Most downloaded biology preprints, since beginning of last month
in category emergency medicine
151 results found. For more information, click each entry to expand.
289 downloads medRxiv emergency medicine
Background: In recent studies, up to half of immunocompromised (IC) subject populations fail to develop antibodies after COVID-19 vaccination. Purpose and Methods: Here, we explore whether T-cells which respond to the spike (S) antigenic sequence and its less conserved S1, and the conserved S2 component are present in serial samples before and after each dose of mRNA1273 or BNT162b2 vaccines in 20 healthy immunocompetent subjects. Single samples from 7 vaccinated IC subjects were also tested. Simultaneously, we measured IgG antibodies to the receptor binding domain (RBD) of S1, and anti-S IgG, and frequencies of monocytic CD14+HLA-DR- (M-MDSC) and polymorphonuclear CD14-CD15+CD11b+ (PMN-MDSC) myeloid-derived suppressor cells. Results: In healthy subjects, S1-, S2-, and S-reactive CD4 and CD8 T-cell frequencies showed a numeric but not statistically significant decrease after the first vaccine dose and were accompanied by increased MDSC frequencies (p<0.05). After the second dose, S2- and S-reactive CD4 and CD8 cells and MDSC approached pre-vaccination levels. In healthy subjects, a) S1-reactive CD8 frequencies were significantly higher after the second dose compared with pre-vaccination levels (p=0.015), b) anti-RBD and anti-S IgG were present in all after the second dose. Among seven IC subjects, anti-RBD and anti-S IgG were absent in 4 and 3 subjects, respectively. S1-reactive CD8 cells were identified in 2 of 4 anti-RBD negative subjects. S-reactive CD4 or CD8 cells were identified in all three anti-S negative subjects. Conclusions: In healthy immunocompetent subjects, mRNA vaccines induce antibodies to the spike antigenic sequences and augment CD8 cells reactive to the S1 spike sequence, which is more specific for the SARS-CoV-2 virus. In this exploratory cohort of vaccinated immunocompromised subjects, S1-reactive CD8 cells can be detected in some who are negative for RBD antibody, and S-reactive T-cells are present in all who are negative for spike antibody.
213 downloads medRxiv emergency medicine
Background: The demand for pulse oximeters is high in the current COVID-19 pandemic. Despite their popularity, clinical studies to evaluate the reliability in obtaining information on a patient's oxygenation status, are lacking. Aim: To evaluate the performance of pulse oximeters under clinical conditions, with arterial blood gas measurement (SaO2) as reference standard. Methods: We studied the accuracy of ten top-selling pulse oximeters in Europe and the USA in an intensive care population at the Flevoziekenhuis in Almere, the Netherlands. The studied pulse oximeters were: AFAC FS10D, AGPTEK FS10C, ANAPULSE ANP 100, Cocobear, Contec CMS50D1, HYLOGY MD-H37, Mommed YM101, PRCMISEMED F4PRO, PULOX PO-200, and Zacurate Pro Series 500DL. Adult patients in whom an SaO2 measurement was obtained as part of routine care were asked for inclusion. Directly after obtaining the SaO2 blood sample we obtained the pulse oximeter readings (SpO2) of the investigational devices, in random order. Outcomes were bias (SpO2-SaO2) mean, root mean square difference (ARMS), mean absolute error (MAE), and accuracy in identifying hypoxemia (SaO2<=90%). As a clinical index test, we included a hospital-grade SpO2-monitor. Results: In 35 consecutive patients we obtained 2,258 SpO2-readings and 234 SaO2-samples. Mean bias ranged from -0.6 to -4.8. None of the pulse oximeters had an ARMS<=3%, the requirement set by ISO-standards and required for FDA 501(k) clearance. The MAE ranged from 2.3 to 5.1, and 5 out of 10 pulse oximeters met the requirements of [≤]3%. For hypoxemia, negative predictive values were 98-99%. Positive predictive values ranged from 11-30%. Highest accuracy (95%CI) were found for Contec CMS50D1; 91% (86-94) and Zacurate Pro Series 500DL; 90% (85-94). The hospital-grade SpO2-monitor had an ARMS of 3.0 and MAE of 1.9, and an accuracy of 95% (91-97%). Conclusion: Direct-to-consumer pulse oximeters do not meet ISO-standards required for FDA-clearance, but can accurately rule out hypoxemia.
