[Respiratory disorders of post-COVID-19 syndrome].

AIM: Assess the functional state of trespiratory system and effectiveness of therapeutic tactics for broncho-obstructive syndrome (BOS) in patients in the post-COVID period. MATERIALS AND METHODS: A two-center cohort prospective study included 10 456 and 89 patients, respectively. A comprehensive assessment of the respiratory system included clinical, laboratory and functional data, spirometry, body plethysmography, and a study of diffusive capacity of the lungs (DLCO). Therapy consisted of budesonide suspension or fixed combination beclomethasone dipropionate/formoterol (EMD BDP/FORM). RESULTS: The frequency of BOS in the cohort was 72% (7497 patients). In 13% (n=974) of cases, bronchial asthma was diagnosed for the first time, in 4.4% (n=328) - chronic obstructive pulmonary disease. Risk factors for the development and decrease in DLCO in the post-COVID period were identified. In the group of complex instrumental examination of lung function, the absence of violations of spirometric data and indicators determined by body plethysmography was determined. CONCLUSION: Risk factors for BOS in post-COVID period are atopy, a history of frequent acute respiratory infections, smoking, blood eosinophilia, moderate and severe forms of COVID-19. The advantage of a fixed combination of EMD BDP/FORM in MART mode compared with nebulized suspension budesonide + solution of salbutamol in treatment of BOS was shown. Risk factors for DLCO disorders were established: severe COVID-19, hospitalization in the intensive care unit, the need for additional oxygen therapy.

The association between inhaled corticosteroid and the risks of SARS-COV-2 infection: A systematic review and meta-analysis.

BACKGROUND: The effect of inhaled corticosteroid (ICS) on the risk of severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) infection is unclear. METHODS: We performed a systematic review and meta-analysis of clinical studies that assessed the association between the use of ICS and the risk of SARS-COV-2 infection. PubMed, Web of Science, Scopus, Cochrane Library and Google Scholar were searched to January 1st, 2023. ROBINS-I was used to assess risk of bias of included studies. The outcome of interest was the risk of SARS-COV-2 infection in patients and odds ratio (OR) with 95% confidence interval (95% CI) were calculated using Comprehensive Meta-analysis software version 3. RESULTS: Twelve studies involving seven observational cohort studies, three case-control studies, and two cross-sectional studies were included in this meta-analysis. Overall, compared to non-ICS use, the pooled odds ratio (OR) of the risk of SARS-COV-2 infection was 0.997 (95% confidence interval [CI] 0.664-1.499; p = 0.987) for patients with ICS use. Subgroup analyses demonstrated no statistical significance in the increased risk of SARS-COV-2 infection in patients with ICS monotherapy or in combination with bronchodilators (pooled OR=1.408; 95% CI=0.693-2.858; p = 0.344 in ICS monotherapy, and pooled OR=1.225; 95% CI=0.533-2.815; p = 0.633 in ICS combination, respectively). In addition, no significant association was observed between ICS use and the risk of SARS-COV-2 infection for patients with COPD (pooled OR=0.715; 95% CI=0.415-1.230; p = 0.225) and asthma (pooled OR=1.081; 95% CI=0.970-1.206; p = 0.160). CONCLUSIONS: The use of ICS, either monotherapy or in combination with bronchodilators, does not have impact on the risk of SARS-COV-2 infection.

Impact of the COVID-19 Pandemic on the Prescribing of Antiasthmatic Treatments in Portugal: A Nationwide Study.

