Burnout among surgeons before and during the SARS-CoV-2 pandemic: an international survey

Background: SARS-CoV-2 pandemic has had many significant impacts within the surgical realm, and surgeons have been obligated to reconsider almost every aspect of daily clinical practice. Methods: This is a cross-sectional study reported in compliance with the CHERRIES guidelines and conducted through an online platform from June 14th to July 15th, 2020. The primary outcome was the burden of burnout during the pandemic indicated by the validated Shirom-Melamed Burnout Measure. Results: Nine hundred fifty-four surgeons completed the survey. The median length of practice was 10 years; 78.2% included were male with a median age of 37 years old, 39.5% were consultants, 68.9% were general surgeons, and 55.7% were affiliated with an academic institution. Overall, there was a significant increase in the mean burnout score during the pandemic; longer years of practice and older age were significantly associated with less burnout. There were significant reductions in the median number of outpatient visits, operated cases, on-call hours, emergency visits, and research work, so, 48.2% of respondents felt that the training resources were insufficient. The majority (81.3%) of respondents reported that their hospitals were included in the management of COVID-19, 66.5% felt their roles had been minimized; 41% were asked to assist in non-surgical medical practices, and 37.6% of respondents were included in COVID-19 management. Conclusions: There was a significant burnout among trainees. Almost all aspects of clinical and research activities were affected with a significant reduction in the volume of research, outpatient clinic visits, surgical procedures, on-call hours, and emergency cases hindering the training. Trial registration: The study was registered on clicaltrials.gov "NCT04433286" on 16/06/2020

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Study of nanoparticles deposition in a human upper airway model using a dynamic turbulent Schmidt number

In this paper, the nanoparticles deposition in the upper portion of the human respiratory system is studied by using a dynamic turbulent Schmidt number. The flow and particle governing equations are solved using large eddy simulation (LES) with a localized dynamic subgrid scale closure of the residual stress tensor and the scalar flux term. The flow solution and the particle transport are dynamically coupled and thus, the turbulent momentum and mass diffusivity are calculated from the resolved flow and particle concentration fields. The methodology is applied to an extrathoracic oral airway model for several particle diameters ranging from 10 nm to 52 nm at a breathing rate of 30 L/min. The results are compared to the previously published RANS and experimental data. It is observed that the current methodology improves the quality of results for flow and particle deposition considerably. It is also noticed that the turbulent Schmidt number is quite different from its typically assumed values. Keywords: LES, Nanoparticles deposition, Upper airway model, Dynamic turbulent Schmidt numbe

Study of nanoparticles deposition in a human upper airway model using a dynamic turbulent Schmidt number

In this paper, the nanoparticles deposition in the upper portion of the human respiratory system is studied by using a dynamic turbulent Schmidt number. The flow and particle governing equations are solved using large eddy simulation (LES) with a localized dynamic subgrid scale closure of the residual stress tensor and the scalar flux term. The flow solution and the particle transport are dynamically coupled and thus, the turbulent momentum and mass diffusivity are calculated from the resolved flow and particle concentration fields. The methodology is applied to an extrathoracic oral airway model for several particle diameters ranging from 10 nm to 52 nm at a breathing rate of 30 L/min. The results are compared to the previously published RANS and experimental data. It is observed that the current methodology improves the quality of results for flow and particle deposition considerably. It is also noticed that the turbulent Schmidt number is quite different from its typically assumed values. Keywords: LES, Nanoparticles deposition, Upper airway model, Dynamic turbulent Schmidt numbe

Quantifying Fenestration Effect on Thermal Comfort in Naturally Ventilated Classrooms

This study seeks to evaluate thermal comfort in naturally ventilated classrooms to draw sustainable solutions that reduce the dramatic energy consumed in mechanically ventilated spaces. Passive ventilation scenarios are generated using alternations of openings on the windward and leeward sides to evaluate their effects on thermal comfort. Twenty-eight experiments were carried in Bahrain during winter inside an exposed classroom, the experiments were grouped into five scenarios namely: “single-inlet single-outlet” SISO, “single-inlet double-outlet” SIDO, “double-inlet single-outlet” DISO, “double-inlet double-outlet” DIDO and “single-side ventilation” SSV. The findings indicate that single-side ventilation did not offer comfort except at high airspeed, while comfort is attained by using cross-ventilation at ambient temperature between 21.8–26.8 °C. The temperature difference between monitored locations and the inlet is inversely proportional to the number of air changes per hour. The DISO scenario accomplishes the lowest temperature difference. Using cross-ventilation instead of single-side ventilation reduces the temperature differences between 0.5–2.5 °C and increases airspeed up to three folds. According to the measured findings, the DISO cross-ventilation scenario is a valid sustainable solution adaptable to climatic variation locally and beyond with zero-energy consumption and zero emissions

