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Hoffmann O, Tempel H, Wolf S, Gratopp A, Salih F. Loss of cerebral blood flow and cerebral perfusion pressure in brain death: A transcranial Duplex ultrasonography study. J Crit Care 2022; 71:154091. [PMID: 35714454 DOI: 10.1016/j.jcrc.2022.154091] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 05/09/2022] [Accepted: 05/27/2022] [Indexed: 11/25/2022]
Abstract
PURPOSE We investigated cerebral perfusion pressure (CPP) at the time loss of cerebral blood flow (CBF) occurred during brain death (BD). We hypothesized that a critical closing pressure (CrCP) may be reached before CPP drops to 0 mmHg. MATERIALS AND METHODS 14 patients with increasing intracranial pressure (ICP) leading to BD were included. Transcranial Duplex (TCD) ultrasonography was used to investigate CBF. Starting at a CPP of 30 mmHg, TCD was repeated until waveforms indicated loss of CBF. We then analyzed CPP by the time TCD indicated absent CBF and clinical BD was established. RESULTS In 12 patients, CPP was positive when clinical BD was manifest and TCD illustrated absent CBF. Across all patients, mean CPP at clinical BD manifestation was 10.0 mmHg (range 0-20 mmHg); mean CPP by the time CBF stopped was 7.5 mmHg (0-20 mmHg). In four patients, clinical BD preceded loss of CBF. Here, the mean CPP difference from clinical BD to loss of CBF was 8.8 mmHg (5-15 mmHg). CONCLUSIONS CrCP may be reached although CPP is still positive, resulting in complete loss of CBF and BD. By including bedside TCD, neuromonitoring may contribute to early identification of patients at risk to experience loss of CBF and subsequent BD.
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Affiliation(s)
- Olaf Hoffmann
- Alexianer St. Josefs-Krankenhaus Potsdam, Dept. of Neurology, Allee nach Sanssouci 7, 14471 Potsdam, Germany; Charité-Universitätsmedizin Berlin, NeuroCure Clinical Research Center, Charitéplatz 1, 10117 Berlin, Germany; Medizinische Hochschule Brandenburg Theodor Fontane, Fehrbelliner Str. 38, 16816 Neuruppin, Germany
| | - Hannah Tempel
- Charité-Universitätsmedizin Berlin, Dept. of Neurology, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Stefan Wolf
- Charité-Universitätsmedizin Berlin, Dept. of Neurosurgery, Charité-Platz 1, 10117 Berlin, Germany
| | - Alexander Gratopp
- Charité-Universitätsmedizin Berlin, Dept. of Pediatric Respiratory Medicine, Immunology and Critical Care Medicine, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Farid Salih
- Charité-Universitätsmedizin Berlin, Dept. of Neurology, Augustenburger Platz 1, 13353 Berlin, Germany.
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2
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Zhang Z, Hwang M, Kilbaugh TJ, Sridharan A, Katz J. Cerebral microcirculation mapped by echo particle tracking velocimetry quantifies the intracranial pressure and detects ischemia. Nat Commun 2022; 13:666. [PMID: 35115552 PMCID: PMC8814032 DOI: 10.1038/s41467-022-28298-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 01/14/2022] [Indexed: 12/26/2022] Open
Abstract
Affecting 1.1‰ of infants, hydrocephalus involves abnormal accumulation of cerebrospinal fluid, resulting in elevated intracranial pressure (ICP). It is the leading cause for brain surgery in newborns, often causing long-term neurologic disabilities or even death. Since conventional invasive ICP monitoring is risky, early neurosurgical interventions could benefit from noninvasive techniques. Here we use clinical contrast-enhanced ultrasound (CEUS) imaging and intravascular microbubble tracking algorithms to map the cerebral blood flow in hydrocephalic pediatric porcine models. Regional microvascular perfusions are quantified by the cerebral microcirculation (CMC) parameter, which accounts for the concentration of micro-vessels and flow velocity in them. Combining CMC with hemodynamic parameters yields functional relationships between cortical micro-perfusion and ICP, with correlation coefficients exceeding 0.85. For cerebral ischemia cases, the nondimensionalized cortical micro-perfusion decreases by an order of magnitude when ICP exceeds 50% of the MAP. These findings suggest that CEUS-based CMC measurement is a plausible noninvasive method for assessing the ICP and detecting ischemia.
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Affiliation(s)
- Zeng Zhang
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Misun Hwang
- Department of Radiology, Children's Hospital of Philadelphia, Philadelphia, PA, USA.,Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Todd J Kilbaugh
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Anush Sridharan
- Department of Radiology, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Joseph Katz
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD, USA.
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3
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Everitt A, Root B, Calnan D, Manwaring P, Bauer D, Halter R. A bioimpedance-based monitor for real-time detection and identification of secondary brain injury. Sci Rep 2021; 11:15454. [PMID: 34326387 PMCID: PMC8322167 DOI: 10.1038/s41598-021-94600-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 07/13/2021] [Indexed: 01/01/2023] Open
Abstract
Secondary brain injury impacts patient prognosis and can lead to long-term morbidity and mortality in cases of trauma. Continuous monitoring of secondary injury in acute clinical settings is primarily limited to intracranial pressure (ICP); however, ICP is unable to identify essential underlying etiologies of injury needed to guide treatment (e.g. immediate surgical intervention vs medical management). Here we show that a novel intracranial bioimpedance monitor (BIM) can detect onset of secondary injury, differentiate focal (e.g. hemorrhage) from global (e.g. edema) events, identify underlying etiology and provide localization of an intracranial mass effect. We found in an in vivo porcine model that the BIM detected changes in intracranial volume down to 0.38 mL, differentiated high impedance (e.g. ischemic) from low impedance (e.g. hemorrhagic) injuries (p < 0.001), separated focal from global events (p < 0.001) and provided coarse 'imaging' through localization of the mass effect. This work presents for the first time the full design, development, characterization and successful implementation of an intracranial bioimpedance monitor. This BIM technology could be further translated to clinical pathologies including but not limited to traumatic brain injury, intracerebral hemorrhage, stroke, hydrocephalus and post-surgical monitoring.
