scholarly journals COVID-19: minimising contaminated aerosol spreading during CPAP treatment

2020 ◽  
Vol 105 (6) ◽  
pp. 669-671
Author(s):  
Snorri Donaldsson ◽  
Lars Naver ◽  
Baldvin Jonsson ◽  
Thomas Drevhammar
Keyword(s):  
Healthcare Workers ◽  
Work Of Breathing ◽  
Lung Model ◽  
Non Invasive ◽  
Cpap Treatment ◽  
Aerosol Generation ◽  
Viral Particles ◽  
A Minor ◽  
Expiratory Limb ◽  
Cpap Devices

BackgroundThe COVID-19 pandemic has raised concern for healthcare workers getting infected via aerosol from non-invasive respiratory support of infants. Attaching filters that remove viral particles in air from the expiratory limb of continuous positive airway pressure (CPAP) devices should theoretically decrease the risk. However, adding filters to the expiratory limb could add to expiratory resistance and thereby increase the imposed work of breathing (WOB).ObjectiveTo evaluate the effects on imposed WOB when attaching filters to the expiratory limb of CPAP devices.MethodsTwo filters were tested on three CPAP systems at two levels of CPAP in a mechanical lung model. Main outcome was imposed WOB.ResultsThere was a minor increase in imposed WOB when attaching the filters. The differences between the two filters were small.ConclusionTo minimise contaminated aerosol generation during CPAP treatment, filters can be attached to expiratory tubing with only a minimal increase in imposed WOB in a non-humidified environment. Care has to be taken to avoid filter obstruction and replace filters as recommended.

scholarly journals Short-term effects of synchronized vs. non-synchronized NIPPV in preterm infants: study protocol for an unmasked randomized crossover trial

Trials ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Francesco Cresi ◽  
Federica Chiale ◽  
Elena Maggiora ◽  
Silvia Maria Borgione ◽  
Mattia Ferroglio ◽  
...  
Keyword(s):  
Preterm Infants ◽  
Work Of Breathing ◽  
Respiratory Rhythm ◽  
Assisted Ventilation ◽  
Positive Pressure ◽  
Invasive Ventilation ◽  
Short Term ◽  
Non Invasive ◽  
Non Invasive Ventilation ◽  
Short Term Effects

Abstract Background Non-invasive ventilation (NIV) has been recommended as the best respiratory support for preterm infants with respiratory distress syndrome (RDS). However, the best NIV technique to be used as first intention in RDS management has not yet been established. Nasal intermittent positive pressure ventilation (NIPPV) may be synchronized (SNIPPV) or non-synchronized to the infant’s breathing efforts. The aim of the study is to evaluate the short-term effects of SNIPPV vs. NIPPV on the cardiorespiratory events, trying to identify the best ventilation modality for preterm infants at their first approach to NIV ventilation support. Methods An unmasked randomized crossover study with three treatment phases was designed. All newborn infants < 32 weeks of gestational age with RDS needing NIV ventilation as first intention or after extubation will be consecutively enrolled in the study and randomized to the NIPPV or SNIPPV arm. After stabilization, enrolled patients will be alternatively ventilated with two different techniques for two time frames of 4 h each. NIPPV and SNIPPV will be administered with the same ventilator and the same interface, maintaining continuous assisted ventilation without patient discomfort. During the whole duration of the study, the patient’s cardiorespiratory data and data from the ventilator will be simultaneously recorded using a polygraph connected to a computer. The primary outcome is the frequency of episodes of oxygen desaturation. Secondary outcomes are the number of the cardiorespiratory events, FiO2 necessity, newborn pain score evaluation, synchronization index, and thoracoabdominal asynchrony. The calculated sample size was of 30 patients. Discussion It is known that NIPPV produces a percentage of ineffective acts due to asynchronies between the ventilator and the infant’s breaths. On the other hand, an ineffective synchronization could increase work of breathing. Our hypothesis is that an efficient synchronization could reduce the respiratory work and increase the volume per minute exchanged without interfering with the natural respiratory rhythm of the patient with RDS. The results of this study will allow us to evaluate the effectiveness of the synchronization, demonstrating whether SNIPPV is the most effective non-invasive ventilation mode in preterm infants with RDS at their first approach to NIV ventilation. Trial registration ClinicalTrials.gov NCT03289936. Registered on September 21, 2017.

