Unique vascular complication following extended VV-ECMO support

Objectives: To present an unusual complication related to prolonged ECMO support in a patient with COVID19 induced acute respiratory syndrome (ARDS). Method(s): Clinical chart review of the care process after obtaining the informed consent from the patient. Result(s): A 48-year-old female with COVID-19 infection during second wave of pandemic in August 2021 progressed to severe ARDS. She was put on VV-ECMO support after failing conventional therapy for refractory hypoxemia. Her cannulation configuration included a 25 F venous drainage cannula in the right femoral vein and a 21 F venous return cannula in the right Internal Jugular (IJ) vein. Cannulations were performed using the ;Seldinger technique;under USG guidance, and no difficulties or complications were reported. Her hospital course was notable for delirium, and intermittent bleeding from the cannula sites. After 80 days of support, she showed adequate respiratory improvement which allowed ECMO decannulation. She continued to show improvement, and was eventually discharged after 102 days of total hospital stay. During her 6 weeks follow-up clinic visit a palpable thrill was noted at the jugular ECMO cannula site. A CT angiogram of the neck demonstrated a large venous varix connecting the right IJ and the left common carotid artery with filling from the left common carotid artery. ECMO cannulation site complications such as aneurysm, clots, infections and stenosis are well known. What was unusual in this case is the nature of the aneurysm given that there were no arterial procedures performed on the left side of the neck. She was managed by an ;Amplatzer plug;to the carotid artery at the level of the connection to the varix without any complications. Conclusion(s): Longer duration of ECMO support needs careful follow-up for timely recognition and management of vascular complications. (Figure Presented).

Sizing Horizontal Geothermal Heat Exchangers for Community Greenhouses in Montreal

Community greenhouses are important for the production of local food and reduction of food supply insecurities within cities. As we've seen with Covid-19, pandemics highlight the criticality of local food access to underprivileged urban districts. Since almost 60 % of the energy used in greenhouses is spent in heating and cooling, ground heat exchangers (GHEs) can play a significant role in supplying temperature regulation, but geothermal heat pump systems tend to be expensive for community organizations. An efficient way to reduce GHEs installation costs is to dig trenches to install the system horizontally and cover a part of heating and cooling loads only. In order to ensure cost effectiveness and optimize operations, this type of system was studied for urban greenhouses where ground space can be limited. Sizing calculations were performed for GHEs of a 7.62 m x 15.24 m greenhouse located on the Island of Montreal where the annual, monthly, and hourly energy consumption were estimated from previous building simulations. Three scenarios were used to specify sizing of the system in terms of excavation dimensions and percentage of the greenhouse peak loads covered;(1) number and length of trenches required for a horizontal GHE (HGHE) covering 100% of cooling and heating loads;(2) number and length of trenches required for an HGHE to cover 100% of peak heating loads and 60% of peak cooling loads and;(3) the percentage of heating and cooling peak loads that can be covered by an HGHE located under the greenhouse with similar dimensions (around 116 m2). Estimated excavation dimensions for cases 1 and 2 are 51.8 m x 8 m (414.4 m2) and 40.8 m x 8 m (326.4 m2). Estimated percentage of peak loads covered for case 3 is 40% of heating peak loads and 30% of cooling peak loads. © 2022 Geothermal Resources Council. All rights reserved.

A risk-averse two-stage stochastic programming model for a joint multi-item capacitated line balancing and lot-sizing problem

In this paper, a comprehensive production planning problem under uncertain demand is investigated. The problem intertwines two NP-hard optimization problems: an assembly line balancing problem and a capacitated lot-sizing problem. The problem is modelled as a two-stage stochastic program assuming a risk-averse decision maker. Efficient solution procedures are proposed for tackling the problem. A case study related to mask production is presented. Several insights are provided stemming from the COVID-19 pandemic. Finally, the results of a series of computational tests are reported. (c) 2021 Elsevier B.V. All rights reserved.

