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1.
Clin Lab ; 68(1)2022 Jan 01.
Article in English | MEDLINE | ID: covidwho-1622821

ABSTRACT

BACKGROUND: Since December 2019, there has been a global outbreak of COVID-19. As of the end of July 2020, more than 600,000 deaths had been reported globally. The purpose of this paper is to further explore the application of non-invasive ventilation in severe COVID-19 patients. METHODS: A retrospective study was conducted to included 57 confirmed COVID-19 patients, among which 36 cases were severe. According to different oxygen inhalation methods, they were divided into non-invasive ventilator assisted ventilation group with 21 cases (group A) and 15 cases of nasal catheter oxygen inhalation group (group B). The data of respiration (RR), heart rate (HR), partial arterial pressure of oxygen (PaO2), partial arterial pressure of carbon dioxide (PaCO2), and oxygenation index (OI) before the treatment of noninvasive ventilator assisted ventilation or nasal catheter oxygen treatment at 24, 48, and 72 hours of treatment of the 2 groups were collected and analyzed to determine whether the above indicators were statistically different in each time period. RESULTS: After 24 hours of treatment with noninvasive ventilator assisted ventilation in group A, RR gradually decreased, PaO2 and OI were significantly higher than before treatment, while after 24 hours of treatment, PaO2, RR, HR and other indexes in group B showed no significant improvement, and OI increased gradually after 48 hours of treatment, with statistically significant difference compared with that before treatment. CONCLUSIONS: Early adoption of non-invasive ventilation can effectively improve the hypoxic state of patients with severe COVID-19. The combination of underlying diseases will not prolong the use of non-invasive ventilation.


Subject(s)
COVID-19 , Humans , Respiration, Artificial , Retrospective Studies , SARS-CoV-2 , Ventilators, Mechanical
2.
Rev Peru Med Exp Salud Publica ; 38(3): 391-398, 2021.
Article in Spanish, English | MEDLINE | ID: covidwho-1599823

ABSTRACT

OBJECTIVE: To develop a methodology for evaluating the level of respiratory protection provided by respirators, surgical masks and community face masks used by the Peruvian population; protection was evaluated against particles of a size similar to those containing active SARS-CoV-2 virus. MATERIALS AND METHODS: A direct linear relationship has been determined between the logarithm of the concentration of airborne particles and the elapsed time; thus, it is possible to compare the quantity of particles inside and outside of the mask or respirator in the same time period, as well as to obtain the percentage of respiratory protection for each evaluated sample. RESULTS: A methodology was established to evaluate the level of respiratory protection against aerosols smaller than 5.0 µm. Also, the use of accessories such as rubber bands or adjusters behind the head and neck, and the use of robust nasal clips, significantly increased the level of respiratory protection against particles with a high probability of containing SARS-CoV-2. CONCLUSIONS: We found concordance between the obtained respiratory protection values and those expected, considering the filtration level of the material used for each surgical mask or respirator, as well as the tightness. A significant increase in the levels of respiratory protection was observed.


OBJETIVO: Desarrollar una metodología para evaluar el nivel de protección respiratoria de respiradores, mascarillas quirúrgicas y mascarillas comunitarias que usa la población peruana, usando partículas de un tamaño similar a las que contienen al virus activo del SARS-CoV-2. MATERIALES Y MÉTODOS: Se ha determinado una relación lineal directa entre el logaritmo de la concentración de partículas suspendidas en aire y el tiempo transcurrido; por lo cual es posible comparar la cantidad de partículas internas y externas a la mascarilla o respirador en un mismo periodo y conocer el porcentaje de protección respiratoria de cada muestra evaluada. RESULTADOS: Se ha logrado implementar una metodología para evaluar el nivel de protección respiratoria ante aerosoles menores a 5,0 µm. Asimismo, el empleo de accesorios como ligas o ajustadores detrás de cabeza y nuca, y el uso de clips nasales robustos, incrementan significativamente el nivel de protección respiratoria ante partículas con alta probabilidad de contener al SARS-CoV-2. CONCLUSIONES: Se observa una concordancia entre los valores de protección respiratoria obtenidos y los esperados, considerando el nivel de filtración del material empleado de cada mascarilla quirúrgica o respirador, y su nivel de ajuste. Se observó un incremento significativo en los niveles de protección respiratoria.


