JOAO BATISTA BORGES SOBRINHO DORINI
Projetos de Pesquisa
Unidades Organizacionais
LIM/09 - Laboratório de Pneumologia, Hospital das Clínicas, Faculdade de Medicina
7 resultados
Resultados de Busca
Agora exibindo 1 - 7 de 7
- Dynamic Mechanical Interactions Between Neighboring Airspaces Determine Cyclic Opening and Closure in Injured Lung(2017) BROCHE, Ludovic; PERCHIAZZI, Gaetano; PORRA, Liisa; TANNOIA, Angela; PELLEGRINI, Mariangela; DEROSA, Savino; SINDACO, Alessandra; BORGES, Joao Batista; DEGRUGILLIERS, Loic; LARSSON, Anders; HEDENSTIERNA, Goran; WEXLER, Anthony S.; BRAVIN, Alberto; VERBANCK, Sylvia; SMITH, Bradford J.; BATES, Jason H. T.; BAYAT, SamObjectives: Positive pressure ventilation exposes the lung to mechanical stresses that can exacerbate injury. The exact mechanism of this pathologic process remains elusive. The goal of this study was to describe recruitment/derecruitment at acinar length scales over short-time frames and test the hypothesis that mechanical interdependence between neighboring lung units determines the spatial and temporal distributions of recruitment/derecruitment, using a computational model. Design: Experimental animal study. Setting: International synchrotron radiation laboratory. Subjects: Four anesthetized rabbits, ventilated in pressure controlled mode. Interventions: The lung was consecutively imaged at - 1.5-minute intervals using phase-contrast synchrotron imaging, at positive end expiratory pressures of 12, 9, 6, 3, and 0 cm H2O before and after lavage and mechanical ventilation induced injury. The extent and spatial distribution of recruitment/derecruitment was analyzed by subtracting subsequent images. In a realistic lung structure, we implemented a mechanistic model in which each unit has individual pressures and speeds of opening and closing. Derecruited and recruited lung fractions (F-derecruaed, F-recruited) were computed based on the comparison of the aerated volumes at successive time points. Measurements and Main Results: Alternative recruitment/derecruitment occurred in neighboring alveoli over short-time scales in all tested positive end-expiratory pressure levels and despite stable pressure controlled mode. The computational model reproduced this behavior only when parenchymal interdependence between neighboring acini was accounted for. Simulations closely mimicked the experimental magnitude of F-derecruited and F-recruited when mechanical interdependence was included, while its exclusion gave F-recruited values of zero at positive end -expiratory pressure greater than or equal to 3 cm H2O. Conclusions: These findings give further insight into the microscopic behavior of the injured lung and provide a means of testing protective-ventilation strategies to prevent recruitment/derecruitment and subsequent lung damage. (Crit Care Med 2017; 45:687-694)
- Does Regional Lung Strain Correlate With Regional Inflammation in Acute Respiratory Distress Syndrome During Nonprotective Ventilation? An Experimental Porcine Study(2018) RETAMAL, Jaime; HURTADO, Daniel; VILLARROEL, Nicolas; BRUHN, Alejandro; BUGEDO, Guillermo; AMATO, Marcelo Britto Passos; COSTA, Eduardo Leite Vieira; HEDENSTIERNA, Goeran; LARSSON, Anders; BORGES, Joao BatistaObjective: 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 [F-18]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, 4cm H2O) and high inspiratory pressures (mean plateau pressure, 45cm 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 (20.33.4 to 14.0 +/- 4.9mL/cm H2O; p < 0.05) and oxygenation (Pao(2)/Fio(2), 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 [F-18]fluoro-2-deoxy-D-glucose uptake observed in the positron emission tomography images, resulting in a positive spatial correlation between both variables (median R-2 = 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.
