JOAO BATISTA BORGES SOBRINHO DORINI
Projetos de Pesquisa
Unidades Organizacionais
LIM/09 - Laboratório de Pneumologia, Hospital das Clínicas, Faculdade de Medicina
35 resultados
Resultados de Busca
Agora exibindo 1 - 10 de 35
- Validation of bohr dead space measured by volumetric capnography(2012) TUSMAN, G.; SUAREZ-SIPMANN, F.; BORGES, J. B.; HEDENSTIERNA, G.; BOHM, S. H.Purpose: Bohr’s dead space (VDBohr) is commonly calculated using end-tidal CO2 instead of the true alveolar partial pressure of CO2 (PACO2). The aim of this work was to validate VDBohr using PACO2 derived from volumetric capnography (VC) against VDBohr with PACO2 values obtained from the standard alveolar air formula. Methods: Expired gases of seven lung-lavaged pigs were analyzed at different lung conditions using mainstream VC and multiple inert gas elimination technique (MIGET). Paco2 was determined by VC as the midpoint of the slope of phase III of the capnogram, while mean expired partial pressure of CO2 (PeCO2) was calculated as the mean expired fraction of CO2 times the barometric minus the water vapor pressure. Miget estimated expired CO2 output (VCO2) and PeCO2 by its V/Q algorithms. Then, PACO2 was obtained applying the alveolar air formula (PACO2 = VCO2/alveolar ventilation). Results: We found close linear correlations between the two methods for calculating both PACO2 (r = 0.99) and VDBohr (r = 0.96), respectively (both p\0.0001). Mean PACO2 from VC was very similar to the one obtained by MIGET with a mean bias of -0.10 mmHg and limits of agreement between -2.18 and 1.98 mmHg. Mean VDBohr from VC was close to the value obtained by MIGET with a mean bias of 0.010 ml and limits of agreement between -0.044 and 0.064 ml. Conclusions: VDBohr can be calculated with accuracy using volumetric capnography. © Springer-Verlag Berlin Heidelberg 2006, 2009, 2012.
article Feasibility of Ga-68-labeled Siglec-9 peptide for the imaging of acute lung inflammation: a pilot study in a porcine model of acute respiratory distress syndrome(2016) RETAMAL, Jaime; SORENSEN, Jens; LUBBERINK, Mark; SUAREZ-SIPMANN, Fernando; BORGES, Joao Batista; FEINSTEIN, Ricardo; JALKANEN, Sirpa; ANTONI, Gunnar; HEDENSTIERNA, Goran; ROIVAINEN, Anne; LARSSON, Anders; VELIKYAN, IrinaThere is an unmet need for noninvasive, specific and quantitative imaging of inherent inflammatory activity. Vascular adhesion protein-1 (VAP-1) translocates to the luminal surface of endothelial cells upon inflammatory challenge. We hypothesized that in a porcine model of acute respiratory distress syndrome (ARDS), positron emission tomography (PET) with sialic acid-binding immunoglobulin-like lectin 9 (Siglec-9) based imaging agent targeting VAP-1 would allow quantification of regional pulmonary inflammation. ARDS was induced by lung lavages and injurious mechanical ventilation. Hemodynamics, respiratory system compliance (Crs) and blood gases were monitored. Dynamic examination using [O-15]water PET-CT (10 min) was followed by dynamic (90 min) and whole-body examination using VAP-1 targeting Ga-68-labeled 1,4,7,10-tetraaza cyclododecane-1,4,7-tris-acetic acid-10-ethylene glycol-conjugated Siglec-9 motif peptide ([Ga-68]Ga-DOTA-Siglec-9). The animals received an anti-VAP-1 antibody for post-mortem immunohistochemistry assay of VAP-1 receptors. Tissue samples were collected post-mortem for the radioactivity uptake, histology and immunohistochemistry assessment. Marked reduction of oxygenation and Crs, and higher degree of inflammation were observed in ARDS animals. [Ga-68]Ga-DOTA-Siglec-9 PET showed significant uptake in lungs, kidneys and urinary bladder. Normalization of the net uptake rate (K-i) for the tissue perfusion resulted in 4-fold higher uptake rate of [Ga-68]Ga-DOTA-Siglec-9 in the ARDS lungs. Immunohistochemistry showed positive VAP-1 signal in the injured lungs. Detection of pulmonary inflammation associated with a porcine model of ARDS was possible with [Ga-68]Ga-DOTA-Siglec-9 PET when using kinetic modeling and normalization for tissue perfusion.