Subject(s)
COVID-19 , Masks , Aerosols , Humans , SARS-CoV-2 , Ventilators, Mechanical
3.
Front Public Health ; 9: 753048, 2021.
Article in English | MEDLINE | ID: covidwho-1590788

ABSTRACT

Background: The rapidly growing imbalance between supply and demand for ventilators during the COVID-19 pandemic has highlighted the principles for fair allocation of scarce resources. Failing to address public views and concerns on the subject could fuel distrust. The objective of this study was to determine the priorities of the Iranian public toward the fair allocation of ventilators during the COVID-19 pandemic. Methods: This anonymous community-based national study was conducted from May 28 to Aug 20, 2020, in Iran. Data were collected via the Google Forms platform, using an online self-administrative questionnaire. The questionnaire assessed participants' assigned prioritization scores for ventilators based on medical and non-medical criteria. To quantify participants' responses on prioritizing ventilator allocation among sub-groups of patients with COVID-19 who need mechanical ventilation scores ranging from -2, very low priority, to +2, very high priority were assigned to each response. Results: Responses of 2,043 participants, 1,189 women, and 1,012 men, were analyzed. The mean (SD) age was 31.1 (9.5), being 32.1 (9.3) among women, and 29.9 (9.6) among men. Among all participants, 274 (13.4%) were healthcare workers. The median of assigned priority score was zero (equal) for gender, age 41-80, nationality, religion, socioeconomic, high-profile governmental position, high-profile occupation, being celebrities, employment status, smoking status, drug abuse, end-stage status, and obesity. The median assigned priority score was +2 (very high priority) for pregnancy, and having <2 years old children. The median assigned priority score was +1 (high priority) for physicians and nurses of patients with COVID-19, patients with nobel research position, those aged <40 years, those with underlying disease, immunocompromise status, and malignancy. Age>80 was the only factor participants assigned -1 (low priority) to. Conclusions: Participants stated that socioeconomic factors, except for age>80, should not be involved in prioritizing mechanical ventilators at the time of resources scarcity. Front-line physicians and nurses of COVID-19 patients, pregnant mothers, mothers who had children under 2 years old were given high priority.


Subject(s)
COVID-19 , Adult , Aged , Aged, 80 and over , Child, Preschool , Female , Health Care Rationing , Humans , Infant , Iran/epidemiology , Male , Middle Aged , Pandemics , Public Opinion , SARS-CoV-2 , Surveys and Questionnaires , Ventilators, Mechanical
4.
Sci Rep ; 11(1): 24436, 2021 12 24.
Article in English | MEDLINE | ID: covidwho-1585781

ABSTRACT

Patients diagnosed with diabetes mellitus (DM) who are infected with severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) belong to the most vulnerable patient subgroups. Emerging data has shown increased risks of severe infections, increased in ICU admissions, longer durations of admission, and increased mortality among coronavirus disease 2019 (COVID-19) patients with diabetes. We performed a subgroup analysis comparing the outcomes of patients diagnosed with DM (n = 2191) versus patients without DM (n = 8690) on our data from our study based on a nationwide, comparative, retrospective, cohort study among adult, hospitalized COVID-19 patients involving 37 hospital sites from around the Philippines. We determined distribution differences between two independent samples using Mann-Whitney U and t tests. Data on the time to onset of mortality, respiratory failure, intensive care unit (ICU) admission were used to build Kaplan-Meier curves and to compute for hazard ratios (HR). The odds ratios (OR) for longer ventilator dependence, longer ICU stay, and longer hospital stays were computed via multivariate logistic regression. Adjusted hazard ratios (aHR) and ORs (aOR) with 95% CI were calculated. We included a total of 10,881 patients with confirmed COVID-19 infection (2191 have DM while 8690 did not have DM). The median age of the DM cohort was 61, with a female to male ratio of 1:1.25 and more than 50% of the DM population were above 60 years old. The aOR for mortality was significantly higher among those in the DM group by 1.46 (95% CI 1.28-1.68; p < 0.001) as compared to the non-DM group. Similarly, the aOR for respiratory failure was also significantly higher among those in the DM group by 1.67 (95% CI 1.46-1.90). The aOR for developing severe COVID-19 at nadir was significantly higher among those in the DM group by 1.85 (95% CI 1.65-2.07; p < 0.001). The aOR for ICU admission was significantly higher among those in the DM group by 1.80 (95% CI 1.59-2.05) than those in the non-DM group. DM patients had significantly longer duration of ventilator dependence (aOR 1.33, 95% CI 1.08-1.64; p = 0.008) and longer hospital admission (aOR 1.13, 95% CI 1.01-1.26; p = 0.027). The presence of DM among COVID-19 patients significantly increased the risk of mortality, respiratory failure, duration of ventilator dependence, severe/critical COVID-19, ICU admission, and length of hospital stay.