- Open Lung in Lateral Decubitus With Differential Selective Positive End-Expiratory Pressure in an Experimental Model of Early Acute Respiratory Distress Syndrome(2015) BORGES, Joao Batista; SENTURK, Mert; AHLGREN, Oskar; HEDENSTIERNA, Goran; LARSSON, AndersObjective: After lung recruitment, lateral decubitus and differential lung ventilation may enable the titration and application of optimum-selective positive end-expiratory pressure values for the dependent and nondependent lungs. We aimed at compare the effects of optimum-selective positive end-expiratory pressure with optimum global positive end-expiratory pressure on regional collapse and aeration distribution in an experimental model of acute respiratory distress syndrome. Design: Prospective laboratory investigation. Setting: University animal research laboratory. Subjects: Seven piglets. Interventions: A one-hit injury acute respiratory distress syndrome model was established by repeated lung lavages. After replacing the tracheal tube by a double-lumen one, we initiated lateral decubitus and differential ventilation. After maximum-recruitment maneuver, decremental positive end-expiratory pressure titration was performed. The positive end-expiratory pressure corresponding to maximum dynamic compliance was defined globally (optimum global positive end-expiratory pressure) and for each individual lung (optimum-selective positive end-expiratory pressure). After new maximum-recruitment maneuver, two steps were performed in randomized order (15 min each): ventilation applying the optimum global positive end-expiratory pressure and the optimum-selective positive end-expiratory pressure. CT scans were acquired at end expiration and end inspiration. Measurements and Main Results: Aeration homogeneity was evaluated as a nondependent/dependent ratio (percent of total gas content in upper lung/percent of total gas content in lower lung) and tidal recruitment as the difference in the percent mass of nonaerated tissue between expiration and inspiration. At the end of the 15-minute optimum-selective positive end-expiratory pressure, compared with the optimum global positive end-expiratory pressure, resulted in 1) decrease in the percent mass of collapse in the lower lung at expiratory CT (19% 15% vs 4% +/- 5%; p = 0.03); 2) decrease in the nondependent/dependent ratio between the optimum global positive end-expiratory pressure-expiratory-CT and optimum-selective positive end-expiratory pressure-expiratory-CT (3.7 +/- 1.2 vs 0.8 +/- 0.5; p = 0.01); 3) decrease in the nondependent/dependent ratio between the optimum global positive end-expiratory pressure-inspiratory-CT and optimum-selective positive end-expiratory pressure-inspiratory-CT (2.8 +/- 1.1 vs 0.6 +/- 0.3; p = 0.01); and 4) less tidal recruitment (p = 0.049). Conclusions: After maximum lung recruitment, lateral decubitus and differential lung ventilation enabled the titration of optimum-selective positive end-expiratory pressure values for the dependent and the nondependent lungs, made possible the application of an optimized regional open lung approach, promoted better aeration distribution, and minimized lung tissue inhomogeneities.
- Early Inflammation Mainly Affects Normally and Poorly Aerated Lung in Experimental Ventilator-Induced Lung Injury*(2014) BORGES, Joao Batista; COSTA, Eduardo L. V.; SUAREZ-SIPMANN, Fernando; WIDSTROM, Charles; LARSSON, Anders; AMATO, Marcelo; HEDENSTIERNA, GoranObjective: The common denominator in most forms of ventilator-induced lung injury is an intense inflammatory response mediated by neutrophils. PET with [F-18]fluoro-2-deoxy-d-glucose can be used to image cellular metabolism, which, during lung inflammatory processes, mainly reflects neutrophil activity, allowing the study of regional lung inflammation in vivo. The aim of this study was to assess the location and magnitude of lung inflammation using PET imaging of [F-18]fluoro-2-deoxy-d-glucose in a porcine experimental model of early acute respiratory distress syndrome. Design: Prospective laboratory investigation. Setting: A university animal research laboratory. Subjects: Seven piglets submitted to experimental ventilator-induced lung injury and five healthy controls. Interventions: Lung injury was induced by lung lavages and 210 minutes of injurious mechanical ventilation using low positive end-expiratory pressure and high inspiratory pressures. All animals were subsequently studied with dynamic PET imaging of [F-18]fluoro-2-deoxy-d-glucose. CT scans were acquired at end expiration and end inspiration. Measurements and Main Results: [F-18]fluoro-2-deoxy-d-glucose uptake rate was computed for the whole lung, four isogravitational regions, and regions grouping voxels with similar density. Global and intermediate gravitational zones [F-18]fluoro-2-deoxy-d-glucose uptakes were higher in ventilator-induced lung injury piglets compared with controls animals. Uptake of normally and poorly aerated regions was also higher in ventilator-induced lung injury piglets compared with control piglets, whereas regions suffering tidal recruitment or tidal hyperinflation had [F-18]fluoro-2-deoxy-d-glucose uptakes similar to controls. Conclusions: The present findings suggest that normally and poorly aerated regionscorresponding to intermediate gravitational zonesare the primary targets of the inflammatory process accompanying early experimental ventilator-induced lung injury. This may be attributed to the small volume of the aerated lung, which receives most of ventilation.
