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- Bachmann, M. Consuelo, et al.
(författare)
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Electrical impedance tomography in acute respiratory distress syndrome
- 2018
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Ingår i: Critical Care. - : BioMed Central. - 1364-8535 .- 1466-609X. ; 22
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Forskningsöversikt (refereegranskat)abstract
- Acute respiratory distress syndrome (ARDS) is a clinical entity that acutely affects the lung parenchyma, and is characterized by diffuse alveolar damage and increased pulmonary vascular permeability. Currently, computed tomography (CT) is commonly used for classifying and prognosticating ARDS. However, performing this examination in critically ill patients is complex, due to the need to transfer these patients to the CT room. Fortunately, new technologies have been developed that allow the monitoring of patients at the bedside. Electrical impedance tomography (EIT) is a monitoring tool that allows one to evaluate at the bedside the distribution of pulmonary ventilation continuously, in real time, and which has proven to be useful in optimizing mechanical ventilation parameters in critically ill patients. Several clinical applications of EIT have been developed during the last years and the technique has been generating increasing interest among researchers. However, among clinicians, there is still a lack of knowledge regarding the technical principles of EIT and potential applications in ARDS patients. The aim of this review is to present the characteristics, technical concepts, and clinical applications of EIT, which may allow better monitoring of lung function during ARDS.
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| 2. |
- Retamal, Jaime, et al.
(författare)
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Does Regional Lung Strain Correlate With Regional Inflammation in Acute Respiratory Distress Syndrome During Nonprotective Ventilation? : An Experimental Porcine Study
- 2018
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Ingår i: Critical Care Medicine. - 0090-3493 .- 1530-0293. ; 46:6, s. e591-e599
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: It is known that ventilator-induced lung injury causes increased pulmonary inflammation. It has been suggested that one of the underlying mechanisms may be strain. The aim of this study was to investigate whether lung regional strain correlates with regional inflammation in a porcine model of acute respiratory distress syndrome.DESIGN: Retrospective analysis of CT images and positron emission tomography images using [18F]fluoro-2-deoxy-D-glucose.SETTING: University animal research laboratory.SUBJECTS: Seven piglets subjected to experimental acute respiratory distress syndrome and five ventilated controls.INTERVENTIONS: Acute respiratory distress syndrome was induced by repeated lung lavages, followed by 210 minutes of injurious mechanical ventilation using low positive end-expiratory pressures (mean, 4 cm H2O) and high inspiratory pressures (mean plateau pressure, 45 cm H2O). All animals were subsequently studied with CT scans acquired at end-expiration and end-inspiration, to obtain maps of volumetric strain (inspiratory volume - expiratory volume)/expiratory volume, and dynamic positron emission tomography imaging. Strain maps and positron emission tomography images were divided into 10 isogravitational horizontal regions-of-interest, from which spatial correlation was calculated for each animal.MEASUREMENTS AND MAIN RESULTS: The acute respiratory distress syndrome model resulted in a decrease in respiratory system compliance (20.3 ± 3.4 to 14.0 ± 4.9 mL/cm H2O; p < 0.05) and oxygenation (PaO2/FIO2, 489 ± 80 to 92 ± 59; p < 0.05), whereas the control animals did not exhibit changes. In the acute respiratory distress syndrome group, strain maps showed a heterogeneous distribution with a greater concentration in the intermediate gravitational regions, which was similar to the distribution of [18F]fluoro-2-deoxy-D-glucose uptake observed in the positron emission tomography images, resulting in a positive spatial correlation between both variables (median R2 = 0.71 [0.02-0.84]; p < 0.05 in five of seven animals), which was not observed in the control animals.CONCLUSION: In this porcine acute respiratory distress syndrome model, regional lung strain was spatially correlated with regional inflammation, supporting that strain is a relevant and prominent determinant of ventilator-induced lung injury.
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