Subject(s)
COVID-19/pathology , Diabetes Mellitus/diagnosis , Adolescent , Adult , Aged , COVID-19/complications , COVID-19/mortality , COVID-19/virology , Diabetes Mellitus/pathology , Female , Hospital Mortality , Humans , Length of Stay , Male , Middle Aged , Odds Ratio , Philippines , Proportional Hazards Models , Respiratory Insufficiency/etiology , Retrospective Studies , Risk Factors , SARS-CoV-2/isolation & purification , Severity of Illness Index , Ventilators, Mechanical , Young Adult
5.
PLoS One ; 16(3): e0247575, 2021.
Article in English | MEDLINE | ID: covidwho-1573727

ABSTRACT

INTRODUCTION: The COVID-19 pandemic has led to widespread shortages of N95 respirators and other personal protective equipment (PPE). An effective, reusable, locally-manufactured respirator can mitigate this problem. We describe the development, manufacture, and preliminary testing of an open-hardware-licensed device, the "simple silicone mask" (SSM). METHODS: A multidisciplinary team developed a reusable silicone half facepiece respirator over 9 prototype iterations. The manufacturing process consisted of 3D printing and silicone casting. Prototypes were assessed for comfort and breathability. Filtration was assessed by user seal checks and quantitative fit-testing according to CSA Z94.4-18. RESULTS: The respirator originally included a cartridge for holding filter material; this was modified to connect to standard heat-moisture exchange (HME) filters (N95 or greater) after the cartridge showed poor filtration performance due to flow acceleration around the filter edges, which was exacerbated by high filter resistance. All 8 HME-based iterations provided an adequate seal by user seal checks and achieved a pass rate of 87.5% (N = 8) on quantitative testing, with all failures occurring in the first iteration. The overall median fit-factor was 1662 (100 = pass). Estimated unit cost for a production run of 1000 using distributed manufacturing techniques is CAD $15 in materials and 20 minutes of labor. CONCLUSION: Small-scale manufacturing of an effective, reusable N95 respirator during a pandemic is feasible and cost-effective. Required quantities of reusables are more predictable and less vulnerable to supply chain disruption than disposables. With further evaluation, such devices may be an alternative to disposable respirators during public health emergencies. The respirator described above is an investigational device and requires further evaluation and regulatory requirements before clinical deployment. The authors and affiliates do not endorse the use of this device at present.


Subject(s)
COVID-19/prevention & control , Equipment Design/instrumentation , Filtration/instrumentation , Pandemics/prevention & control , Personal Protective Equipment , Respiratory Protective Devices , Ventilators, Mechanical , Equipment Reuse , Face , Humans , Materials Testing/instrumentation , N95 Respirators , Occupational Exposure/prevention & control , Printing, Three-Dimensional/instrumentation , SARS-CoV-2/pathogenicity
6.
J Prev Med Hyg ; 62(3): E625-E627, 2021 Sep.
Article in English | MEDLINE | ID: covidwho-1573927

