The Experts below are selected from a list of 7638 Experts worldwide ranked by ideXlab platform
Peter M Spieth - One of the best experts on this subject based on the ideXlab platform.
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higher levels of spontaneous breathing induce Lung recruitment and reduce global stress strain in Experimental Lung Injury
Anesthesiology, 2014Co-Authors: Andreas Güldner, Alessandro Beda, Barbel Wiedemann, Anja Braune, Nadja Carvalho, Stefan Zeidler, Gerd Wunderlich, Michael Andreeff, Christopher Uhlig, Peter M SpiethAbstract:Background:Spontaneous breathing (SB) in the early phase of the acute respiratory distress syndrome is controversial. Biphasic positive airway pressure/airway pressure release ventilation (BIPAP/APRV) is commonly used, but the level of SB necessary to maximize potential beneficial effects is unknown
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comparative effects of proportional assist and variable pressure support ventilation on Lung function and damage in Experimental Lung Injury
Critical Care Medicine, 2012Co-Authors: Peter M Spieth, Alessandro Beda, Nadja C. Carvalho, Andreas Güldner, Thomas Nowack, Anke Krause, Ines Rentzsch, Sabina Suchantke, Serge C Thal, Kristin EngelhardAbstract:Objective:To investigate the effects of proportional assist ventilation, variable pressure support, and conventional pressure support ventilation on Lung function and damage in Experimental acute Lung Injury.Design:Randomized Experimental study.Setting:University hospital research facility.Subjects:
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distribution of regional Lung aeration and perfusion during conventional and noisy pressure support ventilation in Experimental Lung Injury
Journal of Applied Physiology, 2011Co-Authors: Alysson R Carvalho, Alessandro Beda, Nadja C. Carvalho, Andreas Güldner, Maximilano Cuevas, Stephanie Spieth, Christian Stroczynski, Barbel Wiedemann, Peter M Spieth, Thea KochAbstract:In acute Lung Injury (ALI), pressure support ventilation (PSV) may improve oxygenation compared with pressure-controlled ventilation (PCV), and benefit from random variation of pressure support (no...
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effects of perfluorohexane vapor in the treatment of Experimental Lung Injury
Pulmonary Pharmacology & Therapeutics, 2010Co-Authors: Jorg U Bleyl, Peter M Spieth, Matthias Hubler, Marcelo Gama De Abreu, Axel R Heller, Manuel Heintz, Matthias Schlemmer, Roland Koch, Thea KochAbstract:Abstract Rationale We investigated the effects of vaporized perfluorohexane (PFH) on pulmonary vascular tone, pulmonary vascular resistance and peak inspiratory pressure as well as lipid mediator formation in the treatment of calcium ionophore induced Lung Injury in a model of the isolated perfused and ventilated rabbit Lungs. Methods Lung Injury was induced in isolated perfused and ventilated rabbit Lungs by calcium ionophore A23187. Lungs were treated with either 4.5 vol.% (4.5 vol.% PFH; n = 6) or 18 vol.% (18 vol.% PFH; n = 6) PFH. Six Lungs remained untreated (Control). In addition 5 Lungs (PFH-sham) remained uninjured receiving 18 vol.% PFH only. Mean pulmonary artery pressure (mPAP), peak inspiratory pressure ( P max ), and Lung weight (weight) were monitored for 120 min. Experiments were terminated before when the increase in Lung weight exceeded 40 g. Perfusate samples were taken at regular intervals for analysis of TXB 2 , 6-keto-PGF 1 and LTB 4 . Results Controls reached the study end point significantly earlier than both PFH groups. Significant differences were found for a weight gain of 10 g and 20 g between the control and the 4.5 vol.% PFH and the 18 vol.% PFH. Differences in mPAP were more pronounced in the 4.5 vol.% PFH. However increases in P max were more marked in 4.5 vol.% PFH. TXA 2 -, PGI 2 -, and LTB 4 -levels were significantly lower in PFH groups. Uninjured Lungs remained unaffected by the presence of 18 vol.% PFH. Conclusion Inflammatory Lung Injury was attenuated by the treatment with 4.5 vol.% PFH and 18 vol.% PFH vapor in the isolated perfused rabbit Lung. Therapeutic effects were more pronounced with a concentration of 4.5 vol.% PFH.