Thermal performance of domed roof in air-conditioned spaces

Due to their thermal performance, domed roofs are one of the passive solutions that affect energy consumption in buildings. The thermal performance of domed roofs has been investigated in many naturally ventilated spaces. However, few studies have discussed their performance in conditioned spaces. Therefore, this study introduces a computational comparison between domed and flat roofs to investigate their impact on thermal comfort inside a conditioned mosque. At an earlier stage, field measurements were carried out inside a Bahraini mosque to acquire its indoor air conditions during the summer period of 2021, in addition to validating the computational model. The findings of this study confirm that, under mechanical cooling conditions, the flat roof offers a lower indoor temperature than the domed roof by 0.4 °C and 0.1 °C for open and closed doors, respectively. Similarly, the air velocity is lower by approximately 0.01 m/s for both door modes. The overall PMV values of the flat roof are also lower by 0.07 and 0.01, while the PPD values are lower by 0.20, and 0.34 for open and closed doors, respectively. Based on these small differences, it can be concluded that the thermal performance of both roofing systems behaves equally in conditioned spaces. However, the air patterns are substantially different, the overall thermal performance is similar. This similarity drives building designers to rethink the thermal performance of the domed roofs in air-conditioned spaces with such a hot climate, regardless of their aesthetic and acoustical behaviour

New graphical method for assessing the integration of phase change materials into building envelope

One technique to reduce the demand for cooling load in buildings is inserting phase change materials (PCM) into building envelopes. In this study, a new method is performed to facilitate the selection of the type of PCM. The hypothesis is tested through a case of a traditional wall in Cairo, Egypt. The merit of each case is assessed based on the peak and average heat flow to the studied room. The outcome of this study is presented in the form of selection graphs to facilitate the selection of PCM type with no need for detailed calculations. Guidelines were drawn from the results and are directly reflected in the graphical representation. The average load is represented in one graph that depends only on the thermal resistance of the added layer. On the other hand, the peak load could be estimated through two graphs. The graphs combine the effect of the melting temperature, the latent heat capacity, the sensible heat capacity, and the thermal resistance of the PCM

Exhaled CO2-based tracer gas for measuring ventilation rates and energy consumption with application to worship places

Using the tracer gas technique, ventilation rates were estimated in an air-conditioned mosque located in Bahrain. Exhaled CO2 concentrations were traced for different occupancy levels and periods, i.e., 20–200 worshippers during ½ h, 1-h, and 2-h periods. The three known methods of tracer gas technique, namely build-up, steady-state, and decay methods, were examined with reference to measured ventilation rates. In addition to investigating the impact of ventilation rates and operating schedules on the cooling energy consumed. A ½ h occupancy showed a poor correlation between exhaled CO2 concentration and occupancy level, which means it misleads estimating ventilation rates in mosques. In contrast, the 1-h and 2-h occupancy periods showed a strong correlation. The steady-state method overestimated ventilation rates by 10%, while the build-up and decay methods showed 58% and 68%, respectively. Using the 5-prayers operating schedule instead of the on-24-hours schedule reduced the cooling energy consumed by 8%

Studying comfort and energy usage for different room arrangements using a simplified flow pattern for highly-cooled and conventional operations

Simulations are carried out on 2-D models representing rooms having different supply/return arrangements with flat and curved ceiling. The velocity and temperature fields are used to assess comfort and energy usage. A simplified flow pattern is deduced from the flow field. This pattern describes the flow as a main stream travelling from the inlet to the exit adhered to walls along its path, thus collecting the load directly from these walls. This main stream induces an eddy that collects the load from the rest of the boundaries and transfers this load to the main stream. When this main stream passes directly through the occupied zone, the large velocity disturbs comfort. The larger the portion of load carried directly by the main stream, the lesser is the energy use. When the inlet and exit are on the same wall, the main stream might follow a short-cut beyond certain supply angles. Curving the ceiling is seen to retard the onset of the short-cut. Keywords: Comfort, Air diffusion performance index ADPI, Effective draft Temperature CFD, Cold air system, Curved ceilin