ABSTRACT

Background: Cases of COVID-19 infection have increased sharply in Europe since August 2020, and the WHO recommend the use of respirators in situations where keeping distance is not possible. The purpose of this study was to evaluate the impact of the use of respirators on infection cases and viral deaths in European countries. Methods: COVID-19 cases and related deaths in 29 countries relative to population were searched through the WHO database on 15.10.2020. Recent 14-day cases in relation to the population were retrieved from the European Center for Disease Prevention and Control's website, covering the period from 1 to 14 October 2020. Information related to the use of respirators was retrieved from the IHME database of the University of Washington at time point, 1.6.2020. Results: The proportion of people using of respirators at 1.6.2020 correlate negatively to the reported cases of disease (Rs = -0.528) and to deaths (Rs = -0.553). No significant correlation was found for recent cases or mortality. Countries with at least 60% respirator use did not differ from other countries. Conclusion: Long-term use of respirators appears to reduce disease incidence and death in the population.


Subject(s)
COVID-19 , Europe/epidemiology , Humans , Pandemics/prevention & control , SARS-CoV-2 , Ventilators, Mechanical
7.
Polim Med ; 51(2): 91-102, 2021.
Article in English | MEDLINE | ID: covidwho-1575456

ABSTRACT

Coronavirus Disease 2019 (COVID-19) pandemic caused an increase in the demand for personal protective equipment (PPE) and disruptions in production chains, resulting in an acute shortage of PPE. A possible solution to this problem was additive manufacturing (AM) technology - allowing for a quick start of the production of PPE and potentially able to meet the demand until the production is restored. In addition, AM allows for the production of PPE prototypes with potentially greater comfort of use or degree of protection. In order to assess the production of PPE in AM during the COVID-19 pandemic, previously published articles in this field were analyzed. After analyzing abstracts and full texts, 30 original works were selected from the initially collected 487 articles. Based on the analyzed literature, it was found that there are not enough studies comparing traditional and AM PPE as well as not enough comparisons of the different types of AM PPE with each other. In many cases, researchers focused only on the subjective assessment of the comfort of using PPE, without assessing their effectiveness in preventing infections. Despite that, AM has a great potential to quickly produce lacking PPE. Respirators and shields made by AM were rated by the vast majority of users as comfortable to wear. Some of the respirators could be adapted to a specific user, by designing on the basis of a face scan or after warming up the finished print and modeling the shape.


Subject(s)
COVID-19 , Personal Protective Equipment , Humans , Pandemics/prevention & control , SARS-CoV-2 , Ventilators, Mechanical
8.
IEEE J Biomed Health Inform ; 25(11): 4110-4118, 2021 11.
Article in English | MEDLINE | ID: covidwho-1570200

ABSTRACT

Almost 25% of COVID-19 patients end up in ICU needing critical mechanical ventilation support. There is currently no validated objective way to predict which patients will end up needing ventilator support, when the disease is mild and not progressed. N = 869 patients from two sites (D1: N = 822, D2: N = 47) with baseline clinical characteristics and chest CT scans were considered for this study. The entire dataset was randomly divided into 70% training, D1train (N = 606) and 30% test-set (Dtest: D1test (N = 216) + D2 (N = 47)). An expert radiologist delineated ground-glass-opacities (GGOs) and consolidation regions on a subset of D1train, (D1train_sub, N = 88). These regions were automatically segmented and used along with their corresponding CT volumes to train an imaging AI predictor (AIP) on D1train to predict the need of mechanical ventilators for COVID-19 patients. Finally, top five prognostic clinical factors selected using univariate analysis were integrated with AIP to construct an integrated clinical and AI imaging nomogram (ClAIN). Univariate analysis identified lactate dehydrogenase, prothrombin time, aspartate aminotransferase, %lymphocytes, albumin as top five prognostic clinical features. AIP yielded an AUC of 0.81 on Dtest and was independently prognostic irrespective of other clinical parameters on multivariable analysis (p<0.001). ClAIN improved the performance over AIP yielding an AUC of 0.84 (p = 0.04) on Dtest. ClAIN outperformed AIP in predicting which COVID-19 patients ended up needing a ventilator. Our results across multiple sites suggest that ClAIN could help identify COVID-19 with severe disease more precisely and likely to end up on a life-saving mechanical ventilation.