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regional Lung aeration and ventilation during pressure support and biphasic positive airway pressure ventilation in Experimental Lung Injury
Critical Care, 2010Co-Authors: Marcelo Gama De Abreu, Barbel Wiedemann, Thea Koch, Peter M Spieth, Alysson R Carvalho, Paolo Pelosi, Maximiliano Cuevas, Volker Hietschold, C Stroszczynski, Edmund KochAbstract:There is an increasing interest in biphasic positive airway pressure with spontaneous breathing (BIPAP+SBmean), which is a combination of time-cycled controlled breaths at two levels of continuous positive airway pressure (BIPAP+SBcontrolled) and non-assisted spontaneous breathing (BIPAP+SBspont), in the early phase of acute Lung Injury (ALI). However, pressure support ventilation (PSV) remains the most commonly used mode of assisted ventilation. To date, the effects of BIPAP+SBmean and PSV on regional Lung aeration and ventilation during ALI are only poorly defined. In 10 anesthetized juvenile pigs, ALI was induced by surfactant depletion. BIPAP+SBmean and PSV were performed in a random sequence (1 h each) at comparable mean airway pressures and minute volumes. Gas exchange, hemodynamics, and inspiratory effort were determined and dynamic computed tomography scans obtained. Aeration and ventilation were calculated in four zones along the ventral-dorsal axis at Lung apex, hilum and base. Compared to PSV, BIPAP+SBmean resulted in: 1) lower mean tidal volume, comparable oxygenation and hemodynamics, and increased PaCO2 and inspiratory effort; 2) less nonaerated areas at end-expiration; 3) decreased tidal hyperaeration and re-aeration; 4) similar distributions of ventilation. During BIPAP+SBmean: i) BIPAP+SBspont had lower tidal volumes and higher rates than BIPAP+SBcontrolled; ii) BIPAP+SBspont and BIPAP+SBcontrolled had similar distributions of ventilation and aeration; iii) BIPAP+SBcontrolled resulted in increased tidal re-aeration and hyperareation, compared to PSV. BIPAP+SBspont showed an opposite pattern. In this model of ALI, the reduction of tidal re-aeration and hyperaeration during BIPAP+SBmean compared to PSV is not due to decreased nonaerated areas at end-expiration or different distribution of ventilation, but to lower tidal volumes during BIPAP+SBspont. The ratio between spontaneous to controlled breaths seems to play a pivotal role in reducing tidal re-aeration and hyperaeration during BIPAP+SBmean.
Marcelo Gama De Abreu - One of the best experts on this subject based on the ideXlab platform.
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effects of perfluorohexane vapor in the treatment of Experimental Lung Injury
Pulmonary Pharmacology & Therapeutics, 2010Co-Authors: Jorg U Bleyl, Peter M Spieth, Matthias Hubler, Marcelo Gama De Abreu, Axel R Heller, Manuel Heintz, Matthias Schlemmer, Roland Koch, Thea KochAbstract:Abstract Rationale We investigated the effects of vaporized perfluorohexane (PFH) on pulmonary vascular tone, pulmonary vascular resistance and peak inspiratory pressure as well as lipid mediator formation in the treatment of calcium ionophore induced Lung Injury in a model of the isolated perfused and ventilated rabbit Lungs. Methods Lung Injury was induced in isolated perfused and ventilated rabbit Lungs by calcium ionophore A23187. Lungs were treated with either 4.5 vol.% (4.5 vol.% PFH; n = 6) or 18 vol.% (18 vol.% PFH; n = 6) PFH. Six Lungs remained untreated (Control). In addition 5 Lungs (PFH-sham) remained uninjured receiving 18 vol.% PFH only. Mean pulmonary artery pressure (mPAP), peak inspiratory pressure ( P max ), and Lung weight (weight) were monitored for 120 min. Experiments were terminated before when the increase in Lung weight exceeded 40 g. Perfusate samples were taken at regular intervals for analysis of TXB 2 , 6-keto-PGF 1 and LTB 4 . Results Controls reached the study end point significantly earlier than both PFH groups. Significant differences were found for a weight gain of 10 g and 20 g between the control and the 4.5 vol.% PFH and the 18 vol.% PFH. Differences in mPAP were more pronounced in the 4.5 vol.% PFH. However increases in P max were more marked in 4.5 vol.% PFH. TXA 2 -, PGI 2 -, and LTB 4 -levels were significantly lower in PFH groups. Uninjured Lungs remained unaffected by the presence of 18 vol.% PFH. Conclusion Inflammatory Lung Injury was attenuated by the treatment with 4.5 vol.% PFH and 18 vol.% PFH vapor in the isolated perfused rabbit Lung. Therapeutic effects were more pronounced with a concentration of 4.5 vol.% PFH.