PURPOSE: The coronavirus disease 2019 (COVID-19) pandemic has had a profound impact on everyday life, the environment, and health care services. A shift from in-person medical appointments to telemedicine was a main adjustment. Such changes can have repercussions on the control and management of chronic respiratory diseases, such as asthma. The available data suggest that there was an overall decrease in asthma-related morbidities during the first year of the pandemic. Therefore, the goal of this study was to quantify the effects of the pandemic on the prescribing of antiasthmatic treatments in outpatient care (public and private health care). METHODS: This before-after study used a time series approach based on data from monthly prescriptions of antiasthmatic drugs (anti-inflammatory drugs and bronchodilators) dated between April 2018 and March 2021. An interrupted time series (ITS) design was used for assessing changes in antiasthmatic prescribing patterns in the short and long terms after COVID-19 was recognized as a pandemic. The results are complemented with seasonal autoregressive integrated moving average (sARIMA) models. FINDINGS: The ITS analysis showed a non-significant increase in antiasthmatic prescribing in the short term. In the long term, after the pandemic was declared, a statistically significant decrease was observed in the prescribing of antiasthmatics (in anti-inflammatory drugs and, more pronounced, in bronchodilators). In the sARIMA model, the mean monthly volume of antiasthmatic prescriptions was 18.1% lower than predicted. The numbers of months outside of the 95% CIs were different between anti-inflammatory drugs (1 month) and bronchodilators (7 months). IMPLICATIONS: The prescribing of antiasthmatic drugs in the long term was significantly decreased with the COVID-19 pandemic, with a greater effect in the case of bronchodilators.

Reducing the Risk of Mortality in Chronic Obstructive Pulmonary Disease With Pharmacotherapy: A Narrative Review.

In 2020, chronic obstructive pulmonary disease (COPD) was the fifth leading cause of death in the United States excluding COVID-19, and its mortality burden has been rising since the 1980s. Smoking cessation, long-term oxygen therapy, noninvasive ventilation, and lung volume reduction surgery have had a beneficial effect on mortality; however, until recently, the effects of pharmacologic therapies on all-cause mortality have been unclear. Inhaled pharmacologic treatments for patients with COPD include combinations of long-acting muscarinic receptor antagonists (LAMAs), long-acting-ß2-agonists (LABAs), and inhaled corticosteroids (ICS). The recent IMPACT and ETHOS clinical trials reported mortality benefits with ICS/LAMA/LABA triple therapy compared with LAMA/LABA dual therapy. In IMPACT, fluticasone furoate/umeclidinium/vilanterol therapy significantly reduced the risk of on-/off-treatment all-cause mortality vs umeclidinium/vilanterol (hazard ratio, 0.72; 95% CI, 0.53 to 0.99; P=.042). The ETHOS trial found a reduction in the risk of on-/off-treatment all-cause mortality in patients treated with budesonide/glycopyrrolate/formoterol vs glycopyrrolate/formoterol (hazard ratio, 0.51 [0.33 to 0.80]; nominal P=.0035). Both trials included populations of patients with symptomatic COPD at high risk of future exacerbations, and a post hoc analysis of the final retrieved vital status data suggested that the observed mortality benefits are conferred by the ICS component. In conclusion, triple therapy reduces the risk of mortality in patients with symptomatic COPD characterized by moderate or severe airflow obstruction and a recent history of moderate or severe exacerbations. This benefit is likely to be driven by reductions in exacerbations. Future research efforts should focus on improving the long-term prognosis of patients living with COPD.

Intensive critical care and management of asthmatic and smoker patients in COVID-19 infection.

This century's most serious catastrophe, COVID-19, has been dubbed "the most life-threatening disaster ever". Asthmatic persons are even more prone to COVID-19's complex interplay with the underlying inflammatory condition. In order to protect themselves against COVID-19, asthmatic patients must be very vigilant in their usage of therapeutic techniques and drugs (e.g., bronchodilators, 5-lipoxygenase inhibitors), which may be accessed to deal with mild, moderate, and severe COVID-19 indications. People with asthma may have more severe COVID-19 symptoms, which may lead to a worsening of their condition. Several cytokines were found to be elevated in the bronchial tracts of patients with acute instances of COVID-19, suggesting that this ailment may aggravate asthma episodes by increasing inflammation. The intensity of COVID-19 symptoms is lessened in patients with asthma who have superior levels of T-cells. Several antibiotics, antivirals, antipyretics, and anti-inflammatory drugs have been suggested to suppress COVID-19 symptoms in asthmatic persons. Furthermore, smokers are more likely to have aggravated repercussions in COVID-19 infection. Being hospitalized to critical care due to COVID-19, needing mechanical breathing, and suffering from serious health repercussions, are all possible outcomes for someone who has previously smoked. Smoking damages airways and alveoli, which significantly raises the risk of COVID-19-related health complications. Patients with a previous record of smoking are predisposed to severe COVID-19 disease symptoms that essentially require a combination of bronchodilators, mucolytics, antivirals, and antimuscarinic drugs, to cope with the situation. The present review discusses the care and management of asthmatic and smoker patients in COVID-19 infection.