Cost minimizing planning of container inspection and repair in multiple facilities.

A problem of optimal mid-term or long-term planning of inspection and repair of freight containers in multiple facilities is introduced and investigated. The containers are of different types and quality levels, which define their repair costs and workforce requirements. The objective function includes the total holding, inspection, repair, transportation and rejection costs. We propose a deterministic, time-dependent, integer linear min-cost multi-commodity network-flow formulation. The problem is shown to be polynomially solvable if there is a single facility, a single time period and all the containers are repairable and have to be repaired. It is shown to be NP-hard for three important special cases. The computational results of our experiments on randomly generated instances based on real data show that instances of sizes 3 facilities, 4 container types and up to 9 container quality levels can be solved with CPLEX in 5 minutes on a conventional PC, even for 30 periods, with an optimality gap of less than 3%. This is sufficient for medium-term or weekly planning or for short-term recovery planning. However, there are instances of the same magnitude, but with 360 periods of a considerably longer planning horizon, for which an optimality gap of 28% remained even after 10 hours of CPLEX computation.

Image-Based Web Application for Respirator Sizing: Contactless Mask-Fitting during a Pandemic

At the beginning of the COVID-19 pandemic, many hospitals and healthcare institutions lacked an adequate supply of masks and other personal protective equipment. Moreover, protocols that were in place to ensure healthcare workers had appropriately sized masks consumed precious time and resources. Any determination of a user's correct respirator size demanded an in person assessment and had the potential to waste multiple respirators. Here we introduce IBARS (Image-based Application for Respirator Sizing), a novel tool which provides respirator size recommendations based on a facial image and basic user demographics. This solution obviates the need for an in person assessment, providing an accurate size recommendation within seconds. The application has the potential to reduce time-per-worker respirator fitting, reduce overall respirator usage, and increase safety by providing hospitals with a non-contact option for sizing. Furthermore, future applications may assist healthcare institutions optimize supply chains by providing rapid assessments and reassessments of appropriate respirator sizes used by their workers. Early testing indicated accuracy of 71.3% for the software (N=16), and further testing is underway at Houston Methodist Hospital.

Gate Assigment and Fleet Sizing of Apron Buses including social distancing metrics in an international airport using discrete event simulation

The COVID - 19 pandemic has impacted the aeronautical industry demanding new conditions in the transfer of passengers on air flights. These new conditions involve ensuring that passengers can maintain an adequate distance to minimize the chances of contagion. This implies that airports can resize their resources to meet these conditions. It is critical to be able to keep social distancing in the passenger boarding and unboarding processes, then the apron buses and gates used in these processes becomes critical. The bus fleet sizing needs to be calculated considering passengers needs to keep social distancing in their travel from and to the aircrafts. In a similar way gates need to be assigned considering a reduction in the use of neighboring doors to reduce the number of passengers in the same waiting room. The complexity of this problem lies in being able to incorporate the social distancing as an action parameter to obtain adequate solutions in the context of sizing the apron bus fleet and assigning doors. The contagion risk becomes an indicator related to social distancing in the position and movements made in the apron buses. So, it is proposed to incorporate these conditions in a simulation model that allows obtaining the estimation of the apron bus fleet and the allocation of gates as a result while showing the contagion risk as a decision parameter. © 2022 IEEE.