- Effects on Pulmonary Vascular Mechanics of Two Different Lung-Protective Ventilation Strategies in an Experimental Model of Acute Respiratory Distress Syndrome(2017) SANTOS, Arnoldo; GOMEZ-PENALVER, Eva; MONGE-GARCIA, M. Ignacio; RETAMAL, Jaime; BORGES, Joao Batista; TUSMAN, Gerardo; HEDENSTIERNA, Goran; LARSSON, Anders; SUAREZ-SIPMANN, FernandoObjectives: To compare the effects of two lung-protective ventilation strategies on pulmonary vascular mechanics in early acute respiratory distress syndrome. Design: Experimental study. Setting: University animal research laboratory. Subjects: Twelve pigs (30.8 +/- 2.5 kg). Interventions: Acute respiratory distress syndrome was induced by repeated lung lavages and injurious mechanical ventilation. Thereafter, animals were randomized to 4 hours ventilation according to the Acute Respiratory Distress Syndrome Network protocol or to an open lung approach strategy. Pressure and flow sensors placed at the pulmonary artery trunk allowed continuous assessment of pulmonary artery resistance, effective elastance, compliance, and reflected pressure waves. Respiratory mechanics and gas exchange data were collected. Measurements and Main Results: Acute respiratory distress syndrome led to pulmonary vascular mechanics deterioration. Four hours after randomization, pulmonary vascular mechanics was similar in Acute Respiratory Distress Syndrome Network and open lung approach: resistance (578 +/- 252 vs 626 +/- 153 dyn. s/cm(5); p = 0.714), effective elastance, (0.63 +/- 0.22 vs 0.58 +/- 0.17 mm Hg/mL; p = 0.710), compliance (1.19 +/- 0.8 vs 1.50 +/- 0.27 mL/mm Hg; p = 0.437), and reflection index (0.36 +/- 0.04 vs 0.34 +/- 0.09; p = 0.680). Open lung approach as compared to Acute Respiratory Distress Syndrome Network was associated with improved dynamic respiratory compliance (17.3 +/- 2.6 vs 10.5 +/- 1.3 mL/cm H2O; p < 0.001), driving pressure (9.6 +/- 1.3 vs 19.3 +/- 2.7 cm H2O; p < 0.001), and venous admixture (0.05 +/- 0.01 vs 0.22 +/- 0.03, p < 0.001) and lower mean pulmonary artery pressure (26 +/- 3 vs 34 +/- 7 mm Hg; p = 0.045) despite of using a higher positive endexpiratory pressure (17.4 +/- 0.7 vs 9.5 +/- 2.4 cm H2O; p < 0.001). Cardiac index, however, was lower in open lung approach (1.42 +/- 0.16 vs 2.27 +/- 0.48 L/min; p = 0.005). Conclusions: In this experimental model, Acute Respiratory Distress Syndrome Network and open lung approach affected pulmonary vascular mechanics similarly. The use of higher positive end-expiratory pressures in the open lung approach strategy did not worsen pulmonary vascular mechanics, improved lung mechanics, and gas exchange but at the expense of a lower cardiac index.