- Hyperoxia affects the regional pulmonary ventilation/perfusion ratio: an electrical impedance tomography study(2014) LI, Y.; TESSELAAR, E.; BORGES, J. B.; BOHM, S. H.; SJOBERG, F.; JANEROT-SJOBERG, B.Background The way in which hyperoxia affects pulmonary ventilation and perfusion is not fully understood. We investigated how an increase in oxygen partial pressure in healthy young volunteers affects pulmonary ventilation and perfusion measured by thoracic electrical impedance tomography (EIT). Methods Twelve semi-supine healthy male volunteers aged 21-36 years were studied while breathing room air and air-oxygen mixtures (FiO2) that resulted in predetermined transcutaneous oxygen partial pressures (tcPO2) of 20, 40 and 60kPa. The magnitude of ventilation (Zv) and perfusion (ZQ)-related changes in cyclic impedance variations, were determined using an EIT prototype equipped with 32 electrodes around the thorax. Regional changes in ventral and dorsal right lung ventilation (V) and perfusion (Q) were estimated, and V/Q ratios calculated. Results There were no significant changes in Zv with increasing tcPO2 levels. ZQ in the dorsal lung increased with increasing tcPO2 (P=0.01), whereas no such change was seen in the ventral lung. There was a simultaneous decrease in V/Q ratio in the dorsal region during hyperoxia (P=0.04). Two subjects did not reach a tcPO2 of 60kPa despite breathing 100% oxygen. Conclusion These results indicate that breathing increased concentrations of oxygen induces pulmonary vasodilatation in the dorsal lung even at small increases in FiO2. Ventilation remains unchanged. Local mismatch of ventilation and perfusion occurs in young healthy men, and the change in ventilation/perfusion ratio can be determined non-invasively by EIT.
- Multiple inert gas elimination technique by micropore membrane inlet mass spectrometry-a comparison with reference gas chromatography(2013) KRETZSCHMAR, Moritz; SCHILLING, Thomas; VOGT, Andreas; ROTHEN, Hans Ulrich; BORGES, Joao Batista; HACHENBERG, Thomas; LARSSON, Anders; BAUMGARDNER, James E.; HEDENSTIERNA, GoranThe mismatching of alveolar ventilation and perfusion (V-A/Q) is the major determinant of impaired gas exchange. The gold standard for measuring V-A/Q distributions is based on measurements of the elimination and retention of infused inert gases. Conventional multiple inert gas elimination technique (MIGET) uses gas chromatography (GC) to measure the inert gas partial pressures, which requires tonometry of blood samples with a gas that can then be injected into the chromatograph. The method is laborious and requires meticulous care. A new technique based on micropore membrane inlet mass spectrometry (MMIMS) facilitates the handling of blood and gas samples and provides nearly real-time analysis. In this study we compared MIGET by GC and MMIMS in 10 piglets: 1) 3 with healthy lungs; 2) 4 with oleic acid injury; and 3) 3 with isolated left lower lobe ventilation. The different protocols ensured a large range of normal and abnormal V-A/Q distributions. Eight inert gases (SF6, krypton, ethane, cyclopropane, desflurane, enflurane, diethyl ether, and acetone) were infused; six of these gases were measured with MMIMS, and six were measured with GC. We found close agreement of retention and excretion of the gases and the constructed V-A/Q distributions between GC and MMIMS, and predicted Pa-O2 from both methods compared well with measured Pa-O2. V-A/Q by GC produced more widely dispersed modes than MMIMS, explained in part by differences in the algorithms used to calculate V-A/Q distributions. In conclusion, MMIMS enables faster measurement of V-A/Q, is less demanding than GC, and produces comparable results.
