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Tenfen L, Simon Machado R, Mathias K, Piacentini N, Joaquim L, Bonfante S, Danielski LG, Engel NA, da Silva MR, Rezin GT, de Quadros RW, Gava FF, Petronilho F. Short-term hyperoxia induced mitochondrial respiratory chain complexes dysfunction and oxidative stress in lung of rats. Inhal Toxicol 2024; 36:174-188. [PMID: 38449063 DOI: 10.1080/08958378.2024.2322497] [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: 05/31/2023] [Accepted: 02/18/2024] [Indexed: 03/08/2024]
Abstract
BACKGROUND Oxygen therapy is an alternative for many patients with hypoxemia. However, this practice can be dangerous as oxygen is closely associated with the development of oxidative stress. METHODS Male Wistar rats were exposed to hyperoxia with a 40% fraction of inspired oxygen (FIO2) and hyperoxia (FIO2 = 60%) for 120 min. Blood and lung tissue samples were collected for gas, oxidative stress, and inflammatory analyses. RESULTS Hyperoxia (FIO2 = 60%) increased PaCO2 and PaO2, decreased blood pH and caused thrombocytopenia and lymphocytosis. In lung tissue, neutrophil infiltration, nitric oxide concentration, carbonyl protein formation and the activity of complexes I and II of the mitochondrial respiratory chain increased. FIO2 = 60% decreased SOD activity and caused several histologic changes. CONCLUSION In conclusion, we have experimentally demonstrated that short-term exposure to high FIO2 can cause oxidative stress in the lung.
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Affiliation(s)
- Leonardo Tenfen
- Graduate Program in Health Sciences, Health Sciences Unit, University of South Santa Catarina, Tubarão, Brazil
| | - Richard Simon Machado
- Graduate Program in Health Sciences, Health Sciences Unit, University of South Santa Catarina, Tubarão, Brazil
| | - Khiany Mathias
- Graduate Program in Health Sciences, Health Sciences Unit, University of South Santa Catarina, Tubarão, Brazil
| | - Natalia Piacentini
- Laboratory of Experimental Neurology, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, Brazil
| | - Larissa Joaquim
- Graduate Program in Health Sciences, Health Sciences Unit, University of South Santa Catarina, Tubarão, Brazil
| | - Sandra Bonfante
- Graduate Program in Health Sciences, Health Sciences Unit, University of South Santa Catarina, Tubarão, Brazil
| | - Lucineia Gainski Danielski
- Laboratory of Experimental Neurology, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, Brazil
| | - Nicole Alessandra Engel
- Graduate Program in Health Sciences, Health Sciences Unit, University of South Santa Catarina, Tubarão, Brazil
| | - Mariella Reinol da Silva
- Graduate Program in Health Sciences, Health Sciences Unit, University of South Santa Catarina, Tubarão, Brazil
| | - Gislaine Tezza Rezin
- Graduate Program in Health Sciences, Health Sciences Unit, University of South Santa Catarina, Tubarão, Brazil
| | | | - Fernanda Frederico Gava
- Laboratory of Experimental Neurology, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, Brazil
| | - Fabricia Petronilho
- Laboratory of Experimental Neurology, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, Brazil
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Datzmann T, Münz F, Hoffmann A, Moehrke E, Binzenhöfer M, Gröger M, Kapapa T, Mathieu R, Mayer S, Zink F, Gässler H, Wolfschmitt EM, Hogg M, Merz T, Calzia E, Radermacher P, Messerer DAC. An exploratory study investigating the effect of targeted hyperoxemia in a randomized controlled trial in a long-term resuscitated model of combined acute subdural hematoma and hemorrhagic shock in cardiovascular healthy pigs. Front Immunol 2023; 14:1123196. [PMID: 37114041 PMCID: PMC10126345 DOI: 10.3389/fimmu.2023.1123196] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 03/14/2023] [Indexed: 04/29/2023] Open
Abstract
Severe physical injuries and associated traumatic brain injury and/or hemorrhagic shock (HS) remain leading causes of death worldwide, aggravated by accompanying extensive inflammation. Retrospective clinical data indicated an association between mild hyperoxemia and improved survival and outcome. However, corresponding prospective clinical data, including long-term resuscutation, are scarce. Therefore, the present study explored the effect of mild hyperoxemia for 24 hours in a prospective randomized controlled trial in a long-term resuscitated model of combined acute subdural hematoma (ASDH) and HS. ASDH was induced by injecting 0.1 ml × kg-1 autologous blood into the subdural space and HS was triggered by passive removal of blood. After 2 hours, the animals received full resuscitation, including retransfusion of the shed blood and vasopressor support. During the first 24 hours, the animals underwent targeted hyperoxemia (PaO2 = 200 - 250 mmHg) or normoxemia (PaO2 = 80 - 120 mmHg) with a total observation period of 55 hours after the initiation of ASDH and HS. Survival, cardiocirculatory stability, and demand for vasopressor support were comparable between both groups. Likewise, humoral markers of brain injury and systemic inflammation were similar. Multimodal brain monitoring, including microdialysis and partial pressure of O2 in brain tissue, did not show significant differences either, despite a significantly better outcome regarding the modified Glasgow Coma Scale 24 hours after shock that favors hyperoxemia. In summary, the present study reports no deleterious and few beneficial effects of mild targeted hyperoxemia in a clinically relevant model of ASDH and HS with long-term resuscitation in otherwise healthy pigs. Further beneficial effects on neurological function were probably missed due to the high mortality in both experimental groups. The present study remains exploratory due to the unavailability of an a priori power calculation resulting from the lack of necessary data.