Bronchoscopic management of bronchopleural fistula due to COVID-19 a nonsurgical option

Background: COVID-19 has become a dreadful pandemic. One of the important complication is the development of pneumothorax/ pneumomediastinum which gets further complicated by bronchopleural fistula. Case Study: A 44year male patient with severe COVID pneumonia developed Left sided pneumothorax and treated conservatively with ICD and negative suctioning for 2 months and referred to us with persistent pneumothorax with BPF. As patient was unfit for surgery, bronchoscopic management was planned. With flexible bronchoscope, 6F Fogarty balloon was passed and inflated, leak site was identified in left upper lobe upper division. A Watanabe spigot size 5 was deposited at the opening of upper division and manipulated to apical segment. Other small openings were sealed with cyanoacrylate glue and autologous blood patch. After procedure negative suction was reapplied. Repeat Xray showed resolution of pneumothorax. Pleurodesis was done with talc slurry, post pleurodesis showed no pneumothorax and ICD was removed. Patient was discharged, follow up X ray after 4weeks showed no evidence of pneumothorax. Discussion: In most cases of BPF, leak seals after tube thoracostomy, only 3-5% will continue to have persistent leak. For medically inoperable cases, bronchoscopic balloon occlusion of site and subsequent injection with fibrin glue, liquid bioadhesive or blood patch can be done. For large leak;Amplatzer device, stents, spigots, coils are used. Conclusion: Bronchoscopic treatment can work well for a medically inoperable, complicated pneumothorax in COVID-19 disease.

Development of an ergonomic protective suit for physiotherapists during the COVID-19

During the COVID-19 pandemic, the provision of appropriate protective clothing for medical staff who must continue to perform their duties at this period is of particular importance. Physiotherapists are not allowed to suspend working during this time either, and the specifics of their work is close contact with the patient within various movements during the therapy process. Inadequate (intended for general use) protective clothing affects work capacity in the aspects of movement restriction, thermal comfort and thereby increasing energy consumption. For the design and supply of personal protective equipment (PPE) and protective clothing of the best possible quality, PPE should be explored in a systemic approach (holistics) to assess anthropometric fit and ergonomics, material properties and thermal performance. This study investigated anthropometric characteristics of target group representatives;sizing, fit and design flaws of protective suits for physiotherapists;provision of mobility in the protective clothing of physiotherapists;the protective suit fabric layer interaction with the human body and the importance of subjective evaluation of fit and ergonomics of PPE (made by specialists and wearers). The results of the study promote the usage of objective knowledge of anthropometry and ergonomics as well as subjective assessment findings in the development of protective suits for physiotherapists. © The Author(s) 2022.

Characterisation of Particle Size and Viability of SARS-CoV-2 Aerosols from a Range of Nebuliser Types Using a Novel Sampling Technique.

Little is understood about the impact of nebulisation on the viability of SARS-CoV-2. In this study, a range of nebulisers with differing methods of aerosol generation were evaluated to determine SARS-CoV-2 viability following aerosolization. The aerosol particle size distribution was assessed using an aerosol particle sizer (APS) and SARS-CoV-2 viability was determined after collection into liquid media using All-Glass Impingers (AGI). Viable particles of SARS-CoV-2 were further characterised using the Collison 6-jet nebuliser in conjunction with novel sample techniques in an Andersen size-fractioning sampler to predict lung deposition profiles. Results demonstrate that all the tested nebulisers can generate stable, polydisperse aerosols (Geometric standard deviation (GSD) circa 1.8) in the respirable range (1.2 to 2.2 µm). Viable fractions (VF, units PFU/particle, the virus viability as a function of total particles produced) were circa 5 × 10-3. VF and spray factors were not significantly affected by relative humidity, within this system where aerosols were in the spray tube an extremely short time. The novel Andersen sample collection methods successfully captured viable virus particles across all sizes; with most particle sizes below 3.3 µm. Particle sizes, in MMAD (Mass Median Aerodynamic Diameters), were calculated from linear regression of log10-log10 transformed cumulative PFU data, and calculated MMADs accorded well with APS measurements and did not differ across collection method types. These data will be vital in informing animal aerosol challenge models, and infection prevention and control policies.

Quantitative Evaluation of Subglottic Stenosis Using Ultrashort Echo Time MRI in a Rabbit Model.