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Affiliation(s)
- Alicia Everitt
- Thayer School of Engineering, Dartmouth College, HB 8000, 14 Engineering Dr., Hanover, NH, 03755, USA.
| | - Brandon Root
- Neurological Surgery, Dartmouth Hitchcock Medical Center, Lebanon, NH, 03766, USA
| | - Daniel Calnan
- Neurological Surgery, Dartmouth Hitchcock Medical Center, Lebanon, NH, 03766, USA
| | | | - David Bauer
- Neurological Surgery, Dartmouth Hitchcock Medical Center, Lebanon, NH, 03766, USA
| | - Ryan Halter
- Thayer School of Engineering, Dartmouth College, HB 8000, 14 Engineering Dr., Hanover, NH, 03755, USA.,Neurological Surgery, Dartmouth Hitchcock Medical Center, Lebanon, NH, 03766, USA
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4
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Zhou D, Stobdan T, Visk D, Xue J, Haddad GG. Genetic interactions regulate hypoxia tolerance conferred by activating Notch in excitatory amino acid transporter 1-positive glial cells in Drosophila melanogaster. G3 (BETHESDA, MD.) 2021; 11:jkab038. [PMID: 33576765 PMCID: PMC8022968 DOI: 10.1093/g3journal/jkab038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Accepted: 01/28/2021] [Indexed: 12/26/2022]
Abstract
Hypoxia is a critical pathological element in many human diseases, including ischemic stroke, myocardial infarction, and solid tumors. Of particular significance and interest of ours are the cellular and molecular mechanisms that underlie susceptibility or tolerance to low O2. Previous studies have demonstrated that Notch signaling pathway regulates hypoxia tolerance in both Drosophila melanogaster and humans. However, the mechanisms mediating Notch-conferred hypoxia tolerance are largely unknown. In this study, we delineate the evolutionarily conserved mechanisms underlying this hypoxia tolerant phenotype. We determined the role of a group of conserved genes that were obtained from a comparative genomic analysis of hypoxia-tolerant D.melanogaster populations and human highlanders living at the high-altitude regions of the world (Tibetans, Ethiopians, and Andeans). We developed a novel dual-UAS/Gal4 system that allows us to activate Notch signaling in the Eaat1-positive glial cells, which remarkably enhances hypoxia tolerance in D.melanogaster, and, simultaneously, knock down a candidate gene in the same set of glial cells. Using this system, we discovered that the interactions between Notch signaling and bnl (fibroblast growth factor), croc (forkhead transcription factor C), or Mkk4 (mitogen-activated protein kinase kinase 4) are important for hypoxia tolerance, at least in part, through regulating neuronal development and survival under hypoxic conditions. Becausethese genetic mechanisms are evolutionarily conserved, this group of genes may serve as novel targets for developing therapeutic strategies and have a strong potential to be translated to humans to treat/prevent hypoxia-related diseases.
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Affiliation(s)
- Dan Zhou
- Division of Respiratory Medicine, Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA
| | - Tsering Stobdan
- Division of Respiratory Medicine, Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA
| | - DeeAnn Visk
- Division of Respiratory Medicine, Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA
| | - Jin Xue
- Division of Respiratory Medicine, Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA
| | - Gabriel G Haddad
- Department of Neurosciences, University of California at San Diego, La Jolla, CA 92093, USA
- Rady Children’s Hospital, San Diego, CA 92123, USA
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5
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Tageldeen MK, Gowers SAN, Leong CL, Boutelle MG, Drakakis EM. Traumatic brain injury neuroelectrochemical monitoring: behind-the-ear micro-instrument and cloud application. J Neuroeng Rehabil 2020; 17:114. [PMID: 32825829 PMCID: PMC7441655 DOI: 10.1186/s12984-020-00742-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 08/04/2020] [Indexed: 01/15/2023] Open
Abstract
Background Traumatic Brain Injury (TBI) is a leading cause of fatality and disability worldwide, partly due to the occurrence of secondary injury and late interventions. Correct diagnosis and timely monitoring ensure effective medical intervention aimed at improving clinical outcome. However, due to the limitations in size and cost of current ambulatory bioinstruments, they cannot be used to monitor patients who may still be at risk of secondary injury outside the ICU. Methods We propose a complete system consisting of a wearable wireless bioinstrument and a cloud-based application for real-time TBI monitoring. The bioinstrument can simultaneously record up to ten channels including both ECoG biopotential and neurochemicals (e.g. potassium, glucose and lactate), and supports various electrochemical methods including potentiometry, amperometry and cyclic voltammetry. All channels support variable gain programming to automatically tune the input dynamic range and address biosensors’ falling sensitivity. The instrument is flexible and can be folded to occupy a small space behind the ear. A Bluetooth Low-Energy (BLE) receiver is used to wirelessly connect the instrument to a cloud application where the recorded data is stored, processed and visualised in real-time. Bench testing has been used to validate device performance. Results The instrument successfully monitored spreading depolarisations (SDs) - reproduced using a signal generator - with an SNR of 29.07 dB and NF of 0.26 dB. The potentiostat generates a wide voltage range from -1.65V to +1.65V with a resolution of 0.8mV and the sensitivity of the amperometric AFE was verified by recording 5 pA currents. Different potassium, glucose and lactate concentrations prepared in lab were accurately measured and their respective working curves were constructed. Finally,the instrument achieved a maximum sampling rate of 1.25 ksps/channel with a throughput of 105 kbps. All measurements were successfully received at the cloud. Conclusion The proposed instrument uniquely positions itself by presenting an aggressive optimisation of size and cost while maintaining high measurement accuracy. The system can effectively extend neuroelectrochemical monitoring to all TBI patients including those who are mobile and those who are outside the ICU. Finally, data recorded in the cloud application could be used to help diagnosis and guide rehabilitation.
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Affiliation(s)
- Momen K Tageldeen
- Bioinspired VLSI Circuits and Systems Group, Department of Bioengineering, Imperial College London, Exhibition Road, London, SW7 2AZ, UK
| | - Sally A N Gowers
- Biomedical Sensors Group, Department of Bioengineering, Imperial College London, Exhibition Road, London, SW7 2AZ, UK
| | - Chi L Leong
- Biomedical Sensors Group, Department of Bioengineering, Imperial College London, Exhibition Road, London, SW7 2AZ, UK
| | - Martyn G Boutelle
- Biomedical Sensors Group, Department of Bioengineering, Imperial College London, Exhibition Road, London, SW7 2AZ, UK
| | - Emmanuel M Drakakis
- Bioinspired VLSI Circuits and Systems Group, Department of Bioengineering, Imperial College London, Exhibition Road, London, SW7 2AZ, UK.