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regional Lung aeration and ventilation during pressure support and biphasic positive airway pressure ventilation in Experimental Lung Injury
Critical Care, 2010Co-Authors: Marcelo Gama De Abreu, Barbel Wiedemann, Thea Koch, Peter M Spieth, Alysson R Carvalho, Paolo Pelosi, Maximiliano Cuevas, Volker Hietschold, C Stroszczynski, Edmund KochAbstract:There is an increasing interest in biphasic positive airway pressure with spontaneous breathing (BIPAP+SBmean), which is a combination of time-cycled controlled breaths at two levels of continuous positive airway pressure (BIPAP+SBcontrolled) and non-assisted spontaneous breathing (BIPAP+SBspont), in the early phase of acute Lung Injury (ALI). However, pressure support ventilation (PSV) remains the most commonly used mode of assisted ventilation. To date, the effects of BIPAP+SBmean and PSV on regional Lung aeration and ventilation during ALI are only poorly defined. In 10 anesthetized juvenile pigs, ALI was induced by surfactant depletion. BIPAP+SBmean and PSV were performed in a random sequence (1 h each) at comparable mean airway pressures and minute volumes. Gas exchange, hemodynamics, and inspiratory effort were determined and dynamic computed tomography scans obtained. Aeration and ventilation were calculated in four zones along the ventral-dorsal axis at Lung apex, hilum and base. Compared to PSV, BIPAP+SBmean resulted in: 1) lower mean tidal volume, comparable oxygenation and hemodynamics, and increased PaCO2 and inspiratory effort; 2) less nonaerated areas at end-expiration; 3) decreased tidal hyperaeration and re-aeration; 4) similar distributions of ventilation. During BIPAP+SBmean: i) BIPAP+SBspont had lower tidal volumes and higher rates than BIPAP+SBcontrolled; ii) BIPAP+SBspont and BIPAP+SBcontrolled had similar distributions of ventilation and aeration; iii) BIPAP+SBcontrolled resulted in increased tidal re-aeration and hyperareation, compared to PSV. BIPAP+SBspont showed an opposite pattern. In this model of ALI, the reduction of tidal re-aeration and hyperaeration during BIPAP+SBmean compared to PSV is not due to decreased nonaerated areas at end-expiration or different distribution of ventilation, but to lower tidal volumes during BIPAP+SBspont. The ratio between spontaneous to controlled breaths seems to play a pivotal role in reducing tidal re-aeration and hyperaeration during BIPAP+SBmean.
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effects of different levels of pressure support variability in Experimental Lung Injury
Anesthesiology, 2009Co-Authors: Peter M Spieth, Andreas Güldner, Thea Koch, Alysson R Carvalho, Paolo Pelosi, Oleg Kirichuk, Marcelo Gama De AbreuAbstract:Background Noisy pressure support ventilation has been reported to improve respiratory function compared to conventional assisted mechanical ventilation. We aimed at determining the optimal level of pressure support variability during noisy pressure support ventilation. Methods Twelve pigs were anesthetized and mechanically ventilated. Acute Lung Injury was induced by surfactant depletion. At four levels of pressure support variability (coefficients of variation of pressure support equal to 7.5, 15, 30, and 45%, 30 min each, crossover design, special Latin squares sequence), we measured respiratory variables, gas exchange, hemodynamics, inspiratory effort, and comfort of breathing. The mean level of tidal volume was constant among variability levels. Results Compared to conventional pressure support ventilation, different levels of variability in pressure support improved the elastance of the respiratory system, peak airway pressure, oxygenation, and intrapulmonary shunt. Oxygenation and venous admixture benefited more from intermediate (30%) levels of variability, whereas elastance and peak airway pressure improved linearly with increasing variability. Heart rate as well as mean arterial and pulmonary arterial pressures decreased slightly at intermediate to high (30-45%) levels of variability in pressure support. Inspiratory effort and comfort of breathing were not importantly influenced by increased variability in pressure support. Conclusion In a surfactant depletion model of acute Lung Injury, variability of pressure support improves Lung function. The variability level of 30% seems to represent a reasonable compromise to improve Lung functional variables during noisy pressure support ventilation.