Subject(s)
COVID-19 , Artificial Intelligence , Humans , Lung , Nomograms , Retrospective Studies , SARS-CoV-2 , Tomography, X-Ray Computed , Ventilators, Mechanical
9.
Anesthesiology ; 135(6): 951-962, 2021 12 01.
Article in English | MEDLINE | ID: covidwho-1546049

ABSTRACT

Respiratory viruses are transmitted via respiratory particles that are emitted when people breath, speak, cough, or sneeze. These particles span the size spectrum from visible droplets to airborne particles of hundreds of nanometers. Barrier face coverings ("cloth masks") and surgical masks are loose-fitting and provide limited protection from airborne particles since air passes around the edges of the mask as well as through the filtering material. Respirators, which fit tightly to the face, provide more effective respiratory protection. Although healthcare workers have relied primarily on disposable filtering facepiece respirators (such as N95) during the COVID-19 pandemic, reusable elastomeric respirators have significant potential advantages for the COVID-19 and future respiratory virus pandemics. However, currently available elastomeric respirators were not designed primarily for healthcare or pandemic use and require further development to improve their suitability for this application. The authors believe that the development, implementation, and stockpiling of improved elastomeric respirators should be an international public health priority.


Subject(s)
COVID-19/epidemiology , Elastomers/standards , Equipment Design/standards , Health Personnel/standards , Occupational Exposure/standards , Ventilators, Mechanical/standards , COVID-19/prevention & control , COVID-19/transmission , Equipment Design/methods , Equipment Reuse/standards , Humans , Occupational Exposure/prevention & control , Pandemics/prevention & control
10.
Intellect Dev Disabil ; 59(6): 441-445, 2021 12 01.
Article in English | MEDLINE | ID: covidwho-1528706

ABSTRACT

In the COVID-19 pandemic, concerns exist that ventilator triage policies may lead to discrimination against people with disabilities. This study evaluates whether preclinical medical students demonstrate bias towards people with disabilities during an educational ventilator-allocation exercise. Written student responses to a triage simulation activity were analyzed to describe ventilator priority rankings and to identify themes regarding disability. Disability status was not cited as a reason to withhold a ventilator. Key themes observed in ventilator triage decisions included life expectancy, comorbidities, and social worth. Although disability discrimination has historically been perpetuated by health care professionals, it is encouraging that preclinical medical students did not demonstrate explicit bias against people with disabilities in ventilator triage scenarios.


Subject(s)
COVID-19 , Disabled Persons , Intellectual Disability , Students, Medical , Humans , Pandemics , SARS-CoV-2 , Ventilators, Mechanical
11.
Int J Artif Organs ; 44(11): 861-867, 2021 Nov.
Article in English | MEDLINE | ID: covidwho-1526574

ABSTRACT

Acute respiratory distress syndrome (ARDS) in COVID-19 patients is associated with poor clinical outcomes and high mortality rates, despite the use of mechanical ventilation. Veno-Venous Extracorporeal membrane Oxygenation (VV-ECMO) in these patients is a viable salvage therapy. We describe clinical outcomes and survival rates in 52 COVID-19 patients with ARDS treated with early VV-ECMO at a large, high-volume center ECMO program. Outcomes included arterial blood gases, respiratory parameters, inflammatory markers, adverse events, and survival rates. Patients' mean age was 47.8 ± 12.1 years, 33% were female, and 75% were Hispanic. At the end of study period, 56% (n = 29) of the patients survived and were discharged and 44% (n = 23) of the patients expired. Survival rate was 75.0% (9 out of 12) in patients placed on ECMO prior to mechanical ventilation. Longer duration on mechanical ventilation prior to ECMO intervention was associated with a 31% (aOR = 1.31, 95% CI, 1.00-1.70) increased odds of mortality after adjusting for age, gender, BMI, number of comorbid conditions, and post-ECMO ventilator days. Early and effective ECMO intervention in critical ill COVID-19 patients might be a valuable strategy in critical care settings to increase their odds of survival.