Bronchodilators in Tobacco-Exposed Persons with Symptoms and Preserved Lung Function.

BACKGROUND: Many persons with a history of smoking tobacco have clinically significant respiratory symptoms despite an absence of airflow obstruction as assessed by spirometry. They are often treated with medications for chronic obstructive pulmonary disease (COPD), but supporting evidence for this treatment is lacking. METHODS: We randomly assigned persons who had a tobacco-smoking history of at least 10 pack-years, respiratory symptoms as defined by a COPD Assessment Test score of at least 10 (scores range from 0 to 40, with higher scores indicating worse symptoms), and preserved lung function on spirometry (ratio of forced expiratory volume in 1 second [FEV1] to forced vital capacity [FVC] ≥0.70 and FVC ≥70% of the predicted value after bronchodilator use) to receive either indacaterol (27.5 µg) plus glycopyrrolate (15.6 µg) or placebo twice daily for 12 weeks. The primary outcome was at least a 4-point decrease (i.e., improvement) in the St. George's Respiratory Questionnaire (SGRQ) score (scores range from 0 to 100, with higher scores indicating worse health status) after 12 weeks without treatment failure (defined as an increase in lower respiratory symptoms treated with a long-acting inhaled bronchodilator, glucocorticoid, or antibiotic agent). RESULTS: A total of 535 participants underwent randomization. In the modified intention-to-treat population (471 participants), 128 of 227 participants (56.4%) in the treatment group and 144 of 244 (59.0%) in the placebo group had at least a 4-point decrease in the SGRQ score (difference, -2.6 percentage points; 95% confidence interval [CI], -11.6 to 6.3; adjusted odds ratio, 0.91; 95% CI, 0.60 to 1.37; P = 0.65). The mean change in the percent of predicted FEV1 was 2.48 percentage points (95% CI, 1.49 to 3.47) in the treatment group and -0.09 percentage points (95% CI, -1.06 to 0.89) in the placebo group, and the mean change in the inspiratory capacity was 0.12 liters (95% CI, 0.07 to 0.18) in the treatment group and 0.02 liters (95% CI, -0.03 to 0.08) in the placebo group. Four serious adverse events occurred in the treatment group, and 11 occurred in the placebo group; none were deemed potentially related to the treatment or placebo. CONCLUSIONS: Inhaled dual bronchodilator therapy did not decrease respiratory symptoms in symptomatic, tobacco-exposed persons with preserved lung function as assessed by spirometry. (Funded by the National Heart, Lung, and Blood Institute and others; RETHINC ClinicalTrials.gov number, NCT02867761.).

Pathogenic role of cytokines in COVID-19, its association with contributing co-morbidities and possible therapeutic regimens.