189 downloads medRxiv emergency medicine
For the past 50 years, positive pressure ventilation has been a cornerstone of treatment for respiratory failure. Consensus surrounding the epidemiology of respiratory failure has permitted a relatively good fit between the supply of ventilators and the demand. However, the current COVID-19 pandemic has increased demand for mechanical ventilators well beyond supply. Respiratory failure complicates most critically ill patients with COVID-19 and is characterized by highly heterogeneous pulmonary parenchymal involvement, profound hypoxemia and pulmonary vascular injury. The profound increase in the incidence of respiratory failure has exposed critical shortages in the supply of mechanical ventilators, and those with the necessary skills to treat. While most traditional ventilators rely on an internal compressor and mixer to moderate and control the gas mixture delivered to a patient, the current emergency climate has catalyzed alternative designs that might enable greater flexibility in terms of supply chain, manufacturing, storage and maintenance. Design considerations of these 'emergency response' ventilators have generally fallen into two categories: those that rely on mechanical compression of a known volume of gas and those powered by an internal compressor to deliver time cycled pressure- or volume-limited gas to the patient. The present work introduces a low-cost, ventilator designed and built in accordance with the Emergence Use guidance provided by the US Food and Drug Administration (FDA) wherein an external gas supply feeds into the ventilator and time limited flow interruption guarantees tidal volume. The goal of this device is to allow a patient to be treated by a single ventilator platform, capable of supporting the various treatment paradigms during a potential COVID-19 related hospitalization. This is a unique aspect of this design as it attempts to become a one-device-one-visit solution to the problem. The device is designed as a single use ventilator that is sufficiently robust to treat a patient being mechanically ventilated. The overall design philosophy and its applicability in this new crisis-laden world view is first described, followed by both bench top and animal testing results used to confirm the precision, capability, safety and reliability of this low cost and novel approach to mechanical ventilation during the COVID-19 pandemic. The ventilator is shown to perform in a range of critical requirements listed in the FDA emergency regulations and can safely and effectively ventilate a porcine subject. As of August 2020, only 13 emergency ventilators have been authorized by the FDA, and this work represents the first to publish animal data using the ventilator. This proof-of-concept provides support for this cost-effective, readily mass-produced ventilator that can be used to support patients when the demand for ventilators outstrips supply in hospital settings worldwide. More details for this project can be found at https://ventilator.stanford.edu/
182 downloads medRxiv emergency medicine
Introduction Hypoxia is the main cause of morbidity and mortality in COVID-19. During the COVID-19 pandemic some countries have reduced access to supplemental oxygen (e.g. oxygen rationing), whereas other nations have maintained and even improved access to supplemental oxygen. We examined whether such variation in the access to supplemental oxygen had any bearing on mortality in COVID-19. Methods Three independent investigators searched for, identified and extracted the nationally recommended target oxygen levels for the commencement of oxygen in COVID-19 pneumonia from the 29 worst affected countries. Mortality estimates were calculated from three independent sources. We then applied linear regression analysis to examine for potential association between national targets for the commencement of oxygen and case fatality rates. Results Of the 26 nations included, 15 had employed conservative oxygen strategies to manage COVID-19 pneumonia. Of them, Belgium, France, USA, Canada, China, Germany, Mexico, Spain, Sweden and the UK guidelines advised commencing oxygen when oxygen saturations (SpO2) fell to 91% or less. Target SpO2 ranged from 92% to 95% in the other 16 nations. Linear regression analysis demonstrated a strong inverse correlation between the national target for the commencement of oxygen and national case fatality rates (Spearmans Rho = -0.622, p < 0.001). Conclusion Our study highlights the disparity in oxygen provision for COVID-19 patients between the nations analysed, and indicates such disparity in access to supplemental oxygen may represent a modifiable factor associated with mortality during the pandemic.
