Rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART): Study protocol for a randomized controlled trial

Background: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). Methods/Design: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH(2)O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure <= 30 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. Discussion: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration method.Hospital do Coracao (HCor) as part of the Program 'Hospitais de Excelencia a Servico do SUS (PROADI-SUS)'Brazilian Ministry of Healt

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

<i>Cryptococcus neoformans</i> Is Internalized by Receptor-Mediated or ‘Triggered’ Phagocytosis, Dependent on Actin Recruitment

<div><p>Cryptococcosis by the encapsulated yeast <i>Cryptococcus neoformans</i> affects mostly immunocompromised individuals and is a frequent neurological complication in AIDS patients. Recent studies support the idea that intracellular survival of <i>Cryptococcus</i> yeast cells is important for the pathogenesis of cryptococcosis. However, the initial steps of <i>Cryptococcus</i> internalization by host cells remain poorly understood. Here, we investigate the mechanism of <i>Cryptococcus neoformans</i> phagocytosis by peritoneal macrophages using confocal and electron microscopy techniques, as well as flow cytometry quantification, evaluating the importance of fungal capsule production and of host cell cytoskeletal elements for fungal phagocytosis. Electron microscopy analyses revealed that capsular and acapsular strains of <i>C. neoformans</i> are internalized by macrophages via both ‘zipper’ (receptor-mediated) and ‘trigger’ (membrane ruffle-dependent) phagocytosis mechanisms. Actin filaments surrounded phagosomes of capsular and acapsular yeasts, and the actin depolymerizing drugs cytochalasin D and latrunculin B inhibited yeast internalization and actin recruitment to the phagosome area. In contrast, nocodazole and paclitaxel, inhibitors of microtubule dynamics decreased internalization but did not prevent actin recruitment to the site of phagocytosis. Our results show that different uptake mechanisms, dependent on both actin and tubulin dynamics occur during yeast internalization by macrophages, and that capsule production does not affect the mode of <i>Cryptococcus</i> uptake by host cells.</p></div

Actin recruitment is inhibited by cytochalasin D.

<p>Confocal laser scanning microscopy of <i>C. neoformans</i> capsular strain H99 interacting with macrophages (single confocal plane). DIC showing internalized yeasts (arrows); and confocal images showing actin filaments (red), microtubules (green), yeast (blue) and host DNA (blue, indicated by ‘n’). Actin is recruited to the site of phagocytosis in untreated cells (A), and actin recruitment was inhibited by 0.5 µM cytochalasin D (B). In contrast, treatment with 5 µM nocodazole (C) or with a combination of nocodazole and cytochalasin D (D) did not inhibit actin recruitment to the phagosome area. Scale bars, 5 µm.</p

Treatment with both cytochalasin D and nocodazole did not increase the inhibitory effect.

<p>Quantification of the internalization (A) and the attachment (B) to macrophages of <i>C. neoformans</i> yeast cells from capsular (H99 and B3501) and acapsular (CAP67 and CAP 59) strains, in the absence of cytoskeletal inhibitors or in the presence of cytochalasin D and nocodazole. The metabolic viability of <i>C. neoformans</i> strains H99 and CAP59 was measured using the FUN®-1 dye (C) and the metabolic viability of macrophages was measured by MTS/PMS (D) after incubation with cytoskeletal inhibitors for 2 h. Yeast cells fixed with 70% ethanol, and macrophages with 4% formaldehyde, were used as a positive control for the loss of cell viability in each method. Graphs show normalized mean values and standard deviation from three experiments (A–B) and mean and standard deviation from absolute values of fluorescence intensity (C) and absorbance (D).*p<0.05; **p<0.01; ***p<0.001.</p

Uptake of <i>Cryptococcus</i> strains by trigger-like and zipper-like structures.

<p>Scanning electron microscopy of <i>C. neoformans</i> capsular strain H99 (A–E) and acapsular strain CAP59 (F–G) interacting with peritoneal macrophages. Improved preservation of macrophage membranes was obtained with routine SEM fixation (A–B; F–G), although post-fixation in the presence of sucrose provided better capsule preservation and allowed visualization of direct interactions between the capsule and host cell membranes, prior to internalization (C–E). Both trigger-like (arrow in A and F) and zipper-like (arrow-head in B and G) uptake structures were observed. Scale bars, 1 µm (A–C; F–G) and 0.5 µm (D–E).</p

Involvement of the cytoskeleton in the yeast-macrophage interaction.

<p>Scanning electron microscopy of membrane extracted macrophages interacting with <i>C. neoformans</i> strains H99 (A) and CAP59 (B and C), showing cytoskeletal filaments associated with yeasts in untreated samples (A–B). After 5 µm nocodazole treatment (C) the area surrounding yeast cells appeared mostly devoid of cytoskeletal components but association with yeast still occurred (inset in C). Scale bars, 2 µm.</p