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noisy pressure support ventilation a pilot study on a new assisted ventilation mode in Experimental Lung Injury
Critical Care Medicine, 2008Co-Authors: Marcelo Gama De Abreu, Peter M Spieth, Alysson R Carvalho, Paolo Pelosi, Matthias Hubler, Boriana Neykova, Christiane Walter, Anna Schreiberferstl, Peter Aikele, Thea KochAbstract:Objective:To describe and evaluate the effects of the new noisy pressure support ventilation (noisy PSV) on Lung physiologic variables.Design:Crossover design with four modes of mechanical ventilation.Setting:Experimental research facility of a university hospital.Subjects:A total of 12 pigs weighin
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effects of vaporized perfluorohexane and partial liquid ventilation on regional distribution of alveolar damage in Experimental Lung Injury
Intensive Care Medicine, 2007Co-Authors: Peter M Spieth, Barbel Wiedemann, Thea Koch, Matthias Hubler, Lilla Knels, Michael Kasper, Andre Domingues Quelhas, Amelie Lupp, Antonio Giannella Neto, Marcelo Gama De AbreuAbstract:Objective To determine whether the patterns of distribution of histological effects of vaporized perfluorohexane (PFH) and partial liquid ventilation (PLV) differ significantly in acute Lung Injury.
Thea Koch - One of the best experts on this subject based on the ideXlab platform.
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effect of perfluorohexane on the expression of cellular adhesion molecules and surfactant protein a in human mesothelial cells in vitro
Artificial Cells Blood Substitutes and Biotechnology, 2011Co-Authors: Dirk Haufe, Klaus G Dahmen, Oliver Tiebel, Matthias Hubler, Thea KochAbstract:Abstract: The intraperitoneal instillation of perfluorocarbons augmented systemic oxygenation and was protective in mesenteric ischemia-reperfusion and Experimental Lung Injury. To study biocompatibility and potential anti-inflammatory effects of intraperitoneal perfluorocarbons, we evaluated the influence of perfluorohexane and/or inflammatory stimuli on human mesothelial cells in vitro. Perfluorohexane exposure neither impaired cell viability nor induced cellular activation. TNFα enhanced ICAM-1 expression, which was not attenuated by simultaneous perfluorohexane treatment. Concentration of intracellular surfactant protein A tended to be higher in perfluorohexane treated cells compared to controls. Our in vitro data add further evidence that intraperitoneal perfluorocarbon application is feasible without adverse local effects.
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distribution of regional Lung aeration and perfusion during conventional and noisy pressure support ventilation in Experimental Lung Injury
Journal of Applied Physiology, 2011Co-Authors: Alysson R Carvalho, Alessandro Beda, Nadja C. Carvalho, Andreas Güldner, Maximilano Cuevas, Stephanie Spieth, Christian Stroczynski, Barbel Wiedemann, Peter M Spieth, Thea KochAbstract:In acute Lung Injury (ALI), pressure support ventilation (PSV) may improve oxygenation compared with pressure-controlled ventilation (PCV), and benefit from random variation of pressure support (no...
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effects of perfluorohexane vapor in the treatment of Experimental Lung Injury
Pulmonary Pharmacology & Therapeutics, 2010Co-Authors: Jorg U Bleyl, Peter M Spieth, Matthias Hubler, Marcelo Gama De Abreu, Axel R Heller, Manuel Heintz, Matthias Schlemmer, Roland Koch, Thea KochAbstract:Abstract Rationale We investigated the effects of vaporized perfluorohexane (PFH) on pulmonary vascular tone, pulmonary vascular resistance and peak inspiratory pressure as well as lipid mediator formation in the treatment of calcium ionophore induced Lung Injury in a model of the isolated perfused and ventilated rabbit Lungs. Methods Lung Injury was induced in isolated perfused and ventilated rabbit Lungs by calcium ionophore A23187. Lungs were treated with either 4.5 vol.% (4.5 vol.% PFH; n = 6) or 18 vol.% (18 vol.% PFH; n = 6) PFH. Six Lungs remained untreated (Control). In addition 5 Lungs (PFH-sham) remained uninjured receiving 18 vol.% PFH only. Mean pulmonary artery pressure (mPAP), peak inspiratory pressure ( P max ), and Lung weight (weight) were monitored for 120 min. Experiments were terminated before when the increase in Lung weight exceeded 40 g. Perfusate samples were taken at regular intervals for analysis of TXB 2 , 6-keto-PGF 1 and LTB 4 . Results Controls reached the study end point significantly earlier than both PFH groups. Significant differences were found for a weight gain of 10 g and 20 g between the control and the 4.5 vol.% PFH and the 18 vol.% PFH. Differences in mPAP were more pronounced in the 4.5 vol.% PFH. However increases in P max were more marked in 4.5 vol.% PFH. TXA 2 -, PGI 2 -, and LTB 4 -levels were significantly lower in PFH groups. Uninjured Lungs remained unaffected by the presence of 18 vol.% PFH. Conclusion Inflammatory Lung Injury was attenuated by the treatment with 4.5 vol.% PFH and 18 vol.% PFH vapor in the isolated perfused rabbit Lung. Therapeutic effects were more pronounced with a concentration of 4.5 vol.% PFH.