182 downloads medRxiv emergency medicine
ABSTRACT Background: Widespread reports suggest the characteristics and disease course of coronavirus disease 2019 (COVID-19) and influenza differ, yet detailed comparisons of their clinical manifestations are lacking. Objective: Comparison of the epidemiology and clinical characteristics of COVID-19 patients with those of influenza patients in previous seasons at the same hospital Design: Admission rates, clinical measurements, and clinical outcomes from confirmed COVID-19 cases between March 1 and April 30, 2020 were compared with those from confirmed influenza cases in the previous five influenza seasons (8 months each) beginning September 1, 2014. Setting: Large tertiary care teaching hospital in Boston, Massachusetts Participants: Laboratory-confirmed COVID-19 and influenza inpatients Measurements: Patient demographics and medical history, mortality, incidence and duration of mechanical ventilation, incidences of vasopressor support and renal replacement therapy, hospital and intensive care admissions. Results: Data was abstracted from medical records of 1052 influenza patients and 583 COVID-19 patients. An average of 210 hospital admissions for influenza occurred per 8-month season compared to 583 COVID-19 admissions over two months. The median weekly number of COVID-19 patients requiring mechanical ventilation was 17 (IQR: 4, 34) compared to a weekly median of 1 (IQR: 0, 2) influenza patient (p=0.001). COVID-19 patients were significantly more likely to require mechanical ventilation (31% vs 8%), and had significantly higher mortality (20% vs. 3%; p<0.001 for all). Relatively more COVID-19 patients on mechanical ventilation lacked pre-existing conditions compared with mechanically ventilated influenza patients (25% vs 4%, p<0.001). Limitation: This is a single-center study which could limit generalization. Conclusion: COVID-19 resulted in more hospitalizations, higher morbidity, and higher mortality than influenza at the same hospital.
177 downloads medRxiv emergency medicine
Aim. To manage patients with suspected coronavirus disease (COVID-19) when they arrive at the hospital emergency department (ED), a clinical severity score is required to quickly identify patients requiring immediate hospital admission and close monitoring. The aim of this study was to evaluate, within the context of the pandemic, the performance of National Early Warning Score 2 (NEWS-2) to anticipate the admission of patients with suspected COVID-19 to a specialised emergency care unit. Methods. This retrospective study was conducted on patients presenting at the COVID-19 entrance of the ED of the Vert-Galant private hospital (Paris, France) during the first national pandemic peak from March 20 to April 20, 2020. All patients completed a questionnaire and clinical data and vital signs were recorded. Statistical analysis and modelling were used to estimate the ability of different scores (NEWS-2, qSOFA, CRB-65) to predict hospital emergency admission and/or early COVID-19 diagnosis. Results. NEWS-2, with a cut off value of 5, predicted hospital admission with 82% sensitivity, 98% specificity and an area under the curve (AUC) of 96%. NEWS-2 was superior to qSOFA and CRB-65 scores for predicting hospital admission of COVID-19 patients. Multilinear or logistic regression analysis of clinical data did not improve this result. Conclusion. NEWS-2 is an excellent score to predict hospital admission of COVID-19 patients.
176 downloads medRxiv emergency medicine
Importance: Coronavirus disease 2019 (COVID-19) is a pandemic with no specific drugs and high mortality. The most urgent thing is to find effective treatments. Objective: To determine whether hydroxychloroquine application may be associated with a decreased risk of death in critically ill COVID-19 patients and what is potential mechanism. Design, Setting and Patients: This retrospective study included all 568 critically ill COVID-19 patients who were confirmed by pathogen laboratory tests despite antiviral treatment and had severe acute respiratory distress syndrome, PAO2/FIO2 <300 with need of mechanical ventilation in Tongji Hospital, Wuhan, between February 1 of 2020 to April 8 of 2020. All 568 patients received comparable basic treatments including antiviral drugs and antibiotics, and 48 of them additionally received oral hydroxychloroquine (HCQ) treatment (200 mg twice a day for 7-10 days). Primary endpoint is mortality of patients, and inflammatory cytokines levels were compared between hydroxychloroquine and non-hydroxychloroquine (NHCQ) treatments. MAIN OUTCOMES AND MEASURES: In-hospital death and hospital stay time (day) were obtained, level of inflammatory cytokine (IL-6) was measured and compared between HCQ and NHCQ treatments. RESULTS: The median age of 568 critically ill patients is 68 (57, 76) years old with 37.0% being female. Mortalities are 18.8% (9/48) in HCQ group and 45.8% (238/520) in NHCQ group (p<0.001). The time of hospital stay before patient death is 15 (10-21) days and 8 (4 - 14) days for the HCQ and NHCQ groups, respectively (p<0.05). The level of inflammatory cytokine IL-6 was significantly lowered from 22.2 (8.3-118.9) pg/mL at the beginning of the treatment to 5.2 (3.0-23.4) pg/ml (p<0.05) at the end of the treatment in the HCQ group but there is no change in the NHCQ group. CONCLUSIONS AND RELEVANCE: Hydroxychloroquine treatment is significantly associated with a decreased mortality in critically ill patients with COVID-19 through attenuation of inflammatory cytokine storm. Therefore, hydroxychloroquine should be prescribed for treatment of critically ill COVID-19 patients to save lives.