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6
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Datzmann T, Kapapa T, Scheuerle A, McCook O, Merz T, Unmuth S, Hoffmann A, Mathieu R, Mayer S, Mauer UM, Röhrer S, Yilmazer-Hanke D, Möller P, Nussbaum BL, Calzia E, Gröger M, Hartmann C, Radermacher P, Wepler M. In-depth characterization of a long-term, resuscitated model of acute subdural hematoma-induced brain injury. J Neurosurg 2019; 134:223-234. [PMID: 31860806 DOI: 10.3171/2019.9.jns191789] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 09/13/2019] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Acute subdural hematoma (ASDH) is a leading entity in brain injury. Rodent models mostly lack standard intensive care, while large animal models frequently are only short term. Therefore, the authors developed a long-term, resuscitated porcine model of ASDH-induced brain injury and report their findings. METHODS Anesthetized, mechanically ventilated, and instrumented pigs with human-like coagulation underwent subdural injection of 20 mL of autologous blood and subsequent observation for 54 hours. Continuous bilateral multimodal brain monitoring (intracranial pressure [ICP], cerebral perfusion pressure [CPP], partial pressure of oxygen in brain tissue [PbtO2], and brain temperature) was combined with intermittent neurological assessment (veterinary modified Glasgow Coma Scale [MGCS]), microdialysis, and measurement of plasma protein S100β, GFAP, neuron-specific enolase [NSE], nitrite+nitrate, and isoprostanes. Fluid resuscitation and continuous intravenous norepinephrine were targeted to maintain CPP at pre-ASDH levels. Immediately postmortem, the brains were taken for macroscopic and histological evaluation, immunohistochemical analysis for nitrotyrosine formation, albumin extravasation, NADPH oxidase 2 (NOX2) and GFAP expression, and quantification of tissue mitochondrial respiration. RESULTS Nine of 11 pigs survived the complete observation period. While ICP significantly increased after ASDH induction, CPP, PbtO2, and the MGCS score remained unaffected. Blood S100β levels significantly fell over time, whereas GFAP, NSE, nitrite+nitrate, and isoprostane concentrations were unaltered. Immunohistochemistry showed nitrotyrosine formation, albumin extravasation, NOX2 expression, fibrillary astrogliosis, and microglial activation. CONCLUSIONS The authors describe a clinically relevant, long-term, resuscitated porcine model of ASDH-induced brain injury. Despite the morphological injury, maintaining CPP and PbtO2 prevented serious neurological dysfunction. This model is suitable for studying therapeutic interventions during hemorrhage-induced acute brain injury with standard brain-targeted intensive care.
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Affiliation(s)
- Thomas Datzmann
- 1Institut für Anästhesiologische Pathophysiologie und Verfahrensentwicklung
- 2Klinik für Anästhesiologie
| | | | | | - Oscar McCook
- 1Institut für Anästhesiologische Pathophysiologie und Verfahrensentwicklung
| | - Tamara Merz
- 1Institut für Anästhesiologische Pathophysiologie und Verfahrensentwicklung
| | - Sarah Unmuth
- 1Institut für Anästhesiologische Pathophysiologie und Verfahrensentwicklung
| | - Andrea Hoffmann
- 1Institut für Anästhesiologische Pathophysiologie und Verfahrensentwicklung
| | - René Mathieu
- 5Klinik für Neurochirurgie, Bundeswehrkrankenhaus Ulm; and
| | - Simon Mayer
- 5Klinik für Neurochirurgie, Bundeswehrkrankenhaus Ulm; and
| | - Uwe Max Mauer
- 5Klinik für Neurochirurgie, Bundeswehrkrankenhaus Ulm; and
| | - Stefan Röhrer
- 6Abteilung für Neurochirurgie, Klinikum Aalen, Germany
| | | | - Peter Möller
- 8Institut für Pathologie, Universitätsklinikum, Ulm
| | - Benedikt Lukas Nussbaum
- 1Institut für Anästhesiologische Pathophysiologie und Verfahrensentwicklung
- 2Klinik für Anästhesiologie
| | - Enrico Calzia
- 1Institut für Anästhesiologische Pathophysiologie und Verfahrensentwicklung
| | - Michael Gröger
- 1Institut für Anästhesiologische Pathophysiologie und Verfahrensentwicklung
| | - Clair Hartmann
- 1Institut für Anästhesiologische Pathophysiologie und Verfahrensentwicklung
- 2Klinik für Anästhesiologie
| | - Peter Radermacher
- 1Institut für Anästhesiologische Pathophysiologie und Verfahrensentwicklung
| | - Martin Wepler
- 1Institut für Anästhesiologische Pathophysiologie und Verfahrensentwicklung
- 2Klinik für Anästhesiologie
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7
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Wang NN, Chen GN, Qu B, Yu F, Sheng GN, Shi Y. Effect of Hypotensive Brain Death on the Donor Liver and Its Mechanism in an Improved Bama Miniature Pig (Sus scrofa domestica) Model. Transplant Proc 2019; 51:951-959. [PMID: 30979488 DOI: 10.1016/j.transproceed.2019.01.029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Accepted: 01/04/2019] [Indexed: 11/28/2022]
Abstract
BACKGROUND We aimed to observe the effect of hypotensive brain death on the donor liver and understand its pathophysiological mechanism in improved pig model. METHODS The model was induced using the modified intracranial water sac inflation method in 16 Bama miniature pigs. Effects of hypotensive brain death on liver function and tissue morphology were evaluated via changes in liver function enzyme index, liver tissue alkaline phosphatase levels, hourly bile flow, and liver tissue pathology. Its pathophysiological mechanism was examined on the basis of changes in portal vein blood flow, hepatic artery blood flow, portal venous endotoxin level, and liver tissue cytokine levels. RESULTS After model establishment, portal vein blood flow, hepatic arterial blood flow, hourly bile flow, and alkaline phosphatase content in hepatic tissue significantly decreased, and serum aspartate aminotransferase, alkaline phosphatase, and lactate dehydrogenase levels significantly increased. Hematoxylin-eosin staining of liver tissue showed that after model establishment, hepatic tissue injury was gradually aggravated and hepatic cells were irreversibly damaged at 7 hours. Portal vein endotoxin levels significantly increased after brain death. Tumor necrosis factor α, interleukin 1, and endothelin 1 levels in liver tissues significantly increased at 3, 6, and 12 hours after brain death (P < .05), and hypoxia-inducible factor 1-α and nitric oxide levels significantly decreased (P < .05). CONCLUSIONS Hepatic injury was progressively aggravated under hypotensive brain death. The mechanism of donor liver injury under hypotensive brain death may involve low liver perfusion, release of intestinal endotoxin and inflammatory factors (eg, tumor necrosis factor α and interleukin 1), decreased hypoxia-inducible factor 1-α, and endothelin 1 and nitric oxide imbalance.