The Covid-19, a threatening pandemic, was originated from China in December 2019 and spread quickly to all over the world. The pathogenesis of coronavirus is linked with the disproportionate response of the immune system. This involves the systemic inflammatory reaction which is characterized by marked pro-inflammatory cytokine release commonly known as cytokine release storm (CRS). The pro inflammatory cytokines are involved in cascade of pulmonary inflammation, hyper coagulation and thrombosis which may be lethal for the individual. That's why, it is very important to have understanding of pro inflammatory cytokines and their pathological role in SARS-CoV-2. The pathogenesis of Covid is not the same in every individual, it can vary due to the presence of pre-existing comorbidities like suffering from already an inflammatory disease such as rheumatoid arthritis (RA), inflammatory bowel disease (IBD), chronic obstructive pulmonary disease (COPD), an immune-compromised patients suffering from Diabetes Mellitus (DM) and Tuberculosis (TB) are more vulnerable morbidity and complications following COVID-19. This review is particularly related to COVID-19 patients having comorbidity of other inflammatory diseases. We have discussed the brief pathogenesis of COVID-19 and cytokines release storm with reference to other co-morbidities including RA, IBD, COPD, DM and TB. The available therapeutic regimens for COVID-19 including cytokine inhibitors, anti-viral, anti-biotic, bronchodilators, JAK- inhibitors, immunomodulators and anti-fibrotic agents have also been discussed briefly. Moreover, newly emerging medicines in the clinical trials have also been discussed which are found to be effective in treating Covid-19.

Bronchiolitis.

Viral bronchiolitis is the most common cause of admission to hospital for infants in high-income countries. Respiratory syncytial virus accounts for 60-80% of bronchiolitis presentations. Bronchiolitis is diagnosed clinically without the need for viral testing. Management recommendations, based predominantly on high-quality evidence, advise clinicians to support hydration and oxygenation only. Evidence suggests no benefit with use of glucocorticoids or bronchodilators, with further evidence required to support use of hypertonic saline in bronchiolitis. Evidence is scarce in the intensive care unit. Evidence suggests use of high-flow therapy in bronchiolitis is limited to rescue therapy after failure of standard subnasal oxygen only in infants who are hypoxic and does not decrease rates of intensive care unit admission or intubation. Despite systematic reviews and international clinical practice guidelines promoting supportive rather than interventional therapy, universal de-implementation of interventional care in bronchiolitis has not occurred and remains a major challenge.

Impact of acute temperature and air pollution exposures on adult lung function: A panel study of asthmatics.

BACKGROUND: Individuals with respiratory conditions, such as asthma, are particularly susceptible to adverse health effects associated with higher levels of ambient air pollution and temperature. This study evaluates whether hourly levels of fine particulate matter (PM2.5) and dry bulb globe temperature (DBGT) are associated with the lung function of adult participants with asthma. METHODS AND FINDINGS: Global positioning system (GPS) location, respiratory function (measured as forced expiratory volume at 1 second (FEV1)), and self-reports of asthma medication usage and symptoms were collected as part of the Exposure, Location, and Lung Function (ELF) study. Hourly ambient PM2.5 and DBGT exposures were estimated by integrating air quality and temperature public records with time-activity patterns using GPS coordinates for each participant (n = 35). The relationships between acute PM2.5, DBGT, rescue bronchodilator use, and lung function collected in one week periods and over two seasons (summer/winter) were analyzed by multivariate regression, using different exposure time frames. In separate models, increasing levels in PM2.5, but not DBGT, were associated with rescue bronchodilator use. Conversely DBGT, but not PM2.5, had a significant association with FEV1. When DBGT and PM2.5 exposures were placed in the same model, the strongest association between cumulative PM2.5 exposures and the use of rescue bronchodilator was identified at the 0-24 hours (OR = 1.030; 95% CI = 1.012-1.049; p-value = 0.001) and 0-48 hours (OR = 1.030; 95% CI = 1.013-1.057; p-value = 0.001) prior to lung function measure. Conversely, DBGT exposure at 0 hours (ß = 3.257; SE = 0.879; p-value>0.001) and 0-6 hours (ß = 2.885; SE = 0.903; p-value = 0.001) hours before a reading were associated with FEV1. No significant interactions between DBGT and PM2.5 were observed for rescue bronchodilator use or FEV1. CONCLUSIONS: Short-term increases in PM2.5 were associated with increased rescue bronchodilator use, while DBGT was associated with higher lung function (i.e. FEV1). Further studies are needed to continue to elucidate the mechanisms of acute exposure to PM2.5 and DBGT on lung function in asthmatics.