172 downloads medRxiv emergency medicine
With the recent COVID-19 pandemic, healthcare systems all over the world are struggling to manage the massive increase in emergency department (ED) visits. This has put an enormous demand on medical professionals. Increased wait times in the ED increases the risk of infection transmission. In this work we present an open-source, low cost, off-body system to assist in the automatic triage of patients in the ED based on widely available hardware. The system initially focuses on two symptoms of the infection - fever and cyanosis. The use of visible and far-infrared cameras allows for rapid assessment at a 1m distance, thus reducing the load on medical staff and lowering the risk of spreading the infection within hospitals. Its utility can be extended to a general clinical setting in non-emergency times as well to reduce wait time, channel the time and effort of healthcare professionals to more critical tasks and also prioritize severe cases. Our system consists of a Raspberry Pi 4, a Google Coral USB accelerator, a Raspberry Pi Camera v2 and a FLIR Lepton 3.5 Radiometry Long-Wave Infrared Camera with an associated IO module. Algorithms running in real-time detect the presence and body parts of individual(s) in view, and segments out the forehead and lip regions using PoseNet. The temperature of the forehead-eye area is estimated from the infrared camera image and cyanosis is assessed from the image of the lips in the visible spectrum. In our preliminary experiments, an accuracy of $97% was achieved for detecting fever and $77% for the detection of cyanosis, with a sensitivity of 91% and area under the receiver operating characteristic curve of 0.91. Heart rate and respiratory effort are also estimated from the visible camera. Although preliminary results are promising, we note that the entire system needs to be optimized before use and assessed for efficacy. The use of low-cost instrumentation will not produce temperature readings and identification of cyanosis that is acceptable in many situations. For this reason, we are releasing the full code stack and system design to allow others to rapidly iterate and improve the system. This may be of particular benefit in low-resource settings, and low-to-middle income countries in particular, which are just beginning to be affected by COVID-19.
156 downloads medRxiv emergency medicine
Supervised machine learning algorithms deployed in acute healthcare settings use data describing historical episodes to predict clinical outcomes. Clinical settings are dynamic environments and the underlying data distributions characterising episodes can change with time (a phenomenon known as data drift), and so can the relationship between episode characteristics and associated clinical outcomes (so-called, concept drift). We demonstrate how explainable machine learning can be used to monitor data drift in a predictive model deployed within a hospital emergency department. We use the COVID-19 pandemic as an exemplar cause of data drift, which has brought a severe change in operational circumstances. We present a machine learning classifier trained using (pre-COVID-19) data, to identify patients at high risk of admission to hospital during an emergency department attendance. We evaluate our models performance on attendances occurring pre-pandemic (AUROC 0.856 95%CI [0.852, 0.859]) and during the COVID-19 pandemic (AUROC 0.826 95%CI [0.814, 0.837]). We demonstrate two benefits of explainable machine learning (SHAP) for models deployed in healthcare settings: (1) By tracking the variation in a features SHAP value relative to its global importance, a complimentary measure of data drift is found which highlights the need to retrain a predictive model. (2) By observing the relative changes in feature importance emergent health risks can be identified.
154 downloads medRxiv emergency medicine
Background: A growing number of epidemiological cases are proving the possibility of airborne transmission of coronavirus disease 2019 (COVID-19). Ensuring adequate ventilation rate is essential to reduce the risk of infection in confined spaces. Methods: We obtained the quantum generation rate by a COVID-19 infector with a reproductive number based fitting approach, and then estimated the association between infected probability and ventilation rate with the Wells-Riley equation. Results: The estimated quantum generation rate of COVID-19 is 14-48 /h. To ensure infected probabolity less than 1%, ventilation rate lareger than common values (100-350 m3/h and 1200-4000 m3/h for 15 minutes and 3 hours exposure, respectively) is required. If both the infector and susceptibles wear masks, the ventilation rate ensuring less than 1% infected probability is reduced to 50-180 m3/h and 600-2000 m3/h correspondingly, which is easier to be achieved by normal ventilation mode applied in some typical scenarios, including offices, classrooms, buses and aircraft cabins. Interpretation: The risk of potential airborne transmission in confined spaces cannot be ignored. Strict preventive measures that have been widely adopted should be effective in reducing the risk of airborne transmitted infection.
