rigshospitalet, Copenhagen, Denmark
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9
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Dahl RH, Berg RMG, Taudorf S, Bailey DM, Lundby C, Larsen FS, Møller K. A reassessment of the blood-brain barrier transport of large neutral amino acids during acute systemic inflammation in humans. Clin Physiol Funct Imaging 2017; 38:656-662. [PMID: 28795486 DOI: 10.1111/cpf.12463] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 07/03/2017] [Indexed: 11/30/2022]
Abstract
We reassessed data from a previous study on the transcerebral net exchange of large neutral amino acids (LNAAs) using a novel mathematical model of blood-brain barrier (BBB) transport. The study included twelve healthy volunteers who received a 4-h intravenous lipopolysaccharide (LPS) infusion (total dose: 0·3 ng/kg), a human experimental model of the systemic inflammatory response during the early stages of sepsis. Cerebral blood flow and arterial-to-jugular venous LNAA concentrations were measured prior to and after LPS, and the BBB transport and brain extracellular concentrations of LNAAs were calculated. The arterial concentration and unidirectional cerebral influx of phenylalanine increased after LPS. The BBB transport of tyrosine was unaffected, while its concentration in the brain extracellular fluid increased. These findings suggest that LPS infusion leads to an increased cerebral uptake of phenylalanine, which is then metabolized to tyrosine. This may reflect a neuroprotective mechanism that 'detoxifies' excess intracerebral phenylalanine in the clinical setting of sepsis.
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Affiliation(s)
- Rasmus H Dahl
- Neurointensive Care Unit 2093, Department of Neuroanaesthesiology, University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Ronan M G Berg
- Department of Clinical Physiology and Nuclear Medicine, Bispebjerg and Frederiksberg Hospitals, Copenhagen, Denmark.,Centre of Inflammation and Metabolism, University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Sarah Taudorf
- Centre of Inflammation and Metabolism, University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Damian M Bailey
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Treforest, UK
| | - Carsten Lundby
- Center for Integrative Human Physiology, Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Fin S Larsen
- Department of Hepatology, University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Kirsten Møller
- Neurointensive Care Unit 2093, Department of Neuroanaesthesiology, University Hospital Rigshospitalet, Copenhagen, Denmark.,Centre of Inflammation and Metabolism, University Hospital Rigshospitalet, Copenhagen, Denmark
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Feng Q, Ai YH, Gong H, Wu L, Ai ML, Deng SY, Huang L, Peng QY, Zhang LN. Characterization of Sepsis and Sepsis-Associated Encephalopathy. J Intensive Care Med 2017; 34:938-945. [PMID: 28718340 DOI: 10.1177/0885066617719750] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND Sepsis and sepsis-associated encephalopathy (SAE) are common intensive care unit (ICU) diseases; the morbidity and mortality are high. The present study analyzed the sensitivity of different diagnostic criteria of sepsis 1.0 and 3.0, epidemiological characteristics of sepsis and SAE, and explored its risk factors for death, short-term, and long-term prognosis. METHODS The retrospective study included patients in ICU from January 2015 to June 2016. After excluding 58 patients, 175 were assigned to either an SAE or a non-SAE group (patients with sepsis but no encephalopathy). The sensitivity of the diagnostic criteria was compared between sepsis 1.0 and 3.0, respectively. Between-group differences in baseline data, Acute Physiology and Chronic Health Evaluation II score (APACHE II score), Sequential Organ Failure Assessment score (SOFA score), etiological data, biochemical indicators, and 28-day and 180-day mortality rates were analyzed. Survival outcomes and long-term prognosis were observed, and risk factors for death were analyzed through 180-day follow-up. RESULTS The sensitivity did not differ significantly between the diagnostic criteria of sepsis 1.0 and 3.0 (P = .286). The 42.3% incidence of SAE presented a significantly high APACHE II and SOFA scores as well as 28-day mortality and 180-day mortality (all P < .001). The incidence of death was 37.1%. The multivariate stepwise regression analysis demonstrated that the risk of death in SAE group was significantly higher than the non-SAE group (P < .001). Sepsis-associated encephalopathy is a risk factor for sepsis-related death (relative risk [RR] = 2.868; 95% confidence interval: 1.730-4.754; P < .001). Although males showed a significantly high rate of 28-day and 180-day mortality (P = .035 and .045), it was not an independent risk factor for sepsis-related death (P = .072). The long-term prognosis of patients with sepsis was poor with decreased quality of life. No significant difference was observed in prognosis between the SAE and non-SAE groups (P > .05). CONCLUSION Both diagnostic criteria cause misdiagnosis, and the sensitivity did not differ significantly. The incidence of SAE was high, and 28-day and 180-day mortality rates were significantly higher than those without SAE. Sepsis-associated encephalopathy is a risk factor for poor outcome. The overall long-term prognosis of patients with sepsis was poor, and the quality of life decreased.
