De novo Powered Air-Purifying Respirator Design and Fabrication for Pandemic Response

The rapid spread of COVID-19 and disruption of normal supply chains resulted in severe shortages of personal protective equipment (PPE), particularly devices with few suppliers such as powered air-purifying respirators (PAPRs). A scarcity of information describing design and performance criteria represents a substantial barrier to new approaches to address these shortages. We sought to apply open-source product development to PAPRs to enable alternative sources of supply and further innovation. We describe the design, prototyping, validation, and user testing of locally manufactured, modular, PAPR components, including filter cartridges and blower units, developed by the Greater Boston Pandemic Fabrication Team (PanFab). Two designs, one with a fully custom-made filter and blower unit housing, and the other with commercially available variants (the "Custom" and "Commercial" designs respectively) were developed. Engineering performance of the prototypes was measured and safety validated using NIOSH-equivalent tests on apparatus available under pandemic conditions, at university laboratories. Feedback on designs was obtained from four individuals, including two clinicians working in an ambulatory clinical setting and two research technical staff for whom PAPR use is a standard part of occupational PPE. Respondents rated the PanFab Custom PAPR a 4 to 5 on a 5 Likert-scale 1) as compared to current PPE options, 2) for the sense of security with use in a clinical setting, and 3) for comfort. The three other versions of the designs (with a commercial blower unit, filter, or both) performed favorably, with survey responses consisting of scores ranging from 3-5. Engineering testing and clinical feedback demonstrate that the PanFab designs represents favorable alternative PAPRs in terms of user comfort, mobility, and sense of security. A nonrestrictive license promotes innovation in respiratory protection for current and future medical emergencies.

SOX10 is as specific as S100 protein in detecting metastases of melanoma in lymph nodes and is recommended for sentinel lymph node assessment.

BACKGROUND: Sentinel lymph node (SLN) biopsy remains crucial for melanoma staging. The European Organisation for Research and Treatment of Cancer Melanoma Group recommends performing immunohistochemical stainings for reproducible identification of melanoma metastases. S100 protein (pS100) is a commonly used melanocytic antigen because of its high sensitivity in spite of relatively low specificity. SRY-related HMG-box 10 protein (SOX10) is a transcription factor characterising neural crest-derived cells. It is uniformly expressed mostly in the nuclei of melanocytes, neural, and myoepithelial cells. Pathologists sometimes prefer SOX10 as a melanoma marker, but it has not yet been investigated on a large-scale to confirm that it is reliable and recommendable for routine SLN evaluation. METHODS: Four hundred one treatment-naïve lymph node (LN) metastatic melanomas were included in high-density tissue microarrays and were assessed for the presence of SOX10 and pS100 by immunohistochemistry. The slides were digitalised, shared and evaluated by a panel of experienced melanoma pathologists. RESULTS: The vast majority of melanomas were double-positive for pS100 and SOX10 (93.2%); a small percentage of the cases (3.9%) were double-negative melanomas. Discordance between the two markers was observed: 1.9% pS100(-)/SOX10(+) and 0.75% pS100(+)/SOX10(-). SOX10 was not expressed by immune cell types in the LN, resulting in a less controversial interpretation of the staining. CONCLUSIONS: SOX10 is as equally specific as pS100 for the detection of melanoma metastases in LNs. The interpretation of SOX10 staining is highly reproducible among different centres and different pathologists because of the absence of staining of immune cells.

3D Printed frames to enable reuse and improve the fit of N95 and KN95 respirators

BackgroundIn response to supply shortages during the COVID-19 pandemic, N95 filtering facepiece respirators (FFRs or "masks"), which are typically single-use devices in healthcare settings, are routinely being used for prolonged periods and in some cases decontaminated under "reuse" and "extended use" policies. However, the reusability of N95 masks is often limited by degradation or breakage of elastic head bands and issues with mask fit after repeated use. The purpose of this study was to develop a frame for N95 masks, using readily available materials and 3D printing, which could replace defective or broken bands and improve fit. ResultsAn iterative design process yielded a mask frame consisting of two 3D-printed side pieces, malleable wire links that users press against their face, and cut lengths of elastic material that go around the head to hold the frame and mask in place. Volunteers (n= 41; average BMI= 25.5), of whom 31 were women, underwent qualitative fit with and without mask frames and one or more of four different brands of FFRs conforming to US N95 or Chinese KN95 standards. Masks passed qualitative fit testing in the absence of a frame at rates varying from 48 - 92% (depending on mask model and tester). For individuals for whom a mask passed testing, 75-100% (average = 86%) also passed testing with a frame holding the mask in place. Among users for whom a mask failed in initial fit testing, 41% passed using a frame. Success varied with mask model and across individuals. ConclusionsThe use of mask frames can prolong the lifespan of N95 and KN95 masks by serving as a substitute for broken or defective bands without adversely affecting fit. Frames also have the potential to improve fit for some individuals who cannot fit existing masks. Frames therefore represent a simple and inexpensive way of extending the life and utility of PPE in short supply. For clinicians and institutions interested in mask frames, designs and specifications are provided without restriction for use or modification. To ensure adequate performance in clinical settings, qualitative fit testing with user-specific masks and frames is required.

