When pressure does not mean volume? Body mass index may account for the dissociation

Low tidal volume (VT 6 ml/predicted body weight) pressure limited (plateau pressure <30 cmH2O) protective ventilation as proposed by the ARDS Network was associated with an improvement in mortality and is considered the gold standard for acute respiratory distress syndrome (ARDS) ventilation strategies. Limiting plateau pressure minimizes ventilator-induced lung injury by reducing the trans-pulmonary pressure, which is the real alveolar distending pressure. However, in the presence of chest wall elastance impairment, as observed in obese patients, plateau pressure underestimates the trans-pulmonary pressure and derecrutiment at low distending pressure could occur. Moreover, low tidal volume to keep plateau pressure <30 cmH2O could be associated with large differences compared to measured total lung capacity. Quantitative bedside techniques that are able to measure lung volumes together with trans-pulmonary pressure could expand our chances to tailor mechanical ventilation in ARDS patients

Filtering out the Noise: Evaluating the Impact of Noise and Sound Reduction Strategies on Sleep Quality for ICU Patients

The review article by Xie and colleagues examines the impact of noise and noise reduction strategies on sleep quality for critically ill patients. Evaluating the impact of noise on sleep quality is challenging, as it must be measured relative to other factors that may be more or less disruptive to patients\u27 sleep. Such factors may be difficult for patients, observers, and polysomnogram interpreters to identify, due to our limited understanding of the causes of sleep disruption in the critically ill, as well as the challenges in recording and quantifying sleep stages and sleep fragmentation in the intensive care unit. Furthermore, most research in this field has focused on noise level, whereas acousticians typically evaluate additional parameters such as noise spectrum and reverberation time. The authors highlight the disparate results and limitations of existing studies, including the lack of attention to other acoustic parameters besides sound level, and the combined effects of different sleep disturbing factors

Factors that influence career progression among postdoctoral clinical academics: a scoping review of the literature

Background: The future of academic medicine is uncertain. Concerns regarding the future availability of qualified and willing trainee clinical academics have been raised worldwide. Of significant concern is our failure to retain postdoctoral trainee clinical academics, who are likely to be our next generation of leaders in scientific discovery. / Objectives: To review the literature about factors that may influence postdoctoral career progression in early career clinical academics. / Design: This study employed a scoping review method. Three reviewers separately assessed whether the articles found fit the inclusion criteria. / Data sources: PubMed, Scopus, Web of Science and Google Scholar (1991–2015). / Article selection: The review encompassed a broad search of English language studies published anytime up to November 2015. All articles were eligible for inclusion, including research papers employing either quantitative or qualitative methods, as well as editorials and other summary articles. / Data extraction: Data extracted from included publications were charted according to author(s), sample population, study design, key findings, country of origin and year of publication. / Results: Our review identified 6 key influences: intrinsic motivation, work–life balance, inclusiveness, work environment, mentorship and availability of funding. It also detected significant gaps within the literature about these influences. / Conclusions: Three key steps are proposed to help support postdoctoral trainee clinical academics. These focus on ensuring that researchers feel encouraged in their workplace, involved in collaborative dialogue with key stakeholders and able to access reliable information regarding their chosen career pathway. Finally, we highlight recommendations for future research

The impact of heavy vehicle traffic trends on the overdesign of flexible asphalt pavements

Given their environmental impact, the careful design of asphalt pavements is crucial. Previous research has highlighted the influence of several parameters on the outputs of different pavement design methods. In this study, the focus is on heavy vehicle trends, considering both the percentage of heavy vehicles in the average traffic flow and its evolution over time, which is usually included as a growth factor in the design inputs. Since these factors are very often assumed to be based on old estimates, the first aim of this study was to update them by exploring a recent series of continuous data collected on the Italian motorway network and showing how to infer estimates from historical traffic data. Subsequently, the variability of these input factors is introduced in standard pavement design methods to assess their influence on the design process and to quantify the risk of overdesign. While the analysis of historical heavy vehicle traffic data may reveal an overall zero-growth traffic tendency, different scenarios should be considered and assessed in cost-benefit analyses given the not negligible influence of growth factors on pavement thicknesses. This influence is shown here in different simulated design conditions, with different initial traffic volumes, share of heavy vehicles, and resilient moduli

Optimal planning of safety improvements on road sites belonging to different categories within large networks: An integrated multi-layer framework