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Affiliation(s)
- N-N Wang
- Postgraduate Training Base, Affiliated Hospital of Logistics University of Chinese People's Armed Police Force, Jinzhou Medical University, Tianjin, China
| | - G-N Chen
- Postgraduate Training Base, Affiliated Hospital of Logistics University of Chinese People's Armed Police Force, Jinzhou Medical University, Tianjin, China
| | - B Qu
- Postgraduate Training Base, Affiliated Hospital of Logistics University of Chinese People's Armed Police Force, Jinzhou Medical University, Tianjin, China.
| | - F Yu
- Department of Emergency, the Seventh Affiliated Hospital of Sun Yat-Sen University, Shenzhen, China
| | - G-N Sheng
- Organ Transplantation Center, Tianjin First Center Hospital, Nankai District, Tianjin, China
| | - Y Shi
- Organ Transplantation Center, Tianjin First Center Hospital, Nankai District, Tianjin, China.
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8
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Roth C, Ferbert A, Matthaei J, Kaestner S, Engel H, Gehling M. Progress of intracranial pressure and cerebral perfusion pressure in patients during the development of brain death. J Neurol Sci 2019; 398:171-175. [PMID: 30731304 DOI: 10.1016/j.jns.2019.01.048] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Revised: 01/26/2019] [Accepted: 01/28/2019] [Indexed: 10/27/2022]
Abstract
BACKGROUND Clinical investigations of brain death are supposed to prove absence of cerebral perfusion. However, only limited data are available documenting intracranial pressure (ICP) and cerebral perfusion pressure (CPP) during the development of brain death. Our study presents additional data to understand the course of ICP and CPP in patients developing brain death. MATERIAL AND METHODS We analyzed retrospective data of 18 patients with ICP monitoring during the development of brain death due to primary brain lesions. ICP and CPP values were continuously measured between two clinically defined time points: 1. non-reactive and widened pupils, 2. brain death determination. We analyzed ICP and CPP at the above-mentioned end points. Additionally, we investigated maximum ICP and minimal CPP values between these time points. RESULTS Patients developed fixed and dilated pupils with a median of 38 h before brain death determination. During brain death determination median ICP and median CPP were 103.5 and -2.5 mmHg, respectively. Maximum ICP before brain death determination was significantly higher and minimal CPP values were significantly lower compared to the time point of brain death. During the investigation period all patients experienced ICP values >95 mmHg and CPP < 10 mmHg. All but one patient had documented CPP values of ≤0 mmHg. This single patient had a minimum CPP of 8 mmHg with a maximum ICP of 145 mmHg. CONCLUSION Cerebral perfusion pressure during brain death determination may be positive in some patients. Our results showed variable values of ICP and CPP. However, extremely elevated ICP values before or during brain death in combination with low CPP values suggest absence of cerebral perfusion. The occurrence of positive CPP values during brain death determination therefore depends on the time point at which brain death determination is performed.
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Affiliation(s)
- Christian Roth
- Department of Neurology, DRK-Kliniken Nordhessen, Kassel, Germany; Department of Neurology, University of Marburg, Germany.
| | | | | | | | - Holger Engel
- Department of Plastic-Reconstructive, Aesthetic and Handsurgery, Klinikum Kassel, Kassel, Germany
| | - Markus Gehling
- Department of Anesthesiology, University of Marburg, Marburg, Germany; Pain Center, Kassel, Germany
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9
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Abstract
Multiple trauma (MT) associated with hemorrhagic shock (HS) might lead to cerebral hypoperfusion and brain damage. We investigated cerebral alterations using a new porcine MT/HS model without traumatic brain injury (TBI) and assessed the neuroprotective properties of mild therapeutic hypothermia. Male pigs underwent standardized MT with HS (45% or 50% loss of blood volume) and resuscitation after 90/120 min (T90/T120). In additional groups (TH90/TH120) mild hypothermia (33°C) was induced following resuscitation. Normothermic or hypothermic sham animals served as controls. Intracranial pressure, cerebral perfusion pressure (CPP), and cerebral oxygenation (PtiO2) were recorded up to 48.5 h. Serum protein S-100B and neuron-specific enolase (NSE) were measured by ELISA. Cerebral inflammation was quantified on hematoxylin and eosin -stained brain slices; Iba1, S100, and inducible nitric oxide synthase (iNOS) expression was assessed using immunohistochemistry. Directly after MT/HS, CPP and PtiO2 were significantly lower in T90/T120 groups compared with sham. After resuscitation both parameters showed a gradual recovery. Serum protein S-100B and NSE increased temporarily as a result of MT/HS in T90 and T90/T120 groups, respectively. Cerebral inflammation was found in all groups. Iba1-staining showed significant microgliosis in T90 and T120 animals. iNOS-staining indicated a M1 polarization. Mild hypothermia reduced cerebral inflammation in the TH90 group, but resulted in increased iNOS activation. In this porcine long-term model, we did not find evidence of gross cerebral damage when resuscitation was initiated within 120 min after MT/HS without TBI. However, trauma-related microglia activation and M1 microglia polarization might be a consequence of temporary hypoxia/ischemia and further research is warranted to detail underlying mechanisms. Interestingly, mild hypothermia did not exhibit neuroprotective properties when initiated in a delayed fashion.