Rapid prototyping and clinical testing of a reusable face shield for health care workers responding to the COVID-19 pandemic

Due to supply chain disruption, the COVID-19 pandemic has caused severe shortages in personal protective equipment (PPE) for health care professionals. Local fabrication based on 3D printing is one way to address this challenge, particularly in the case of simple products such as protective face shields. As a consequence, many public domain designs for face shields have become available. No clear path exists, however, for introducing a locally fabricated and unapproved product into a clinical setting. In a US health care setting, face shields are regulated by the Food and Drug Administration (FDA); similar policies exist in other countries. We describe a research protocol under which rapid iteration on an existing design, coupled with clinical feedback and real-world testing in an emergency department, allowed a face shield to be implemented by the members of the incident command team at a major academic medical center. We describe our design and testing process and provide an overview of regulatory considerations associated with fabrication and testing of face shields and related products. All designs, materials used, testing protocols, and survey results are reported in full to facilitate the execution of similar face shield efforts in other clinical settings. Our work serves as a case study for development of a robust local response to pandemics and other health care emergencies, with implications for healthcare professionals, hospital administrators, regulatory agencies and concerned citizens.

Peripheral Intravenous Cannula Insertion and Use in the Emergency Department: An Intervention Study.

OBJECTIVES: The objective was to examine cannulation practice and effectiveness of a multimodal intervention to reduce peripheral intravenous cannula (PIVC) insertion in emergency department (ED) patients. METHODS: A prospective before and after study and cost analysis was conducted at a single tertiary ED in Australia. Data were collected 24 hours a day for 2 weeks pre- and post implementation of a multimodal intervention. PIVC placement and utilization within 24 hours were evaluated in all eligible patients. RESULTS: A total of 4,173 participants were included in the analysis. PIVCs were placed in 42.1% of patients' pre intervention and 32.4% post intervention, a reduction of 9.8% (95% confidence interval [CI] = 6.8 to -12.72%). PIVC usage within 24 hours of admission was 70.5% pre intervention and 83.4% post intervention, an increase of 12.9% (95% CI = 8.8% to 17.0%). Sixty-six patients were observed in the ED for cost analysis. The mean time per PIVC insertion was 15.3 (95% CI = 12.6 to 17.9) minutes. PIVC insertion cost, including staff time and consumables per participant, was A$22.79 (95% CI = A$19.35 to A$26.23). CONCLUSIONS: The intervention reduced PIVC placement in the ED and increased the percentage of PIVCs placed that were used. This program benefits patients and health services alike, with potential for large cost savings.

Predictors of parental perceptions and concerns about child weight.

Appropriate levels of parental perception and concern about child weight are important components of successful obesity treatment, but the factors that contribute to these attitudes need clarification. The aim of this study was to identify child and parent characteristics that best predict parental perceptions and concerns about child weight. A cross-sectional design was used to assess characteristics of parents (e.g. age, income, and feeding attitudes) and children (e.g. body composition, ad libitum intake, and reported physical activity). Results are reported for 75, 4-6year-olds from diverse ethnicities. Perceived child weight and concern were measured with the Child Feeding Questionnaire (CFQ). Multiple linear regression was used to identify the best models for perceived child weight and concern. For perceived child weight, the best model included parent age, children's laboratory intake of sugar-sweetened beverages (SSBs) and palatable buffet items, and two measures of child body composition (ratio of trunk fat-to-total fat and ratio of leg fat-to-total fat). For concern, child android/gynoid fat ratio explained the largest amount of variance, followed by restrictive feeding and SSB intake. Parental perceptions and concerns about child weight are best explained by models that account for children's eating behavior and body fat distribution.

Phlebotonics for haemorrhoids

BACKGROUND Haemorrhoids are variceal dilatations of the anal and perianal venous plexus and often develop secondary to the persistently elevated venous pressure within the haemorrhoidal plexus. Phlebotonics are a heterogenous class of drugs consisting of plant extracts (i.e. flavonoids) and synthetic compounds (i.e. calcium dobesilate). Although their precise mechanism of action has not been fully established, they are known to improve venous tone, stabilize capillary permeability and increase lymphatic drainage. They have been used to treat a variety of conditions including chronic venous insufficiency, lymphoedema and haemorrhoids. OBJECTIVE The aim of this review was to investigate the efficacy of phlebotonics in alleviating the signs, symptoms and severity of haemorrhoidal disease and verify their effect post-haemorrhoidectomy. METHODS Search methods: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library 2011 issue 9, MEDLINE (1950 to September 2011) and EMBASE (1974 to September 2011). Selection criteria: Only randomized controlled trials evaluating the use of phlebotonics in treating haemorrhoidal disease were used. No cross-over or cluster-randomized trials were included for analysis and any trial which had a quasi-random method of allocation was excluded. Data collection and analysis: Two authors independently extracted the data and analyzed the eligibility of the data for inclusion. Disagreements were resolved by meaningful discussion. MAIN RESULTS We considered twenty-four studies for inclusion in the final analysis. Twenty of these studies (enrolling a total of 2344 participants) evaluated the use of phlebotonics versus a control intervention. One of these twenty studies evaluated the use of phlebotonics with a medical intervention and another study with rubber band ligation. AUTHORS' CONCLUSIONS The evidence suggests that there is a potential benefit in using phlebotonics ...

Phacolytic glaucoma: are there 2 forms?

We report a case of acute phacolytic glaucoma in which only protein was present in the anterior chamber without macrophages. We propose that this study represents a type of phacolytic glaucoma characterized by a hyperacute presentation caused by rapid leakage of degenerated lens proteins into the aqueous humor as opposed to a second type with a more gradual onset and with phacolytic macrophages in the aqueous humor resulting from an immunologic response to liquefied lens proteins. Thus, 2 forms, perhaps at ends of a spectrum of clinical manifestations of phacolytic glaucoma, may exist with distinct characteristics and pathophysiology.

Surfing, Windsurfing, Snowboarding, and Skateboarding.

In brief With the rise in popularity of board sports, primary care physicians need to understand the injury risks and environmental hazards faced by surfers, windsurfers, snowboarders, and skateboarders. Physicians can play an important role by telling patients about injury prevention strategies, including using proper equipment, wearing protective gear, taking lessons, and riding in terrain and weather conditions appropriate for one's skill level.