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Ferlini L, Su F, Creteur J, Taccone FS, Gaspard N. Cerebral autoregulation and neurovascular coupling are progressively impaired during septic shock: an experimental study. Intensive Care Med Exp 2020; 8:44. [PMID: 32797301 PMCID: PMC7426896 DOI: 10.1186/s40635-020-00332-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 07/21/2020] [Indexed: 12/14/2022] Open
Abstract
Background Alteration of the mechanisms of cerebral blood flow (CBF) regulation might contribute to the pathophysiology of sepsis-associated encephalopathy (SAE). However, previous clinical studies on dynamic cerebral autoregulation (dCA) in sepsis had several cofounders. Furthermore, little is known on the potential impairment of neurovascular coupling (NVC) in sepsis. The aim of our study was to determine the presence and time course of dCA and NVC alterations in a clinically relevant animal model and their potential impact on the development of SAE. Methods Thirty-six anesthetized, mechanically ventilated female sheep were randomized to sham procedures (sham, n = 15), sepsis (n = 14), or septic shock (n = 7). Blood pressure, CBF, and electrocorticography were continuously recorded. Pearson’s correlation coefficient Lxa and transfer function analysis were used to estimate dCA. NVC was assessed by the analysis of CBF variations induced by cortical gamma activity (Eγ) peaks and by the magnitude-squared coherence (MSC) between the spontaneous fluctuations of CBF and Eγ. Cortical function was estimated by the alpha-delta ratio. Wilcoxon signed rank and rank sum tests, Friedman tests, and RMANOVA test were used as appropriate. Results Sepsis and sham animals did not differ neither in dCA nor in NVC parameters. A significant impairment of dCA occurred only after septic shock (Lxa, p = 0.03, TFA gain p = 0.03, phase p = 0.01). Similarly, NVC was altered during septic shock, as indicated by a lower MSC in the frequency band 0.03–0.06 Hz (p < 0.001). dCA and NVC impairments were associated with cortical dysfunction (reduction in the alpha-delta ratio (p = 0.03)). Conclusions A progressive loss of dCA and NVC occurs during septic shock and is associated with cortical dysfunction. These findings indicate that the alteration of mechanisms controlling cortical perfusion plays a late role in the pathophysiology of SAE and suggest that alterations of CBF regulation mechanisms in less severe phases of sepsis reported in clinical studies might be due to patients’ comorbidities or other confounders. Furthermore, a mean arterial pressure targeting therapy aiming to optimize dCA might not be sufficient to prevent neuronal dysfunction in sepsis since it would not improve NVC.
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Affiliation(s)
- Lorenzo Ferlini
- Department of Neurology, Erasme Hospital, Université Libre de Bruxelles, Route de Lennik 808, 1070, Bruxelles, Belgium.
| | - Fuhong Su
- Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles, Bruxelles, Belgium
| | - Jacques Creteur
- Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles, Bruxelles, Belgium
| | - Fabio Silvio Taccone
- Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles, Bruxelles, Belgium
| | - Nicolas Gaspard
- Department of Neurology, Erasme Hospital, Université Libre de Bruxelles, Route de Lennik 808, 1070, Bruxelles, Belgium
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Garofalo AM, Lorente-Ros M, Goncalvez G, Carriedo D, Ballén-Barragán A, Villar-Fernández A, Peñuelas Ó, Herrero R, Granados-Carreño R, Lorente JA. Histopathological changes of organ dysfunction in sepsis. Intensive Care Med Exp 2019; 7:45. [PMID: 31346833 PMCID: PMC6658642 DOI: 10.1186/s40635-019-0236-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 03/07/2019] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Sepsis is a highly lethal disorder. Organ dysfunction in sepsis is not defined as a clinicopathological entity but rather by changes in clinical, physiological, or biochemical parameters. Pathogenesis and specific treatment of organ dysfunction in sepsis are unknown. The study of the histopathological correlate of organ dysfunction in sepsis will help understand its pathogenesis. METHODS We searched in PubMed, EMBASE, and Scielo for original articles on kidney, brain, and liver dysfunction in human sepsis. A defined search strategy was designed, and pertinent articles that addressed the histopathological changes in sepsis were retrieved for review. Only studies considered relevant in the field were discussed. RESULTS Studies on acute kidney injury (AKI) in sepsis reveal that acute tubular necrosis is less prevalent than other changes, indicating that kidney hypoperfusion is not the predominant pathogenetic mechanism of sepsis-induced AKI. Other more predominant histopathological changes are apoptosis, interstitial inflammation, and, to a lesser extent, thrombosis. Brain pathological findings include white matter hemorrhage and hypercoagulability, microabscess formation, central pontine myelinolysis, multifocal necrotizing leukoencephalopathy, metabolic changes, ischemic changes, and apoptosis. Liver pathology in sepsis includes steatosis, cholangiolitis and intrahepatic cholestasis, periportal inflammation, and apoptosis. There is no information on physiological or biochemical biomarkers of the histopathological findings. CONCLUSIONS Histopathological studies may provide important information for a better understanding of the pathogenesis of organ dysfunction in sepsis and for the design of potentially effective therapies. There is a lack of clinically available biomarkers for the identification of organ dysfunction as defined by the histological analysis.