scholarly journals What is in a Viral Stock: Perspectives and Current Limitations of Flow Virometry

2020 ◽  
Author(s):  
Timothy K. Soh ◽  
Jens B. Bosse
Keyword(s):  
Flow Cytometry ◽  
Full Potential ◽  
Multiple Objects ◽  
Virus Particles ◽  
Viral Particles ◽  
Viral Stock ◽  
Infected Cells ◽  
A Minor ◽  
Unique Capability

Herpesviruses produce a plethora of pleomorphic and heterogeneous particle populations. The composition and biological role of these is not understood. Detailed analysis has been challenging due to the lack of multidimensional identification and purification methodologies. Fluorescence-activated cell sorting (FACS), originally developed to sort objects with at least ten thousand-fold larger volumes, has recently been applied to cellular exosomes as well as viral particles and has been dubbed nanoscale flow cytometry or &ldquo;flow virometry&rdquo;. In comparison to other nanoparticles, herpesvirus concentrations can be measured with high precision using simple culturing methods. Here, we used this unique capability to evaluate a standard FACS sorter. We demonstrate that detection and separation capabilities were insufficient to distinguish infectious fluorescent viral populations from populations lacking fluorescence and infectivity. Moreover, fluorescent populations did not contain single virus particles but mostly aggregates. On top, analysis of viral samples by flow cytometry was confounded by swarm detection, as multiple objects are measured simultaneously and interpreted as a single object. Despite these technical difficulties, comparison of crude supernatant to gradient purified HCMV revealed that infectious virus is a minor proportion of the particles released from infected cells. Our data stress the need for a set of standardized controls and protocols when applying FACS to biological nanoparticles and highlights technical challenges that need to be solved before flow virometry can achieve its full potential.

scholarly journals A Large Cohort Study of SARS-CoV-2 Detection in Saliva: A Non-Invasive Alternative Diagnostic Test for Patients with Bleeding Disorders

Viruses ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2361
Author(s):  
Josiane Iole França Lopes ◽  
Carlos Alexandre da Costa Silva ◽  
Rodrigo Guimarães Cunha ◽  
Alexandra Martins Soares ◽  
Maria Esther Duarte Lopes ◽  
...  
Keyword(s):  
Healthcare Workers ◽  
Hospitalized Patients ◽  
Bleeding Disorders ◽  
Hematological Diseases ◽  
Non Invasive ◽  
Qrt Pcr ◽  
Large Cohort Study ◽  
The Mean ◽  
Sensitivity Specificity ◽  
Higher Sensitivity

Diagnosis of SARS-CoV-2 infections is mostly based on the nasopharyngeal swabs (NPS). However, this collection is invasive and uncomfortable, especially for children and patients with coagulopathies, whose NPS collection often causes bleeding. Thus, the aim of this study was to evaluate the usefulness and accuracy of saliva for the diagnosis of COVID-19 in patients presenting bleeding disorders. Samples of NPS, oropharyngeal swabs (OPS), and saliva were collected simultaneously from 1159 hospitalized patients with hematological diseases and from 524 healthcare workers, both symptomatic and asymptomatic for SARS-CoV-2. All samples were evaluated for SARS-CoV-2 by qRT-PCR. SARS-CoV-2 was detected in NPS, OPS and saliva from 16.9%, 14.4% and 15.6% individuals, respectively. Tests in saliva showed sensitivity, specificity, and overall agreement of 73.3%, 96.9% and 92.7% (=0.74), respectively. Salivary tests had good accuracy (AUC = 0.7) for discriminating negative and positive qRT-PCR for SARS-CoV-2. Higher sensitivity was observed in symptomatic than in non-symptomatic patients, as well as in healthy subjects than in patients with hematological disease, in both OPS and saliva. The mean viral load in NPS was significantly higher than in OPS and in saliva samples (p < 0.001). Saliva is a good diagnostic tool to detect SARS-CoV-2, especially among patients symptomatic for COVID-19, and is a valuable specimen for mass screening of hospitalized patients with hematological diseases, especially for those that with bleeding disorders.

scholarly journals Experimental Evaluation of Perfluorocarbon Aerosol Generation with Two Novel Nebulizer Prototypes