Indian Guidelines on Nebulization Therapy.

Inhalational therapy, today, happens to be the mainstay of treatment in obstructive airway diseases (OADs), such as asthma, chronic obstructive pulmonary disease (COPD), and is also in the present, used in a variety of other pulmonary and even non-pulmonary disorders. Hand-held inhalation devices may often be difficult to use, particularly for children, elderly, debilitated or distressed patients. Nebulization therapy emerges as a good option in these cases besides being useful in the home care, emergency room and critical care settings. With so many advancements taking place in nebulizer technology; availability of a plethora of drug formulations for its use, and the widening scope of this therapy; medical practitioners, respiratory therapists, and other health care personnel face the challenge of choosing appropriate inhalation devices and drug formulations, besides their rational application and use in different clinical situations. Adequate maintenance of nebulizer equipment including their disinfection and storage are the other relevant issues requiring guidance. Injudicious and improper use of nebulizers and their poor maintenance can sometimes lead to serious health hazards, nosocomial infections, transmission of infection, and other adverse outcomes. Thus, it is imperative to have a proper national guideline on nebulization practices to bridge the knowledge gaps amongst various health care personnel involved in this practice. It will also serve as an educational and scientific resource for healthcare professionals, as well as promote future research by identifying neglected and ignored areas in this field. Such comprehensive guidelines on this subject have not been available in the country and the only available proper international guidelines were released in 1997 which have not been updated for a noticeably long period of over two decades, though many changes and advancements have taken place in this technology in the recent past. Much of nebulization practices in the present may not be evidence-based and even some of these, the way they are currently used, may be ineffective or even harmful. Recognizing the knowledge deficit and paucity of guidelines on the usage of nebulizers in various settings such as inpatient, out-patient, emergency room, critical care, and domiciliary use in India in a wide variety of indications to standardize nebulization practices and to address many other related issues; National College of Chest Physicians (India), commissioned a National task force consisting of eminent experts in the field of Pulmonary Medicine from different backgrounds and different parts of the country to review the available evidence from the medical literature on the scientific principles and clinical practices of nebulization therapy and to formulate evidence-based guidelines on it. The guideline is based on all possible literature that could be explored with the best available evidence and incorporating expert opinions. To support the guideline with high-quality evidence, a systematic search of the electronic databases was performed to identify the relevant studies, position papers, consensus reports, and recommendations published. Rating of the level of the quality of evidence and the strength of recommendation was done using the GRADE system. Six topics were identified, each given to one group of experts comprising of advisors, chairpersons, convenor and members, and such six groups (A-F) were formed and the consensus recommendations of each group was included as a section in the guidelines (Sections I to VI). The topics included were: A. Introduction, basic principles and technical aspects of nebulization, types of equipment, their choice, use, and maintenance B. Nebulization therapy in obstructive airway diseases C. Nebulization therapy in the intensive care unit D. Use of various drugs (other than bronchodilators and inhaled corticosteroids) by nebulized route and miscellaneous uses of nebulization therapy E. Domiciliary/Home/Maintenance nebulization therapy; public & health care workers education, and F. Nebulization therapy in COVID-19 pandemic and in patients of other contagious viral respiratory infections (included later considering the crisis created due to COVID-19 pandemic). Various issues in different sections have been discussed in the form of questions, followed by point-wise evidence statements based on the existing knowledge, and recommendations have been formulated.

Long-term pulmonary sequelae in adolescents post-SARS-CoV-2 infection.