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10
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Salih F, Hoffmann O, Brandt SA, Masuhr F, Schreiber S, Weissinger F, Rocco A, Wolf S. Safety of apnea testing for the diagnosis of brain death: a comprehensive study on neuromonitoring data and blood gas analysis. Eur J Neurol 2019; 26:887-892. [DOI: 10.1111/ene.13903] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 12/06/2018] [Indexed: 11/27/2022]
Affiliation(s)
- F. Salih
- Department of Neurology Charité‐Universitätsmedizin Berlin Berlin Germany
| | - O. Hoffmann
- Department of Neurology St. Josefs‐Krankenhaus Potsdam Germany
| | - S. A. Brandt
- Department of Neurology Charité‐Universitätsmedizin Berlin Berlin Germany
| | - F. Masuhr
- Department of Neurology Bundeswehrkrankenhaus Berlin Berlin Germany
| | - S. Schreiber
- Department of Neurology Asklepios Fachklinikum Brandenburg Germany
| | - F. Weissinger
- Department of Neurology Vivantes Humboldt‐Klinikum Berlin Germany
| | - A. Rocco
- Department of Neurology Charité‐Universitätsmedizin Berlin Berlin Germany
| | - S. Wolf
- Department of Neurosurgery Charité‐Universitätsmedizin Berlin Berlin Germany
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11
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Caccioppola A, Carbonara M, Macrì M, Longhi L, Magnoni S, Ortolano F, Triulzi F, Zanier ER, Zoerle T, Stocchetti N. Ultrasound-tagged near-infrared spectroscopy does not disclose absent cerebral circulation in brain-dead adults. Br J Anaesth 2018; 121:588-594. [PMID: 30115257 DOI: 10.1016/j.bja.2018.04.038] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 04/09/2018] [Accepted: 05/04/2018] [Indexed: 10/14/2022] Open
Abstract
BACKGROUND Near-infrared spectroscopy, a non-invasive technique for monitoring cerebral oxygenation, is widely used, but its accuracy is questioned because of the possibility of extra-cranial contamination. Ultrasound-tagged near-infrared spectroscopy (UT-NIRS) has been proposed as an improvement over previous methods. We investigated UT-NIRS in healthy volunteers and in brain-dead patients. METHODS We studied 20 healthy volunteers and 20 brain-dead patients with two UT-NIRS devices, CerOx™ and c-FLOW™ (Ornim Medical, Kfar Saba, Israel), which measure cerebral flow index (CFI), a parameter related to changes in cerebral blood flow (CBF). Monitoring started after the patients had been declared brain dead for a median of 34 (range: 11-300) min. In 11 cases, we obtained further demonstration of absent CBF. RESULTS In healthy volunteers, CFI was markedly different in the two hemispheres in the same subject, with wide variability amongst subjects. In brain-dead patients (median age: 64 yr old, 45% female; 20% traumatic brain injury, 40% subarachnoid haemorrhage, and 40% intracranial haemorrhage), the median (inter-quartile range) CFI was 41 (36-47), significantly higher than in volunteers (33; 27-36). CONCLUSIONS In brain-dead patients, where CBF is absent, the UT-NIRS findings can indicate an apparently perfused brain. This might reflect an insufficient separation of signals from extra-cranial structures from a genuine appraisal of cerebral perfusion. For non-invasive assessment of CBF-related parameters, the near-infrared spectroscopy still needs substantial improvement.
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Affiliation(s)
- A Caccioppola
- Neuroscience Intensive Care Unit, Department of Anesthesia and Critical Care, Fondazione IRCCS Cà Granda-Ospedale Maggiore Policlinico, Milan, Italy
| | - M Carbonara
- Neuroscience Intensive Care Unit, Department of Anesthesia and Critical Care, Fondazione IRCCS Cà Granda-Ospedale Maggiore Policlinico, Milan, Italy
| | - M Macrì
- Neuroscience Intensive Care Unit, Department of Anesthesia and Critical Care, Fondazione IRCCS Cà Granda-Ospedale Maggiore Policlinico, Milan, Italy
| | - L Longhi
- Neurosurgical Intensive Care Unit, Department of Anesthesia and Critical Care Medicine, Azienda Socio Sanitaria Territoriale Papa Giovanni XXIII, Bergamo, Italy
| | - S Magnoni
- Neuroscience Intensive Care Unit, Department of Anesthesia and Critical Care, Fondazione IRCCS Cà Granda-Ospedale Maggiore Policlinico, Milan, Italy
| | - F Ortolano
- Neuroscience Intensive Care Unit, Department of Anesthesia and Critical Care, Fondazione IRCCS Cà Granda-Ospedale Maggiore Policlinico, Milan, Italy
| | - F Triulzi
- Department of Neuroradiology, Fondazione IRCCS Cà Granda-Ospedale Maggiore Policlinico, Milan, Italy; Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
| | - E R Zanier
- Department of Neuroscience, Laboratory of Acute Brain Injury and Therapeutic Strategies, IRCCS Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy
| | - T Zoerle
- Neuroscience Intensive Care Unit, Department of Anesthesia and Critical Care, Fondazione IRCCS Cà Granda-Ospedale Maggiore Policlinico, Milan, Italy
| | - N Stocchetti
- Neuroscience Intensive Care Unit, Department of Anesthesia and Critical Care, Fondazione IRCCS Cà Granda-Ospedale Maggiore Policlinico, Milan, Italy; Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy.
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12
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Cerebrospinal fluid and brain extracellular fluid in severe brain trauma. HANDBOOK OF CLINICAL NEUROLOGY 2018; 146:237-258. [DOI: 10.1016/b978-0-12-804279-3.00014-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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13
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Küchler J, Wojak J, Abusamha A, Ditz C, Tronnier VM, Gliemroth J. Analysis of extracellular brain chemistry during percutaneous dilational tracheostomy: A retrospective study of 19 patients. Clin Neurol Neurosurg 2017; 159:1-5. [PMID: 28511149 DOI: 10.1016/j.clineuro.2017.05.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 04/30/2017] [Accepted: 05/08/2017] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The purpose of this study was to analyze changes in brain tissue chemistry around percutaneous dilational tracheostomy (PDT) in patients with acute brain injury (ABI) in a retrospective single-center analysis. PATIENTS AND METHODS We included 19 patients who had continuous monitoring of brain tissue chemistry and intracranial pressure (ICP) during a 20h period before and after PDT. Different microdialysis parameters (lactate, pyruvate, lactate pyruvate ratio (LPR), glycerol and glutamate) and values of ICP, cerebral perfusion pressure (CPP) and brain tissue oxygenation (PBrO2) were recorded per hour. Mean values were compared between a 10h period before PDT (prePDT) and after PDT (postPDT). RESULTS Mean values of cerebral lactate, pyruvate, LPR, glycerol and glutamate did not differ significantly between prePDT and postPDT. In addition, the rate of patients, which exceeded the known threshold was similar between prePDT and postPDT. Only one patient showed a strong increase of cerebral glycerol during the postPDT period, but analysis of subcutaneous glycerol could exclude an intracerebral event. ICP, CPP and PBrO2 did not exhibit significant changes. CONCLUSIONS We could exclude the occurrence of cerebral metabolic crisis and the excess release of cerebral glutamate and glycerol in a series of 19 patients. Our results support the safety of PDT in patients with ABI.
