Journal of Aerosol Medicine and Pulmonary Drug Delivery最新文献

{"title":"Safety and Efficacy of 2.5 mg and 1.25 mg Nebulized Salbutamol Compared with Placebo on Transient Tachypnea of the Newborns: A Triple-Blind Phase II/III Parallel Randomized Controlled Trial.","authors":"Farhad Abolhasan Choobdar, Zahra Vahedi, Ali Mazouri, Mohammad Torkaman, Nastaran Khosravi, Nasrin Khalesi, Zahra Soltani, Arash Mohazzab, Rezvan Ashkanipour","doi":"10.1089/jamp.2023.0043","DOIUrl":"10.1089/jamp.2023.0043","url":null,"abstract":"<p><p><b><i>Background:</i></b> To evaluate the safety and efficacy of 2.5 and 1.25 mg nebulized salbutamol on Transient Tachypnea of the Newborn (TTN) compared with placebo. <b><i>Methods:</i></b> We conducted a triple-blind, phase II/III parallel randomized controlled trial in two university-affiliated hospitals with neonatal intensive care units. Newborns with a confirmed diagnosis of TTN, with gestational age >35 weeks and gestational weight >2 kg were included. Cases of asphyxia, meconium aspiration syndrome, and persistent pulmonary hypertension were excluded. Ninety eligible patients were randomly allocated in three intervention groups (2.5 mg salbutamol, 1.25 mg salbutamol, and placebo), and a single-dose nebulized product was prescribed 6 hours after the birth. Safety outcomes included postintervention tachycardia, hyperglycemia, hypokalemia, and changes in blood pressure. To evaluate the efficacy, the duration of postintervention tachypnea, TTN clinical score, and clinical and paraclinical respiratory indices were assessed. Parents, Outcome assessors, and data analyzer were blind to the intervention. <b><i>Results:</i></b> There was no adverse reaction, including tachycardia, hypokalemia, and jitteriness. Both groups of salbutamol recipients showed significant improvement regarding respiratory rate, TTN clinical score, and oxygenation indices compared with the placebo (<i>p</i>-values <0.001). Nonstatistically significant higher hospital stay was observed in the placebo group. Single 2.5 mg salbutamol nebulization showed a little better outcome than the dose of 1.25 mg, although we could not find statistical superiority. <b><i>Conclusion:</i></b> The newly applied single high dose of 2.5 mg nebulized salbutamol is safe in treating TTN and leads to notable faster improvement of respiratory status without any considerable adverse reaction. <b><i>Registry code:</i></b> IRCT20190328043133N1.</p>","PeriodicalId":14940,"journal":{"name":"Journal of Aerosol Medicine and Pulmonary Drug Delivery","volume":" ","pages":"180-188"},"PeriodicalIF":2.0,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140870189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Changes in Peak Inspiratory Flow After Acute Bronchodilation: An Observational Study of Patients with Stable Chronic Obstructive Pulmonary Disease.","authors":"Roy A Pleasants, Asif Shaikh, Ashley G Henderson, Valentina Bayer, M Bradley Drummond","doi":"10.1089/jamp.2023.0045","DOIUrl":"10.1089/jamp.2023.0045","url":null,"abstract":"<p><p><b><i>Introduction:</i></b> Identifying factors influencing peak inspiratory flow (PIF) is essential for aerosol drug delivery in stable patients with chronic obstructive pulmonary disease. While a minimum PIF for dry powder inhalers (DPIs) is established, acute bronchodilator (BD) effects on PIF remain unknown. <b><i>Materials and Methods:</i></b> An inspiratory flow meter (In-Check™ DIAL) was used to measure PIF in stable patients during a 24-week observational cross-sectional study. Additionally, bronchodilator responsiveness (BDR) was determined using the In-Check DIAL device and spirometry. Patients received four puffs of albuterol, and pre- and post-BD PIF, forced expiratory volume in one second (FEV₁), and forced vital capacity were measured. Sixty-three patients completed acute BDR data collection from July 31, 2019, to November 9, 2021. Primary endpoints were pre- and post-BD spirometry and PIF. Statistical analyses included PIF correlations with FEV₁. BD change was assessed according to inhaler resistance and sex (subgroup analysis). <b><i>Results:</i></b> Median patient age was 64.8 years, 85.7% were non-Hispanic White, and 57.1% were female. The median increase in absolute PIF (In-Check DIAL) was 5.0 L/min, and the % PIF change was 8.9%. With albuterol, 57.1% experienced a PIF BD change >5.0%, whereas 49.2% experienced a change >10.0%. Similarly, 55.6% experienced an FEV₁ BD change >5.0% and 28.6% had a >10.0% FEV₁ BD change with albuterol. PIF was weakly correlated with FEV₁ BD change (absolute; % PIF; <i>r</i> = 0.28 [<i>p</i> = 0.02]; <i>r</i> = 0.21 [<i>p</i> = 0.11]). Pre- and post-BD median PIF were 75.5 and 83.5 L/min for low-to-medium-resistance DPI and 45.0 and 52.0 L/min for high-resistance, respectively. The median increases in pre- and post-BD PIF were 9.0 L/min in males and 4.5 L/min in females. In contrast to when using the In-Check DIAL device, we observed no consistent bronchodilatory effects on PIF measured by spirometry. <b><i>Conclusions:</i></b> Using the In-Check DIAL device, ∼50% of patients experienced >10% PIF increase after acute BD, potentially enhancing medication lung deposition. Further research is required to understand PIF's impact on medication delivery. ClinicalTrials.gov Identifier: NCT04168775.</p>","PeriodicalId":14940,"journal":{"name":"Journal of Aerosol Medicine and Pulmonary Drug Delivery","volume":" ","pages":"171-179"},"PeriodicalIF":2.0,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141175196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prevalence and Management of Chronic Obstructive Pulmonary Disease in the Gulf Countries with a Focus on Inhaled Pharmacotherapy.","authors":"Donald P Tashkin, Igor Barjaktarevic, Julio Gomez-Seco, Naser Hassan Behbehani, Arkady Koltun, Urooj Alam Siddiqui","doi":"10.1089/jamp.2023.0016","DOIUrl":"10.1089/jamp.2023.0016","url":null,"abstract":"<p><p><b><i>Background:</i></b> Chronic obstructive pulmonary disease (COPD) is a preventable, progressive disease and the third leading cause of death worldwide. The epidemiological data of COPD from Gulf countries are very limited, as it remains underdiagnosed and underestimated. Risk factors for COPD include tobacco cigarette smoking, water pipe smoking (Shisha), exposure to air pollutants, occupational dusts, fumes, and chemicals. Inadequate treatment of COPD leads to worsening of disease. The 2024 GOLD guidelines recommend use of inhaled bronchodilators, corticosteroids, and adjunct therapies for treatment and management of COPD patients based on an individual assessment of the severity of symptoms and risk of exacerbations. This article reviews COPD pharmacotherapy in the Gulf countries and explores the role of nebulization in the management of COPD in this region. <b><i>Methods:</i></b> To review the COPD pharmacotherapy in the Gulf Countries, literature search was conducted using PubMed, Medline, Cochrane Systematic Reviews, and Google Scholar databases (before December 2022), using search terms such as COPD, nebulization, inhalers/inhalation, aerosols, and Gulf countries. Relevant articles from the reference list of identified studies were reviewed. Consensus statements, expert opinion, and other published review articles were included. <b><i>Results:</i></b> In the Gulf countries, pressurized metered-dose inhalers (pMDIs), dry powder inhalers (DPIs), soft mist inhalers, and nebulizers are used for drug delivery to COPD patients. pMDIs and DPIs are most prone to errors in technique and other common device handling errors. Nebulization is another mode of inhalation drug delivery, which is beneficial in certain patient populations such as the elderly and patients with cognitive impairment, motor or neuromuscular disorders, and other comorbidities. <b><i>Conclusion:</i></b> There is no major difference between Gulf countries and rest of the world in the approach to management of COPD. Nebulizers should be considered for patients who have difficulties in accessing or using MDIs and DPIs, irrespective of geographical location.</p>","PeriodicalId":14940,"journal":{"name":"Journal of Aerosol Medicine and Pulmonary Drug Delivery","volume":" ","pages":"189-201"},"PeriodicalIF":2.0,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141175204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Acute Effect of E-Cigarette Inhalation on Mucociliary Clearance in E-Cigarette Users.","authors":"William D Bennett, Phillip W Clapp, Kirby L Zeman, Jihong Wu, Brian Ring, Ilona Jaspers","doi":"10.1089/jamp.2023.0027","DOIUrl":"10.1089/jamp.2023.0027","url":null,"abstract":"<p><p><b><i>Background:</i></b> Recent studies show e-cigarette (EC) users have increased rates of chronic bronchitic symptoms that may be associated with depressed mucociliary clearance (MCC). Little is known about the acute or chronic effects of EC inhalation on <i>in vivo</i> MCC. <b><i>Methods:</i></b> <i>In vivo</i> MCC was measured in young adult vapers (<i>n</i> = 5 males, mean age = 21) after controlled inhalation of a radiolabeled (Tc99m sulfur colloid) aerosol. Whole-lung clearance of radiolabeled deposited particles was measured over a 90-minute period