- Zero expiratory pressure and low oxygen concentration promote heterogeneity of regional ventilation and lung densities(2016) BORGES, J. B.; PORRA, L.; PELLEGRINI, M.; TANNOIA, A.; DEROSA, S.; LARSSON, A.; BAYAT, S.; PERCHIAZZI, G.; HEDENSTIERNA, G.BackgroundIt is not well known what is the main mechanism causing lung heterogeneity in healthy lungs under mechanical ventilation. We aimed to investigate the mechanisms causing heterogeneity of regional ventilation and parenchymal densities in healthy lungs under anesthesia and mechanical ventilation. MethodsIn a small animal model, synchrotron imaging was used to measure lung aeration and regional-specific ventilation (sV.). Heterogeneity of ventilation was calculated as the coefficient of variation in sV. (CVsV.). The coefficient of variation in lung densities (CVD) was calculated for all lung tissue, and within hyperinflated, normally and poorly aerated areas. Three conditions were studied: zero end-expiratory pressure (ZEEP) and FIO2 0.21; ZEEP and FIO2 1.0; PEEP 12 cmH(2)O and F(I)O(2)1.0 (Open Lung-PEEP = OLP). ResultsThe mean tissue density at OLP was lower than ZEEP-1.0 and ZEEP-0.21. There were larger subregions with low sV. and poor aeration at ZEEP-0.21 than at OLP: 12.9 9.0 vs. 0.6 +/- 0.4% in the non-dependent level, and 17.5 +/- 8.2 vs. 0.4 +/- 0.1% in the dependent one (P = 0.041). The CVsV. of the total imaged lung at PEEP 12 cmH(2)O was significantly lower than on ZEEP, regardless of FIO2, indicating more heterogeneity of ventilation during ZEEP (0.23 +/- 0.03 vs. 0.54 +/- 0.37, P = 0.049). CVD changed over the different mechanical ventilation settings (P = 0.011); predominantly, CVD increased during ZEEP. The spatial distribution of the CVD calculated for the poorly aerated density category changed with the mechanical ventilation settings, increasing in the dependent level during ZEEP. ConclusionZEEP together with low FIO2 promoted heterogeneity of ventilation and lung tissue densities, fostering a greater amount of airway closure and ventilation inhomogeneities in poorly aerated regions.
- How large is the lung recruitability in early acute respiratory distress syndrome: a prospective case series of patients monitored by computed tomography(2012) MATOS, Gustavo F. J. de; STANZANI, Fabiana; PASSOS, Rogerio H.; FONTANA, Mauricio F.; ALBALADEJO, Renata; CASERTA, Raquel E.; SANTOS, Durval C. B.; BORGES, Joao Batista; AMATO, Marcelo B. P.; BARBAS, Carmen S. V.Introduction: The benefits of higher positive end expiratory pressure (PEEP) in patients with acute respiratory distress syndrome (ARDS) have been modest, but few studies have fully tested the ""open-lung hypothesis"". This hypothesis states that most of the collapsed lung tissue observed in ARDS can be reversed at an acceptable clinical cost, potentially resulting in better lung protection, but requiring more intensive maneuvers. The short-/middle-term efficacy of a maximum recruitment strategy (MRS) was recently described in a small physiological study. The present study extends those results, describing a case-series of non-selected patients with early, severe ARDS submitted to MRS and followed until hospital discharge or death. Methods: MRS guided by thoracic computed tomography (CT) included two parts: a recruitment phase to calculate opening pressures (incremental steps under pressure-controlled ventilation up to maximum inspiratory pressures of 60 cmH(2)O, at constant driving-pressures of 15 cmH(2)O); and a PEEP titration phase (decremental PEEP steps from 25 to 10 cmH2O) used to estimate the minimum PEEP to keep lungs open. During all steps, we calculated the size of the non-aerated (-100 to +100 HU) compartment and the recruitability of the lungs (the percent mass of collapsed tissue re-aerated from baseline to maximum PEEP). Results: A total of 51 severe ARDS patients, with a mean age of 50.7 years (84% primary ARDS) was studied. The opening plateau-pressure was 59.6 (+/- 5.9 cmH(2)O), and the mean PEEP titrated after MRS was 24.6 (+/- 2.9 cmH(2)O). Mean PaO2/FiO(2) ratio increased from 125 (+/- 43) to 300 (+/- 103; P < 0.0001) after MRS and was sustained above 300 throughout seven days. Non-aerated parenchyma decreased significantly from 53.6% (interquartile range (IQR): 42.5 to 62.4) to 12.7% (IQR: 4.9 to 24.2) (P < 0.0001) after MRS. The potentially recruitable lung was estimated at 45% (IQR: 25 to 53). We did not observe major barotrauma or significant clinical complications associated with the maneuver. Conclusions: MRS could efficiently reverse hypoxemia and most of the collapsed lung tissue during the course of ARDS, compatible with a high lung recruitability in non-selected patients with early, severe ARDS. This strategy should be tested in a prospective randomized clinical trial.