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Affiliation(s)
- Jan Küchler
- Department of Neurosurgery, University of Lübeck, Germany.
| | - Jann Wojak
- Department of Neurosurgery, University of Lübeck, Germany
| | | | - Claudia Ditz
- Department of Neurosurgery, University of Lübeck, Germany
| | | | - Jan Gliemroth
- Department of Neurosurgery, University of Lübeck, Germany
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14
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Angeli S, Stylianopoulos T. Experimental measurements and mathematical modeling towards quantification of brain swelling stress. J Biomech 2017; 56:42-47. [PMID: 28285745 DOI: 10.1016/j.jbiomech.2017.02.028] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 02/13/2017] [Accepted: 02/26/2017] [Indexed: 11/25/2022]
Abstract
Traumatic brain injury results in brain tissue swelling which can be a life threatening condition due to skull confinement. While previous efforts successfully measured the exhibited volume change in brain tissue swelling, no data exist to provide information about the exhibited stresses. In this study, confined compression mechanical testing was employed to measure swelling stress in murine brain tissue samples by varying the ionic concentration of the bathing solutions. Subsequently, computer simulations of the experimental protocol were employed to confirm a triphasic mathematical model describing the effect and provide insights into the experimental data. We measured the swelling stress to be in the range of 1.2-6.7kPa (9.0-50.2mmHg) depending on the ionic strength of the bathing solution, while a good correspondence was demonstrated among the experimentally measured and simulated responses. Furthermore, the mathematical model featured the osmotic pressure as the primary contributor to the swelling stress, while a parametric analysis showed that the densities of the intracellular fixed charges and of the non-permeable solutes significantly affect the swelling stress.
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Affiliation(s)
- Stelios Angeli
- Cancer Biophysics Laboratory, Department of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia 1678, Cyprus
| | - Triantafyllos Stylianopoulos
- Cancer Biophysics Laboratory, Department of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia 1678, Cyprus.
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15
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Abstract
Microdialysis enables the chemistry of the extracellular interstitial space to be monitored. Use of this technique in patients with acute brain injury has increased our understanding of the pathophysiology of several acute neurological disorders. In 2004, a consensus document on the clinical application of cerebral microdialysis was published. Since then, there have been significant advances in the clinical use of microdialysis in neurocritical care. The objective of this review is to report on the International Microdialysis Forum held in Cambridge, UK, in April 2014 and to produce a revised and updated consensus statement about its clinical use including technique, data interpretation, relationship with outcome, role in guiding therapy in neurocritical care and research applications.
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16
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Salih F, Holtkamp M, Brandt SA, Hoffmann O, Masuhr F, Schreiber S, Weissinger F, Vajkoczy P, Wolf S. Intracranial pressure and cerebral perfusion pressure in patients developing brain death. J Crit Care 2016; 34:1-6. [PMID: 27288600 DOI: 10.1016/j.jcrc.2016.03.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 03/08/2016] [Accepted: 03/10/2016] [Indexed: 11/15/2022]
Abstract
PURPOSE We investigated whether a critical rise of intracranial pressure (ICP) leading to a loss of cerebral perfusion pressure (CPP) could serve as a surrogate marker of brain death (BD). MATERIALS AND METHODS We retrospectively analyzed ICP and CPP of patients in whom BD was diagnosed (n = 32, 16-79 years). Intracranial pressure and CPP were recorded using parenchymal (n = 27) and ventricular probes (n = 5). Data were analyzed from admission until BD was diagnosed. RESULTS Intracranial pressure was severely elevated (mean ± SD, 95.5 ± 9.8 mm Hg) in all patients when BD was diagnosed. In 28 patients, CPP was negative at the time of diagnosis (-8.2 ± 6.5 mm Hg). In 4 patients (12.5%), CPP was reduced but not negative. In these patients, minimal CPP was 4 to 18 mm Hg. In 1 patient, loss of CPP occurred 4 hours before apnea completed the BD syndrome. CONCLUSIONS Brain death was universally preceded by a severe reduction of CPP, supporting loss of cerebral perfusion as a critical step in BD development. Our data show that a negative CPP is neither sufficient nor a prerequisite to diagnose BD. In BD cases with positive CPP, we speculate that arterial blood pressure dropped below a critical closing pressure, thereby causing cessation of cerebral blood flow.
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Affiliation(s)
- Farid Salih
- Department of Neurology, Charité-Universitätsmedizin, 13353 Berlin, Germany.
| | - Martin Holtkamp
- Department of Neurology, Charité-Universitätsmedizin, 13353 Berlin, Germany
| | - Stephan A Brandt
- Department of Neurology, Charité-Universitätsmedizin, 13353 Berlin, Germany
| | - Olaf Hoffmann
- Department of Neurology, St Josefs-Krankenhaus, 14471 Potsdam, Germany
| | - Florian Masuhr
- Department of Neurology, Bundeswehr-Krankenhaus, 10115 Berlin, Germany
| | - Stephan Schreiber
- Department of Neurology, Charité-Universitätsmedizin, 13353 Berlin, Germany
| | - Florian Weissinger
- Department of Neurology, Charité-Universitätsmedizin, 13353 Berlin, Germany
| | - Peter Vajkoczy
- Department of Neurosurgery, Charité-Universitätsmedizin, 13353 Berlin, Germany
| | - Stefan Wolf
- Department of Neurosurgery, Charité-Universitätsmedizin, 13353 Berlin, Germany
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17
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Baker LA, Lee KCL, Palacios Jimenez C, Alibhai H, Chang YM, Leckie PJ, Mookerjee RP, Davies NA, Andreola F, Jalan R. Circulating microRNAs Reveal Time Course of Organ Injury in a Porcine Model of Acetaminophen-Induced Acute Liver Failure. PLoS One 2015; 10:e0128076. [PMID: 26018205 PMCID: PMC4446266 DOI: 10.1371/journal.pone.0128076] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2015] [Accepted: 04/23/2015] [Indexed: 12/19/2022] Open
Abstract
Acute liver failure is a rare but catastrophic condition which can progress rapidly to multi-organ failure. Studies investigating the onset of individual organ injury such as the liver, kidneys and brain during the evolution of acute liver failure, are lacking. MicroRNAs are short, non-coding strands of RNA that are released into the circulation following tissue injury. In this study, we have characterised the release of both global microRNA and specific microRNA species into the plasma using a porcine model of acetaminophen-induced acute liver failure. Pigs were induced to acute liver failure with oral acetaminophen over 19h±2h and death occurred 13h±3h thereafter. Global microRNA concentrations increased 4h prior to acute liver failure in plasma (P<0.0001) but not in isolated exosomes, and were associated with increasing plasma levels of the damage-associated molecular pattern molecule, genomic DNA (P<0.0001). MiR122 increased around the time of onset of acute liver failure (P<0.0001) and was associated with increasing international normalised ratio (P<0.0001). MiR192 increased 8h after acute liver failure (P<0.0001) and was associated with increasing creatinine (P<0.0001). The increase in miR124-1 occurred concurrent with the pre-terminal increase in intracranial pressure (P<0.0001) and was associated with decreasing cerebral perfusion pressure (P<0.002). Conclusions: MicroRNAs were released passively into the circulation in response to acetaminophen-induced cellular damage. A significant increase in global microRNA was detectable prior to significant increases in miR122, miR192 and miR124-1, which were associated with clinical evidence of liver, kidney and brain injury respectively.