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Affiliation(s)
- Thomas Datzmann
- Institute for Anesthesiological Pathophysiology and Process Engineering, Ulm University, Ulm, Germany
| | - Franziska Münz
- Institute for Anesthesiological Pathophysiology and Process Engineering, Ulm University, Ulm, Germany
- Department of Anesthesiology and Intensive Care Medicine, University Hospital Ulm, Ulm, Germany
| | - Andrea Hoffmann
- Institute for Anesthesiological Pathophysiology and Process Engineering, Ulm University, Ulm, Germany
| | - Elena Moehrke
- Institute for Anesthesiological Pathophysiology and Process Engineering, Ulm University, Ulm, Germany
| | - Martha Binzenhöfer
- Institute for Anesthesiological Pathophysiology and Process Engineering, Ulm University, Ulm, Germany
| | - Michael Gröger
- Institute for Anesthesiological Pathophysiology and Process Engineering, Ulm University, Ulm, Germany
| | - Thomas Kapapa
- Department of Neurosurgery, University Hospital Ulm, Ulm, Germany
| | - René Mathieu
- Department of Neurosurgery, German Federal Armed Forces Hospital Ulm, Ulm, Germany
| | - Simon Mayer
- Department of Neurosurgery, German Federal Armed Forces Hospital Ulm, Ulm, Germany
| | - Fabian Zink
- Institute for Anesthesiological Pathophysiology and Process Engineering, Ulm University, Ulm, Germany
| | - Holger Gässler
- Department of Anesthesiology, Intensive Care Medicine, Emergency Medicine and Pain Therapy, German Armed Forces Hospital Ulm, Ulm, Germany
| | - Eva-Maria Wolfschmitt
- Institute for Anesthesiological Pathophysiology and Process Engineering, Ulm University, Ulm, Germany
| | - Melanie Hogg
- Institute for Anesthesiological Pathophysiology and Process Engineering, Ulm University, Ulm, Germany
| | - Tamara Merz
- Institute for Anesthesiological Pathophysiology and Process Engineering, Ulm University, Ulm, Germany
- Department of Anesthesiology and Intensive Care Medicine, University Hospital Ulm, Ulm, Germany
| | - Enrico Calzia
- Institute for Anesthesiological Pathophysiology and Process Engineering, Ulm University, Ulm, Germany
| | - Peter Radermacher
- Institute for Anesthesiological Pathophysiology and Process Engineering, Ulm University, Ulm, Germany
| | - David Alexander Christian Messerer
- Institute for Anesthesiological Pathophysiology and Process Engineering, Ulm University, Ulm, Germany
- Department of Transfusion Medicine and Hemostaseology, Friedrich-Alexander University Erlangen-Nuremberg, University Hospital Erlangen, Erlangen, Germany
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3
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Fritz C, Jaeger D, Luo Y, Lardenois E, Badat B, Roquet FE, Rigollot M, Kimmoun A, Tran N'G, Richard JCM, Chouihed T, Levy B. IMPACT OF DIFFERENT VENTILATION STRATEGIES ON GAS EXCHANGES AND CIRCULATION DURING PROLONGED MECHANICAL CARDIO-PULMONARY RESUSCITATION IN A PORCINE MODEL. Shock 2022; 58:119-127. [PMID: 34710880 DOI: 10.1097/shk.0000000000001880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
ABSTRACT Background: Optimal ventilation during cardio-pulmonary resuscitation (CPR) is still controversial. Ventilation is expected to provide sufficient arterial oxygen content and adequate carbon dioxide removal, while minimizing the risk of circulatory impairment. The objective of the present study was to compare three ventilation strategies in a porcine model during mechanical continuous chest compressions (CCC) according to arterial oxygenation and hemodynamic impact. Method: Ventricular fibrillation was induced and followed by five no-flow minutes and thirty low-flow minutes resuscitation with mechanical-CCC without vasopressive drugs administration. Three groups of eight Landras pig were randomized according to the ventilation strategy: 1. Standard nonsynchronized volume-control mode (SD-group); 2. synchronized bilevel pressure-controlled ventilation (CPV-group); 3. continuous insufflation with Boussignac Cardiac-Arrest Device (BC-group). We assessed 1. arterial blood gases, 2. macro hemodynamics, 3. tissular cerebral macro and micro-circulation and 4. airway pressure, minute ventilation at baseline and every 5 minutes during the protocol. Results: Arterial PaO2 level was higher at each measurement time in SD-group (>200 mm Hg) compare to CPV-group and BC-group ( P < 0.01). In BC-group, arterial PaCO2 level was significantly higher (>90mm Hg) than in SD and CPV groups ( P < 0.01). There was no difference between groups concerning hemodynamic parameters, cerebral perfusion and microcirculation. Conclusion: Ventilation modalities in this porcine model of prolonged CPR influence oxygenation and decarboxylation without impairing circulation and cerebral perfusion. Synchronized bi-level pressure-controlled ventilation' use avoid hyperoxia and was as efficient as asynchronized volume ventilation to maintain alveolar ventilation and systemic perfusion during prolonged CPR.
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Ercole A. Normalising renal tissue oxygen tension with higher inspired oxygen concentration may be falsely reassuring. Comment on Br J Anaesth 2020;125:192-200. Br J Anaesth 2020; 126:e32. [PMID: 33187636 DOI: 10.1016/j.bja.2020.10.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 09/22/2020] [Accepted: 10/17/2020] [Indexed: 11/30/2022] Open
Affiliation(s)
- Ari Ercole
- Division of Anaesthesia, University of Cambridge and Neurosciences/Trauma Critical Care Unit, Addenbrooke's Hospital, Cambridge, UK.
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Gray ME, Marland JRK, Dunare C, Blair EO, Meehan J, Tsiamis A, Kunkler IH, Murray AF, Argyle D, Dyson A, Singer M, Potter MA. In vivo validation of a miniaturized electrochemical oxygen sensor for measuring intestinal oxygen tension. Am J Physiol Gastrointest Liver Physiol 2019; 317:G242-G252. [PMID: 31188641 PMCID: PMC6734375 DOI: 10.1152/ajpgi.00050.2019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Recent advances in the fields of electronics and microfabrication techniques have led to the development of implantable medical devices for use within the field of precision medicine. Monitoring visceral surface tissue O2 tension (PTo2) by means of an implantable sensor is potentially useful in many clinical situations, including the perioperative management of patients undergoing intestinal resection and anastomosis. This concept could provide a means by which treatment could be tailored to individual patients. This study describes the in vivo validation of a novel, miniaturized electrochemical O2 sensor to provide real-time data on intestinal PTo2. A single O2 sensor was placed onto the serosal surface of the small intestine of anesthetized rats that were exposed to ischemic (superior mesenteric artery occlusion) and hypoxemic (alterations in inspired fractional O2 concentrations) insults. Control experiments demonstrated that the sensors can function and remain stable in an in vivo environment. Intestinal PTo2 decreased following superior mesenteric artery occlusion and with reductions in inspired O2 concentrations. These results were reversible after reinstating blood flow or by increasing inspired O2 concentrations. We have successfully developed an anesthetized rat intestinal ischemic and hypoxic model for validation of a miniaturized O2 sensor to provide real-time measurement of intestinal PTo2. Our results support further validation of the sensors in physiological conditions using a large animal model to provide evidence of their use in clinical applications where monitoring visceral surface tissue O2 tension is important.NEW & NOTEWORTHY This is the first report of real-time continuous measurements of intestinal oxygen tension made using a microfabricated O2 sensor. Using a developed rodent model, we have validated this sensor's ability to accurately measure dynamic and reversible changes in intestinal oxygenation that occur through ischemic and hypoxemic insults. Continuous monitoring of local intestinal oxygenation could have value in the postoperative monitoring of patients having undergone intestinal surgery.
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Affiliation(s)
- Mark E. Gray
- 1The Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom,2Cancer Research United Kingdom Edinburgh Centre and Division of Pathology Laboratories, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Jamie R. K. Marland
- 3School of Engineering, Institute for Integrated Micro and Nano Systems, Edinburgh, United Kingdom
| | - Camelia Dunare
- 3School of Engineering, Institute for Integrated Micro and Nano Systems, Edinburgh, United Kingdom
| | - Ewen O. Blair
- 3School of Engineering, Institute for Integrated Micro and Nano Systems, Edinburgh, United Kingdom
| | - James Meehan
- 2Cancer Research United Kingdom Edinburgh Centre and Division of Pathology Laboratories, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Andreas Tsiamis
- 3School of Engineering, Institute for Integrated Micro and Nano Systems, Edinburgh, United Kingdom
| | - Ian H. Kunkler
- 3School of Engineering, Institute for Integrated Micro and Nano Systems, Edinburgh, United Kingdom
| | - Alan F. Murray
- 3School of Engineering, Institute for Integrated Micro and Nano Systems, Edinburgh, United Kingdom
| | - David Argyle
- 1The Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Alex Dyson
- 4Bloomsbury Institute of Intensive Care Medicine, Division of Medicine, University College London, London, United Kingdom
| | - Mervyn Singer
- 4Bloomsbury Institute of Intensive Care Medicine, Division of Medicine, University College London, London, United Kingdom
| | - Mark A. Potter
- 5Department of Surgery, Western General Hospital, Edinburgh, United Kingdom
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6
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Parker T, Brealey D, Dyson A, Singer M. Optimising organ perfusion in the high-risk surgical and critical care patient: a narrative review. Br J Anaesth 2019; 123:170-176. [PMID: 31054772 DOI: 10.1016/j.bja.2019.03.027] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 02/18/2019] [Accepted: 03/12/2019] [Indexed: 12/18/2022] Open
Abstract
Maintenance or prompt restoration of an oxygen supply sufficient to facilitate adequate cellular metabolism is fundamental in maintaining organ function. This is particularly relevant when metabolic needs change markedly, for example in response to major surgery or critical illness. The consequences of inadequate tissue oxygenation include wound and anastomotic breakdown, organ dysfunction, and death. However, our ability to identify those at risk and to promptly recognise and correct tissue hypoperfusion is limited. Reliance is placed upon surrogate markers of tissue oxygenation such as arterial blood pressure and serum lactate that are insensitive to early organ compromise. Advances in oxygen sensing technology will facilitate monitoring in various organ beds and allow more precise titration of therapies to physiologically relevant endpoints. Clinical trials will be needed to evaluate any impact on outcomes, however accurate on-line monitoring of the adequacy of tissue oxygenation offers the promise of a paradigm shift in resuscitation and perioperative practice. This narrative review examines current evidence for goal-directed therapy in the optimisation of organ perfusion in high-risk surgical and critically ill patients, and offers arguments to support the potential utility of tissue oxygen monitoring.