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regional Lung aeration and ventilation during pressure support and biphasic positive airway pressure ventilation in Experimental Lung Injury
Critical Care, 2010Co-Authors: Marcelo Gama De Abreu, Barbel Wiedemann, Thea Koch, Peter M Spieth, Alysson R Carvalho, Paolo Pelosi, Maximiliano Cuevas, Volker Hietschold, C Stroszczynski, Edmund KochAbstract:There is an increasing interest in biphasic positive airway pressure with spontaneous breathing (BIPAP+SBmean), which is a combination of time-cycled controlled breaths at two levels of continuous positive airway pressure (BIPAP+SBcontrolled) and non-assisted spontaneous breathing (BIPAP+SBspont), in the early phase of acute Lung Injury (ALI). However, pressure support ventilation (PSV) remains the most commonly used mode of assisted ventilation. To date, the effects of BIPAP+SBmean and PSV on regional Lung aeration and ventilation during ALI are only poorly defined. In 10 anesthetized juvenile pigs, ALI was induced by surfactant depletion. BIPAP+SBmean and PSV were performed in a random sequence (1 h each) at comparable mean airway pressures and minute volumes. Gas exchange, hemodynamics, and inspiratory effort were determined and dynamic computed tomography scans obtained. Aeration and ventilation were calculated in four zones along the ventral-dorsal axis at Lung apex, hilum and base. Compared to PSV, BIPAP+SBmean resulted in: 1) lower mean tidal volume, comparable oxygenation and hemodynamics, and increased PaCO2 and inspiratory effort; 2) less nonaerated areas at end-expiration; 3) decreased tidal hyperaeration and re-aeration; 4) similar distributions of ventilation. During BIPAP+SBmean: i) BIPAP+SBspont had lower tidal volumes and higher rates than BIPAP+SBcontrolled; ii) BIPAP+SBspont and BIPAP+SBcontrolled had similar distributions of ventilation and aeration; iii) BIPAP+SBcontrolled resulted in increased tidal re-aeration and hyperareation, compared to PSV. BIPAP+SBspont showed an opposite pattern. In this model of ALI, the reduction of tidal re-aeration and hyperaeration during BIPAP+SBmean compared to PSV is not due to decreased nonaerated areas at end-expiration or different distribution of ventilation, but to lower tidal volumes during BIPAP+SBspont. The ratio between spontaneous to controlled breaths seems to play a pivotal role in reducing tidal re-aeration and hyperaeration during BIPAP+SBmean.
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effects of different levels of pressure support variability in Experimental Lung Injury
Anesthesiology, 2009Co-Authors: Peter M Spieth, Andreas Güldner, Thea Koch, Alysson R Carvalho, Paolo Pelosi, Oleg Kirichuk, Marcelo Gama De AbreuAbstract:Background Noisy pressure support ventilation has been reported to improve respiratory function compared to conventional assisted mechanical ventilation. We aimed at determining the optimal level of pressure support variability during noisy pressure support ventilation. Methods Twelve pigs were anesthetized and mechanically ventilated. Acute Lung Injury was induced by surfactant depletion. At four levels of pressure support variability (coefficients of variation of pressure support equal to 7.5, 15, 30, and 45%, 30 min each, crossover design, special Latin squares sequence), we measured respiratory variables, gas exchange, hemodynamics, inspiratory effort, and comfort of breathing. The mean level of tidal volume was constant among variability levels. Results Compared to conventional pressure support ventilation, different levels of variability in pressure support improved the elastance of the respiratory system, peak airway pressure, oxygenation, and intrapulmonary shunt. Oxygenation and venous admixture benefited more from intermediate (30%) levels of variability, whereas elastance and peak airway pressure improved linearly with increasing variability. Heart rate as well as mean arterial and pulmonary arterial pressures decreased slightly at intermediate to high (30-45%) levels of variability in pressure support. Inspiratory effort and comfort of breathing were not importantly influenced by increased variability in pressure support. Conclusion In a surfactant depletion model of acute Lung Injury, variability of pressure support improves Lung function. The variability level of 30% seems to represent a reasonable compromise to improve Lung functional variables during noisy pressure support ventilation.