Planning road safety interventions on large road networks implies several layers of complexity in the decision-making process. In fact, the following simultaneous problems should be addressed: estimating safety performances on the different road elements of the network, identifying sites showing high potential for improvement with respect to reference values, defining the possible types of safety measures to be implemented and their anticipated effect on traffic safety, limiting the number of interventions given fixed budget constraints. This study proposes an integrated multi-layer framework which takes into account the above-defined problems into a single optimization procedure which provides the number and type of safety interventions to be implemented over a wide road network composed of different categories of road elements. The proposed framework is based on the following peculiar aspects: the potential for safety improvement is quantitatively assessed based on the estimation of safety performances for each road category, a bi-level thresholding process integrated in the optimization process is used to highlight sites for interventions, the anticipated outcome of safety measures is quantitatively assessed as well through available crash reduction factors. The proposed methodology is applied to a case study which analyzes a sample of real roads belonging to a province-wide road network composed of various road elements (i.e., different categories of segments and intersections), under different budget constraints. Results demonstrate the applicability and flexibility of the proposed approach, which could be used for planning purposes, independently of the particular geographic location. Clearly, the approach is valid at the planning stage, given that several details of the different layers of analysis are necessarily simplified, while they should be studied in detail at the single intervention project stage

Effects of Berlin speed cushions in urban restricted speed zones: a case study in Bari, Italy

The widespread European policy towards urban sustainable mobility requires some engineering-related interventions on the existing urban road network, such as traffic calming measures. There is a substantial amount of research assessing the effects of different traffic calming measures, even if there is no unanimous evidence for some of them, such as speed cushions (in particular Berlin speed cushions). Some research on speed cushions has been conducted, even if different results were achieved, also varying with the country and context of installation. Moreover, some of these studies are old and they need to be updated, given the continuous transformation of urban environments. In agreement with the City of Bari, thanks to ASSET-Puglia Region funds, the Italian Ministry of Infrastructures and Transport has granted permission to install speed cushions on three urban streets located in restricted speed zones (≤30 km/h) in the City of Bari, to test their effects on vehicular traffic. In this context, this article is aimed at assessing the preliminary results obtained, considering the effects on vehicular speeds. The study design is a typical before-and-after study, in which speeds are measured using a laser speed gun on the three selected road segments before and after the implementation of speed cushions (for each segment, the cushion has a different width). Visual observations were also useful to detect the effects of speed cushions on trajectories and speeds of two-wheeled vehicles. The preliminary analysis of speed profiles revealed a consistent decrease in speed for all the three test sites (in particular the operating speed V85, which is reduced by up to approximately 30%). Moreover, it seems that the decrease in speed is more evident as the cushion width decreases

Rethinking Acute Respiratory Distress Syndrome after COVID-19: If a “Better” Definition Is the Answer, What Is the Question?

The definition of acute respiratory distress syndrome (ARDS) has a somewhat controversial history, with some even questioning the need for the term "ARDS." This controversy has been amplified by the coronavirus disease (COVID-19) pandemic given the marked increase in the incidence of ARDS, the relatively new treatment modalities that do not fit neatly with the Berlin definition, and the difficulty of making the diagnosis in resource-limited settings. We propose that attempts to revise the definition of ARDS should apply the framework originally developed by psychologists and social scientists and used by other medical disciplines to generate and assess definitions of clinical syndromes that do not have gold standards. This framework is structured around measures of reliability, feasibility, and validity. Future revisions of the definition of ARDS should contain the purpose, the methodology, and the framework for empirically testing any proposed definition. Attempts to revise critical illness syndromes' definitions usually hope to make them "better"; our recommendation is that future attempts use the same criteria used by other fields in defining what "better" means

An Integrated Design Framework for Safety Interventions on Existing Urban Roads-Development and Case Study Application

The need for improving urban road safety, livability, and sustainability is evident.Quantitative estimates and qualitative methods/strategies can be used by road safety practitionersto design safety interventions. This study proposes a flexible integrated design framework forsafety interventions on existing urban road segments and intersections that integrates quantitativeand qualitative methods. The proposed design framework is divided into four stages of the safetymanagement process: End of Network Screening, Diagnosis, Selection of Countermeasures, andEconomic Assessment. Pilot applications of the proposed method were performed on existing roadsof the urban road network of the Municipality of Bari, Italy. Results from the application wereuseful to highlight some possible problems in the different stages of the design process. In particular,the discussed problems include a lack of crash and traffic data, difficulties with defining the roadfunctional classifications, including rural-to-urban transitions, a lack of local inspection procedures,the recurrent problems from diagnosis, difficulties regarding the safety assessment of cyclinginfrastructures and sight distances, the criteria for grouping countermeasures into sets, and the choiceof appropriate predictive methods. In response, appropriate solutions to the highlighted problemswere presented. The usefulness of the proposed method for both practitioners and researcherswas shown