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Affiliation(s)
- Antonio M. Garofalo
- Hospital Universitario de Getafe, Madrid, Spain
- Universidad Europea de Madrid, Madrid, Spain
| | | | | | | | | | | | - Óscar Peñuelas
- Hospital Universitario de Getafe, Madrid, Spain
- CIBER de Enfermedades Respiratorias, Madrid, Spain
| | - Raquel Herrero
- Hospital Universitario de Getafe, Madrid, Spain
- CIBER de Enfermedades Respiratorias, Madrid, Spain
| | | | - José A. Lorente
- Hospital Universitario de Getafe, Madrid, Spain
- Universidad Europea de Madrid, Madrid, Spain
- CIBER de Enfermedades Respiratorias, Madrid, Spain
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Molnár L, Németh N, Berhés M, Hajdú E, Papp L, Molnár Á, Szabó J, Deák Á, Fülesdi B. Assessment of cerebral circulation in a porcine model of intravenously given E. coli induced fulminant sepsis. BMC Anesthesiol 2017; 17:98. [PMID: 28738837 PMCID: PMC5525280 DOI: 10.1186/s12871-017-0389-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Accepted: 07/12/2017] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND The aim of the present work was to assess cerebral hemodynamic changes in a porcine model of E.coli induced fulminant sepsis. METHODS Nineteen healthy female Hungahib pigs, 10-12 weeks old, randomly assigned into two groups: Control (n = 9) or Septic Group (n = 10). In the Sepsis group Escherichia coli culture suspended in physiological saline was intravenously administrated in a continuously increasing manner according to the following protocol: 2 ml of bacterial culture suspended in physiological saline was injected in the first 30 min, then 4 ml of bacterial culture was administered within 30 min, followed by infusion of 32 ml bacterial culture for 2 h. Control animals received identical amount of saline infusion. Systemic hemodynamic parameters were assessed by PiCCo monitoring, and cerebral hemodynamics by transcranial Doppler sonography (transorbital approach) in both groups. RESULTS In control animals, systemic hemodynamic variables and cerebral blood flow velocities and pulsatility indices were relatively stable during the entire procedure. In septic animals shock developed in 165 (IQR: 60-255) minutes after starting the injection of E.coli solution. Blood pressure values gradully decreased, whereas pulse rate increased. A decrease in cardiac index, an increased systemic vascular resistance, and an increased stroke volume variation were observed. Mean cerebral blood flow velocity in the middle cerebral artery did not change during the procedure, but pulsatility index significantly increased. CONCLUSIONS There is vasoconstriction at the level of the cerebral arterioles in the early phase of experimental sepsis that overwhelmes autoregulatory response. These results may serve as additional pathophysiological information on the cerebral hemodynamic changes occurring during the septic process and may contribute to a better understanding of the pathomechanism of septic encephalopathy.
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Affiliation(s)
- Levente Molnár
- Department of Anesthesiology and Intensive Care, University of Debrecen, Faculty of Medicine, Nagyerdei krt. 98, Debrecen, H 4032, Hungary
| | - Norbert Németh
- Department of Operative Techniques and Surgical Research, University of Debrecen, Faculty of Medicine, Debrecen, Hungary
| | - Mariann Berhés
- Department of Anesthesiology and Intensive Care, University of Debrecen, Faculty of Medicine, Nagyerdei krt. 98, Debrecen, H 4032, Hungary
| | - Endre Hajdú
- Department of Anesthesiology and Intensive Care, University of Debrecen, Faculty of Medicine, Nagyerdei krt. 98, Debrecen, H 4032, Hungary
| | - Lóránd Papp
- Department of Anesthesiology and Intensive Care, University of Debrecen, Faculty of Medicine, Nagyerdei krt. 98, Debrecen, H 4032, Hungary
| | - Ábel Molnár
- Department of Operative Techniques and Surgical Research, University of Debrecen, Faculty of Medicine, Debrecen, Hungary
| | - Judit Szabó
- Department of Medical Microbiology, University of Debrecen, Faculty of Medicine, Debrecen, Hungary
| | - Ádám Deák
- Department of Operative Techniques and Surgical Research, University of Debrecen, Faculty of Medicine, Debrecen, Hungary
| | - Béla Fülesdi
- Department of Anesthesiology and Intensive Care, University of Debrecen, Faculty of Medicine, Nagyerdei krt. 98, Debrecen, H 4032, Hungary. .,Outcomes Research Consortium, Cleveland, USA.