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Affiliation(s)
- Qing Feng
- Department of Intensive Care Unit, Xiangya Hospital, Central South University, Changsha, China
| | - Yu-Hang Ai
- Department of Intensive Care Unit, Xiangya Hospital, Central South University, Changsha, China
| | - Hua Gong
- Department of Intensive Care Unit, Xiangya Hospital, Central South University, Changsha, China
| | - Long Wu
- Department of Intensive Care Unit, Xiangya Hospital, Central South University, Changsha, China
| | - Mei-Lin Ai
- Department of Intensive Care Unit, Xiangya Hospital, Central South University, Changsha, China
| | - Song-Yun Deng
- Department of Intensive Care Unit, Xiangya Hospital, Central South University, Changsha, China
| | - Li Huang
- Department of Intensive Care Unit, Xiangya Hospital, Central South University, Changsha, China
| | - Qian-Yi Peng
- Department of Intensive Care Unit, Xiangya Hospital, Central South University, Changsha, China
| | - Li-Na Zhang
- Department of Intensive Care Unit, Xiangya Hospital, Central South University, Changsha, China
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11
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Milewski K, Oria M. What we know: the inflammatory basis of hepatic encephalopathy. Metab Brain Dis 2016; 31:1239-1247. [PMID: 26497651 DOI: 10.1007/s11011-015-9740-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 09/24/2015] [Indexed: 02/07/2023]
Abstract
Central Nervous System (CNS) degeneration appearing in patients with cirrhosis is responsible for cognitive and persistent motor impairments that lead to an important impact on life quality. Brain injury affects certain areas of the CNS that might affect two types of cells: neurons and astrocytes. The process leading to brain injury could be induced by portosystemic shunting accompanied by hyperammonemia and by the activation of peripheral inflammation, manifested as episodic encephalopathy. Hyperammonemia combined with a decrease on the BCA/AAA ratio induces alterations of energetic metabolism and the formation of free radicals in the CNS. This process would be stimulated by the activation of peripheral inflammatory mediators that could act on receptors of the blood brain barrier such as TLR4, activating inflammatory responses in the CNS. As a result, a persistent activation of microglia and an irreversible neuronal and astrocytic injury would be induced. A new knowledge of the mechanisms leading to brain injury in cirrhosis would develop protective strategies to correct changes of nitrogen metabolism and inflammation.
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Affiliation(s)
- K Milewski
- Department of Neurotoxicology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Pawińskiego 5 Str, 02-106, Warsaw, Poland
| | - M Oria
- Translational Research in Fetal Surgery for Congenital Malformations, Center for Fetal, Cellular and Molecular Therapy, Division of Pediatric General and Thoracic Surgery, Cincinnati Children's Hospital Medical Center (CCHMC), 3333 Burnet Avenue, MLC 11020, S 8.400 AT, Cincinnati, OH, 45229-3039, USA.
- Liver Failure Group, UCL Institute for Liver and Digestive Health, Royal Free Hospital, University College London, London, UK.
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12
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Janum S, Nielsen ST, Werner MU, Mehlsen J, Kehlet H, Møller K. Pain perception in healthy volunteers: effect of repeated exposure to experimental systemic inflammation. Innate Immun 2016; 22:546-56. [PMID: 27554053 DOI: 10.1177/1753425916663638] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 07/08/2016] [Indexed: 11/15/2022] Open
Abstract
We aimed to study the relationship between pain perception and cytokine release during systemic inflammation. We present a randomized crossover trial in healthy volunteers (n = 17) in 37 individual trials. Systemic inflammation was induced by an i.v. bolus of Escherichia coli LPS (2 ng/kg) on two separate trial days, with or without a nicotine patch applied 10 h previously. Pain perception at baseline, and 2 and 6 h after LPS was assessed by pressure algometry and tonic heat stimulation at an increasing temperature (45-48℃) during both trials. Compared with baseline, pain pressure threshold was reduced 2 and 6 h after LPS, while heat pain perception was accentuated at all testing temperatures after 2 but not 6 h. The magnitude of changes in pain perception did not correlate to cytokine release. No effect of transdermal nicotine or training status was observed. In conclusion, LPS administration in healthy human volunteers leads to reduction in pain pressure threshold and an increase in pain perception to heat stimuli, supporting a relationship between acute systemic inflammation and pain perception.