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Affiliation(s)
- Thomas Parker
- Bloomsbury Institute of Intensive Care Medicine, Division of Medicine, University College London, London, UK
| | - David Brealey
- Bloomsbury Institute of Intensive Care Medicine, Division of Medicine, University College London, London, UK
| | - Alex Dyson
- Bloomsbury Institute of Intensive Care Medicine, Division of Medicine, University College London, London, UK
| | - Mervyn Singer
- Bloomsbury Institute of Intensive Care Medicine, Division of Medicine, University College London, London, UK.
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7
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Protection of cerebral microcirculation, mitochondrial function, and electrocortical activity by small-volume resuscitation with terlipressin in a rat model of haemorrhagic shock. Br J Anaesth 2018; 120:1245-1254. [DOI: 10.1016/j.bja.2017.11.074] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 08/01/2017] [Accepted: 08/14/2017] [Indexed: 11/19/2022] Open
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8
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9
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Roberts BW, Kilgannon JH, Hunter BR, Puskarich MA, Pierce L, Donnino M, Leary M, Kline JA, Jones AE, Shapiro NI, Abella BS, Trzeciak S. Association Between Early Hyperoxia Exposure After Resuscitation From Cardiac Arrest and Neurological Disability: Prospective Multicenter Protocol-Directed Cohort Study. Circulation 2018; 137:2114-2124. [PMID: 29437118 DOI: 10.1161/circulationaha.117.032054] [Citation(s) in RCA: 144] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 01/04/2018] [Indexed: 02/01/2023]
Abstract
BACKGROUND Studies examining the association between hyperoxia exposure after resuscitation from cardiac arrest and clinical outcomes have reported conflicting results. Our objective was to test the hypothesis that early postresuscitation hyperoxia is associated with poor neurological outcome. METHODS This was a multicenter prospective cohort study. We included adult patients with cardiac arrest who were mechanically ventilated and received targeted temperature management after return of spontaneous circulation. We excluded patients with cardiac arrest caused by trauma or sepsis. Per protocol, partial pressure of arterial oxygen (Pao2) was measured at 1 and 6 hours after return of spontaneous circulation. Hyperoxia was defined as a Pao2 >300 mm Hg during the initial 6 hours after return of spontaneous circulation. The primary outcome was poor neurological function at hospital discharge, defined as a modified Rankin Scale score >3. Multivariable generalized linear regression with a log link was used to test the association between Pao2 and poor neurological outcome. To assess whether there was an association between other supranormal Pao2 levels and poor neurological outcome, we used other Pao2 cut points to define hyperoxia (ie, 100, 150, 200, 250, 350, 400 mm Hg). RESULTS Of the 280 patients included, 105 (38%) had exposure to hyperoxia. Poor neurological function at hospital discharge occurred in 70% of patients in the entire cohort and in 77% versus 65% among patients with versus without exposure to hyperoxia respectively (absolute risk difference, 12%; 95% confidence interval, 1-23). Hyperoxia was independently associated with poor neurological function (relative risk, 1.23; 95% confidence interval, 1.11-1.35). On multivariable analysis, a 1-hour-longer duration of hyperoxia exposure was associated with a 3% increase in risk of poor neurological outcome (relative risk, 1.03; 95% confidence interval, 1.02-1.05). We found that the association with poor neurological outcome began at ≥300 mm Hg. CONCLUSIONS Early hyperoxia exposure after resuscitation from cardiac arrest was independently associated with poor neurological function at hospital discharge.
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Affiliation(s)
| | | | - Benton R Hunter
- Department of Emergency Medicine, Indiana University School of Medicine, Indianapolis (B.R.H., J.A.K.)
| | - Michael A Puskarich
- Department of Emergency Medicine, University of Mississippi Medical Center, Jackson (M.A.P., A.E.J.)
| | - Lisa Pierce
- Department of Medicine, Division of Critical Care Medicine (L.P., S.T.), Cooper University Hospital and Cooper Medical School of Rowan University, Camden, NJ
| | - Michael Donnino
- Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, MA (M.D., N.I.S.)
| | - Marion Leary
- Center for Resuscitation Science and Department of Emergency Medicine, University of Pennsylvania, Philadelphia (M.L., B.S.A.)
| | - Jeffrey A Kline
- Department of Emergency Medicine, Indiana University School of Medicine, Indianapolis (B.R.H., J.A.K.)
| | - Alan E Jones
- Department of Emergency Medicine, University of Mississippi Medical Center, Jackson (M.A.P., A.E.J.)
| | - Nathan I Shapiro
- Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, MA (M.D., N.I.S.)
| | - Benjamin S Abella
- Center for Resuscitation Science and Department of Emergency Medicine, University of Pennsylvania, Philadelphia (M.L., B.S.A.)
| | - Stephen Trzeciak
- Department of Emergency Medicine (B.W.R., J.H.K., S.T.)
