VINICIUS TORSANI
Projetos de Pesquisa
Unidades Organizacionais
Instituto Central, Hospital das Clínicas, Faculdade de Medicina
4 resultados
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conferenceObject Peep Titration In Severe Acute Respiratory Distress Syndrome: Different Physiological Consequences When Guided By Electrical Impedance Tomography Versus Esophageal Pressure(2017) ROLDAN, R.; LIMA, C.; YOSHIDA, T.; SANTIAGO, R. R. D. S.; GOMES, S.; TUCCI, M. R.; BERALDO, M. A.; COSTA, E. L. V.; TORSANI, V.; NAKAMURA, M. A. M.; CARVALHO, C. R. R.; AMATO, M. B. P.- Spontaneous Effort During Mechanical Ventilation: Maximal Injury With Less Positive End-Expiratory Pressure(2016) YOSHIDA, Takeshi; ROLDAN, Rollin; BERALDO, Marcelo A.; TORSANI, Vinicius; GOMES, Susimeire; SANTIS, Roberta R. De; COSTA, Eduardo L. V.; TUCCI, Mauro R.; LIMA, Raul G.; KAVANAGH, Brian P.; AMATO, Marcelo B. P.Objectives: We recently described how spontaneous effort during mechanical ventilation can cause ""pendelluft,"" that is, displacement of gas from nondependent (more recruited) lung to dependent (less recruited) lung during early inspiration. Such transfer depends on the coexistence of more recruited (source) liquid-like lung regions together with less recruited (target) solid-like lung regions. Pendelluft may improve gas exchange, but because of tidal recruitment, it may also contribute to injury. We hypothesize that higher positive end-expiratory pressure levels decrease the propensity to pendelluft and that with lower positive end-expiratory pressure levels, pendelluft is associated with improved gas exchange but increased tidal recruitment. Design: Crossover design. Setting: University animal research laboratory. Subjects: Anesthetized landrace pigs. Interventions: Surfactant depletion was achieved by saline lavage in anesthetized pigs, and ventilator-induced lung injury was produced by ventilation with high tidal volume and low positive end-expiratory pressure. Ventilation was continued in each of four conditions: positive end-expiratory pressure (low or optimized positive end-expiratory pressure after recruitment) and spontaneous breathing (present or absent). Tidal recruitment was assessed using dynamic CT and regional ventilation/perfusion using electric impedance tomography. Esophageal pressure was measured using an esophageal balloon manometer. Measurements and Results: Among the four conditions, spontaneous breathing at low positive end-expiratory pressure not only caused the largest degree of pendelluft, which was associated with improved ventilation/perfusion matching and oxygenation, but also generated the greatest tidal recruitment. At low positive end-expiratory pressure, paralysis worsened oxygenation but reduced tidal recruitment. Optimized positive end-expiratory pressure decreased the magnitude of spontaneous efforts (measured by esophageal pressure) despite using less sedation, from -5.6 +/- 1.3 to -2.0 +/- 0.7 cm H2O, while concomitantly reducing pendelluft and tidal recruitment. No pendelluft was observed in the absence of spontaneous effort. Conclusions: Spontaneous effort at low positive end-expiratory pressure improved oxygenation but promoted tidal recruitment associated with pendelluft. Optimized positive end-expiratory pressure (set after lung recruitment) may reverse the harmful effects of spontaneous breathing by reducing inspiratory effort, pendelluft, and tidal recruitment.
conferenceObject Transpulmonary Pressure Based On Absolute Esophageal Pressure Measurement Predicts Morphological Changes Of Lung Parenchyma In An Experimental Animal Model(2016) FUMAGALLI, J.; ZHANG, C.; TORSANI, V.; PIRRONE, M.; GOMEZ, S.; SANTIS, S. De; TUCCI, M.; RAMOS, O.; LIMA, C.; BENTO, G.; BERRA, L.; KACMAREK, R.; AMATO, M. B. P.- Quantitative Dual-Energy Computed Tomography Predicts Regional Perfusion Heterogeneity in a Model of Acute Lung Injury(2018) KAY, Fernando Uliana; BERALDO, Marcelo A.; NAKAMURA, Maria A. M.; SANTIAGO, Roberta De Santis; TORSANI, Vinicius; GOMES, Susimeire; ROLDAN, Rollin; TUCCI, Mauro R.; ABBARA, Suhny; AMATO, Marcelo B. P.; AMARO JR., EdsonObjective The aims of this study were to investigate the ability of contrast-enhanced dual-energy computed tomography (DECT) for assessing regional perfusion in a model of acute lung injury, using dynamic first-pass perfusion CT (DynCT) as the criterion standard and to evaluate if changes in lung perfusion caused by prone ventilation are similarly demonstrated by DECT and DynCT. Methods This was an institutional review board-approved study, compliant with guidelines for humane care of laboratory animals. A ventilator-induced lung injury protocol was applied to 6 landrace pigs. Perfused blood volume (PBV) and pulmonary blood flow (PBF) were respectively quantified by DECT and DynCT, in supine and prone positions. The lungs were segmented in equally sized regions of interest, namely, dorsal, middle, and ventral. Perfused blood volume and PBF values were normalized by lung density. Regional air fraction (AF) was assessed by triple-material decomposition DECT. Per-animal correlation between PBV and PBF was assessed with Pearson R. Regional differences in PBV, PBF, and AF were evaluated with 1-way analysis of variance and post hoc linear trend analysis ( = 5%). Results Mean correlation coefficient between PBV and PBF was 0.70 (range, 0.55-0.98). Higher PBV and PBF values were observed in dorsal versus ventral regions. Dorsal-to-ventral linear trend slopes were -10.24 mL/100 g per zone for PBV (P < 0.001) and -223.0 mL/100 g per minute per zone for PBF (P < 0.001). Prone ventilation also revealed higher PBV and PBF in dorsal versus ventral regions. Dorsal-to-ventral linear trend slopes were -16.16 mL/100 g per zone for PBV (P < 0.001) and -108.2 mL/100 g per minute per zone for PBF (P < 0.001). By contrast, AF was lower in dorsal versus ventral regions in supine position, with dorsal-to-ventral linear trend slope of +5.77%/zone (P < 0.05). Prone ventilation was associated with homogenization of AF distribution among different regions (P = 0.74). Conclusions Dual-energy computed tomography PBV is correlated with DynCT-PBF in a model of acute lung injury, and able to demonstrate regional differences in pulmonary perfusion. Perfusion was higher in the dorsal regions, irrespectively to decubitus, with more homogeneous lung aeration in prone position.