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Affiliation(s)
- Susanne Janum
- Center of Inflammation and Metabolism, CIM 7641, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark Department of Anesthesiology, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Signe T Nielsen
- Center of Inflammation and Metabolism, CIM 7641, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Mads U Werner
- Multidisciplinary Pain Center, Department of Neuroanesthesiology, Rigshospitalet, Copenhagen, Denmark
| | - Jesper Mehlsen
- Coordinating Research Centre, Frederiksberg Hospital, Frederiksberg, Denmark
| | - Henrik Kehlet
- Institute of Surgical Pathophysiology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Kirsten Møller
- Department of Neuroanesthesiology, Rigshospitalet, University of Copenhagen, Denmark
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13
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Dal-Pizzol F, Tomasi CD, Ritter C. Septic encephalopathy: does inflammation drive the brain crazy? REVISTA BRASILEIRA DE PSIQUIATRIA 2014; 36:251-8. [DOI: 10.1590/1516-4446-2013-1233] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 11/11/2013] [Indexed: 11/21/2022]
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14
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Sawin EA, Murali SG, Ney DM. Differential effects of low-phenylalanine protein sources on brain neurotransmitters and behavior in C57Bl/6-Pah(enu2) mice. Mol Genet Metab 2014; 111:452-61. [PMID: 24560888 PMCID: PMC3995025 DOI: 10.1016/j.ymgme.2014.01.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 01/30/2014] [Indexed: 11/24/2022]
Abstract
Phenylketonuria (PKU) is an inborn error of metabolism caused by a deficiency of the enzyme phenylalanine hydroxylase, which metabolizes phenylalanine (phe) to tyrosine. A low-phe diet plus amino acid (AA) formula is necessary to prevent cognitive impairment; glycomacropeptide (GMP) contains minimal phe and provides a palatable alternative to the AA formula. Our objective was to assess neurotransmitter concentrations in the brain and the behavioral phenotype of PKU mice (Pah(enu2) on the C57Bl/6 background) and how this is affected by low-phe protein sources. Wild type (WT) and PKU mice, both male and female, were fed high-phe casein, low-phe AA, or low-phe GMP diets between 3 and 18 weeks of age. Behavioral phenotype was assessed using the open field and marble burying tests, and brain neurotransmitter concentrations were measured using HPLC with electrochemical detection system. Data were analyzed by 3-way ANOVA with genotype, sex, and diet as the main treatment effects. Brain mass and the concentrations of catecholamines and serotonin were reduced in PKU mice compared to WT mice; the low-phe AA and GMP diets improved these parameters in PKU mice. Relative brain mass was increased in female PKU mice fed the GMP diet compared to the AA diet. PKU mice exhibited hyperactivity and impaired vertical exploration compared to their WT littermates during the open field test. Regardless of genotype or diet, female mice demonstrated increased vertical activity time and increased total ambulatory and horizontal activity counts compared with male mice. PKU mice fed the high-phe casein diet buried significantly fewer marbles than WT control mice fed casein; this was normalized in PKU mice fed the low-phe AA and GMP diets. In summary, C57Bl/6-Pah(enu2) mice showed an impaired behavioral phenotype and reduced brain neurotransmitter concentrations that were improved by the low-phe AA or GMP diets. These data support lifelong adherence to a low-phe diet for PKU.
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Affiliation(s)
- Emily A Sawin
- Department of Nutritional Sciences, University of Wisconsin-Madison, WI 53706, USA.
| | - Sangita G Murali
- Department of Nutritional Sciences, University of Wisconsin-Madison, WI 53706, USA.
| | - Denise M Ney
- Department of Nutritional Sciences, University of Wisconsin-Madison, WI 53706, USA.
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Adam N, Kandelman S, Mantz J, Chrétien F, Sharshar T. Sepsis-induced brain dysfunction. Expert Rev Anti Infect Ther 2013; 11:211-21. [PMID: 23409826 DOI: 10.1586/eri.12.159] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Systemic infection is often revealed by or associated with brain dysfunction, which is characterized by alteration of consciousness, ranging from delirium to coma, seizure or focal neurological signs. Its pathophysiology involves an ischemic process, secondary to impairment of cerebral perfusion and its determinants and a neuroinflammatory process that includes endothelial activation, alteration of the blood-brain barrier and passage of neurotoxic mediators. Microcirculatory dysfunction is common to these two processes. This brain dysfunction is associated with increased mortality, morbidity and long-term cognitive disability. Its diagnosis relies essentially on neurological examination that can lead to specific investigations, including electrophysiological testing or neuroimaging. In practice, cerebrospinal fluid analysis is indisputably required when meningitis is suspected. Hepatic, uremic or respiratory encephalopathy, metabolic disturbances, drug overdose, sedative or opioid withdrawal, alcohol withdrawal delirium or Wernicke's encephalopathy are the main differential diagnoses. Currently, treatment consists mainly of controlling sepsis. The effects of insulin therapy and steroids need to be assessed. Various drugs acting on sepsis-induced blood-brain barrier dysfunction, brain oxidative stress and inflammation have been tested in septic animals but not yet in patients.