Rolf Rossaint - One of the best experts on this subject based on the ideXlab platform.
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hemocompatibility of a miniaturized extracorporeal membrane oxygenation and a pumpless interventional Lung assist in Experimental Lung Injury
Artificial Organs, 2010Co-Authors: R Kopp, Ralf Bensberg, Dietrich Henzler, Anja Niewels, Simone Randerath, Rolf Rossaint, R KuhlenAbstract:Extracorporeal membrane oxygenation (ECMO) is used for most severe acute respiratory distress syndrome cases in specialized centers. Hemocompatibility of devices depends on the size and modification of blood contacting surfaces as well as blood flow rates. An interventional Lung assist using arteriovenous perfusion of a low-resistance oxygenator without a blood pump (NovaLung, Hechingen, Germany) or a miniaturized ECMO with reduced filling volume and a diagonal blood pump (Deltastream, Medos AG, Stolberg, Germany) could optimize hemocompatibility. The aim of the study was to compare hemocompatibility with conventional ECMO. Female pigs were connected to extracorporeal circulation for 24 h after lavage induced Lung Injury (eight per group). Activation of coagulation and immune system as well as blood cell damage was measured. A P value <0.05 was considered significant. Plasmatic coagulation was slightly activated in all groups demonstrated by increased thrombin-anti-thrombin III-complex. No clinical signs of bleeding or thromboembolism occurred. Thrombelastography revealed decreased clotting capacities after miniaturized ECMO, probably due to significantly reduced platelet count. These resulted in reduced dosage of intravenous heparin. Scanning electron microscopy of oxygenator fibers showed significantly increased binding and shape change of platelets after interventional Lung assist. In all groups, hemolysis remained negligible, indicated by low plasma hemoglobin concentration. Interleukin 8 and tumor necrosis factor-alpha concentration as well as leukocyte count remained unchanged. Both devices demonstrated adequate hemocompatibility for safe clinical application, although a missing blood pump did not increase hemocompatibility. Further studies seem necessary to analyze the influence of different blood pumps on platelet drop systematically.
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ventilation with biphasic positive airway pressure in Experimental Lung Injury influence of transpulmonary pressure on gas exchange and haemodynamics
Intensive Care Medicine, 2004Co-Authors: Dietrich Henzler, Ralf Bensberg, Rolf Rossaint, Rolf Dembinski, Nadine Hochhausen, Ralf KuhlenAbstract:We investigated whether improvement in ventilation perfusion (VA/Q) distribution during mechanical ventilation using biphasic positive airway pressure (BIPAP) with spontaneous breathing may be attributed to an effectively increased transpulmonary pressure (PTP) and can also be achieved by increasing PTP during controlled ventilation. In 12 pigs with saline lavage-induced Lung Injury we compared the effects of BIPAP to pressure-controlled ventilation with equal airway pressure (PCVAW) or equal transpulmonary pressure (PCVTP) on VA/Q distribution assessed by the multiple inert gas elimination technique (MIGET). Animal laboratory study. Intrapulmonary shunt was 33±11% during BIPAP, 36±10% during PCVAW and 33±15% during PCVTP (p= n.s.). BIPAP resulted in higher PaO2 than PCVAW (188±83 versus 147±82 mmHg, p<0.05), but not than PCVTP (187±139 mmHg). Oxygen delivery was significantly higher during BIPAP (530±109 ml/min) versus 374±113 ml/min during PCVAW and 353±93 ml/min during PCVTP (p<0.005). Tidal volume with PCVTP increased to 11.9±2.3 ml/kg, compared to 8.5±0.8 with BIPAP and 7.6±1.4 with PCVAW (p<0.001) and cardiac output decreased to 3.5±0.6 l/min (BIPAP 4.9±0.8 and PCVAW 3.9±0.8, p<0.006). In Experimental Lung Injury, BIPAP with preserved spontaneous breathing was effective in increasing regional PTP, since pressure-controlled ventilation with the same PTP resulted in similar gas exchange effects. However, PCVTP caused increased airway pressures and tidal volumes, whereby, with BIPAP, less depression of oxygen delivery and cardiac output were observed. BIPAP could be useful in maintaining pulmonary gas exchange and slightly improving oxygenation without interfering with circulation as strongly as PCV does.