Pharmaceutics ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 19 ◽  
Author(s):  
Iñigo Aramendia ◽  
Unai Fernandez-Gamiz ◽  
Alberto Lopez-Arraiza ◽  
Carmen Rey-Santano ◽  
Victoria Mielgo ◽  
...  
Keyword(s):  
Circular Ring ◽  
Geometric Standard Deviation ◽  
Distilled Water ◽  
Aerodynamic Diameter ◽  
Mean Values ◽  
Non Invasive ◽  
Aerosol Generation ◽  
Non Invasive Ventilation ◽  
Particle Sizer ◽  
Invasive Techniques

The potential of non-invasive ventilation procedures and new minimally invasive techniques has resulted in the research of alternative approaches as the aerosolization for the treatment of respiratory distress syndrome (RDS). The aim of this work was to design two nebulizer prototypes and to evaluate them studying the particle size distribution of the inhaled droplets generated with distilled water and two perfluorocarbons (PFCs). Different experiments were performed with driving pressures of 1–3 bar for each compound. An Aerodynamic Particle Sizer was used to measure the aerodynamic diameter (Da), the mass median aerodynamic diameter (MMAD) and the geometric standard deviation (GSD). The results showed that both prototypes produced heterodisperse aerosols with Da mean values in all cases below 5 µm. The initial experiments with distilled water showed MMAD values lower than 9 µm and up to 15 µm with prototype 1 and prototype 2, respectively. Regarding the PFCs, relatively uniform MMAD values close to 12 µm were achieved. The air delivery with outer lumens of prototype 1 presented more suitable mass distribution for the generation and delivery of a uniform aerosol than the two half-circular ring geometry proposed in the prototype 2.

scholarly journals Risk of COVID-19 Infection in Healthcare Workers Exposed During Use of Non-invasive Ventilation in a Tertiary Care Hospital in OmanRisk of COVID-19 Infection in Healthcare Workers Exposed During Use of Non-invasive Ventilation in a Tertiary Care Hospital in Oman

2021 ◽  
Vol 36 (2) ◽  
pp. e236-e236
Author(s):  
Adil Al Lawati ◽  
Faryal Khamis ◽  
Samiha Al Habsi ◽  
Khazina Al Dalhami
Keyword(s):  
High Risk ◽  
Healthcare Workers ◽  
Tertiary Care Hospital ◽  
Tertiary Care ◽  
Significant Risk ◽  
High Risk Population ◽  
Care Hospital ◽  
Invasive Ventilation ◽  
Non Invasive ◽  
Non Invasive Ventilation

Objectives: Healthcare workers (HCWs), especially those working on the front line, are considered to be at high risk of nosocomial acquisition of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (COVID-19). Little is known about the effectiveness of the recommended protective methods as few reports have described spread of the disease in hospital settings among this high-risk population. We describe the hospital-based transmission of SARS-CoV-2 related to non-invasive ventilation (NIV) in one of the main tertiary care hospitals in Oman. Methods: All exposed patients and HCWs from Royal Hospital were screened, quarantined, and underwent telephone interviews to stratify their risk factors, clinical symptoms, and exposure risk assessment. Results: A total of 46 HCWs and patients tested positive for SARS-CoV-2 after exposure to an index case who received 48 hours of NIV before diagnosing COVID-19 infection. Over half of the exposed (56.5%; n = 26) were nurses, 26.1% (n = 12) were patients, and 15.2% (n = 7) were doctors. None of the HCWs required hospitalization. Sore throat, fever, and myalgia were the most common symptoms. Conclusions: NIV poses a significant risk for SARS-CoV-2 transmission within hospital settings if appropriate infection control measures are not taken.

scholarly journals SALIVA - A PROSPECTIVE DIAGNOSTIC TOOL FOR SARS CoV-2

2020 ◽  
pp. 1-2
Author(s):  
Tarunya Vishwanath ◽  
Shalini Arumugam ◽  
Sathish. R ◽  
Anitha Logaranjini ◽  
Prashanthi Prashanthi
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Diagnostic Tool ◽  
Healthcare Workers ◽  
Standard Technique ◽  
Hubei Province ◽  
Rt Pcr ◽  
Wuhan City ◽  
Non Invasive ◽  
Specimen Collection

Coronavirus disease 2019 (COVID-19) now called the severe acute respiratory syndrome coronavirus 2 (SARS CoV-2) was first identified in Wuhan city, Hubei province, China. Currently RT-PCR using nasopharyngeal and Oropharyngeal swabs is supposed to be the most efficacious and standard technique for COVID testing, but are invasive and have a few drawbacks due to which, saliva as a diagnostic specimen is proposed. Salivary specimen collection is non-invasive and can be self-collected at any time and repeatedly and greatly minimises the exposure of. healthcare workers to COVID-19.