for baseline MCC and associated with controlled periodic vaping over the first 60 minutes of MCC measurements. The vaping challenge was administered from a fourth generation box mod EC containing unflavored e-liquid (65% propylene glycol/35% vegetable glycerin, 3 mg/mL freebase nicotine). The challenge was administered at the start of each 10-minute interval of MCC measurements and consisted of 1 puff every 30 seconds for 5 minutes (i.e., 10 puffs for each 10-minute period for a total of 60 puffs during the initial 60 minutes of MCC measurements). <b><i>Results:</i></b> Compared with baseline, peripheral lung average clearance (%) over the 90 minutes of MCC measures was enhanced, associated with EC challenge, 12 (±6) versus 24 (±6), respectively (<i>p</i> < 0.05 by Wilcoxon signed-rank test). <b><i>Conclusions:</i></b> Acute enhancement of <i>in vivo</i> MCC during EC challenge is contrary to recent studies showing nicotine-associated slowing of ciliary beat and mucus transport at higher nicotine levels than those used here. However, our findings are consistent with an acute increase in fluid volume and mucin secretion to the bronchial airway surface that is likely short lived. Research reported in this publication was supported by the National Institutes of Health R01HL139369 and registered with ClinicalTrials.gov (NCT03700892).</p>","PeriodicalId":14940,"journal":{"name":"Journal of Aerosol Medicine and Pulmonary Drug Delivery","volume":" ","pages":"167-170"},"PeriodicalIF":2.0,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140849166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Effects of Inspiratory Flows, Inspiratory Pause, and Suction Catheter on Aerosol Drug Delivery with Vibrating Mesh Nebulizers During Mechanical Ventilation.","authors":"Hui-Ling Lin, James B Fink, Jie Li","doi":"10.1089/jamp.2023.0026","DOIUrl":"10.1089/jamp.2023.0026","url":null,"abstract":"<p><p><b><i>Background:</i></b> Some experts recommend specific ventilator settings during nebulization for mechanically ventilated patients, such as inspiratory pause, high inspiratory to expiratory ratio, and so on. However, it is unclear whether those settings improve aerosol delivery. Thus, we aimed to evaluate the impact of ventilator settings on aerosol delivery during mechanical ventilation (MV). <b><i>Methods:</i></b> Salbutamol (5.0 mg/2.5 mL) was nebulized by a vibrating mesh nebulizer (VMN) in an adult MV model. VMN was placed at the inlet of humidifier and 15 cm away from the Y-piece of the inspiratory limb. Eight scenarios with different ventilator settings were compared with endotracheal tube (ETT) connecting 15 cm from the Y-piece, including tidal volumes of 6-8 mL/kg, respiratory rates of 12-20 breaths/min, inspiratory time of 1.0-2.5 seconds, inspiratory pause of 0-0.3 seconds, and bias flow of 3.5 L/min. In-line suction catheter was utilized in two scenarios. Delivered drug distal to the ETT was collected by a filter, and drug was assayed by an ultraviolet spectrophotometry (276 nm). <b><i>Results:</i></b> Compared to the use of inspiratory pause, the inhaled dose without inspiratory pause was either higher or similar across all ventilation settings. Inhaled dose was negatively correlated with inspiratory flow with VMN placed at 15 cm away from the Y-piece (<i>r_s</i> = -0.68, <i>p</i> < 0.001) and at the inlet of humidifier (<i>r_s</i> = -0.83, <i>p</i> < 0.001). The utilization of in-line suction catheter reduced inhaled dose, regardless of the ventilator settings and nebulizer placements. <b><i>Conclusions:</i></b> When VMN was placed at the inlet of humidifier, directly connecting the Y-piece to ETT without a suction catheter improved aerosol delivery. In this configuration, the inhaled dose increased as the inspiratory flow decreased, inspiratory pause had either no or a negative impact on aerosol delivery. The inhaled dose was greater with VMN placed at the inlet of humidifier than 15 cm away the Y-piece.</p>","PeriodicalId":14940,"journal":{"name":"Journal of Aerosol Medicine and Pulmonary Drug Delivery","volume":" ","pages":"125-131"},"PeriodicalIF":2.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140335668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimizing Aerosolized Drug Delivery in Clinical Trials in Patients Undergoing Mechanical Ventilation.","authors":"Thomas G O'Riordan","doi":"10.1089/jamp.2024.0015","DOIUrl":"10.1089/jamp.2024.0015","url":null,"abstract":"","PeriodicalId":14940,"journal":{"name":"Journal of Aerosol Medicine and Pulmonary Drug Delivery","volume":" ","pages":"113-114"},"PeriodicalIF":2.