- Department of Medicine, Division of Critical Care Medicine (L.P., S.T.), Cooper University Hospital and Cooper Medical School of Rowan University, Camden, NJ
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10
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O'Driscoll BR, Howard LS, Earis J, Mak V. BTS guideline for oxygen use in adults in healthcare and emergency settings. Thorax 2017; 72:ii1-ii90. [DOI: 10.1136/thoraxjnl-2016-209729] [Citation(s) in RCA: 316] [Impact Index Per Article: 45.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 02/03/2017] [Accepted: 02/12/2017] [Indexed: 12/15/2022]
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11
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Luo X, Chen G, You G, Wang B, Lu M, Zhao J, Wang Y, Yin Y, Zhao L, Zhou H. Gradually increased oxygen administration promoted survival after hemorrhagic shock. Exp Biol Med (Maywood) 2016; 241:1603-10. [PMID: 27190249 DOI: 10.1177/1535370216644996] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Accepted: 03/18/2016] [Indexed: 11/16/2022] Open
Abstract
Gradually increased oxygen administration (GIOA) seems promising in hemorrhagic shock. However, the effects of GIOA on survival remain unclear, and details of GIOA are to be identified. After the induction of hemorrhagic shock, the rats were randomized into five groups (n = 9): normoxic group (Normo), hyperoxic group (Hypero), normoxic to hyperoxic group (GIOA1), long-time hypoxemic to hyperoxic group (GIOA2), and short-time hypoxemic to hyperoxic group (GIOA3). Survival was recorded for 96 h, plasma alanine transaminase, oxidative stress, hemodynamics, and blood gas were measured. The mean survival time of the GIOA3 was significantly longer than that of the Normo, Hypero, and GIOA2. Plasma alanine transaminase levels were significantly lower in the Normo, GIOA1, and GIOA3 compared to the Hypero and GIOA2 at 2 h post-resuscitation (PR). Plasma 3-nitrotyrosine levels at 2 h PR were significantly lower in the GIOA2 and GIOA3 compared to the Normo and Hypero. Central venous oxygen saturation at 2 h PR in the GIOA3 was significantly higher than the Normo; however, no significant difference was observed between GIOA1 and Normo. Besides, at 2 h PR, mean arterial pressure in the GIOA3 was significantly higher than the GIOA2; however, no significant difference was observed between GIOA1 and GIOA2. (1) GIOA could significantly prolong survival time compared to normoxemic resuscitation and hyperoxic resuscitation; (2) early moments of GIOA are critical to the benefits; and (3) hypoxemia at onset of resuscitation may be imperative, more works are needed to determine the optimal initial oxygen concentration of GIOA.
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Affiliation(s)
- Xin Luo
- Department of Blood Products and Substitutes, Institute of Transfusion Medicine, Academy of Military Medical Sciences, Beijing 100850, PR China
| | - Gan Chen
- Department of Blood Products and Substitutes, Institute of Transfusion Medicine, Academy of Military Medical Sciences, Beijing 100850, PR China
| | - Guoxing You
- Department of Blood Products and Substitutes, Institute of Transfusion Medicine, Academy of Military Medical Sciences, Beijing 100850, PR China
| | - Bo Wang
- Department of Blood Products and Substitutes, Institute of Transfusion Medicine, Academy of Military Medical Sciences, Beijing 100850, PR China
| | - Mingzi Lu
- Department of Blood Products and Substitutes, Institute of Transfusion Medicine, Academy of Military Medical Sciences, Beijing 100850, PR China
| | - Jingxiang Zhao
- Department of Blood Products and Substitutes, Institute of Transfusion Medicine, Academy of Military Medical Sciences, Beijing 100850, PR China
| | - Ying Wang
- Department of Blood Products and Substitutes, Institute of Transfusion Medicine, Academy of Military Medical Sciences, Beijing 100850, PR China
| | - Yujing Yin
- Department of Blood Products and Substitutes, Institute of Transfusion Medicine, Academy of Military Medical Sciences, Beijing 100850, PR China
| | - Lian Zhao
- Department of Blood Products and Substitutes, Institute of Transfusion Medicine, Academy of Military Medical Sciences, Beijing 100850, PR China
| | - Hong Zhou
- Department of Blood Products and Substitutes, Institute of Transfusion Medicine, Academy of Military Medical Sciences, Beijing 100850, PR China
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12
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Zhang S, Duehrkop C, Plock JA, Rieben R. Inhalation anesthesia of rats: influence of the fraction of inspired oxygen on limb ischemia/reperfusion injury. Lab Anim 2015; 50:185-97. [PMID: 26345513 DOI: 10.1177/0023677215604531] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Inhalation anesthesia with isoflurane is a well-established and safe method used in small laboratory animals. In most cases oxygen is used as a carrier gas for isoflurane, but room air or mixtures of oxygen with air or nitrous oxide are also being used. Anesthesia is therefore administered using different fractions of inspired oxygen (FiO2), and this may have consequences for the outcome of experiments. The aim of the present study was to investigate the influence of FiO2 on rat hind limb ischemia/reperfusion injury and to refine the used inhalation anesthesia. Male Wistar rats were subjected to 3.5 h of ischemia and 2 h of reperfusion, and divided into three groups according to FiO2 in the O2/air/isoflurane anesthesia gas mixture: 40%, 60%, and 100% O2 Normal, healthy rats were used as controls. Muscle edema and creatine kinase MM, a marker for myocyte necrosis, were significantly increased with 40% FiO2 as compared with 100% FiO2 (P < 0.05). Partial pressure of oxygen, oxygen saturation, and oxyhemoglobin were significantly higher in the 100% O2 group as compared with 40% O2 No significant differences were detected for other parameters, such as the oxidative stress markers malondialdehyde and superoxide dismutase. We conclude that a refined inhalation anesthesia setting using 40% FiO2, reflecting more or less the clinical situation, leads to a more severe and more physiologically relevant reperfusion injury than higher FiO2. Oxidative stress did not correlate with FiO2 and seemed to have no influence on reperfusion injury.
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Affiliation(s)
- S Zhang
- Department of Clinical Research, University of Bern, Bern, Switzerland Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - C Duehrkop
- Department of Immunology, University of Uppsala, Uppsala, Sweden
| | - J A Plock
- Division of Plastic Surgery and Hand Surgery, University Hospital Zurich, Zurich, Switzerland
| | - R Rieben
- Department of Clinical Research, University of Bern, Bern, Switzerland
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13
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De Santis V, Singer M. Tissue oxygen tension monitoring of organ perfusion: rationale, methodologies, and literature review. Br J Anaesth 2015. [PMID: 26198717 DOI: 10.1093/bja/aev162] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Tissue oxygen tension is the partial pressure of oxygen within the interstitial space of an organ bed. As it represents the balance between local oxygen delivery and consumption at any given time, it offers a ready monitoring capability to assess the adequacy of tissue perfusion relative to local demands. This review covers the various methodologies used to measure tissue oxygen tension, describes the underlying physiological and pathophysiological principles, and summarizes human and laboratory data published to date.
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Affiliation(s)
- V De Santis
- Bloomsbury Institute of Intensive Care Medicine, Division of Medicine, University College London, Cruciform Building, Gower Street, London WC1E 6BT, UK
| | - M Singer
- Bloomsbury Institute of Intensive Care Medicine, Division of Medicine, University College London, Cruciform Building, Gower Street, London WC1E 6BT, UK
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14
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Abstract
Dissolved oxygen (i.e., unbound to hemoglobin) is often neglected as a determinant of central venous oxygen saturation (ScvO2) in review articles and textbooks. These statements may lead to potential misinterpretation of SCvO2 value across FiO2 changes. In this study, we aimed to explore the influence of PaO2 and FiO2 on ScvO2 in ventilated critically ill patients. This was a prospective observational study in two surgical intensive care units. Mechanically ventilated and sedated patients with cardiac output and ScvO2 monitoring and PaO2/FiO2 > 200 with inspiratory oxygen (FiO2) ≤ 0.5 were enrolled (cohort [ScvO2]). A second cohort of brain-injured patients with jugular venous oxygen saturation monitoring was studied to assess the application of the results to regional circulation (cohort [SjvO2]). Central venous oxygen saturation was measured at baseline FiO2 and at FiO2 = 1. We finally estimated the participation of the dissolved oxygen (PadissolvO2) to the ScvO2 variations. Twenty patients formed the cohort ScvO2 and eight formed the cohort SjvO2. Central venous oxygen saturation rose from 71% (69%-76%) to 84% (78%-88%) after increasing FiO2, whereas PaO2 rose from 100 (85-124) mmHg to 387 (360-449) mmHg. The rise of ScvO2 was mostly ascribable to the dissolved oxygen. The increase of ScvO2 was not explained by changes in cardiac output or hemoglobin levels. Jugular venous oxygen saturation rose from 71% (58%-78%) to 83% (78%-89%) after increasing FiO2. Arterial dissolved oxygen level can significantly influence the ScvO2 value. Therefore, PaO2 should not be overlooked while considering the ScvO2 value as a therapeutic goal. Interpretation of ScvO2 variations in response to a therapeutic challenge (i.e., fluid challenge, inotropic drug initiation) should be performed at constant FiO2.
