Can Warm, Humidified High-Flow Filtered Air Therapy Be Protective Against Severe Infection from Sars-Cov-2 and Other Respiratory Pathogens?

BACKGROUND Coronavirus disease - 19 (COVID-19) is an infectious disease caused by a newly discovered coronavirus, severe acute respiratory syndrome coronavirus 2 (SARSCoV-2). Anti-SARS-CoV-2 IgM and IgG antibodies can be detected in almost all patients of COVID-19. We sought to evaluate the antibody responses in COVID19 patients and also analyse their potential role in disease prognostication. METHODS All consecutive COVID-19 patients, between ages 20 - 65 years, encountered between April and July 2020 were included and compared to age-matched controls. Severity of the SARS-CoV-2 infection was categorized as none, mild and severe, based on the presence of symptoms, oxygen saturation and need for respiratory support. Serum levels of IgM and IgG antibody assays were obtained, using chemiluminescence immunoassay, after the 2nd week of presentation (range 14 - 60 days). Antibody titres above 10 AU/ml were taken as elevated. RESULTS Of 50 eligible patients, majority (40/50, 80 %) had mild symptoms and oxygen saturations above 94 %. Of the remainder, 10 % (5/50) had severe infection with need for either high flow nasal cannula oxygen or mechanical ventilation while the remainder (10 %; 5/50) were asymptomatic. IgM and IgG seroconversion were noted in almost all COVID-19 patients (46/50, 92 %) compared to healthy controls. While elevated IgG antibody levels were noted in 76 % (38/50), combined elevation of IgM and IgG antibodies is seen in 16 % (8/50) of patients. Seroconversion was markedly profound in patients with severe infection than those with mild infection. Also, greater seroconversion was noted after 21 days of testing compared to 14th day, especially for IgG. CONCLUSIONS Antibody seroconversion to SARS-CoV-2 occurred in majority of patients with COVID-19, with most salient increase in the IgG antibody levels. Antibody titres correlated directly to the disease severity, suggestive of the potential value of antibodies not only in diagnosis but also in prognostication. KEYWORDS COVID-19, Chemiluminescence Immunoassay, Invasive Mechanical Ventilation, High Flow Nasal Oxygen

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Anisotropic Membranes as Substrates for Sem

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100092189 ◽

1976 ◽

Vol 34 ◽

pp. 444-445

Author(s):

Thomas P. Turnbull ◽

W. F. Bowers

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Transmission Electron Microscopy ◽

High Flow ◽

Polymer Chemistry ◽

Surface Porosity ◽

Transmission Electron ◽

Pore Texture ◽

Spongy Layer ◽

Scanning Electron

Until recently the prime purposes of filters have been to produce clear filtrates or to collect particles from solution and then remove the filter medium and examine the particles by transmission electron microscopy. These filters have not had the best characteristics for scanning electron microscopy due to the size of the pores or the surface topography. Advances in polymer chemistry and membrane technology resulted in membranes whose characteristics make them versatile substrates for many scanning electron microscope applications. These polysulphone type membranes are anisotropic, consisting of a very thin (0.1 to 1.5 μm) dense skin of extremely fine, controlled pore texture upon a much thicker (50 to 250μm), spongy layer of the same polymer. Apparent pore diameters can be controlled in the range of 10 to 40 A. The high flow ultrafilters which we are describing have a surface porosity in the range of 15 to 25 angstrom units (0.0015-0.0025μm).

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High Flow Oxygen Therapy and the Pressure to Feed Infants With Acute Respiratory Illness

Perspectives of the ASHA Special Interest Groups ◽

10.1044/2020_persp-19-00158 ◽

2020 ◽

Vol 5 (4) ◽

pp. 1006-1010

Author(s):

Jennifer Raminick ◽

Hema Desai

Keyword(s):

Clinical Practice ◽

Clinical Practice Guidelines ◽

Practice Guidelines ◽

Oxygen Therapy ◽

Respiratory Illness ◽

High Flow ◽

Oral Feeding ◽

Respiratory Support ◽

Acute Respiratory Illness ◽

High Flow Oxygen

Purpose Infants hospitalized for an acute respiratory illness often require the use of noninvasive respiratory support during the initial stage to improve their breathing. High flow oxygen therapy (HFOT) is becoming a more popular means of noninvasive respiratory support, often used to treat respiratory syncytial virus/bronchiolitis. These infants present with tachypnea and coughing, resulting in difficulties in coordinating sucking and swallowing. However, they are often allowed to feed orally despite having high respiratory rate, increased work of breathing and on HFOT, placing them at risk for aspiration. Feeding therapists who work with these infants have raised concerns that HFOT creates an additional risk factor for swallowing dysfunction, especially with infants who have compromised airways or other comorbidities. There is emerging literature concluding changes in pharyngeal pressures with HFOT, as well as aspiration in preterm neonates who are on nasal continuous positive airway pressure. However, there is no existing research exploring the effect of HFOT on swallowing in infants with acute respiratory illness. This discussion will present findings from literature on HFOT, oral feeding in the acutely ill infant population, and present clinical practice guidelines for safe feeding during critical care admission for acute respiratory illness. Conclusion Guidelines for safety of oral feeds for infants with acute respiratory illness on HFOT do not exist. However, providers and parents continue to want to provide oral feeds despite clinical signs of respiratory distress and coughing. To address this challenge, we initiated a process change to use clinical bedside evaluation and a “cross-systems approach” to provide recommendations for safer oral feeds while on HFOT as the infant is recovering from illness. Use of standardized feeding evaluation and protocol have improved consistency of practice within our department. However, further research is still necessary to develop clinical practice guidelines for safe oral feeding for infants on HFOT.

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