Subject(s)
COVID-19 , Extracorporeal Membrane Oxygenation , Respiratory Distress Syndrome , Adult , Extracorporeal Membrane Oxygenation/adverse effects , Female , Humans , Male , Middle Aged , Respiratory Distress Syndrome/diagnosis , Respiratory Distress Syndrome/therapy , SARS-CoV-2 , Ventilators, Mechanical
12.
Occup Med (Lond) ; 71(6-7): 303, 2021 10 01.
Article in English | MEDLINE | ID: covidwho-1522279
13.
Chest ; 160(1): 175-186, 2021 07.
Article in English | MEDLINE | ID: covidwho-1525725

ABSTRACT

BACKGROUND: SARS-CoV-2 aerosolization during noninvasive positive-pressure ventilation may endanger health care professionals. Various circuit setups have been described to reduce virus aerosolization. However, these setups may alter ventilator performance. RESEARCH QUESTION: What are the consequences of the various suggested circuit setups on ventilator efficacy during CPAP and noninvasive ventilation (NIV)? STUDY DESIGN AND METHODS: Eight circuit setups were evaluated on a bench test model that consisted of a three-dimensional printed head and an artificial lung. Setups included a dual-limb circuit with an oronasal mask, a dual-limb circuit with a helmet interface, a single-limb circuit with a passive exhalation valve, three single-limb circuits with custom-made additional leaks, and two single-limb circuits with active exhalation valves. All setups were evaluated during NIV and CPAP. The following variables were recorded: the inspiratory flow preceding triggering of the ventilator, the inspiratory effort required to trigger the ventilator, the triggering delay, the maximal inspiratory pressure delivered by the ventilator, the tidal volume generated to the artificial lung, the total work of breathing, and the pressure-time product needed to trigger the ventilator. RESULTS: With NIV, the type of circuit setup had a significant impact on inspiratory flow preceding triggering of the ventilator (P < .0001), the inspiratory effort required to trigger the ventilator (P < .0001), the triggering delay (P < .0001), the maximal inspiratory pressure (P < .0001), the tidal volume (P = .0008), the work of breathing (P < .0001), and the pressure-time product needed to trigger the ventilator (P < .0001). Similar differences and consequences were seen with CPAP as well as with the addition of bacterial filters. Best performance was achieved with a dual-limb circuit with an oronasal mask. Worst performance was achieved with a dual-limb circuit with a helmet interface. INTERPRETATION: Ventilator performance is significantly impacted by the circuit setup. A dual-limb circuit with oronasal mask should be used preferentially.


Subject(s)
COVID-19 , Continuous Positive Airway Pressure , Disease Transmission, Infectious/prevention & control , Noninvasive Ventilation , Air Filters , Benchmarking/methods , COVID-19/therapy , COVID-19/transmission , Continuous Positive Airway Pressure/adverse effects , Continuous Positive Airway Pressure/instrumentation , Continuous Positive Airway Pressure/methods , Critical Pathways/standards , Critical Pathways/trends , Humans , Infectious Disease Transmission, Patient-to-Professional/prevention & control , Noninvasive Ventilation/adverse effects , Noninvasive Ventilation/instrumentation , Noninvasive Ventilation/methods , Research Design , Respiratory Function Tests/methods , SARS-CoV-2 , Treatment Outcome , Ventilators, Mechanical
14.
J Emerg Med ; 60(5): e138-e139, 2021 05.
Article in English | MEDLINE | ID: covidwho-1492252
15.
PLoS One ; 16(10): e0258245, 2021.
Article in English | MEDLINE | ID: covidwho-1468167