- Open Lung Approach for the Acute Respiratory Distress Syndrome: A Pilot, Randomized Controlled Trial(2016) KACMAREK, Robert M.; VILLAR, Jesus; SULEMANJI, Demet; MONTIEL, Raquel; FERRANDO, Carlos; BLANCO, Jesus; KOH, Younsuck; SOLER, Juan Alfonso; MARTINEZ, Domingo; HERNANDEZ, Marianela; TUCCI, Mauro; BORGES, Joao Batista; LUBILLO, Santiago; SANTOS, Arnoldo; ARAUJO, Juan B.; AMATO, Marcelo B. P.; SUAREZ-SIPMANN, FernandoObjective: The open lung approach is a mechanical ventilation strategy involving lung recruitment and a decremental positive end-expiratory pressure trial. We compared the Acute Respiratory Distress Syndrome network protocol using low levels of positive end-expiratory pressure with open lung approach resulting in moderate to high levels of positive end-expiratory pressure for the management of established moderate/severe acute respiratory distress syndrome. Design: A prospective, multicenter, pilot, randomized controlled trial. Setting: A network of 20 multidisciplinary ICUs. Patients: Patients meeting the American-European Consensus Conference definition for acute respiratory distress syndrome were considered for the study. Interventions: At 12-36 hours after acute respiratory distress syndrome onset, patients were assessed under standardized ventilator settings (Fio(2)0.5, positive end-expiratory pressure 10 cm H2O). If Pao(2)/Fio(2) ratio remained less than or equal to 200 mm Hg, patients were randomized to open lung approach or Acute Respiratory Distress Syndrome network protocol. All patients were ventilated with a tidal volume of 4 to 8 ml/kg predicted body weight. Measurements and Main Results: From 1,874 screened patients with acute respiratory distress syndrome, 200 were randomized: 99 to open lung approach and 101 to Acute Respiratory Distress Syndrome network protocol. Main outcome measures were 60-day and ICU mortalities, and ventilator-free days. Mortality at day-60 (29% open lung approach vs. 33% Acute Respiratory Distress Syndrome Network protocol, p = 0.18, log rank test), ICU mortality (25% open lung approach vs. 30% Acute Respiratory Distress Syndrome network protocol, p = 0.53 Fisher's exact test), and ventilator-free days (8 [0-20] open lung approach vs. 7 [0-20] d Acute Respiratory Distress Syndrome network protocol, p = 0.53 Wilcoxon rank test) were not significantly different. Airway driving pressure (plateau pressure - positive end-expiratory pressure) and Pao(2)/Fio(2) improved significantly at 24, 48 and 72 hours in patients in open lung approach compared with patients in Acute Respiratory Distress Syndrome network protocol. Barotrauma rate was similar in both groups. Conclusions: In patients with established acute respiratory distress syndrome, open lung approach improved oxygenation and driving pressure, without detrimental effects on mortality, ventilator-free days, or barotrauma. This pilot study supports the need for a large, multicenter trial using recruitment maneuvers and a decremental positive end-expiratory pressure trial in persistent acute respiratory distress syndrome.
- Lung Inflammation Persists After 27 Hours of Protective Acute Respiratory Distress Syndrome Network Strategy and Is Concentrated in the Nondependent Lung(2015) BORGES, Joao Batista; COSTA, Eduardo L. V.; BERGQUIST, Maria; LUCCHETTA, Luca; WIDSTROM, Charles; MARIPUU, Enn; SUAREZ-SIPMANN, Fernando; LARSSON, Anders; AMATO, Marcelo B. P.; HEDENSTIERNA, GoranObjective: PET with [F-18]fluoro-2-deoxy-D-glucose can be used to image cellular metabolism, which during lung inflammation mainly reflects neutrophil activity, allowing the study of regional lung inflammation in vivo. We aimed at studying the location and evolution of inflammation by PET imaging, relating it to morphology (CT), during the first 27 hours of application of protective-ventilation strategy as suggested by the Acute Respiratory Distress Syndrome Network, in a porcine experimental model of acute respiratory distress syndrome. Design: Prospective laboratory investigation. Setting: University animal research laboratory. Subjects: Ten piglets submitted to an experimental model of acute respiratory distress syndrome. Interventions: Lung injury was induced by lung lavages and 210 minutes of injurious mechanical ventilation using low positive end-expiratory pressure and high inspiratory pressures. During 27 hours of controlled mechanical ventilation according to Acute Respiratory Distress Syndrome Network strategy, the animals were studied with dynamic PET imaging of [F-18]fluoro-2-deoxy-D-glucose at two occasions with 24-hour interval between them. Measurements and Main Results: [F-18]fluoro-2-deoxy-D-glucose uptake rate was computed for the total lung, four horizontal regions from top to bottom (nondependent to dependent regions) and for voxels grouped by similar density using standard Hounsfield units classification. The global lung uptake was elevated at 3 and 27 hours, suggesting persisting inflammation. In both PET acquisitions, nondependent regions presented the highest uptake (p = 0.002 and p = 0.006). Furthermore, from 3 to 27 hours, there was a change in the distribution of regional uptake (p = 0.003), with more pronounced concentration of inflammation in nondependent regions. Additionally, the poorly aerated tissue presented the largest uptake concentration after 27 hours. Conclusions: Protective Acute Respiratory Distress Syndrome Network strategy did not attenuate global pulmonary inflammation during the first 27 hours after severe lung insult. The strategy led to a concentration of inflammatory activity in the upper lung regions and in the poorly aerated lung regions. The present findings suggest that the poorly aerated lung tissue is an important target of the perpetuation of the inflammatory process occurring during ventilation according to the Acute Respiratory Distress Syndrome Network strategy.