RATIONALE: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes long-term pulmonary sequelae in adults, but little is known about pulmonary outcomes in pediatrics. OBJECTIVE(S): The aim of this study was to describe long-term subjective and objective pulmonary abnormalities after SARS-CoV-2 infection in pediatric populations. METHODS: Single-center, retrospective cohort of patients seen in post-coronavirus disease 2019 (COVID-19) pulmonary clinic in 2021. Subjects evaluated had persistent pulmonary symptoms 4 weeks or more after initial infection. Clinical testing included a 6-min walk test (6MWT), chest X-ray, pre- and postbronchodilator spirometry, plethysmography, and diffusion capacity. Patients were followed 2-to-3-months after the initial visit with repeat testing. The primary outcome was the presence of abnormal pulmonary function testing. Secondary measures included variables associated with pulmonary outcomes. RESULTS: Eighty-two adolescents were seen at a median of 3.5 months postinfection, with approximately 80% reporting two or more symptoms at clinic presentation (cough, chest pain, dyspnea at rest, and exertional dyspnea). At follow-up (~6.5 months) exertional dyspnea persisted for most (67%). Spirometry was normal in 77% of patients, but 31% had a positive bronchodilator response. No abnormalities were noted on plethysmography or diffusion capacity. Clinical phenotypes identified included inhaled corticosteroid responsiveness, paradoxical vocal fold motion disorder, deconditioning, and dysautonomia. Multivariable modeling demonstrated that obesity, anxiety, and resting dyspnea were associated with reduced 6MWT, while female sex and resting dyspnea were associated with higher Borg Dyspnea and Fatigues scores. CONCLUSIONS: This is the largest study to date of pediatric patients with long-term pulmonary sequelae post-COVID-19. Identified clinical phenotypes and risk factors warrant further study and treatment.

Use of a Viral Filter to Reduce Exposure to Exhaled Aerosol Does Not Affect Methacholine Dose Delivery During Bronchoprovocation Testing.

BACKGROUND: Methacholine challenge testing (MCT) is a common bronchoprovocation technique used to assess airway hyper-responsiveness. We previously demonstrated that the addition of a viral filter to the nebulizer exhalation limb substantially reduced expelled particles during MCT. Our aim was to evaluate whether this modification affects the delivered dose of methacholine. METHODS: A mechanical ventilator was connected to a lung simulator with breathing frequency 15 breaths/min, tidal volume 500 mL, inspiratory-expiratory ratio 1:1, with a sinusoidal waveform. We compared methacholine dose delivery using the Hudson Micro Mist or AeroEclipse II BAN nebulizers powered by either a dry gas source or a compressor system. A filter placed in line between the nebulizer and test lung was weighed before and after 1 min of nebulized methacholine delivery. Mean inhaled mass was measured with and without a viral filter on the exhalation limb. Dose delivery was calculated by multiplying the mean inhaled mass by the respirable fraction (particles < 5 µm) and inhalation time. Unpaired t test was used to compare methacholine dose delivery with and without viral filter placement. RESULTS: The addition of a viral filter did not significantly affect methacholine dose delivery across all devices tested. Using a 50-psi dry gas source, dose delivered with or without a viral filter did not differ with the Hudson (422.3 µg vs 282.0 µg, P = .11) or the AeroEclipse nebulizer (563.0 µg vs 657.6 µg, P = .59). Using the compressor, dose delivered with and without a viral filter did not differ with the Hudson (974.0 µg vs 868.0 µg, P = .03) or the AeroEclipse nebulizer (818.0 µg vs 628.5 µg, P = .42). CONCLUSIONS: The addition of a viral filter to the nebulizer exhalation limb did not affect methacholine dose during bronchoprovocation testing. Routine use of a viral filter should be considered to improve pulmonary function technician safety and infection control measures during the ongoing COVID-19 pandemic.

New insights into the optimal management of COPD: extracts from CHEST 2021 annual meeting (October 17-20, 2021).