OBJECTIVE/HYPOTHESIS: To assess the ability of ultra-short echo time (UTE)-MRI to detect subglottic stenosis (SGS) and evaluate response to balloon dilation. To correlate measurements from UTE-MRI with endotracheal-tube (ETT)-sizing and to investigate whether SGS causes change in airway dynamics. STUDY DESIGN: Animal research study. METHODS: Eight adult New-Zealand white rabbits were used as they approximate neonatal airway-size. The airways were measured using ETT-sizing and 3D UTE-MRI at baseline, 2 weeks post-cauterization induced SGS injury, and post-balloon dilation treatment. UTE-MR images were acquired to determine airway anatomy and motion. Airways were segmented from MR images. Cross-sectional area (CSA), major and minor diameters (Dmajor and Dminor ), and eccentricity were measured. RESULTS: Post-injury CSA at SGS was significantly reduced (mean 38%) compared to baseline (P = .003) using UTE-MRI. ETT-sizing correlated significantly with MRI-measured CSA at the SGS location (r = 0.6; P < .01), particularly at the post-injury timepoint (r = 0.93; P < .01). Outer diameter from ETT-sizing (OD) correlated significantly with Dmajor (r = 0.63; P < .01) from UTE-MRI at the SGS location, especially for the post-injury timepoint (r = 0.91; P < .01). Mean CSA of upper trachea did not change significantly between end-expiration and end-inspiration at any timepoint (all P > .05). Eccentricity of the upper trachea increased significantly post-balloon dilation (P < .05). CONCLUSIONS: UTE-MRI successfully detected SGS and treatment response in the rabbit model, with good correlation to ETT-sizing. Balloon dilation increased CSA at SGS, but not to baseline values. SGS did not alter dynamic motion for the trachea in this rabbit model; however, tracheas were significantly eccentric post-balloon dilation. UTE-MRI can detect SGS without sedation or ionizing radiation and may be a non-invasive alternative to ETT-sizing. LEVEL OF EVIDENCE: NA Laryngoscope, 131:E1971-E1979, 2021.

Aerosol and bioaerosol particle size and dynamics from defective sanitary plumbing systems.

Aerosols are readily transported on airstreams through building sanitary plumbing and sewer systems, and those containing microbial pathogens (known as bioaerosols) are recognized as contributors to infection spread within buildings. When a defect occurs in the sanitary plumbing system that affects the system integrity, a cross-transmission route is created that can enable the emission of bioaerosols from the system into the building. These emission occurrences are characterized as short-burst events (typically <1 min in duration) which make them difficult to detect and predict. The characterization of these emission events is the focus of this research. Two methods were used to characterize bioaerosol emission events in a full-scale test rig: (a) an Aerodynamic Particle Sizer (APS) for particle size distribution and concentrations; and (b) a slit-to-agar sampler to enumerate the ingress of a viable tracer microorganism (Pseudomonas putida). The APS data confirmed that most particles (>99.5%) were <5 µm and were therefore considered aerosols. Particles generated within the sanitary plumbing system as a result of a toilet flush leads to emissions into the building during system defect conditions with an equivalence of someone talking loudly for over 6 and a half minutes. There were no particles detected of a size >11 µm anywhere in the system. Particle count was influenced by toilet flush volume, but it was not possible to determine if there was any direct influence from airflow rate since both particle and biological data showed no correlation with upward airflow rates and velocities. Typical emissions resulting from a 6 L toilet flush were in the range of 280-400 particles per second at a concentration of typically 9-12 number per cm3 and a total particle count in the region of 3000 to 4000 particles, whereas the peak emissions from a 1.2 L toilet flush were 60-80 particles per second at a concentration of 2.4-3 number per cm3 and a total particle count in the region of 886 to 1045 particles. The reduction in particles is in direct proportion to the reduction in toilet flush volume. The slit-to-agar sampler was able to provide viable time course CFU data and confirmed the origin of the particles to be the tracer microorganism flushed into the system. The time course data also have characteristics consistent with the unsteady nature of a toilet flush.