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ventilation perfusion distribution related to different inspiratory flow patterns in Experimental Lung Injury
Anesthesia & Analgesia, 2004Co-Authors: Rolf Dembinski, Ralf Bensberg, Dietrich Henzler, Rolf Rossaint, Berit Prusse, R KuhlenAbstract:In acute Lung Injury (ALI), controlled mechanical ventilation with decelerating inspiratory flow (Vdec) has been suggested to improve oxygenation when compared with constant flow (Vcon) by improving the distribution of ventilation and perfusion (VA/𝑄). We performed the present study to test thi
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extracorporeal gas exchange with the deltastream rotary blood pump in Experimental Lung Injury
Artificial Organs, 2003Co-Authors: Rolf Dembinski, Dietrich Henzler, Rolf Rossaint, Rudger Kopp, Nadine Hochhausen, Nicole Oslender, M Max, R KuhlenAbstract:In most severe cases of the acute respiratory distress syndrome, veno-venous extracorporeal membrane oxygenation (ECMO) can be used to facilitate gas exchange. However, the clinical use is limited due to the size and the concomitant risk of severe adverse events of conventionally-used centrifugal blood pumps with high extracorporeal blood volumes. The DeltaStream blood pump is a small-sized rotary blood pump that may reduce extracorporeal blood volume, foreign surfaces, contact activation of the coagulation system, and blood trauma. The aim of the present study was to test the safety and efficacy of the DeltaStream pump for ECMO in animals with normal Lung function and Experimental acute Lung Injury (ALI). Therefore, veno-venous ECMO was performed for 6 hours in mechanically ventilated pigs with normal Lung function (n = 6) and with ALI induced by repeated Lung lavage (n = 6) with a blood flow of 30% of the cardiac output. Gas flow with a F i O 2 of 1.0 was set to equal blood flow. With a mean activated clotting time of 121 ′ 22s, no circulatory impairment or thrombus formation was revealed during ECMO. Furthermore, free plasma Hb did not increase. In controls, hemodynamics and gas exchange remained unchanged. In animals with ALI, hemodynamics remained stable and gas transfer across the extracorporeal oxygenators was optimal, but only in 2 animals was a marked increase in PaO 2 observed. CO 2 removal was efficacious in all animals. We concluded that the DeltaStream blood pump may be used for veno-venous ECMO without major blood damage or hemodynamic impairment.
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high frequency oscillatory ventilation in Experimental Lung Injury effects on gas exchange
Intensive Care Medicine, 2002Co-Authors: Rolf Dembinski, Ralf Bensberg, R Kuhlen, M Max, Johannes Bickenbach, Rolf RossaintAbstract:Objective. To compare ventilation-perfusion (VA/Q) distributions during improvement of oxygenation caused by high-frequency oscillatory ventilation (HFOV) and pressure-controlled mechanical ventilation with high PEEP levels (CMV) in Experimental acute Lung Injury (ALI).
Goran Hedenstierna - One of the best experts on this subject based on the ideXlab platform.
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Lung heterogeneity and deadspace volume in acute respiratory distress syndrome animals using the inspired sinewave test
Physiological Measurement, 2020Co-Authors: Minh C Tran, Goran Hedenstierna, Anders Larsson, Douglas C Crockett, Federico Formenti, Phi Anh Phan, Stephen J Payne, Andrew D FarmeryAbstract:The acute respiratory distress syndrome is associated with a high rate of morbidity and mortality, as patients undergoing mechanical ventilation are at risk of ventilator-induced Lung injuries. OBJECTIVE To measure the Lung heterogeneity and deadspace volume to find safer ventilator strategies. Then, the ventilator settings could offer homogeneous ventilation and theoretically equalise and reduce tidal strain/stress in the Lung parenchyma. APPROACH The Inspired Sinewave Test (IST) is a non-invasive Lung measurement tool, which does not require patients' cooperation. The IST can measure the effective Lung volume, pulmonary blood flow and deadspace volume. We developed a computational simulation of the cardiopulmonary system to allow Lung heterogeneity to be quantified using data solely derived from the IST. Then, the method to quantify Lung heterogeneity using two IST tracer gas frequencies (180s and 60s) was introduced and experimented in the simulation Lungs and in animal models. Thirteen anaesthetised pigs were studied with the IST, both before and after Experimental Lung Injury (saline-lavage ARDS model). The deadspace volume is compared between IST and the SF_{6} Washout method. RESULTS The IST could measure the Lung heterogeneity using two frequencies tracer gases. Furthermore, the value of IST ventilation heterogeneity in ARDS Lungs were higher than in control Lungs at PEEP 10cmH_{2}O (AuC=0.85, p<0.001). Deadspace volume values measured by the IST has a strong relationship with the measured values of the SF_{6} (9mL bias and limits of agreement from -79mL to 57mL in control animals). SIGNIFICANCE the potential impact of the IST technique in the identification of ventilation and perfusion heterogeneity during ventilator support.