141 downloads medRxiv emergency medicine
Background : Rapid testing for COVID-19 has been clearly identified as an essential component of the strategy to control the SARS-CoV-2 epidemic, worldwide. The ID NOW COVID-19 assay is a simple, user-friendly, rapid molecular biology test based on nicking and extension amplification reaction (NEAR). Objectives : The aim of this study was to evaluate the ID NOW COVID-19 assay when used as a point-of-care test (POCT) in our Emergency Department (ED). Type of study : This prospective study enrolled 395 consecutive patients; paired nasopharyngeal swabs were collected from each study participant. The first swab was tested with the ID NOW COVID-19 assay at the point-of-care by ED nurses. The second swab was diluted in viral transport medium (VTM) and sent to the clinical microbiology department for analysis by both the RT-PCR Simplexa test COVID-19 Direct assay as the study reference method, and the ID NOW COVID-19 assay performed in the laboratory. Results : Nasopharyngeal swabs directly tested with the ID NOW COVID-19 assay yielded a sensitivity, specificity, PPV and NPV of 98.0%, 97.5%, 96.2% and 98.7%, respectively, in comparison with the RT-PCR study reference assay. When the ID NOW COVID-19 assay was performed in the laboratory using the VTM samples, the sensitivity decreased to 62.5% and the NPV to 79.7%. Three false negative test results were reported with the ID NOW COVID-19 assay when performed using undiluted swabs directly in the ED; these results were obtained from patients with elevated CT values (>30). Conclusion : We demonstrated that the ID NOW COVID-19 assay, performed as a point of care test in the ED using dry swabs, provides a rapid and reliable alternative to laboratory-based RT-PCR methods
140 downloads medRxiv emergency medicine
Background The investigation of suspected subarachnoid haemorrhage (SAH) presents a diagnostic dilemma. The limited sensitivity of a negative CT brain scan has historically mandated hospital admission and a lumbar puncture to look for evidence of blood in the cerebrospinal fluid. However, emerging evidence has suggested the sensitivity of clinical decision rules and modern CT imaging protocols within early onset of symptoms, may be sufficient to exclude the diagnosis. Methods A prospective, multi-centre, observational study of consecutive adult patients with acute severe non-traumatic headache presenting to emergency departments. We plan to recruit 9000 patients from over a hundred sites across the UK. The primary outcome is adjudicated SAH as defined by neuroimaging or cerebrospinal fluid findings consistent with the diagnosis. Data will be collected on clinical history, examination findings, phlebotomy and imaging results. All participants will be followed for 28-days to identify SAH and other clinically relevant outcomes using case note review, and later Hospital Episode Statistics. A proportionate opt-out model of consent will be used to maximise patient recruitment and study generalisability. Discussion Whilst there is increasing evidence that early neuroimaging strategies for the diagnosis of SAH are very sensitive, there have been no large studies to confirm this in the UK population. Furthermore, the test characteristics of CT brain beyond 6 hours from onset are not well understood and there is limited biological plausibility for this defined time cutpoint. Finally, the performance of the Ottawa clinical decision rule has shown promise in the Canadian population. However, its performance in the UK has not been studied and there are concerns that due to the low specificity it may result in increased, rather than decreased rate of investigations. This study will therefore aim to assess the test characteristics of both a CT brain up to 24h from presentation and the Ottawa SAH clinical decision rule.