ABSTRACT

Since the innovation of our new half-piece elastometric respirator, this type of filtering facepiece respirator (FFR) has been used widely in Thailand. Decontamination methods including ultraviolet C (UVC) germicidal irradiation and 70% alcohol have been implemented to decontaminate these respirators. We then examined the inactivation potential of different decontamination processes on porcine epidemic diarrhea virus (PEDV) and numerous bacterial strains, most of which were skin-derived. To enable rigorous integrity of the masks after repeated decontamination processes, fit tests by the Bitrex test, tensile strength and elongation at break were also evaluated. Our results showed that UVC irradiation at a dose of 3 J/cm2 can eradicate bacteria after 60 min and viruses after 10 min. No fungi were found on the mask surface before decontamination. The good fit test results, tensile strength and elongation at break were still maintained after multiple cycles of decontamination. No evidence of physical degradation was found by gross visual inspection. Alcohol (70%) is also an easy and effective way to eradicate microorganisms on respirators. As the current pandemic is expected to continue for months to years, the need to supply adequate reserves of personnel protective equipment (PPE) and develop effective PPE reprocessing methods is crucial. Our studies demonstrated that the novel silicone mask can be safely reprocessed and decontaminated for many cycles by UVC irradiation, which will help ameliorate the shortage of important protective devices in the COVID-19 pandemic era.


Subject(s)
COVID-19 , Decontamination/methods , Respiratory Protective Devices , Ultraviolet Rays , Ventilators, Mechanical , Humans , Pandemics , Silicones
16.
Sci Rep ; 11(1): 19888, 2021 10 06.
Article in English | MEDLINE | ID: covidwho-1454817

ABSTRACT

To cope with the shortage of filtering facepiece respirators (FFRs) during the coronavirus (COVID-19) pandemic, healthcare institutions were forced to reuse FFRs after applying different decontamination methods including gamma-irradiation (GIR). The aim of this study was to evaluate the effect of GIR on the filtration efficiency (FE) of FFRs and on SARS-CoV-2 detection. The FE of 2 FFRs types (KN95 and N95-3 M masks) was assessed at different particle sizes (0.3-5 µm) following GIR (0-15 kGy) delivered at either typical (1.65 kGy/h) or low (0.5088 kGy/h) dose rates. The detection of two SARS-CoV-2 RNA genes (E and RdRp4) following GIR (0-50 kGy) was carried out using RT-qPCR assay. Both masks showed an overall significant (P < 0.001) reduction in FE with increased GIR doses. No significant differences were observed between GIR dose rates on FE. The GIR exhibited significant increases (P ≤ 0.001) in the cycle threshold values (ΔCt) of both genes, with no detection following high doses. In conclusion, complete degradation of SARS-CoV-2 RNA can be achieved by high GIR (≥ 30 kGy), suggesting its potential use in FFRs decontamination. However, GIR exhibited adverse effects on FE in dose- and particle size-dependent manners, rendering its use to decontaminate FFRs debatable.


Subject(s)
COVID-19/virology , Decontamination/methods , Masks , SARS-CoV-2/isolation & purification , Ventilators, Mechanical , COVID-19/prevention & control , COVID-19/transmission , Filtration , Gamma Rays , Humans , Particle Size
17.
Med Eng Phys ; 92: 71-79, 2021 06.
Article in English | MEDLINE | ID: covidwho-1452333

ABSTRACT

The comprehension of the fluid flow in the upper airways is of paramount importance when treating patients under clinical conditions that demand mechanical ventilation. Barotrauma and overdistension are related to undesirable pressures and might be responsible for morbidity and mortality. In the current work we use computational fluid dynamics to investigate the pressure field in the upper respiratory airways. We performed a set of simulations varying the volumetric flow rate of mechanical ventilators and we have shown that the pressure profile can be calculated by means of the volumetric flow rate in accordance with a mathematical expression given by Pav=aV˙2, where Pav is the average pressure at selected sections of the upper airways and V˙ is the volumetric flow rate. Numerical findings provide evidence that the constant a varies with the location of the plane in the upper airways. We also show that some particular diameters of endotracheal tubes (ETT) must be used with care for a given range of volumetric flow rates. Overall, we document an important relationship among pressure, volumetric flow rate and selected internal diameters from ETT.