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Affiliation(s)
- Nicolas Adam
- General Intensive Care Unit, Raymond Poincaré Teaching Hospital, University of Versailles Saint-Quentin en Yvelines, 104 Boulevard Raymond Poincaré, 92380 Garches, France
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16
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Berg RMG, Taudorf S, Bailey DM, Lundby C, Larsen FS, Pedersen BK, Møller K. Effects of lipopolysaccharide infusion on arterial levels and transcerebral exchange kinetics of glutamate and glycine in healthy humans. APMIS 2012; 120:761-6. [PMID: 22882266 DOI: 10.1111/j.1600-0463.2012.02904.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Accepted: 03/07/2012] [Indexed: 11/29/2022]
Abstract
An imbalance between glutamate and glycine signalling may contribute to sepsis-associated encephalopathy by causing neuronal excitotoxicity. In this study, we therefore investigated the transcerebral exchange kinetics of glutamate and glycine in a human-experimental model of systemic inflammation. Cerebral blood flow (CBF) and arterial to jugular venous concentration differences of glutamate and glycine were determined before and after a 4-h intravenous infusion of Escherichia coli lipopolysaccharide (LPS, total dose of 0.3 ng/kg) in 12 healthy volunteers. The global cerebral net exchange was calculated by multiplying CBF with the arterial to jugular venous differences. LPS induced a systemic inflammatory response with fever, neutrocytosis, and elevated arterial levels of tumour necrosis factor-α. This was associated with a decrease in the arterial levels of both glutamate and glycine; however, their transcerebral exchange kinetics were unaffected. Inflammation-induced alterations of the circulating levels of glutamate and glycine, do not affect the global transcerebral exchange kinetics of these amino acids in healthy humans.
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Affiliation(s)
- Ronan M G Berg
- Centre of Inflammation and Metabolism, Department of Infectious Diseases, University Hospital Rigshospitalet, Copenhagen, Denmark.
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17
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Glutamine acts as a neuroprotectant against DNA damage, beta-amyloid and H2O2-induced stress. PLoS One 2012; 7:e33177. [PMID: 22413000 PMCID: PMC3297635 DOI: 10.1371/journal.pone.0033177] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Accepted: 02/05/2012] [Indexed: 12/04/2022] Open
Abstract
Glutamine is the most abundant free amino acid in the human blood stream and is ‘conditionally essential’ to cells. Its intracellular levels are regulated both by the uptake of extracellular glutamine via specific transport systems and by its intracellular synthesis by glutamine synthetase (GS). Adding to the regulatory complexity, when extracellular glutamine is reduced GS protein levels rise. Unfortunately, this excess GS can be maladaptive. GS overexpression is neurotoxic especially if the cells are in a low-glutamine medium. Similarly, in low glutamine, the levels of multiple stress response proteins are reduced rendering cells hypersensitive to H2O2, zinc salts and DNA damage. These altered responses may have particular relevance to neurodegenerative diseases of aging. GS activity and glutamine levels are lower in the Alzheimer's disease (AD) brain, and a fraction of AD hippocampal neurons have dramatically increased GS levels compared with control subjects. We validated the importance of these observations by showing that raising glutamine levels in the medium protects cultured neuronal cells against the amyloid peptide, Aβ. Further, a 10-day course of dietary glutamine supplementation reduced inflammation-induced neuronal cell cycle activation, tau phosphorylation and ATM-activation in two different mouse models of familial AD while raising the levels of two synaptic proteins, VAMP2 and synaptophysin. Together, our observations suggest that healthy neuronal cells require both intracellular and extracellular glutamine, and that the neuroprotective effects of glutamine supplementation may prove beneficial in the treatment of AD.