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Bellapart J, Cuthbertson K, Dunster K, Diab S, Platts DG, Raffel OC, Gabrielian L, Barnett A, Paratz J, Boots R, Fraser JF. Cerebral Microcirculation during Experimental Normovolaemic Anemia. Front Neurol 2016; 7:6. [PMID: 26869986 PMCID: PMC4735869 DOI: 10.3389/fneur.2016.00006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 01/14/2016] [Indexed: 11/13/2022] Open
Abstract
Anemia is accepted among critically ill patients as an alternative to elective blood transfusion. This practice has been extrapolated to head injury patients with only one study comparing the effects of mild anemia on neurological outcome. There are no studies quantifying microcirculation during anemia. Experimental studies suggest that anemia leads to cerebral hypoxia and increased rates of infarction, but the lack of clinical equipoise, when testing the cerebral effects of transfusion among critically injured patients, supports the need of experimental studies. The aim of this study was to quantify cerebral microcirculation and the potential presence of axonal damage in an experimental model exposed to normovolaemic anemia, with the intention of describing possible limitations within management practices in critically ill patients. Under non-recovered anesthesia, six Merino sheep were instrumented using an intracardiac transeptal catheter to inject coded microspheres into the left atrium to ensure systemic and non-chaotic distribution. Cytometric analyses quantified cerebral microcirculation at specific regions of the brain. Amyloid precursor protein staining was used as an indicator of axonal damage. Animals were exposed to normovolaemic anemia by blood extractions from the indwelling arterial catheter with simultaneous fluid replacement through a venous central catheter. Simultaneous data recording from cerebral tissue oxygenation, intracranial pressure, and cardiac output was monitored. A regression model was used to examine the effects of anemia on microcirculation with a mixed model to control for repeated measures. Homogeneous and normal cerebral microcirculation with no evidence of axonal damage was present in all cerebral regions, with no temporal variability, concluding that acute normovolaemic anemia does not result in short-term effects on cerebral microcirculation in the ovine brain.
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Affiliation(s)
- Judith Bellapart
- Department of Intensive Care, Royal Brisbane and Women's Hospital , Herston, QLD , Australia
| | - Kylie Cuthbertson
- Department of Intensive Care, Royal Brisbane and Women's Hospital , Herston, QLD , Australia
| | - Kimble Dunster
- Critical Care Research Group, University of Queensland, St Lucia, QLD, Australia; Medical Engineering Research Facility, Queensland University of Technology, Brisbane, QLD, Australia
| | - Sara Diab
- Critical Care Research Group, University of Queensland, St Lucia, QLD, Australia; Medical Engineering Research Facility, Queensland University of Technology, Brisbane, QLD, Australia
| | - David G Platts
- Medical Engineering Research Facility, Queensland University of Technology, Brisbane, QLD, Australia; Department of Cardiology, The Prince Charles Hospital, Chermside, QLD, Australia
| | - O Christopher Raffel
- Medical Engineering Research Facility, Queensland University of Technology, Brisbane, QLD, Australia; Department of Cardiology, The Prince Charles Hospital, Chermside, QLD, Australia
| | - Levon Gabrielian
- Medical Research Centre, Medical School, University of South Australia , Adelaide, SA , Australia
| | - Adrian Barnett
- Medical Engineering Research Facility, Queensland University of Technology, Brisbane, QLD, Australia; School of Public Health and Social Work, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia
| | - Jenifer Paratz
- Department of Intensive Care, Royal Brisbane and Women's Hospital , Herston, QLD , Australia
| | - Rob Boots
- Department of Intensive Care, Royal Brisbane and Women's Hospital , Herston, QLD , Australia
| | - John F Fraser
- Critical Care Research Group, University of Queensland, St Lucia, QLD, Australia; Medical Engineering Research Facility, Queensland University of Technology, Brisbane, QLD, Australia; School of Public Health and Social Work, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia; Department of Intensive Care, The Prince Charles Hospital, Chermside, QLD, Australia
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Intracardiac echocardiography guided transeptal catheter injection of microspheres for assessment of cerebral microcirculation in experimental models. Cardiol Res Pract 2013; 2013:595838. [PMID: 24102032 PMCID: PMC3786547 DOI: 10.1155/2013/595838] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2013] [Revised: 08/08/2013] [Accepted: 08/08/2013] [Indexed: 11/24/2022] Open
Abstract
The use of microspheres for the determination of regional microvascular blood flow (RMBF) has previously used different approaches. This study presents for the first time the intracardiac injection of microspheres using transeptal puncture under intracardiac echocardiography guidance. Five Merino sheep were instrumented and cardiovascularly supported according to local guidelines. Two catheter sheaths into the internal jugular vein facilitated the introduction of an intracardiac probe and transeptal catheter, respectively. Five million colour coded microspheres were injected into the left atrium via this catheter. After euthanasia the brain was used as proof of principle and the endpoint for determination of microcirculation at different time points. Homogeneous allocation of microspheres to different regions of the brain was found over time. Alternate slices from both hemispheres showed the following flow ranges: for slice 02; 0.57–1.02 mL/min/g, slice 04; 0.45–1.42 mL/min/g, slice 06; 0.35–1.87 mL/min/g, slice 08; 0.46–1.77 mL/min/g, slice 10; 0.34–1.28 mL/min/g. A mixed effect regression model demonstrated that the confidence interval did include zero suggesting that the apparent variability intra- and intersubject was not statistically significant, supporting the stability and reproducibility of the injection technique. This study demonstrates the feasibility of the transeptal injection of microspheres, showing a homogeneous distribution of blood flow through the brain unchanged over time and has established a new interventional model for the measurement of RMBF in ovine models.