scholarly journals Clinical Interpretation of Cardiopulmonary Exercise Testing: Current Pitfalls and Limitations

2021 ◽  
Vol 12 ◽  
Author(s):  
J. Alberto Neder ◽  
Devin B. Phillips ◽  
Mathieu Marillier ◽  
Anne-Catherine Bernard ◽  
Danilo C. Berton ◽  
...  
Keyword(s):  
Exercise Testing ◽  
Work Of Breathing ◽  
Cardiopulmonary Exercise Testing ◽  
Peak Oxygen Uptake ◽  
Exertional Dyspnea ◽  
Non Invasive ◽  
Cardiopulmonary Exercise ◽  
Direct Measurements ◽  
Severe Impairment ◽  
End Tidal

Several shortcomings on cardiopulmonary exercise testing (CPET) interpretation have shed a negative light on the test as a clinically useful tool. For instance, the reader should recognize patterns of dysfunction based on clusters of variables rather than relying on rigid interpretative algorithms. Correct display of key graphical data is of foremost relevance: prolixity and redundancy should be avoided. Submaximal dyspnea ratings should be plotted as a function of work rate (WR) and ventilatory demand. Increased work of breathing and/or obesity may normalize peak oxygen uptake (V̇O2) despite a low peak WR. Among the determinants of V̇O2, only heart rate is measured during non-invasive CPET. It follows that in the absence of findings suggestive of severe impairment in O2delivery, the boundaries between inactivity and early cardiovascular disease are blurred in individual subjects. A preserved breathing reserve should not be viewed as evidence that “the lungs” are not limiting the subject. In this context, measurements of dynamic inspiratory capacity are key to uncover abnormalities germane to exertional dyspnea. A low end-tidal partial pressure for carbon dioxide may indicate either increased “wasted” ventilation or alveolar hyperventilation; thus, direct measurements of arterial (or arterialized) PO2might be warranted. Differentiating a chaotic breathing pattern from the normal breath-by-breath noise might be complex if the plotted data are not adequately smoothed. A sober recognition of these limitations, associated with an interpretation report free from technicalities and convoluted terminology, is crucial to enhance the credibility of CPET in the eyes of the practicing physician.

scholarly journals Basic principles of neonatal bubble CPAP: effects on CPAP delivery and imposed work of breathing when altering the original design

2020 ◽  
Vol 105 (5) ◽  
pp. 550-554
Author(s):  
Sonja Baldursdottir ◽  
Markus Falk ◽  
Snorri Donaldsson ◽  
Baldvin Jonsson ◽  
Thomas Drevhammar
Keyword(s):  
High Resistance ◽  
Low Income ◽  
Dead Space ◽  
Airway Pressure ◽  
Work Of Breathing ◽  
Lung Model ◽  
Original Design ◽  
Middle Income ◽  
Low Resistance ◽  
Mechanical Lung

BackgroundThe original bubble continuous positive airway pressure (bCPAP) design has wide-bore tubing and a low-resistance interface. This creates a stable airway pressure that is reflected by the submersion depth of the expiratory tubing. Several systems with alterations to the original bCPAP design are now available. Most of these are aimed for use in low-income and middle-income countries and have not been compared with the original design.ObjectiveWe identified three major alterations to the original bCPAP design: (1) resistance of nasal interface, (2) volume of dead space and (3) diameter of expiratory tubing. Our aim was to study the effect of these alterations on CPAP delivery and work of breathing in a mechanical lung model. Dead space should always be avoided and was not further tested.MethodsThe effect of nasal interface resistance and expiratory tubing diameter was evaluated with simulated breathing in a mechanical lung model without interface leakage. The main outcome was delivered CPAP and imposed work of breathing.ResultsHigh-resistance interfaces and narrow expiratory tubing increased the work of breathing. Additionally, narrow expiratory tubing resulted in higher CPAP levels than indicated by the submersion depth.ConclusionOur study shows the significant effect on CPAP delivery and imposed work of breathing when using high-resistance interfaces and narrow expiratory tubing in bCPAP systems. New systems should include low-resistance interfaces and wide-bore tubing and be compared with the original bCPAP. Referring to all systems that bubble as bCPAP is misleading and potentially hazardous.

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