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Ostergaard L, Rudiger A, Wellmann S, Gammella E, Beck-Schimmer B, Struck J, Maggiorini M, Gassmann M. Arginine-vasopressin marker copeptin is a sensitive plasma surrogate of hypoxic exposure. HYPOXIA 2014; 2:143-151. [PMID: 27774473 PMCID: PMC5045063 DOI: 10.2147/hp.s57894] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Background A reduced oxygen supply puts patients at risk of tissue hypoxia, organ damage, and even death. In response, several changes are activated that allow for at least partial adaptation, thereby increasing the chances of survival. We aimed to investigate whether the arginine vasopressin marker, copeptin, can be used as a marker of the degree of acclimatization/adaptation in rats exposed to hypoxia. Methods Sprague-Dawley rats were exposed to 10% oxygen for up to 48 hours. Arterial and right ventricular pressures were measured, and blood gas analysis was performed at set time points. Pulmonary changes were investigated by bronchoalveolar lavage, wet and dry weight measurements, and lung histology. Using a newly developed specific rat copeptin luminescence immunoassay, the regulation of vasopressin in response to hypoxia was studied, as was atrial natriuretic peptide (ANP) by detecting mid-regional proANP. Results With a decreasing oxygen supply, the rats rapidly became cyanotic and inactive. Despite continued exposure to 10% oxygen, all animals recuperated within 16 hours and ultimately survived. Their systemic blood pressure fell with acute (5 minutes) hypoxia but was partially recovered over time. In contrast, right ventricular pressures increased with acute (5 minutes) hypoxia and normalized after 16 hours. No signs of pulmonary inflammation or edema were found despite prolonged hypoxia. Whereas copeptin levels increased significantly after acute (5 minutes) hypoxia and then returned to near baseline after 16 hours, mid-regional proANP levels were even further increased after 16 hours of exposure to hypoxia. Conclusion Plasma copeptin is a sensitive marker of acute (5 minutes) exposure to severe hypoxia, and subsequent regulation can indicate recovery. Copeptin levels can therefore reflect clinical and physiological changes in response to hypoxia and indicate recovery from ongoing hypoxic exposure.
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Affiliation(s)
- Louise Ostergaard
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zürich; Zürich Center for Integrative Human Physiology
| | | | - Sven Wellmann
- Zürich Center for Integrative Human Physiology; Division of Neonatology, University Hospital Zürich, Zürich; Department of Neonatology, University Children's Hospital Basel, Basel, Switzerland
| | - Elena Gammella
- Department of Human Morphology and Biomedical Science, University of Milan, Milan, Italy
| | | | - Joachim Struck
- Research Department, B⋅R⋅A⋅H⋅M⋅S Biomarkers, Thermo Fisher Scientific, Hennigsdorf, Germany
| | - Marco Maggiorini
- Zürich Center for Integrative Human Physiology; Medical Intensive Care Unit, University Hospital Zürich, Zürich, Switzerland
| | - Max Gassmann
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zürich; Zürich Center for Integrative Human Physiology; Universidad Peruana Cayetano Heredia, Lima, Peru
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Dyson A, Ekbal N, Stotz M, Barnes S, Carré J, Tully S, Henderson S, Barrett L, Singer M. Component reductions in oxygen delivery generate variable haemodynamic and stress hormone responses. Br J Anaesth 2014; 113:708-16. [PMID: 24852502 DOI: 10.1093/bja/aeu089] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND In clinical practice, global oxygen delivery (DO2) is often considered as a whole; however pathological and adaptive responses after a decrease in individual constituents of the DO2 equation (cardiac output, haemoglobin, oxyhaemoglobin saturation) are likely to be diverse. We hypothesized that an equivalent decrease in DO2 after reductions in each separate component of the equation would result in different haemodynamic, tissue oxygenation, and stress hormonal responses. METHODS Anaesthetized, fluid-resuscitated male Wistar rats were subjected to circulatory, anaemic, or hypoxic hypoxia (by haemorrhage, isovolaemic haemodilution, and breathing a hypoxic gas mix, respectively), produced either rapidly over 5 min or graded over 30 min, to a targeted 50% decrease in global oxygen delivery. Sham-operated animals acted as controls. Measurements were made of haemodynamics, skeletal muscle tissue oxygen tension, blood gas analysis, and circulating stress hormone levels. RESULTS Whereas haemorrhage generated the largest decrease in cardiac output, and the greatest stress hormone response, haemodilution had the most marked effect on arterial pressure. In contrast, rapid hypoxaemia produced a minor impact on global haemodynamics yet induced the greatest decrease in regional oxygenation. A greater degree of hyperlactataemia was observed with graded insults compared with those administered rapidly. CONCLUSIONS Decreasing global oxygen delivery, achieved by targeted reductions in its separate components, induces varying circulatory, tissue oxygen tension, and stress hormone responses. We conclude that not all oxygen delivery is the same; this disparity should be emphasized in classical teaching and re-evaluated in patient management.
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Affiliation(s)
- A Dyson
- Bloomsbury Institute of Intensive Care Medicine, Division of Medicine, University College London, London, UK
| | - N Ekbal
- Bloomsbury Institute of Intensive Care Medicine, Division of Medicine, University College London, London, UK
| | - M Stotz
- Bloomsbury Institute of Intensive Care Medicine, Division of Medicine, University College London, London, UK Centre for Perioperative Medicine and Critical Care Research, Imperial College Healthcare NHS Trust, St Mary's Hospital, London, UK
| | - S Barnes
- Bloomsbury Institute of Intensive Care Medicine, Division of Medicine, University College London, London, UK
| | - J Carré
- Bloomsbury Institute of Intensive Care Medicine, Division of Medicine, University College London, London, UK
| | - S Tully
- Bloomsbury Institute of Intensive Care Medicine, Division of Medicine, University College London, London, UK
| | - S Henderson
- Bloomsbury Institute of Intensive Care Medicine, Division of Medicine, University College London, London, UK
| | - L Barrett
- Bloomsbury Institute of Intensive Care Medicine, Division of Medicine, University College London, London, UK
| | - M Singer
- Bloomsbury Institute of Intensive Care Medicine, Division of Medicine, University College London, London, UK
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Umbrello M, Dyson A, Pinto BB, Fernandez BO, Simon V, Feelisch M, Singer M. Short-term hypoxic vasodilation in vivo is mediated by bioactive nitric oxide metabolites, rather than free nitric oxide derived from haemoglobin-mediated nitrite reduction. J Physiol 2014; 592:1061-75. [PMID: 24396056 DOI: 10.1113/jphysiol.2013.255687] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Local increases in blood flow--'hypoxic vasodilation'--confer cellular protection in the face of reduced oxygen delivery. The physiological relevance of this response is well established, yet ongoing controversy surrounds its underlying mechanisms. We sought to confirm that early hypoxic vasodilation is a nitric oxide (NO)-mediated phenomenon and to study putative pathways for increased levels of NO, namely production from NO synthases, intravascular nitrite reduction, release from preformed stores and reduced deactivation by cytochrome c oxidase. Experiments were performed on spontaneously breathing, anaesthetized, male Wistar rats undergoing short-term systemic hypoxaemia, who received pharmacological inhibitors and activators of the various NO pathways. Arterial blood pressure, cardiac output, tissue oxygen tension and the circulating pool of NO metabolites (oxidation, nitrosation and nitrosylation products) were measured in plasma and erythrocytes. Hypoxaemia caused a rapid and sustained vasodilation, which was only partially reversed by non-selective NO synthase inhibition. This was associated with significantly lower plasma nitrite, and marginally elevated nitrate levels, suggestive of nitrite bioinactivation. Administration of sodium nitrite had little effect in normoxia, but produced significant vasodilation and increased nitrosylation during hypoxaemia that could not be reversed by NO scavenging. Methodological issues prevented assessment of the contribution, if any, of reduced deactivation of NO by cytochrome c oxidase. In conclusion, acute hypoxic vasodilation is an adaptive NO-mediated response conferred through bioactive metabolites rather than free NO from haemoglobin-mediated reduction of nitrite.