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Toda N, Ayajiki K, Okamura T. Cerebral blood flow regulation by nitric oxide in neurological disorders. Can J Physiol Pharmacol 2010; 87:581-94. [PMID: 19767882 DOI: 10.1139/y09-048] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
There has been a rapid increase in the amount of information on the physiological and pathophysiological roles of nitric oxide (NO) in the brain. This molecule, which is formed by the constitutive isoforms of NO synthase, endothelial (eNOS) and neuronal (nNOS), plays an obligatory role in the regulation of cerebral blood flow and cell viability and in the protection of nerve cells or fibres against pathogenic factors associated with Alzheimer's disease, Huntington's disease, seizures, and migraine. Cerebral blood flow is impaired by decreased formation of NO from endothelial cells, autonomic nitrergic nerves, or brain neurons and also by increased production of reactive oxygen species (ROS). The NO-ROS interaction is an important topic in discussing blood flow and cell viability in the brain. Excessive production of NO by inducible NOS (iNOS) and nNOS in the brain participates in neurotoxicity. Recent studies on brain circulation have provided useful information about the involvement of impaired NO availability or uncontrolled NO production in cerebral pathogenesis, including Alzheimer's disease, seizures, vascular headaches, and inflammatory disorders. Insight into the role of NO in the brain will contribute to our better understanding of cerebral hemodynamic dysfunction and will aid in developing novel therapeutic measures in diseases of the central nervous system.
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Affiliation(s)
- Noboru Toda
- Toyama Institute for Cardiovascular Pharmacology Research, 7-13, 1-Chome, Azuchi-machi, Chuo-ku, Osaka 541-0052, Japan.
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Burkhart CS, Siegemund M, Steiner LA. Cerebral perfusion in sepsis. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2010; 14:215. [PMID: 20236459 PMCID: PMC2887108 DOI: 10.1186/cc8856] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Christoph S Burkhart
- Department of Anesthesia and Intensive Care Medicine, University Hospital, Spitalstrasse 21, Basel, Switzerland
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Lange M, Bröking K, van Aken H, Hucklenbruch C, Bone HG, Westphal M. [Role of ketamine in sepsis and systemic inflammatory response syndrome]. Anaesthesist 2007; 55:883-91. [PMID: 16775727 DOI: 10.1007/s00101-006-1048-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Ketamine is the only intravenous anesthetic that causes an increase in mean arterial pressure without compromising cardiac output. These beneficial effects are basically linked to stimulation of the sympathetic nervous system, inhibition of adenosine triphosphate-sensitive potassium channels and interactions with the nitric oxide pathway. Experimental and clinical studies have shown that ketamine exerts antiinflammatory properties by inhibiting the release of proinflammatory cytokines, such as tumor necrosis factor-alpha and interleukin-6. In addition, there is increasing evidence that early ketamine administration reduces mortality in experimental sepsis models. In view of the current literature ketamine appears to represent a beneficial therapeutic option for long-term sedation of patients with arterial hypotension resulting from sepsis and systemic inflammatory response syndrome (SIRS). However, it has to be taken into account that ketamine inhibits endothelial nitric oxide synthase, thereby potentially aggravating impaired (micro) regional blood flow in sepsis. Future studies are required to investigate the role of ketamine in the treatment of patients with sepsis and SIRS.
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Affiliation(s)
- M Lange
- Klinik und Poliklinik für Anästhesiologie und operative Intensivmedizin, Universitätsklinikum, Albert-Schweitzer-Str. 33, 48149 Münster.
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