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Affiliation(s)
- Luisa A. Baker
- Department of Clinical Science and Services, Royal Veterinary College, Hatfield, Hertfordshire, United Kingdom
| | - Karla C. L. Lee
- Department of Clinical Science and Services, Royal Veterinary College, Hatfield, Hertfordshire, United Kingdom
| | - Carolina Palacios Jimenez
- Department of Clinical Science and Services, Royal Veterinary College, Hatfield, Hertfordshire, United Kingdom
| | - Hatim Alibhai
- Department of Clinical Science and Services, Royal Veterinary College, Hatfield, Hertfordshire, United Kingdom
| | - Yu-Mei Chang
- Department of Clinical Science and Services, Royal Veterinary College, Hatfield, Hertfordshire, United Kingdom
| | - Pamela J. Leckie
- Liver Failure Group, University College London Institute for Liver and Digestive Health, University College London Medical School, Royal Free Hospital, London, United Kingdom
| | - Rajeshwar P. Mookerjee
- Liver Failure Group, University College London Institute for Liver and Digestive Health, University College London Medical School, Royal Free Hospital, London, United Kingdom
| | - Nathan A. Davies
- Liver Failure Group, University College London Institute for Liver and Digestive Health, University College London Medical School, Royal Free Hospital, London, United Kingdom
| | - Fausto Andreola
- Liver Failure Group, University College London Institute for Liver and Digestive Health, University College London Medical School, Royal Free Hospital, London, United Kingdom
| | - Rajiv Jalan
- Liver Failure Group, University College London Institute for Liver and Digestive Health, University College London Medical School, Royal Free Hospital, London, United Kingdom
- * E-mail:
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Lung protective ventilation (ARDSNet) versus airway pressure release ventilation: ventilatory management in a combined model of acute lung and brain injury. J Trauma Acute Care Surg 2015; 78:240-9; discussion 249-51. [PMID: 25757107 DOI: 10.1097/ta.0000000000000518] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND Concomitant lung/brain traumatic injury results in significant morbidity and mortality. Lung protective ventilation (Acute Respiratory Distress Syndrome Network [ARDSNet]) has become the standard for managing adult respiratory distress syndrome; however, the resulting permissive hypercapnea may compound traumatic brain injury. Airway pressure release ventilation (APRV) offers an alternative strategy for the management of this patient population. APRV was hypothesized to retard the progression of acute lung/brain injury to a degree greater than ARDSNet in a swine model. METHODS Yorkshire swine were randomized to ARDSNet, APRV, or sham. Ventilatory settings and pulmonary parameters, vitals, blood gases, quantitative histopathology, and cerebral microdialysis were compared between groups using χ2, Fisher's exact, Student's t test, Wilcoxon rank-sum, and mixed-effects repeated-measures modeling. RESULTS Twenty-two swine (17 male, 5 female), weighing a mean (SD) of 25 (6.0) kg, were randomized to APRV (n = 9), ARDSNet (n = 12), or sham (n = 1). PaO2/FIO2 ratio dropped significantly, while intracranial pressure increased significantly for all three groups immediately following lung and brain injury. Over time, peak inspiratory pressure, mean airway pressure, and PaO2/FIO2 ratio significantly increased, while total respiratory rate significantly decreased within the APRV group compared with the ARDSNet group. Histopathology did not show significant differences between groups in overall brain or lung tissue injury; however, cerebral microdialysis trends suggested increased ischemia within the APRV group compared with ARDSNet over time. CONCLUSION Previous studies have not evaluated the effects of APRV in this population. While our macroscopic parameters and histopathology did not observe a significant difference between groups, microdialysis data suggest a trend toward increased cerebral ischemia associated with APRV over time. Additional and future studies should focus on extending the time interval for observation to further delineate differences between groups.
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Skoglund K, Hillered L, Purins K, Tsitsopoulos PP, Flygt J, Engquist H, Lewén A, Enblad P, Marklund N. The neurological wake-up test does not alter cerebral energy metabolism and oxygenation in patients with severe traumatic brain injury. Neurocrit Care 2015; 20:413-26. [PMID: 23934408 DOI: 10.1007/s12028-013-9876-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND The neurological wake-up test (NWT) is used to monitor the level of consciousness in patients with traumatic brain injury (TBI). However, it requires interruption of sedation and may elicit a stress response. We evaluated the effects of the NWT using cerebral microdialysis (MD), brain tissue oxygenation (PbtiO2), jugular venous oxygen saturation (SjvO2), and/or arterial-venous difference (AVD) for glucose, lactate, and oxygen in patients with severe TBI. METHODS Seventeen intubated TBI patients (age 16-74 years) were sedated using continuous propofol infusion. All patients received intracranial pressure (ICP) and cerebral perfusion pressure (CPP) monitoring in addition to MD, PbtiO2 and/or SjvO2. Up to 10 days post-injury, ICP, CPP, PbtiO2 (51 NWTs), MD (49 NWTs), and/or SjvO2 (18 NWTs) levels during propofol sedation (baseline) and NWT were compared. MD was evaluated at a flow rate of 1.0 μL/min (28 NWTs) or the routine 0.3 μL/min rate (21 NWTs). RESULTS The NWT increased ICP and CPP levels (p < 0.05). Compared to baseline, interstitial levels of glucose, lactate, pyruvate, glutamate, glycerol, and the lactate/pyruvate ratio were unaltered by the NWT. Pathological SjvO2 (<50 % or >71 %; n = 2 NWTs) and PbtiO2 (<10 mmHg; n = 3 NWTs) values were rare at baseline and did not change following NWT. Finally, the NWT did not alter the AVD of glucose, lactate, or oxygen. CONCLUSIONS The NWT-induced stress response resulted in increased ICP and CPP levels although it did not negatively alter focal neurochemistry or cerebral oxygenation in TBI patients.
