VINICIUS TORSANI
Projetos de Pesquisa
Unidades Organizacionais
Instituto Central, Hospital das Clínicas, Faculdade de Medicina
4 resultados
Resultados de Busca
Agora exibindo 1 - 4 de 4
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.
- Volume-controlled Ventilation Does Not Prevent Injurious Inflation during Spontaneous Effort(2017) YOSHIDA, Takeshi; NAKAHASHI, Susumu; NAKAMURA, Maria Aparecida Miyuki; KOYAMA, Yukiko; ROLDAN, Rollin; TORSANI, Vinicius; SANTIS, Roberta R. De; GOMES, Susimeire; UCHIYAMA, Akinori; AMATO, Marcelo B. P.; KAVANAGH, Brian P.; FUJINO, YujiRationale: Spontaneous breathing during mechanical ventilation increases transpulmonary pressure and VT, and worsens lung injury. Intuitively, controlling VT and transpulmonary pressure might limit injury caused by added spontaneous effort. Objectives: To test the hypothesis that, during spontaneous effort in injured lungs, limitation of VT and transpulmonary pressure by volume-controlled ventilation results in less injurious patterns of inflation. Methods: Dynamic computed tomography was used to determine patterns of regional inflation in rabbits with injured lungs during volume-controlled or pressure-controlled ventilation. Transpulmonary pressure was estimated by using esophageal balloon manometry [PL(es)] with and without spontaneous effort. Local dependent lung stress was estimated as the swing (inspiratory change) in transpulmonary pressure measured by intrapleural manometry in dependent lung and was compared with the swing in PL(es). Electrical impedance tomography was performed to evaluate the inflation pattern in a larger animal (pig) and in a patient with acute respiratory distress syndrome. Measurements and Main Results: Spontaneous breathing in injured lungs increased PL(es) during pressure-controlled (but not volume-controlled) ventilation, but the pattern of dependent lung inflation was the same in both modes. In volume-controlled ventilation, spontaneous effort caused greater inflation and tidal recruitment of dorsal regions (greater than twofold) compared with during muscle paralysis, despite the same VT and PL(es). This was caused by higher local dependent lung stress (measured by intrapleural manometry). In injured lungs, esophageal manometry underestimated local dependent pleural pressure changes during spontaneous effort. Conclusions: Limitation of VT and PL(es) by volume-controlled ventilation could not eliminate harm caused by spontaneous breathing unless the level of spontaneous effort was lowered and local dependent lung stress was reduced.
- Chest electrical impedance tomography examination, data analysis, terminology, clinical use and recommendations: consensus statement of the TRanslational EIT developmeNt stuDy group(2017) FRERICHS, Inez; AMATO, Marcelo B. P.; KAAM, Anton H. van; TINGAY, David G.; ZHAO, Zhanqi; GRYCHTOL, Bartlomiej; BODENSTEIN, Marc; GAGNON, Herve; BOHM, Stephan H.; TESCHNER, Eckhard; STENQVIST, Ola; MAURI, Tommaso; TORSANI, Vinicius; CAMPOROTA, Luigi; SCHIBLER, Andreas; WOLF, Gerhard K.; GOMMERS, Diederik; LEONHARDT, Steffen; ADLER, AndyElectrical impedance tomography (EIT) has undergone 30 years of development. Functional chest examinations with this technology are considered clinically relevant, especially for monitoring regional lung ventilation in mechanically ventilated patients and for regional pulmonary function testing in patients with chronic lung diseases. As EIT becomes an established medical technology, it requires consensus examination, nomenclature, data analysis and interpretation schemes. Such consensus is needed to compare, understand and reproduce study findings from and among different research groups, to enable large clinical trials and, ultimately, routine clinical use. Recommendations of how EIT findings can be applied to generate diagnoses and impact clinical decision-making and therapy planning are required. This consensus paper was prepared by an international working group, collaborating on the clinical promotion of EIT called TRanslational EIT developmeNt stuDy group. It addresses the stated needs by providing (1) a new classification of core processes involved in chest EIT examinations and data analysis, (2) focus on clinical applications with structured reviews and outlooks (separately for adult and neonatal/paediatric patients), (3) a structured framework to categorise and understand the relationships among analysis approaches and their clinical roles, (4) consensus, unified terminology with clinical user-friendly definitions and explanations, (5) a review of all major work in thoracic EIT and (6) recommendations for future development (193 pages of online supplements systematically linked with the chief sections of the main document). We expect this information to be useful for clinicians and researchers working with EIT, as well as for industry producers of this technology.