Variable positive end-expiratory pressure can maintain oxygenation in experimental acute respiratory distress syndrome induced by oleic acid in dogs

The use of positive end-expiratory pressure (PEEP) or lung recruitment maneuvers (RM) to improve oxygenation in acute respiratory distress syndrome (ARDS) is used but it may reduce cardiac output (CO). Intermittent PEEP may avoid these complications. Our objective was to determine if variable PEEP compared with constant PEEP is capable of maintaining arterial oxygenation and minimizing hemodynamic alterations with or without RM. Eighteen dogs with ARDS induced by oleic acid were randomized into three equal groups: group 1, low variable PEEP; group 2, high variable PEEP, and group 3, RM + high variable PEEP. All groups were submitted to constant PEEP, followed by variable PEEP (PEEP was increased from 5 to 10 cmH2O in group 1, and from 5 to 18 cmH2O in the other two groups). PaO2 was higher in group 3 (356.2 ± 65.4 mmHg) than in group 1 (92.7 ± 29.7 mmHg) and group 2 (228.5 ± 72.4 mmHg), P 0.05. Variable PEEP is able to maintain PaO2 when performed in combination with RM in dogs with ARDS. After RM, CO was reduced and there was no relevant difference between the variable and constant PEEP periods.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de MedicinaCentro Universitário São CamiloUniversidade de São Paulo Faculdade de Medicina Laboratório de Investigação Médica (LIM 12)UNIFESP, EPM, Depto. de MedicinaSciEL

Pentoxifylline decreases tumor necrosis factor and interleukin-1 during high tidal volume

Tumor necrosis factor-alpha (TNF-alpha) is one of the most important proinflammatory cytokines which plays a central role in host defense and in the acute inflammatory response related to tissue injury. The major source of TNF-alpha are immune cells such as neutrophils and macrophages. We tested the hypothesis that pentoxifylline, a methylxanthine derivative, down-regulates proinflammatory cytokine expression during acute lung injury in rats. Male Wistar rats weighing 250 to 450 g were anesthetized ip with 50 mg/kg sodium thiopental and randomly divided into three groups: group 1 (N = 7): tidal volume (V T) = 7 ml/kg, respiratory rate (RR) = 50 breaths/min and normal saline infusion; group 2 (N = 7): V T = 42 ml/kg, RR = 9 breaths/min and normal saline infusion; group 3 (N = 7): V T = 42 ml/kg, RR = 9 breaths/min and pentoxifylline infusion. The animals were ventilated with an inspired oxygen fraction of 1.0, a positive end-expiratory pressure of 3 cmH2O, and normal saline or pentoxifylline injected into the left femoral vein. The mRNA of TNF-alpha rapidly increased in the lung tissue within 180 min of ventilation with a higher V T with normal saline infusion. The concentrations of inflammatory mediators were decreased in plasma and bronchoalveolar lavage (BAL) in the presence of higher V T with pentoxifylline infusion (TNF-alpha: plasma, 102.2 ± 90.9 and BAL, 118.2 ± 82.1; IL-1ß: plasma, 45.2 ± 42.7 and BAL, 50.2 ± 34.9, P < 0.05). We conclude that TNF-alpha produced by neutrophil influx may function as an alert signal in host defense to induce production of other inflammatory mediators.Universidade Federal de São Paulo (UNIFESP) Departamento de Doenças Infecciosas e Parasitárias Disciplina de PneumologiaUniversidade Federal de São Paulo (UNIFESP) Departamento de Doenças Infecciosas e Parasitárias Laboratório de Ginecologia MolecularUniversidade Federal de São Paulo (UNIFESP) Departamento de Doenças Infecciosas e Parasitárias Laboratório de ImunologiaUniversidade Estadual de Campinas Departamento de Clínica Médica Disciplina e Laboratório de Imunologia ClínicaUNIFESP, Depto. de Doenças Infecciosas e Parasitárias Disciplina de PneumologiaUNIFESP, Depto. de Doenças Infecciosas e Parasitárias Laboratório de Ginecologia MolecularUNIFESP, Depto. de Doenças Infecciosas e Parasitárias Laboratório de ImunologiaSciEL

Predictors of prolonged ventilator weaning and mortality in critically ill patients with COVID-19

ABSTRACT Objective: To identify factors associated with prolonged weaning and mortality in critically ill COVID-19 patients admitted to ICUs and under invasive mechanical ventilation. Methods: Between March of 2020 and July of 2021, we retrospectively recorded clinical and ventilatory characteristics of critically ill COVID-19 patients from the day of intubation to the outcome. We classified the patients regarding the weaning period in accordance with established criteria. A logistic regression analysis was performed to identify variables associated with prolonged weaning and mortality. Results: The study involved 303 patients, 100 of whom (33.0%) had a prolonged weaning period. Most of the patients were male (69.6%), 136 (44.8%) had more than 50% of pulmonary involvement on chest CT, and 93 (30.6%) had severe ARDS. Within the prolonged weaning group, 62% died within 60 days. Multivariate analysis revealed that lung involvement greater than 50% on CT and delay from intubation to the first separation attempt from mechanical ventilation were significantly associated with prolonged weaning, whereas age and prolonged weaning were significantly associated with mortality. Conclusions: Prolonged weaning can be used as a milestone in predicting mortality in critically ill COVID-19 patients. Lung involvement greater than 50% on CT and delay from intubation to the first separation attempt from mechanical ventilation were identified as significant predictors of prolonged weaning. These results might provide valuable information for healthcare professionals when making clinical decisions regarding the management of critically ill COVID-19 patients who are on mechanical ventilation

Statement of Second Brazilian Congress of Mechanical Ventilarion : part I

Resumo não disponíve

Funcao e estrutura pulmonar em caes vagotomizados

BV UNIFESP: Teses e dissertaçõe