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Affiliation(s)
- Karin Skoglund
- Department of Neuroscience, Neurosurgery, Uppsala University Hospital, Uppsala University, 75185, Uppsala, Sweden
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A standardized model of brain death, donor treatment, and lung transplantation for studies on organ preservation and reconditioning. Intensive Care Med Exp 2014; 2:12. [PMID: 26266913 PMCID: PMC4513016 DOI: 10.1186/2197-425x-2-12] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Accepted: 02/05/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND We set a model of brain death, donor management, and lung transplantation for studies on lung preservation and reconditioning before transplantation. METHODS Ten pigs (39.7 ± 5.9 Kg) were investigated. Five animals underwent brain death and were treated as organ donors; the lungs were then procured and cold stored (Ischemia). Five recipients underwent left lung transplantation and post-reperfusion follow-up (Graft). Cardiorespiratory and metabolic parameters were collected. Lung gene expression of cytokines (tumor necrosis factor alpha (TNFα), interleukin-1 beta (IL-1β), interleukin-6 (IL-6), interferon gamma (IFNγ), high mobility group box-1 (HMGB-1)), chemokines (chemokine CC motif ligand-2 (CCL2-MCP-1), chemokine CXC motif ligand-10 (CXCL-10), interleukin-8 (IL-8)), and endothelial activation markers (endothelin-1 (EDN-1), intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), selectin-E (SELE)) was assessed by real-time polymerase chain reaction (PCR). RESULTS Tachycardia and hypertension occurred during brain death induction; cardiac output rose, systemic vascular resistance dropped (P < 0.05), and diabetes insipidus occurred. Lung-protective ventilation strategy was applied: 9 h after brain death induction, PaO2 was 192 ± 12 mmHg at positive end-expiratory pressure (PEEP) 8.0 ± 1.8 cmH2O and FiO2 of 40%; wet-to-dry ratio (W/D) was 5.8 ± 0.5, and extravascular lung water (EVLW) was 359 ± 80 mL. Procured lungs were cold-stored for 471 ± 24 min (Ischemia) at the end of which W/D was 6.1 ± 0.9. Left lungs were transplanted and reperfused (warm ischemia 98 ± 14 min). Six hours after controlled reperfusion, PaO2 was 192 ± 23 mmHg (PEEP 8.7 ± 1.5 cmH2O, FiO2 40%), W/D was 5.6 ± 0.4, and EVLW was 366 ± 117 mL. Levels of IL-8 rose at the end of donor management (BD, P < 0.05); CCL2-MCP-1, IL-8, HMGB-1, and SELE were significantly altered after reperfusion (Graft, P < 0.05). CONCLUSIONS We have set a standardized, reproducible pig model resembling the entire process of organ donation that may be used as a platform to test in vivo and ex vivo strategies of donor lung optimization before transplantation.
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21
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Purins K, Lewén A, Hillered L, Howells T, Enblad P. Brain tissue oxygenation and cerebral metabolic patterns in focal and diffuse traumatic brain injury. Front Neurol 2014; 5:64. [PMID: 24817863 PMCID: PMC4013462 DOI: 10.3389/fneur.2014.00064] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 04/15/2014] [Indexed: 01/14/2023] Open
Abstract
INTRODUCTION Neurointensive care of traumatic brain injury (TBI) patients is currently based on intracranial pressure (ICP) and cerebral perfusion pressure (CPP) targeted protocols. There are reasons to believe that knowledge of brain tissue oxygenation (BtipO2) would add information with the potential of improving patient outcome. The aim of this study was to examine BtipO2 and cerebral metabolism using the Neurovent-PTO probe and cerebral microdialysis (MD) in TBI patients. METHODS Twenty-three severe TBI patients with monitoring of physiological parameters, ICP, CPP, BtipO2, and MD for biomarkers of energy metabolism (glucose, lactate, and pyruvate) and cellular distress (glutamate, glycerol) were included. Patients were grouped according to injury type (focal/diffuse) and placement of the Neurovent-PTO probe and MD catheter (injured/non-injured hemisphere). RESULTS We observed different patterns in BtipO2 and MD biomarkers in diffuse and focal injury where placement of the probe also influenced the results (ipsilateral/contralateral). In all groups, despite fairly normal levels of ICP and CPP, increased MD levels of glutamate, glycerol, or the L/P ratio were observed at BtipO2 <5 mmHg, indicating increased vulnerability of the brain at this level. CONCLUSION Monitoring of BtipO2 adds important information in addition to traditional ICP and CPP surveillance. Because of the different metabolic responses to very low BtipO2 in the individual patient groups we submit that brain tissue oximetry is a complementary tool rather than an alternative to MD monitoring.
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Affiliation(s)
- Karlis Purins
- Section of Neurosurgery, Department of Neuroscience, Uppsala University , Uppsala , Sweden
| | - Anders Lewén
- Section of Neurosurgery, Department of Neuroscience, Uppsala University , Uppsala , Sweden
| | - Lars Hillered
- Section of Neurosurgery, Department of Neuroscience, Uppsala University , Uppsala , Sweden
| | - Tim Howells
- Section of Neurosurgery, Department of Neuroscience, Uppsala University , Uppsala , Sweden
| | - Per Enblad
- Section of Neurosurgery, Department of Neuroscience, Uppsala University , Uppsala , Sweden
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Rady MY, Verheijde JL. No-touch time in donors after cardiac death (nonheart-beating organ donation). Curr Opin Organ Transplant 2013; 18:140-7. [PMID: 23334256 DOI: 10.1097/mot.0b013e32835e29a8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE OF REVIEW To evaluate arterial pulselessness and the no-touch time of 5 min in defining irreversible cessation of cardiorespiratory functions in nonheart-beating donation (NHBD). RECENT FINDINGS Experimental NHBD studies identified compensatory neurohumoral mechanisms elicited in controlled terminal shock after withdrawal of life support. The neurohumoral mechanisms can preserve the viability of the cardiovascular and central nervous systems by: 1) diverting systemic blood flow from nonvital to vital organs; and 2) maintaining the perfusion pressure (arterial to venous pressure gradient minus interstitial tissue pressure) and microcirculation in vital organs. These compensatory mechanisms cause an early onset of splanchnic hypoperfusion and antemortem ischaemia of transplantable organs and preclude irreversible cessation of cardiorespiratory functions after brief periods of circulatory arrest. Allograft ischaemia is associated with primary nonfunction or delayed function in transplant recipients similar in aetiology to organ dysfunction in the postresuscitation phase of shock. SUMMARY In-situ perfusion can reverse ceased cardiac and neurological functions after arterial pulselessness and a no-touch time of 5 min in experimental models. Perfusion pressures are superior to arterial pulselessness in determining reversibility of ceased cardiac and neurological functions in circulatory arrest. Utilizing physiologically relevant circulatory and neurological parameters in NHBD protocols is essential for ascertaining irreversible cessation of vital functions in donors.
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Affiliation(s)
- Mohamed Y Rady
- Department of Critical Care Medicine, Mayo Clinic Hospital, Mayo Clinic, Phoenix, Arizona, USA.
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