SERGIO MARTINS PEREIRA
Projetos de Pesquisa
Unidades Organizacionais
LIM/09 - Laboratório de Pneumologia, Hospital das Clínicas, Faculdade de Medicina
3 resultados
Resultados de Busca
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- High Positive End-Expiratory Pressure Renders Spontaneous Effort Noninjurious(2018) MORAIS, Caio C. A.; KOYAMA, Yukiko; YOSHIDA, Takeshi; PLENS, Glauco M.; GOMES, Susimeire; LIMA, Cristhiano A. S.; RAMOS, Ozires P. S.; PEREIRA, Sergio M.; KAWAGUCHI, Naomasa; YAMAMOTO, Hirofumi; UCHIYAMA, Akinori; BORGES, Joao B.; MELO, Marcos F. Vidal; TUCCI, Mauro R.; AMATO, Marcelo B. P.; KAVANAGH, Brian P.; COSTA, Eduardo L. V.; FUJINO, YujiRationale: In acute respiratory distress syndrome (ARDS), atelectatic solid-like lung tissue impairs transmission of negative swings in pleural pressure (Ppl) that result from diaphragmatic contraction. The localization of more negative Ppl proportionally increases dependent lung stretch by drawing gas either from other lung regions (e.g., nondependent lung [pendelluft]) or from the ventilator. Lowering the level of spontaneous effort and/or converting solid-like to fluid-like lung might render spontaneous effort noninjurious. Objectives: To determine whether spontaneous effort increases dependent lung injury, and whether such injury would be reduced by recruiting atelectatic solid-like lung with positive end-expiratory pressure (PEEP). Methods: Established models of severe ARDS (rabbit, pig) were used. Regional histology (rabbit), inflammation (positron emission tomography; pig), regional inspiratory Ppl (intrabronchial balloon manometry), and stretch (electrical impedance tomography; pig) were measured. Respiratory drive was evaluated in 11 patients with ARDS. Measurements and Main Results: Although injury during muscle paralysis was predominantly in nondependent and middle lung regions at low (vs. high) PEEP, strong inspiratory effort increased injury (indicated by positron emission tomography and histology) in dependent lung. Stronger effort (vs. muscle paralysis) caused local overstretch and greater tidal recruitment in dependent lung, where more negative Ppl was localized and greater stretch was generated. In contrast, high PEEP minimized lung injury by more uniformly distributing negative Ppl, and lowering the magnitude of spontaneous effort (i.e., deflection in esophageal pressure observed in rabbits, pigs, and patients). Conclusions: Strong effort increased dependent lung injury, where higher local lung stress and stretch was generated; effort-dependent lung injury was minimized by high PEEP in severe ARDS, which may offset need for paralysis.
- Individual Positive End-expiratory Pressure Settings Optimize Intraoperative Mechanical Ventilation and Reduce Postoperative Atelectasis(2018) PEREIRA, Sergio M.; TUCCI, Mauro R.; MORAIS, Caio C. A.; SIMOES, Claudia M.; TONELOTTO, Bruno F. F.; POMPEO, Michel S.; KAY, Fernando U.; PELOSI, Paolo; VIEIRA, Joaquim E.; AMATO, Marcelo B. P.Background: Intraoperative lung-protective ventilation has been recommended to reduce postoperative pulmonary complications after abdominal surgery. Although the protective role of a more physiologic tidal volume has been established, the added protection afforded by positive end-expiratory pressure (PEEP) remains uncertain. The authors hypothesized that a low fixed PEEP might not fit all patients and that an individually titrated PEEP during anesthesia might improve lung function during and after surgery. Methods: Forty patients were studied in the operating room (20 laparoscopic and 20 open-abdominal). They underwent elective abdominal surgery and were randomized to institutional PEEP (4 cm H2O) or electrical impedance tomography-guided PEEP (applied after recruitment maneuvers and targeted at minimizing lung collapse and hyperdistension, simultaneously). Patients were extubated without changing selected PEEP or fractional inspired oxygen tension while under anesthesia and submitted to chest computed tomography after extubation. Our primary goal was to individually identify the electrical impedance tomography-guided PEEP value producing the best compromise of lung collapse and hyperdistention. Results: Electrical impedance tomography-guided PEEP varied markedly across individuals (median, 12 cm H2O; range, 6 to 16 cm H2O; 95% CI, 10-14). Compared with PEEP of 4 cm H2O, patients randomized to the electrical impedance tomography-guided strategy had less postoperative atelectasis (6.2 +/- 4.1 vs. 10.8 +/- 7.1% of lung tissue mass; P = 0.017) and lower intraoperative driving pressures (mean values during surgery of 8.0 +/- 1.7 vs. 11.6 +/- 3.8 cm H2O; P < 0.001). The electrical impedance tomography-guided PEEP arm had higher intraoperative oxygenation (435 +/- 62 vs. 266 +/- 76 mmHg for laparoscopic group; P < 0.001), while presenting equivalent hemodynamics (mean arterial pressure during surgery of 80 +/- 14 vs. 78 +/- 15 mmHg; P = 0.821). Conclusions: PEEP requirements vary widely among patients receiving protective tidal volumes during anesthesia for abdominal surgery. Individualized PEEP settings could reduce postoperative atelectasis (measured by computed tomography) while improving intraoperative oxygenation and driving pressures, causing minimum side effects.
- Individualizing Intraoperative Ventilation: Reply(2019) TUCCI, Mauro R.; PEREIRA, Sergio M.; VIEIRA, Joaquim E.; AMATO, Marcelo B. P.