139 downloads medRxiv emergency medicine
Carl Marincowitz, Tony Stone, Peter Bath, Richard Richard Campbell, Janette Turner, Madina Hussein, Richard Pilbery, Benjamin Thomas, Laura Sutton, Fiona Bell, Katie Biggs, Frank Hopfgartner, Suvodeep Mazumdar, Jennifer Petrie, Steve Goodacre
Objective: To assess accuracy of telephone triage in identifying patients who need emergency care amongst those with suspected COVID-19 infection and identify factors which affect triage accuracy. Design: Observational cohort study Setting: Community telephone triage in the Yorkshire and Humber, Bassetlaw, North Lincolnshire and North East Lincolnshire region. Participants: 40, 261 adults who contacted NHS 111 telephone triage services provided by Yorkshire Ambulance Service NHS Trust between the 18th March 2020 and 29th June 2020 with symptoms indicating possible COVID-19 infection were linked to Office for National Statistics death registration data, hospital and general practice electronic health care data collected by NHS Digital. Outcome: Accuracy of triage disposition (self-care/non-urgent clinical assessment versus ambulance dispatch/urgent clinical assessment) was assessed in terms of death or need for organ support at 30, 7 and 3 days from first contact with the telephone triage service. Results: Callers had a 3% (1, 200/40, 261) risk of adverse outcome. Telephone triage recommended self-care or non-urgent assessment for 60% (24, 335/40, 261), with a 1.3% (310/24, 335) risk of subsequent adverse outcome. Telephone triage had 74.2% sensitivity (95% CI: 71.6 to 76.6%) and 61.5% specificity (61% to 62%) for adverse outcomes at 30 days from first contact. Multivariable analysis suggested some co-morbidities (such as chronic respiratory disease) may be over-estimated as predictors of adverse outcome, while the association of diabetes with adverse outcome may be under-estimated. Repeat contact with the service appears to be an important under recognised predictor of adverse outcomes with both 2 contacts (OR 1.77 95% CI: 1.14 to 2.75) and 3 or more contacts (OR 4.02 95% CI: 1.68 to 9.65) associated with clinical deterioration when not provided with an ambulance or urgent clinical assessment. Conclusion: Patients advised to self-care or receive non-urgent clinical assessment had a small but non-negligible risk of serious clinical deterioration. The sensitivity and specificity of telephone triage was comparable to other tools used to triage patient acuity in emergency and urgent care. Repeat contact with telephone services needs recognition as an important predictor of subsequent adverse outcomes.
119 downloads medRxiv emergency medicine
Niv Samuel Mastboim, Alon Angel, Oded Shaham, Tahel Ilan Ber, Roy Navon, Einav Simon, Michal Rosenberg, Yael Israeli, Mary Hainrichson, Noa Avni, Eran Reiner, Paul Feigin, Kfir Oved, Boaz Tadmor, Pierre Singer, Ilya Kagan, Shaul Lev, Dror Diker, Amir Jarjoui, Ramzi Kurd, Eli Ben-Chetrit, Guy Danziger, Cihan Papan, Sergey Motov, Maanit Shapira, Michal Stein, Adi Klein, Tanya Michelle Gottlieb, Eran Eden
BACKGROUND Accurately identifying COVID-19 patients at-risk to deteriorate remains challenging. Tools integrating host-protein expression have proven useful in determining infection etiology and hold potential for prognosticating disease severity. METHODS Adults with COVID-19 were recruited at medical centers in Israel, Germany, and the United States. Severe outcome was defined as intensive care unit admission, non-invasive or invasive ventilation, or death. Tumor necrosis factor related apoptosis inducing ligand (TRAIL) and interferon gamma inducible protein-10 (IP-10; also known as CXCL10) and C-reactive protein (CRP) were measured using an analyzer providing values within 15 minutes. A signature indicating the likelihood of severe outcome was derived generating a score (0-100). Patients were assigned to 4 score bins. RESULTS Between March and November 2020, 518 COVID-19 patients were enrolled, of whom 394 were eligible, 29% meeting a severe outcome. The area under the receiver operating characteristic curve (AUC) of the signature was 0.86 (95% confidence interval: 0.81-0.91). Performance was not confounded by age, sex, or comorbidities and superior to IL-6 (AUC 0.77; p = 0.033) and CRP (AUC 0.78; p < 0.001). Likelihood of severe outcome increased significantly (p < 0.001) with higher scores. The signature differentiated patients who further deteriorated after meeting a severe outcome from those who improved (p = 0.004) and projected 14-day survival probabilities (p < 0.001). CONCLUSION The derived immune-protein signature combined with a rapid measurement platform is an accurate predictive tool for early detection of COVID-19 patients at-risk for severe outcome, facilitating timely care escalation and de-escalation and appropriate resource allocation. FUNDING MeMed funded the study
119 downloads medRxiv emergency medicine
Background Patients transported by paramedics for non-emergent conditions are increasing in Ontario and contribute to an emergency department (ED) crisis. Redirecting certain patients to sub-acute healthcare may be beneficial and suitable. We examined if ED interventions conducted on non-emergent paramedic transported patients could be conducted in sub-acute health centres. Methods A RAND/UCLA modified Delphi study was conducted. Twenty emergency and primary care physicians rated the suitability of the 150 most frequently recorded interventions for completion in sub-acute healthcare centres and provided comments to augment ratings. Interventions were performed on non-emergent adult patients transported by paramedics to an ED, and abstracted from the National Ambulatory Care Reporting System database (January 1, 2014 to March 31, 2018). We used two rounds of a modified Delphi process and set consensus at 70% agreement. Results Consensus was reached on 146 (97.3%) interventions; 103 interventions (68.7%) were suitable for sub-acute centres, 43 (28.7%) for ED only; 4 (2.6%) did not receive consensus. For sub-acute centres, all 103 interventions were rated for urgent care centres; walk-in medical centres were applicable for 46 (30.6%) and nurse practitioner-led clinics for 47 (31.3). Diagnostic imaging availability, physician preferences and staffing were determining factors for discrepancies in sub-acute centre ratings. Interpretation The majority of included ED interventions performed on non-emergent patients transported by paramedics were identified as suitable for urgent care clinics, with one-third being suitable for either walk-in medical centres or nurse practitioner-led clinics. In combination with additional patient details and supports, knowledge of interventions suitable for sub-acute healthcare centres will inform a patient classification model for paramedic-initiated redirection of patients from ED.
