Browsing by Author "Pinheiro, Bruno Valle"

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    Adherence to low tidal volume in the transition to spontaneous ventilation in patients with acute respiratory failure in intensive care units in Latin America (SPIRAL): a study protocol
    (Associacao de Medicina Intensiva Brasileira - AMIB, 2024) Diniz-Silva, Fabia; Pinheiro, Bruno Valle; Reyes, Luis Felipe; Cavalcanti, Alexandre Biasi; Figueredo, Belinda; Rios, Fernando; Machado, Flávia Ribeiro; Preda, Gabriel; Bugedo Tarraza, Guillermo Jaime; Maia, Israel Silva; da Silveira, Leda Tomiko Yamada; Herrera, Luis; Jibaja, Manuel; Ibarra-Estrada, Miguel; Cestari, Mino; Nin, Nicolás; Roldan, Rollin; Dos Santos, Tiago Mendonça; Veiga, Viviane Cordeiro; Bruhn Cruz, Alejandro Rodrigo; Ferreira, Juliana Carvalho
    © 2024, Associacao de Medicina Intensiva Brasileira - AMIB. All rights reserved.Objective: Patients with acute respiratory failure often require mechanical ventilation to reduce the work of breathing and improve gas exchange; however, this may exacerbate lung injury. Protective ventilation strategies, characterized by low tidal volumes (≤ 8mL/kg of predicted body weight) and limited plateau pressure below 30cmH2O, have shown improved outcomes in patients with acute respiratory distress syndrome. However, in the transition to spontaneous ventilation, it can be challenging to maintain tidal volume within protective levels, and it is unclear whether low tidal volumes during spontaneous ventilation impact patient outcomes. We developed a study protocol to estimate the prevalence of low tidal volume ventilation in the first 24 hours of spontaneous ventilation in patients with hypoxemic acute respiratory failure and its association with ventilator-free days and survival. Methods: We designed a multicenter, multinational, cohort study with a 28-day follow-up that will include patients with acute respiratory failure, defined as a partial oxygen pressure/ fraction of inspired oxygen ratio < 300mmHg, in transition to spontaneous ventilation in intensive care units in Latin America. Results: We plan to include 422 patients in ten countries. The primary outcomes are the prevalence of low tidal volume in the first 24 hours of spontaneous ventilation and ventilator-free days on day 28. The secondary outcomes are intensive care unit and hospital mortality, incidence of asynchrony and return to controlled ventilation and sedation. Conclusion: In this study, we will assess the prevalence of low tidal volume during spontaneous ventilation and its association with clinical outcomes, which can inform clinical practice and future clinical trials.
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    Hyperventilation worsens inflammatory lung injury in spontaneously breathing rats
    (2024) Ferreira, Juliana Dias Nascimento; Reboredo, Maycon Moura; Costa, Eduardo Leite Vieira; da Fonseca, Lidia Maria Carneiro; Retamal Montes, Jaime; Santos, Fabricio Junio Mendes; de Paoli, Flavia; da Fonseca, Adenilson de Souza; Lucinda, Leda Marilia Fonseca; Pinheiro, Bruno Valle
    Objectives: Here, we investigated the effects of hyperventilation on acute lung injury (ALI) in spontaneously breathing rats. Methods: Wistar rats were randomized to receive either intraperitoneal lipopolysaccharides (LPS) or saline, and intravenous infusion of NH4Cl (to induce metabolic acidosis and hyperventilation) or saline. Four groups were established: control-control (C-C), control-hyperventilation (C-HV), LPS-control (LPS-C), and LPS-hyperventilation (LPS-HV). Venous blood gases were collected before and after NH4Cl infusion and analyzed to confirm the presence of metabolic acidosis and hyperventilation. After euthanasia, lung injury was assessed using the ALI score, morphometric quantification of perivascular edema, neutrophil counts in the bronchoalveolar lavage, and mRNA expression of biological markers in the lung tissue. Results: Hyperventilation induced inflammatory lung injury in previously healthy lungs and exacerbated injuries previously induced by LPS (ALI score: C-C=0.14 [IQR 0.12; 0.56; 0.62]; p<0.01). Perivascular edema, neutrophil counts in bronchoalveolar lavage, and amphiregulin mRNA expression were higher in the LPS-HV group compared to the control group. Conclusions: Hyperventilation increased inflammatory injury in rats with ALI during spontaneous ventilation. These results suggest that the impact of vigorous spontaneous breathing efforts on worsening inflammatory lung injury warrants further investigation.