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Affiliation(s)
- Michele Umbrello
- Bloomsbury Institute of Intensive Care Medicine, University College London, Cruciform Building, Gower Street, London WC1E 6BT, UK.
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Cornet AD, Kooter AJ, Peters MJL, Smulders YM. The potential harm of oxygen therapy in medical emergencies. Crit Care 2013; 17:313. [PMID: 23635028 PMCID: PMC3672526 DOI: 10.1186/cc12554] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
In medical emergencies, supplemental oxygen is often administrated routinely. Most paramedics and physicians believe that high concentrations of oxygen are life-saving 1. Over the last century, however, a plethora of studies point to possible detrimental effects of hyperoxia induced by supplemental oxygen in a variety of medical emergencies. This viewpoint provides a historical overview and questions the safety of routine high-dose oxygen administration and is based on pathophysiology and (pre)clinical findings in various medical emergencies.
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Affiliation(s)
- Alexander D Cornet
- Department of Internal Medicine, VU University Medical Center, De Boelelaan 1117, 1081 HV Amsterdam, PO BOX 7075, The Netherlands
- Department of Intensive Care Medicine, VU University Medical Center, De Boelelaan 1117, 1081 HV Amsterdam, PO BOX 7075, The Netherlands
- Institute of Cardiovascular Research, VU University Medical Center, De Boelelaan 1117, 1081 HV Amsterdam, PO BOX 7075, The Netherlands
| | - Albertus J Kooter
- Department of Internal Medicine, VU University Medical Center, De Boelelaan 1117, 1081 HV Amsterdam, PO BOX 7075, The Netherlands
- Institute of Cardiovascular Research, VU University Medical Center, De Boelelaan 1117, 1081 HV Amsterdam, PO BOX 7075, The Netherlands
| | - Mike JL Peters
- Department of Internal Medicine, VU University Medical Center, De Boelelaan 1117, 1081 HV Amsterdam, PO BOX 7075, The Netherlands
- Institute of Cardiovascular Research, VU University Medical Center, De Boelelaan 1117, 1081 HV Amsterdam, PO BOX 7075, The Netherlands
| | - Yvo M Smulders
- Department of Internal Medicine, VU University Medical Center, De Boelelaan 1117, 1081 HV Amsterdam, PO BOX 7075, The Netherlands
- Institute of Cardiovascular Research, VU University Medical Center, De Boelelaan 1117, 1081 HV Amsterdam, PO BOX 7075, The Netherlands
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Oxygen in resuscitation: a game of two halves. Resuscitation 2013; 84:715-7. [PMID: 23523826 DOI: 10.1016/j.resuscitation.2013.03.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Revised: 03/13/2013] [Accepted: 03/14/2013] [Indexed: 11/21/2022]
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Dyson A, Simon F, Seifritz A, Zimmerling O, Matallo J, Calzia E, Radermacher P, Singer M. Bladder tissue oxygen tension monitoring in pigs subjected to a range of cardiorespiratory and pharmacological challenges. Intensive Care Med 2012; 38:1868-76. [PMID: 23052956 DOI: 10.1007/s00134-012-2712-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Accepted: 09/06/2012] [Indexed: 10/27/2022]
Abstract
PURPOSE A fall in tissue oxygen tension (tPO(2)) is an early indicator of organ hypoxia in both patients and animal models. We previously demonstrated the utility of bladder tPO(2) in various rodent shock models. As a prelude to clinical testing, we aimed to provide further validation of bladder tPO(2) monitoring in a large animal model undergoing a range of cardiorespiratory insults and vasoactive drug interventions. METHODS Anaesthetized, mechanically ventilated, instrumented female pigs (n = 8) were subjected to a range of short-term cardiorespiratory (changes in inspired oxygen concentration (FiO(2)), haemorrhage, positive end-expiratory pressure) and pharmacologic (inotrope, pressor) challenges. Global haemodynamics, arterial and pulmonary blood gases and bladder tPO(2) were measured before and after each challenge. RESULTS Bladder tPO(2) values fell in line with increasing degrees of hypoxaemia and haemorrhage, and were restored during resuscitation. These changes often preceded those seen in global haemodynamics, arterial base excess and lactate. The rise in bladder tPO(2) with hyperoxia, performed as an oxygen challenge test, was incrementally blunted by progressive haemorrhage. Dobutamine and norepinephrine both increased cardiac output and global O(2) delivery, but had no effect on bladder tPO(2) or lactataemia in these healthy pigs. CONCLUSIONS In this pig model bladder tPO(2) provides a sensitive indicator of organ hypoxia compared to traditional biochemical markers during various cardiorespiratory challenges. This technique offers a potentially useful tool for clinical monitoring.
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Affiliation(s)
- Alex Dyson
- Bloomsbury Institute of Intensive Care Medicine, Division of Medicine, University College London, Cruciform Building, Gower St, London, WC1E 6BT, UK.
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Microvascular and interstitial oxygen tension in the renal cortex and medulla studied in a 4-h rat model of LPS-induced endotoxemia. Shock 2011; 36:83-9. [PMID: 21368713 DOI: 10.1097/shk.0b013e3182169d5a] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The pathophysiology of sepsis-induced acute kidney injury remains poorly understood. As changes in renal perfusion and oxygenation have been shown, we aimed to study the short-term effects of endotoxemia on microvascular and interstitial oxygenation in the cortex and medulla, in conjunction with global and renal hemodynamics. In a 4-h rat model of endotoxemia, we simultaneously assessed renal artery blood flow and microvascular and interstitial oxygen tensions in the renal cortex and medulla using ultrasonic flowmetry, dual wavelength phosphorimetry, and tissue oxygen tension monitoring, respectively. Whereas medullary microvascular and interstitial oxygen tensions decreased promptly in line with macrovascular blood flow, changes in cortical oxygenation were only seen later on. During the entire experimental protocol, the gradient between microvascular PO₂ and tissue oxygen tension remained unchanged in both cortex and outer medulla. At study end, urine output was significantly decreased despite a maintained oxygen consumption rate. In this 4-h rat model of endotoxemia, total renal oxygen consumption and the gradient between microvascular PO₂ and tissue oxygen tension remained unaltered, despite falls in renal perfusion and oxygen delivery and urine output. Taken in conjunction with the decrease in urine output, our results could represent either a functional renal impairment or an adaptive response.