108 downloads medRxiv emergency medicine
We describe a minimum, rapidly scalable ventilator designed for COVID-19 patients with ARDS. Our design philosophy is not only to try to address potential ventilator shortages, but also to account for uncertainties in the supply chains of parts commonly used in traditional ventilators. To do so we employ a modular design approach and broadly explore taking advantage of parts from non-traditional supply chains. In our current prototype, we demonstrate volume control with assist control on a test lung and present a linear actuator-driven pinch valve-based implementation for both pressure control and volume control with decelerating inspiratory flow. We estimate the component cost of the system to be around $500. We publish our draft design documents and current implementation which is open and accessible in the hope that broadening the community globally will accelerate arriving at a solution and that peer review will improve the final design.
106 downloads medRxiv emergency medicine
Background In high-income countries trauma patients are becoming older, more likely to have comorbidities, and are being injured by low-energy mechanisms, chiefly ground-level falls. It is currently unknown whether existing trauma systems improve the outcomes of these patients. This systematic review investigates the association between higher-level trauma center care and outcomes of adult patients who were admitted to hospital due to injuries sustained following low-energy trauma. Methods A pre-registered systematic review (CRD42020211652) of subject databases and grey literature, supplemented by targeted manual searching, was conducted in January 2021. Studies were eligible if they reported outcomes in adults admitted to hospital due to low-energy trauma. Studies were excluded if participants were not adults or were not admitted to hospital. Studies in lower- and middle-income settings were excluded due to differences in demographics and healthcare systems. Risk of bias was assessed by independent reviewers using the Robins-I tool. In the presence of study heterogeneity a narrative synthesis was pre-specified. Results Three observational studies were included from 2,898 unique records. The studies' risk of bias was moderate-to-serious due to potential residual confounding and selection bias. All studies compared outcomes among adults injured by ground-level falls treated in trauma centers verified by the American College of Surgeons in the USA. The studies reported divergent results. One demonstrated improved outcomes in level 3 or 4 trauma centers (Observed: Expected Mortality 0.973, 95%CI 0.971-0.975), one demonstrated improved outcomes in level 1 trauma centers (Adjusted Odds Ratio 0.71, 95%CI 0.56-0.91), and one demonstrated no difference between level 1 or 2 and level 3 or 4 trauma center care (Adjusted Odds Ratio 0.91 (0.80-1.04). Conclusions There is currently no strong evidence for the efficacy of major trauma centers in caring for adult patients injured by a ground-level fall. Further studies at lower risk of bias and studies conducted outwith the USA are required.