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18
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Sepsis-associated encephalopathy. Transl Med UniSa 2012; 2:20-7. [PMID: 23905041 PMCID: PMC3728775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Sepsis-associated encephalopathy (SAE) is defined as a diffuse or multifocal cerebral dysfunction induced by the systemic response to the infection without clinical or laboratory evidence of direct brain infection. Its pathogenesis is multifactorial. SAE generally occurs early during severe sepsis and precedes multiple-organ failure. The most common clinical feature of SAE is the consciousness alteration which ranges from mildly reduced awareness to unresponsiveness and coma. Diagnosis of SAE is primarily clinical and depends on the exclusion of other possible causes of brain deterioration. Electroencephalography (EEG) is almost sensitive, but it is not specific for SAE. Computed Tomography (CT) head scan generally is negative in case of SAE, while Magnetic Resonance Imaging (MRI) can show brain abnormalities in case of SAE, but they are not specific for this condition. Somatosensitive Evoked Potentials (SEPs) are sensitive markers of developing cerebral dysfunction in sepsis. Cerebrospinal fluid (CBF) analysis is generally normal, a part an inconstant elevation of proteins concentration. S100B and NSE have been proposed like biomarkers for diagnosis of SAE, but the existing data are controversial. SAE is reversible even if survivors of severe sepsis have often long lasting or irreversible cognitive and behavioral sequel; however the presence of SAE can have a negative influence on survival. A specific therapy of SAE does not exist and the outcome depends on a prompt and appropriate treatment of sepsis as whole.
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Abstract
In 2010 Critical Care published a large number of articles on critical care aspects of neurologic and neurosurgical conditions. These aspects included investigation of diagnostic criteria for bacterial meningitis, critical illness myopathy and their relationship to systemic inflammation. A number of studies investigated the biology of sepsis-related delirium, its biomarkers, its relationship to inflammation and its impact on outcome. Other teams reported on the use of magnetic resonance imaging, biomarkers and electroencephalogram to predict outcome in patients who were comatose following cardiac arrest. Our understanding of the pathophysiology as well as management of subarachnoid hemorrhage was addressed in several papers. Topics included the effect of hemodynamic treatment of delayed cerebral ischemia, pulmonary edema and the impact of subarachnoid hemorrhage on endocrine function. Finally, outcome from neurocritical care and patients' retrospective willingness to consent to the treatment they received were reported.
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Affiliation(s)
- Michael T Scalfani
- Neurology/Neurosurgery Intensive Care Unit, Department of Neurology, Washington University School of Medicine, Campus Box 8111, 660 S, Euclid Avenue, St Louis, MO 63110, USA
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20
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Abstract
Neuro-oxidative-nitrosative stress may prove the molecular basis underlying brain dysfunction in sepsis. In the current review, we describe how sepsis-induced reactive oxygen and nitrogen species (ROS/RNS) trigger lipid peroxidation chain reactions throughout the cerebrovasculature and surrounding brain parenchyma, due to failure of the local antioxidant systems. ROS/RNS cause structural membrane damage, induce inflammation, and scavenge nitric oxide (NO) to yield peroxynitrite (ONOO(-)). This activates the inducible NO synthase, which further compounds ONOO(-) formation. ROS/RNS cause mitochondrial dysfunction by inhibiting the mitochondrial electron transport chain and uncoupling oxidative phosphorylation, which ultimately leads to neuronal bioenergetic failure. Furthermore, in certain 'at risk' areas of the brain, free radicals may induce neuronal apoptosis. In the present review, we define a role for ROS/RNS-mediated neuronal bioenergetic failure and apoptosis as a primary mechanism underlying sepsis-associated encephalopathy and, in sepsis survivors, permanent cognitive deficits.
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Zampieri FG, Park M, Machado FS, Azevedo LCP. Sepsis-associated encephalopathy: not just delirium. Clinics (Sao Paulo) 2011; 66:1825-31. [PMID: 22012058 PMCID: PMC3180153 DOI: 10.1590/s1807-59322011001000024] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Accepted: 07/04/2011] [Indexed: 02/08/2023] Open
Abstract
Sepsis is a major cause of mortality and morbidity in intensive care units. Organ dysfunction is triggered by inflammatory insults and tissue hypoperfusion. The brain plays a pivotal role in sepsis, acting as both a mediator of the immune response and a target for the pathologic process. The measurement of brain dysfunction is difficult because there are no specific biomarkers of neuronal injury, and bedside evaluation of cognitive performance is difficult in an intensive care unit. Although sepsis-associated encephalopathy was described decades ago, it has only recently been subjected to scientific scrutiny and is not yet completely understood. The pathophysiology of sepsis-associated encephalopathy involves direct cellular damage to the brain, mitochondrial and endothelial dysfunction and disturbances in neurotransmission. This review describes the most recent findings in the pathophysiology, diagnosis, and management of sepsis-associated encephalopathy and focuses on its many presentations.
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Affiliation(s)
- Fernando Godinho Zampieri
- Intensive Care Unit, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil.
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