Subject(s)
Intubation, Intratracheal , Ventilators, Mechanical , Humans , Hydrodynamics , Respiration, Artificial , Respiratory System
18.
Clin Respir J ; 14(3): 214-221, 2020 Mar.
Article in English | MEDLINE | ID: covidwho-1455532

ABSTRACT

BACKGROUND: Patients with neuromuscular disorders (NMDs) are likely to develop respiratory failure which requires noninvasive ventilation (NIV). Ventilation via a mouthpiece (MPV) is an option to offer daytime NIV. OBJECTIVES: To determine the preferred equipment for MPV by patients with NMDs. METHODS: Two MPV equipment sets were compared in 20 patients with NMDs. Set 1, consisted of a non-dedicated ventilator for MPV (PB560, Covidien) with a plastic angled mouthpiece. Set 2, consisted of a dedicated MPV ventilator (Trilogy 100, Philips Respironics) without backup rate and kiss trigger combined with a silicone straw mouthpiece. The Borg dyspnea score, ventilator free time, transcutaneous oxygen saturation (SpO2) and carbon dioxide tension (TcCO2 ) were recorded with and without MPV. Patient perception was assessed by a 17-items list. RESULTS: Carbon dioxide tension measurements and total perception score were not different between the two MPV sets. Dyspnea score was lower with the non-dedicated versus dedicated equipment, 1 (0.5) versus 3 (1-6), P < 0.01. All patients with a ventilator free time lower than 6 hours preferred a set backup rate rather than a kiss trigger. Sixty five percent of patients preferred the commercial arm support and 55% preferred the plastic angled mouthpiece. CONCLUSIONS: Dedicated and non-dedicated MPV equipment are deemed effective and comfortable. Individualization of arm support and mouthpiece is advised to ensure success of MPV. A ventilator free time lower than 6 hours seems to be a useful indicator to a priori set a backup rate rather than a rate at zero associated to the kiss trigger.


Subject(s)
Neuromuscular Diseases/complications , Noninvasive Ventilation/instrumentation , Respiratory Insufficiency/therapy , Ventilators, Mechanical/statistics & numerical data , Adolescent , Adult , Blood Gas Monitoring, Transcutaneous/methods , Carbon Dioxide/metabolism , Case-Control Studies , Cross-Over Studies , Dyspnea/diagnosis , Equipment Design , Female , Humans , Male , Perception , Time Factors , Ventilators, Mechanical/trends , Young Adult
20.
Sci Rep ; 11(1): 18959, 2021 09 23.
Article in English | MEDLINE | ID: covidwho-1437695

ABSTRACT

The COVID-19 pandemic has put massive strains on hospitals, and tools to guide hospital planners in resource allocation during the ebbs and flows of the pandemic are urgently needed. We investigate whether machine learning (ML) can be used for predictions of intensive care requirements a fixed number of days into the future. Retrospective design where health Records from 42,526 SARS-CoV-2 positive patients in Denmark was extracted. Random Forest (RF) models were trained to predict risk of ICU admission and use of mechanical ventilation after n days (n = 1, 2, …, 15). An extended analysis was provided for n = 5 and n = 10. Models predicted n-day risk of ICU admission with an area under the receiver operator characteristic curve (ROC-AUC) between 0.981 and 0.995, and n-day risk of use of ventilation with an ROC-AUC between 0.982 and 0.997. The corresponding n-day forecasting models predicted the needed ICU capacity with a coefficient of determination (R2) between 0.334 and 0.989 and use of ventilation with an R2 between 0.446 and 0.973. The forecasting models performed worst, when forecasting many days into the future (for large n). For n = 5, ICU capacity was predicted with ROC-AUC 0.990 and R2 0.928, and use of ventilator was predicted with ROC-AUC 0.994 and R2 0.854. Random Forest-based modelling can be used for accurate n-day forecasting predictions of ICU resource requirements, when n is not too large.


Subject(s)
COVID-19/epidemiology , Forecasting/methods , Intensive Care Units/trends , Area Under Curve , Computational Biology/methods , Critical Care/statistics & numerical data , Critical Care/trends , Denmark/epidemiology , Hospitalization/trends , Hospitals/trends , Humans , Machine Learning , Pandemics , ROC Curve , Respiration, Artificial/statistics & numerical data , Respiration, Artificial/trends , Retrospective Studies , Risk Assessment/methods , Risk Factors , SARS-CoV-2/pathogenicity , Ventilators, Mechanical/trends
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