105 downloads medRxiv emergency medicine
Cong Feng, Zhi Huang, Lili Wang, Xin Chen, Yongzhi Zhai, Feng Zhu, Yiming Bao, Yingchan Wang, Xiangzheng Su, Sai Huang, Lin Tian, Weixiu Zhu, Wenzheng Sun, Liping Zhang, Qingru Han, Juan Zhang, Fei Pan, Li Chen, Zhihong Zhu, Hongju Xiao, Yu Liu, Gang Liu, Wei Chen, Tanshi Li
Currently, the prevention and control of COVID-19 outside Hubei province in China, and other countries has become more and more critically serious. We developed and validated a diagnosis aid model without CT images for early identification of suspected COVID-19 pneumonia (S-COVID-19-P) on admission in adult fever patients and made the validated model available via an online triage calculator. Patients admitted from Jan 14 to Feb 26, 2020 with the epidemiological history of exposure to COVID-19 were included [Model development (n = 132) and validation (n = 32)]. Candidate features included clinical symptoms, routine laboratory tests and other clinical information on admission. Features selection and model development were based on Lasso regression. The primary outcome is the development and validation of a diagnosis aid model for S-COVID-19-P early identification on admission. The development cohort contains 26 S-COVID-19-P and 7 confirmed COVID-19 pneumonia cases. The model performance in held-out testing set and validation cohort resulted in AUCs of 0.841 and 0.938, F-1 score of 0.571 and 0.667, recall of 1.000 and 1.000, specificity of 0.727 and 0.778, and the precision of 0.400 and 0.500. Based on this model, an optimized strategy for S-COVID-19-P early identification in fever clinics has also been designed. S-COVID-19-P could be identified early by a machine-learning model only used collected clinical information without CT images on admission in fever clinics with 100% recall score. The well performed and validated model has been deployed as an online triage tool, which is available at: https://intensivecare.shinyapps.io/COVID19/.
105 downloads medRxiv emergency medicine
Aim: To investigate the difference in both numbers and acuity of presentations to the Paediatric Emergency Department (PED) during the peak time period of the current global SARS-CoV-2 pandemic. Design: This single centre retrospective observational study used routinely collected electronic health data to compare patient presentation characteristics between 21st March and 26th April 2020 compared to the equivalent time period in 2019. Results: There was a 90% decrease in attendances to PED, with a 10.23% reduction re-attendance rate. Children presenting were younger during the pandemic, with a median age difference of 2 years. They were more likely to present in an ambulance (9.63%), be admitted to hospital (5.75%) and be assigned the highest two Manchester triage categories (6.26%). There was a non-significant trend towards longer lengths of stay. The top 10 presenting complaints remained constant (although the order changed) between time periods. There was no difference in mortality or admission to PICU. Implications: Our data demonstrates that there has been a significant decrease in numbers of children seeking emergency department care. It suggests that presenting patients were proportionally sicker during the pandemic; however, we would argue that this is more in keeping with appropriate acuity for PED presentations, as there were no differences in PICU admission rate or mortality. We explore some of the possible reasons behind the decrease in presentations and the implications for service planning ahead of the winter months.
102 downloads medRxiv emergency medicine
OBJECTIVES: This study investigated the level of public awareness, knowledge and attitudes towards BLS among non-medical adult Omanis in Muscat City, Oman and explored the association between knowledge and attitude and the socio-demographic characteristics. DESIGN: Cross sectional design was used. Convenience sampling method in Muscat city from February to March 2020. Setting: The study setting was based in Muscat City, Oman. Participants: 426 Adults, non-medical Omanis, able to read and write Arabic Language, were included between February and March 2020. METHODS: Adopted, validated, online Arabic questionnaire was used, including four parts of 37 questions on socio-demographic information, awareness, knowledge and attitude. The results were presented in tables with descriptions. FINDINGS: Majority of participants were in age groups, 28-37 years (50.0%) and 18-27 years (35.7%); were female (57.0%); married (58.5%), single (39.9%); had secondary (31.5%), diploma (27.2%), bachelors(32.4%) education levels; and worked in government (28.6%), private sector (25.4%). Significantly, large proportion of them (62.0%) were aware about BLS. However, knowledge total scores were not normally distributed (0.917, P<0.001), with minimum, maximum, median and mean knowledge total score of 0 out of 15, 13 out of 15, 3 out of 15, 3.6 respectively. Also, attitude total scores were not normally distributed (0.976, P<0.001), with minimum, maximum, median and mean attitude total scores of 30 out of 65, 65 out of 65, 55 out of 65, 54.5 respectively. CONCLUSIONS: The awareness of non-medical adults toward Basic Life Support was substantial, whereas, knowledge level toward BLS was very low despite of its differences with respect to socio-demographic characteristics. In contrast, all participants had positive attitude toward BLS. Therefore, this study is advocating the need for mandatory training in Basic Life Support for all non-medics in the country as well as incorporating Basic Life Support teaching in school curriculum.
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