- Ventilation Distribution Studies Comparing Technegas and ""Gallgas"" Using (GaCl3)-Ga-68 as the Label(2011) BORGES, Joao Batista; VELIKYAN, Irina; LANGSTROM, Bengt; SORENSEN, Jens; ULIN, Johan; MARIPUU, Enn; SANDSTROM, Mattias; WIDSTROM, Charles; HEDENSTIERNA, GoranVentilation distribution can be assessed by SPECT with Technegas. This study was undertaken in piglets with different degrees of ventilation inhomogeneity to compare PET using Ga-68-labeled pseudogas or ""Gallgas"" with Technegas. Methods: Twelve piglets were studied in 3 groups: control, lobar obstruction, and diffuse airway obstruction. Two more piglets were assessed for lung volume (functional residual capacity). Results: In controls, SPECT and PET images showed an even distribution of radioactivity. With lobar obstruction, the absence of ventilation of the obstructed lobe was visible with both techniques. In diffuse airway obstruction, SPECT images showed an even distribution of radioactivity, and PET images showed more varied radioactivity over the lung. Conclusion: PET provides detailed ventilation distribution images and a better appreciation of ventilation heterogeneity. Gallgas with PET is a promising new diagnostic tool for the assessment of ventilation distribution.
- Real-time ventilation and perfusion distributions by electrical impedance tomography during one-lung ventilation with capnothorax(2015) REINIUS, H.; BORGES, J. B.; FREDEN, F.; JIDEUS, L.; CAMARGO, E. D. L. B.; AMATO, M. B. P.; HEDENSTIERNA, G.; LARSSON, A.; LENNMYR, F.BackgroundCarbon dioxide insufflation into the pleural cavity, capnothorax, with one-lung ventilation (OLV) may entail respiratory and hemodynamic impairments. We investigated the online physiological effects of OLV/capnothorax by electrical impedance tomography (EIT) in a porcine model mimicking the clinical setting. MethodsFive anesthetized, muscle-relaxed piglets were subjected to first right and then left capnothorax with an intra-pleural pressure of 19cm H2O. The contra-lateral lung was mechanically ventilated with a double-lumen tube at positive end-expiratory pressure 5 and subsequently 10cm H2O. Regional lung perfusion and ventilation were assessed by EIT. Hemodynamics, cerebral tissue oxygenation and lung gas exchange were also measured. ResultsDuring right-sided capnothorax, mixed venous oxygen saturation (P=0.018), as well as a tissue oxygenation index (P=0.038) decreased. There was also an increase in central venous pressure (P=0.006), and a decrease in mean arterial pressure (P=0.045) and cardiac output (P=0.017). During the left-sided capnothorax, the hemodynamic impairment was less than during the right side. EIT revealed that during the first period of OLV/capnothorax, no or very minor ventilation on the right side could be seen (33% vs. 97 +/- 3%, right vs. left, P=0.007), perfusion decreased in the non-ventilated and increased in the ventilated lung (18 +/- 2% vs. 82 +/- 2%, right vs. left, P=0.03). During the second OLV/capnothorax period, a similar distribution of perfusion was seen in the animals with successful separation (84 +/- 4% vs. 16 +/- 4%, right vs. left). ConclusionEIT detected in real-time dynamic changes in pulmonary ventilation and perfusion distributions. OLV to the left lung with right-sided capnothorax caused a decrease in cardiac output, arterial oxygenation and mixed venous saturation.
- 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)
- Electrical impedance tomography in acute respiratory distress syndrome(2018) BACHMANN, M. Consuelo; MORAIS, Caio; BUGEDO, Guillermo; BRUHN, Alejandro; MORALES, Arturo; BORGES, Joao B.; COSTA, Eduardo; RETAMAL, JaimeAcute 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.