INTRODUCTION: Discordance between real-world prescribing patterns and global treatment guidelines for the treatment of chronic obstructive pulmonary disease (COPD) with inhaled single or dual long-acting bronchodilator maintenance therapy is increasingly being reported in the literature, particularly with regard to addition of inhaled corticosteroids (ICS). Patient-related factors, e.g. inhalation technique and inspiratory flow, are key to disease control in COPD. Treatment discordance and patient-related factors can lead to high-cost side effects and sub-optimal treatment benefit; furthermore, the COVID-19 pandemic has led to new challenges in COPD management. AREAS COVERED: This article summarizes a series of presentations sponsored by Boehringer Ingelheim and delivered at the annual CHEST congress 2021 (October 17-20, 2021) that explored new insights into the optimal management of COPD. EXPERT OPINION/COMMENTARY: There is a concerning high degree of discordance with GOLD recommendations. Dual therapy without addition of ICS does not increase exacerbation risk and could reduce pneumonia risk, and unnecessary prescription of triple therapy has financial implications. Clinic-based spirometry may not reflect the home setting, and training is required; inhalers that operate independently of users' inhalation profiles should be considered. Integration of digital healthcare solutions into clinical studies is suggested in the post-COVID setting, although further evaluation is required.

Mitigating Fugitive Aerosols During Aerosol Delivery via High-Flow Nasal Cannula Devices.

BACKGROUND: Aerosol delivery via high-flow nasal cannula (HFNC) has attracted clinical interest in recent years. However, both HFNC and nebulization are categorized as aerosol-generating procedures (AGPs). In vitro studies raised concerns that AGPs had high transmission risk. Very few in vivo studies examined fugitive aerosols with nebulization via HFNC, and effective methods to mitigate aerosol dispersion are unknown. METHODS: Two HFNC devices (Airvo 2 and Vapotherm) with or without a vibrating mesh nebulizer were compared; HFNC alone, surgical mask over HFNC interface, and HFNC with face tent scavenger were used in a random order for 9 healthy volunteers. Fugitive aerosol concentrations at sizes of 0.3-10.0 µm were continuously measured by particle sizers placed at 1 and 3 ft from participants. On a different day, 6 of the 9 participants received 6 additional nebulizer treatments via vibrating mesh nebulizer or small-volume nebulizer (SVN) with a face mask or a mouthpiece with/without an expiratory filter. In vitro simulation was employed to quantify inhaled dose of albuterol with vibrating mesh nebulizer via Airvo 2 and Vapotherm. RESULTS: Compared to baseline, neither HFNC device generated higher aerosol concentrations. Compared to HFNC alone, vibrating mesh nebulizer via Airvo 2 generated higher 0.3-1.0 µm particles (all P < .05), but vibrating mesh nebulizer via Vapotherm did not. Concentrations of 1.0-3.0 µm particles with vibrating mesh nebulizer via Airvo 2 were similar with vibrating mesh nebulizer and a mouthpiece/face mask but less than SVN with a mouthpiece/face mask (all P < .05). Placing a surgical mask over HFNC during nebulization reduced 0.5-1.0 µm particles (all P < .05) to levels similar to the use of a nebulizer with mouthpiece and expiratory filter. In vitro the inhaled dose of albuterol with vibrating mesh nebulizer via Airvo 2 was ≥ 6 times higher than vibrating mesh nebulizer via Vapotherm. CONCLUSIONS: During aerosol delivery via HFNC, Airvo 2 generated higher inhaled dose and consequently higher fugitive aerosols than Vapotherm. Simple measures, such as placing a surgical mask over nasal cannula during nebulization via HFNC, could effectively reduce fugitive aerosol concentrations.

Nebulizer systems: a new frontier for therapeutics and targeted delivery.

Drug delivery via the pulmonary route is a cornerstone in the pharmaceutical sector as an alternative to oral and parenteral administration. Nebulizer inhalation treatment offers multiple drug administration, easily employed with tidal breathing, suitable for children and elderly, can be adapted for severe patients and visible spray ensures patient satisfaction. This review discusses the operational and mechanical characteristics of nebulizer delivery devices in terms of aerosol production processes, their usage, benefits and drawbacks that are currently shaping the contemporary landscape of inhaled drug delivery. With the advent of particle engineering, novel inhaled nanosystems can be successfully developed to increase lung deposition and decrease pulmonary clearance. The above-mentioned advances might pave the path for treating a life-threatening disorder like severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which is also discussed in the current state of the art.