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Kitamura T, Sato K, Kawamura G, Yamada Y. The involvement of adenosine triphosphate-sensitive potassium channels in the different effects of sevoflurane and propofol on glucose metabolism in fed rats. Anesth Analg 2011; 114:110-6. [PMID: 22127813 DOI: 10.1213/ane.0b013e3182373552] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Recently, we reported marked differences in the effects of sevoflurane and propofol on glucose metabolism; glucose use is impaired by sevoflurane, but not by propofol. Opening of adenosine triphosphate-sensitive potassium channels (K(ATP) channels) in β islet cells attenuates insulin secretion, while inhibition of K(ATP) channels in β islet cells increases insulin secretion. It is reported that volatile anesthetics open K(ATP) channels, whereas propofol inhibits K(ATP) channels. In this study, we examined the effects of sevoflurane and propofol on glucose metabolism under normovolemic and hypovolemic conditions, focusing on insulin secretion. METHODS Anesthesia was induced with sevoflurane (3% in 1 L/min oxygen) in all rats. After surgical preparation, rats were assigned to 2 groups. Anesthesia was maintained with sevoflurane (2% in 1 L/min oxygen) in the 1st group, and with propofol (a bolus dose of 30 mg/kg followed by continuous infusion at a rate of 30 mg · kg(-1) · h(-1)) in the 2nd group. Each group was divided into 3 subgroups: rats without pretreatment, rats pretreated with glibenclamide, and rats pretreated with nicorandil. After a 30-minute stabilization period, we withdrew 15 mL/kg of blood to induce hypovolemia. We evaluated glucose metabolism under both normovolemic and hypovolemic conditions by measuring blood glucose levels and plasma insulin levels. RESULTS Under both normovolemia and hypovolemia, glucose levels in rats anesthetized with sevoflurane were significantly higher than those in rats anesthetized with propofol, and insulin levels in rats anesthetized with sevoflurane were significantly lower than those in rats anesthetized with propofol. Glibenclamide, a K(ATP) channel inhibitor, significantly decreased glucose levels and significantly increased insulin levels under sevoflurane anesthesia, suggesting that sevoflurane decreases insulin secretion by opening K(ATP) channels in β islet cells. Glibenclamide significantly decreased glucose levels and significantly increased insulin levels under propofol anesthesia as well; however, insulin levels in rats pretreated with glibenclamide under propofol anesthesia were much higher than those in rats pretreated with glibenclamide under sevoflurane anesthesia. Furthermore, insulin levels in rats without pretreatment under propofol anesthesia seemed to be equal to or higher than those in rats pretreated with glibenclamide under sevoflurane anesthesia. These results suggest that there are marked differences in the effects of sevoflurane and propofol on insulin secretion regulated by K(ATP) channels in β islet cells. Nicorandil, a K(ATP) channel opener, produced no significant effects on glucose metabolism under both sevoflurane and propofol anesthesia. CONCLUSIONS Insulin secretion regulated by K(ATP) channels in β islet cells is involved, at least in part, in the different effects of sevoflurane and propofol on glucose metabolism.
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Affiliation(s)
- Takayuki Kitamura
- Department of Anesthesiology, Faculty of Medicine, University of Tokyo, Japan.
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Abstract
Airway management has been emphasized as crucial to effective resuscitation of patients in cardiac arrest. However, recent research has shown that coronary and cerebral perfusion should be prioritized rather than airway management. Endotracheal intubation has been deemphasized. This article reviews the current state of the literature regarding airway management of the patient in cardiac arrest. Ventilatory management strategies are also discussed.
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Abstract
PURPOSE OF REVIEW The holy grail of circulatory monitoring is an accurate, continuous and relatively noninvasive means of assessing the adequacy of organ perfusion. This could be then advantageously used to direct therapeutic interventions to prevent both under-treatment and over-treatment and thus improve outcomes. However, in view of the heterogeneous response (adaptive or maladaptive) of different organs to various shock states, any monitor of perfusion adequacy cannot reflect every organ system, but should at least detect early deterioration in a 'canary' organ. Tissue oxygen tension reflects the balance between local oxygen supply and demand, and could thus be a potentially useful monitoring modality. This article examines the different technologies available and reviews the current literature regarding its utility as a monitor. RECENT FINDINGS Tissue oxygen tension, measured at a variety of sites in both human and laboratory studies, does appear to be a sensitive indicator of organ perfusion in different shock states. However, responses can vary not only between organs and between different shock states, but also over time. These changes reflect the particular oxygen supply-demand balance present in that tissue bed at that specific time point in the disease process. The response to a dynamic oxygen challenge test provides further information that allows severity to be more readily differentiated. SUMMARY Monitoring of tissue oxygen tension may offer a potentially useful tool for clinical management though significant validation needs to be first performed to confirm its promise.
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Knight AR, Fry LE, Clancy RL, Pierce JD. Understanding the effects of oxygen administration in haemorrhagic shock. Nurs Crit Care 2011; 16:28-35. [PMID: 21199552 DOI: 10.1111/j.1478-5153.2010.00403.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
AIMS AND OBJECTIVES the aim of this article is to provide a review of the literature regarding oxygen administration and the use of oxygen in patients experiencing haemorrhagic shock (HS). RESULTS oxygen is administered to patients to assist them in maintaining oxygenation. The administration of oxygen is complex and varies significantly among patients. In order to optimize patient care, clinicians need to be aware of the potential effects, both beneficial and harmful, that oxygen can have on the body. INCLUSION AND EXCLUSION CRITERIA literature inclusion criteria for this article was any article (1995 to present) pertaining to oxygen administration and HS. Also included were articles related to tissue injury caused by an overabundance of free radicals with the administration of oxygen. Articles related to oxygen and wound healing, pollution, aerospace, food and industrial uses were excluded. CONCLUSIONS this review of the literature provides an overview of the use of oxygen in clinical practice and HS. The harmful effects of oxygen are highlighted to alert the clinician to this potential when there is an overabundance of oxygen. RELEVANCE TO CLINICAL PRACTICE oxygen is one of the most common drugs used in the medical community; however, the effects of oxygen on the body are not well understood. The use of oxygen if not prescribed correctly can cause cellular damage and death. Clinicians need to be more aware of the effects of oxygen and the damage it may cause if not administered properly.
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Affiliation(s)
- Amanda R Knight
- School of Nursing, University of Kansas Medical Center, Kansas City, KS 66160, USA.