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real time effects of peep and tidal volume on regional ventilation and perfusion in Experimental Lung Injury
Intensive Care Medicine Experimental, 2020Co-Authors: Joao Batista Borges, Goran Hedenstierna, Anders Larsson, John N Cronin, Douglas C Crockett, Federico FormentiAbstract:Background Real-time bedside information on regional ventilation and perfusion during mechanical ventilation (MV) may help to elucidate the physiological and pathophysiological effects of MV settin ...
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dynamic single slice ct estimates whole Lung dual energy ct variables in pigs with and without Experimental Lung Injury
Intensive Care Medicine Experimental, 2019Co-Authors: John N Cronin, Goran Hedenstierna, Anders Larsson, Joao Batista Borges, Douglas C Crockett, Andrew D Farmery, Minh C Tran, Luigi Camporota, Federico FormentiAbstract:Dynamic single-slice CT (dCT) is increasingly used to examine the intra-tidal, physiological variation in aeration and Lung density in Experimental Lung Injury. The ability of dCT to predict whole-Lung values is unclear, especially for dual-energy CT (DECT) variables. Additionally, the effect of inspiration-related Lung movement on CT variables has not yet been quantified. Eight domestic pigs were studied under general anaesthesia, including four following saline-lavage surfactant depletion (Lung Injury model). DECT, dCT and whole-Lung images were collected at 12 ventilatory settings. Whole-Lung single energy scans images were collected during expiratory and inspiratory apnoeas at positive end-expiratory pressures from 0 to 20 cmH2O. Means and distributions of CT variables were calculated for both dCT and whole-Lung images. The cranio-caudal displacement of the anatomical slice was measured from whole-Lung images. Mean CT density and volume fractions of soft tissue, gas, iodinated blood, atelectasis, poor aeration, normal aeration and overdistension correlated between dCT and the whole Lung (r2 0.75–0.94) with agreement between CT density distributions (r 0.89–0.97). Inspiration increased the matching between dCT and whole-Lung values and was associated with a movement of 32% (SD 15%) of the imaged slice out of the scanner field-of-view. This effect introduced an artefactual increase in dCT mean CT density during inspiration, opposite to that caused by the underlying physiology. Overall, dCT closely approximates whole-Lung aeration and density. This approximation is improved by inspiration where a decrease in CT density and atelectasis can be interpreted as physiological rather than artefactual.
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open Lung approach ventilation abolishes the negative effects of respiratory rate in Experimental Lung Injury
Acta Anaesthesiologica Scandinavica, 2016Co-Authors: Goran Hedenstierna, Joao Batista Borges, Jaime Retamal, Alejandro Bruhn, Ricardo Feinstein, Fernando Suarezsipmann, Anders LarssonAbstract:BACKGROUND: We recently reported that a high respiratory rate was associated with less inflammation than a low respiratory rate, but caused more pulmonary edema in a model of ARDS when an ARDSNet v ...
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cardiorespiratory effects of spontaneous breathing in two different models of Experimental Lung Injury a randomized controlled trial
Critical Care, 2008Co-Authors: Dirk Varelmann, Anders Magnusson, Goran Hedenstierna, Jorg Zinserling, Christian Putensen, Thomas Muders, Ulf Guenther, Hermann WriggeAbstract:Introduction Acute Lung Injury (ALI) can result from various insults to the pulmonary tissue. Experimental and clinical data suggest that spontaneous breathing (SB) during pressure-controlled ventilation (PCV) in ALI results in better Lung aeration and improved oxygenation. Our objective was to evaluate whether the addition of SB has different effects in two different models of ALI.