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Dyson A, Rudiger A, Singer M. Temporal changes in tissue cardiorespiratory function during faecal peritonitis. Intensive Care Med 2011; 37:1192-200. [PMID: 21533572 DOI: 10.1007/s00134-011-2227-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2010] [Accepted: 03/21/2011] [Indexed: 12/23/2022]
Abstract
PURPOSE Sepsis affects both macro- and micro-circulatory transport of oxygen to tissues, causing regional hypoxia. However, this relationship is poorly characterized with respect to inter-organ variability, disease severity and the evolution to organ dysfunction. We hypothesized that an early circulatory insult precedes the development of organ dysfunction, and is more severe in predicted non-survivors. Consequently, we assessed temporal changes in myocardial function and regional tissue oxygenation in peripheral and deep organs in a rat model of faecal peritonitis. We also examined the utility of a dynamic oxygen challenge test to assess the microcirculation. METHODS Awake, tethered, fluid-resuscitated male Wistar rats were randomized to receive intraperitoneal injection of faecal slurry, or to act as controls. At either 6 or 24 h post insult, rats were anaesthetized and underwent echocardiography, arterial cannulation and placement of tissue oxygen probes in peripheral (muscle, bladder) and deep (liver and renal cortex) organ beds. Measurements were repeated during fluid loading and an oxygen challenge test (administration of high oxygen concentrations). RESULTS Early sepsis (6 h) was characterized by a fall in global oxygen delivery with concurrent decreases in muscle, renal cortical and, especially, liver tissue PO2. By contrast, during established sepsis (24 h), myocardial and circulatory function had largely recovered despite increasing clinical unwellness, hyperlactataemia and biochemical evidence of organ failure. O2 challenge revealed an early depression of response that, by 24 h, had improved in all organ beds bar the kidney. CONCLUSIONS This long-term septic model exhibited an early decline in tissue oxygenation, the degree of which related to predicted mortality. Clinical and biochemical deterioration, however, progressed despite cardiovascular recovery. Early circulatory dysfunction may thus be an important trigger for downstream processes that result in multi-organ failure. Furthermore, the utility of tissue PO2 monitoring to highlight the local oxygen supply-demand balance, and dynamic O2 challenge testing to assess microcirculatory function merit further investigation.
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Affiliation(s)
- Alex Dyson
- Bloomsbury Institute of Intensive Care Medicine, Department of Medicine and Wolfson Institute for Biomedical Research, University College London, Cruciform Building, Gower St., London, WC1E 6BT, UK
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Douzinas EE, Betrosian A, Giamarellos-Bourboulis EJ, Tasoulis MK, Prigouris P, Livaditi O, Andrianakis I, Goutas N, Vlachodimitropoulos D, Pelekanou A, Villiotou V, Legakis I, Chrousos GP. Hypoxemic resuscitation from hemorrhagic shock prevents lung injury and attenuates oxidative response and IL-8 overexpression. Free Radic Biol Med 2011; 50:245-53. [PMID: 21062641 DOI: 10.1016/j.freeradbiomed.2010.10.712] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Revised: 09/25/2010] [Accepted: 10/27/2010] [Indexed: 12/20/2022]
Abstract
We investigated whether hypoxemic resuscitation from hemorrhagic shock prevents lung injury and explored the mechanisms involved. We subjected rabbits to hemorrhagic shock for 60 min by exsanguination to a mean arterial pressure of 40 mm Hg. By modifying the fraction of the inspired oxygen, we performed resuscitation under normoxemia (group NormoxRes, P(a)O(2)=95-105 mm Hg) or hypoxemia (group HypoxRes, P(a)O(2)=35-40 mm Hg). Animals not subjected to shock constituted the sham group (P(a)O(2)=95-105 mm Hg). We performed bronchoalveolar lavage (BAL) fluid, lung wet-to-dry weight ratio, and morphological studies. U937 monocyte-like cells were incubated with BAL fluid from each group. Cell peroxides, malondialdehyde, proteins, and cytokines in the BAL fluid were lower in sham than in shocked animals and in HypoxRes than in NormoxRes animals. The inverse was true for ascorbic acid and reduced glutathione. Lung edema, lung neutrophil infiltration, myeloperoxidase, and interleukin (IL)-8 gene expression were reduced in lungs of HypoxRes compared with NormoxRes animals. A colocalized higher expression of IL-8 and nitrotyrosine was found in lungs of NormoxRes animals compared to HypoxRes animals. The BAL fluid of NormoxRes animals compared with HypoxRes animals exerted a greater stimulation of U937 monocyte-like cells for proinflammatory cytokine release, particularly for IL-8. In the presence of p38-MAPK and Syk inhibitors and monosodium urate crystals, IL-8 release was reduced. We conclude that hypoxemic resuscitation from hemorrhagic shock ameliorates lung injury and reduces oxygen radical generation and lung IL-8 expression.
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Affiliation(s)
- Emmanuel E Douzinas
- Third Department of Critical Care Medicine, University of Athens Medical School, Evgenidio Hospital, Athens 115 28, Greece.
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Abstract
The current practice of mechanical ventilation comprises the use of the least inspiratory O2 fraction associated with an arterial O2 tension of 55 to 80 mm Hg or an arterial hemoglobin O2 saturation of 88% to 95%. Early goal-directed therapy for septic shock, however, attempts to balance O2 delivery and demand by optimizing cardiac function and hemoglobin concentration, without making use of hyperoxia. Clearly, it has been well-established for more than a century that long-term exposure to pure O2 results in pulmonary and, under hyperbaric conditions, central nervous O2 toxicity. Nevertheless, several arguments support the use of ventilation with 100% O2 as a supportive measure during the first 12 to 24 hrs of septic shock. In contrast to patients without lung disease undergoing anesthesia, ventilation with 100% O2 does not worsen intrapulmonary shunt under conditions of hyperinflammation, particularly when low tidal volume-high positive end-expiratory pressure ventilation is used. In healthy volunteers and experimental animals, exposure to hyperoxia may cause pulmonary inflammation, enhanced oxidative stress, and tissue apoptosis. This, however, requires long-term exposure or injurious tidal volumes. In contrast, within the timeframe of a perioperative administration, direct O2 toxicity only plays a negligible role. Pure O2 ventilation induces peripheral vasoconstriction and thus may counteract shock-induced hypotension and reduce vasopressor requirements. Furthermore, in experimental animals, a redistribution of cardiac output toward the kidney and the hepato-splanchnic organs was observed. Hyperoxia not only reverses the anesthesia-related impairment of the host defense but also is an antibiotic. In fact, perioperative hyperoxia significantly reduced wound infections, and this effect was directly related to the tissue O2 tension. Therefore, we advocate mechanical ventilation with 100% O2 during the first 12 to 24 hrs of septic shock. However, controlled clinical trials are mandatory to test the safety and efficacy of this approach.
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Monitoring the microcirculation in the critically ill patient: current methods and future approaches. Intensive Care Med 2010; 36:1813-25. [DOI: 10.1007/s00134-010-2005-3] [Citation(s) in RCA: 266] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2010] [Accepted: 07/14/2010] [Indexed: 11/25/2022]
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Antonelli M, Azoulay E, Bonten M, Chastre J, Citerio G, Conti G, De Backer D, Lemaire F, Gerlach H, Hedenstierna G, Joannidis M, Macrae D, Mancebo J, Maggiore SM, Mebazaa A, Preiser JC, Pugin J, Wernerman J, Zhang H. Year in review in Intensive Care Medicine 2009: II. Neurology, cardiovascular, experimental, pharmacology and sedation, communication and teaching. Intensive Care Med 2010; 36:412-27. [PMID: 20107763 PMCID: PMC2820226 DOI: 10.1007/s00134-010-1770-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2010] [Accepted: 01/13/2010] [Indexed: 01/16/2023]
Affiliation(s)
- Massimo Antonelli
- Department of Intensive Care and Anesthesiology, Policlinico Universitario A. Gemelli, Università Cattolica del Sacro Cuore, Largo A Gemelli 8, 00168 Rome, Italy.
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Douzinas EE. Progressive hemorrhage: administer oxygen or early resuscitation? Intensive Care Med 2009; 35:1664-6. [DOI: 10.1007/s00134-009-1576-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2009] [Accepted: 06/28/2009] [Indexed: 11/28/2022]
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