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140849586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Interrupting Heated Humidification on Nebulized Drug Delivery Efficiency, Temperature, and Absolute Humidity During Mechanical Ventilation: A Multi-Lab <i>In Vitro</i> Study.","authors":"Sophie Jacquier, Hui-Ling Lin, Jie Li, Caylie A Sheridan, Paul Karabelas, Jui-Fang Liu, Stephan Ehrmann, James B Fink","doi":"10.1089/jamp.2023.0028","DOIUrl":"10.1089/jamp.2023.0028","url":null,"abstract":"<p><p><b><i>Introduction:</i></b> During mechanical ventilation (MV), inspired gases require heat and humidification. However, such conditions may be associated with reduced aerosol delivery efficiency. The practice of turning off heated humidification before nebulization and the impact of nebulization on humidity in a dry ventilator circuit remain topics of debate. This study aimed to assess the effect of turning off heated humidification on inhaled dose and humidity with nebulizer use during adult MV. <b><i>Methods:</i></b> A bronchodilator (albuterol) and two antibiotics (Colistimethate sodium and Amikacin sulfate) were nebulized with a vibrating mesh nebulizer placed at the humidifier inlet and in the inspiratory limb at the Y-piece. Additionally, albuterol was nebulized using a jet nebulizer in both placements. Aerosol particle size distribution was determined through a cascade impactor. Absolute humidity (AH) and temperature of inspired gases were determined with anemometer/hygrometers before, during, and after nebulization, before, during, and up to 60 minutes after interrupting active humidification. Aerosol collected on a filter distal to the endotracheal tube and on impactor stages were eluted and assayed by spectrophotometry. <b><i>Results:</i></b> The inhaled dose was greater when both nebulizers were placed at the humidifier inlet than the inspiratory limb at the Y-piece. Irrespective of the nebulizer types and placements, the inhaled dose either decreased or showed no significant change after the humidifier was turned off. The aerosol particle size ranged from 1.1 to 2.7 μm. With interruption of active humidification, humidity of inspired gas quickly dropped below recommended levels, and nebulization in dry ventilator circuit produced an AH between 10 and 20 mgH₂O/L, lower than the recommended minimum of 30 mgH₂O/L. <b><i>Conclusion:</i></b> Interrupting active humidification during MV before nebulization did not improve aerosol delivery efficiency for bronchodilator or antibiotics, but did reduce humidity below recommended levels.</p>","PeriodicalId":14940,"journal":{"name":"Journal of Aerosol Medicine and Pulmonary Drug Delivery","volume":" ","pages":"115-124"},"PeriodicalIF":2.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140335667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New Generation Nebulizers.","authors":"Martin Knoch","doi":"10.1089/jamp.2024.29116.mk","DOIUrl":"10.1089/jamp.2024.29116.mk","url":null,"abstract":"<p><p>Standard nebulizers are intended for general purpose use and typically are continuously operated jet or ultrasonic nebulizers. Evolutionary developments such as breath-enhanced and breath-triggered devices have improved delivery efficiency and ease of use, yet are still suitable for delivery of nebulized medications approved in this category. However, recent developments of vibrating membrane or mesh nebulizers have given rise to a significant increase in delivery efficiency requiring reformulation of former drug products or development of new formulations to match the enhanced delivery characteristics of these new devices. In addition, the electronic nature of the new devices enables tailoring to specific applications and patient groups, such as guiding or facilitating optimal breathing and improving adherence to the therapeutic regimen. Addressing these patient needs leads to new nebulization technologies being embedded in devices with fundamentally distinct functionality, modes of operation and patient interfaces. Therefore, new generation nebulizers can no longer be regarded as one category with fairly similar performance characteristics but must be clinically tested and approved as drug/device combinations together with the specific drug formulation, similar to the approval of pressurized metered-dose inhalers and dry powder inhalers. From a regulatory viewpoint, it is required that drug and device are associated with each other as combinations by clear, mutually conforming labels or, even more desirably, by distinct container-closure systems (closed system nebulizer).</p>","PeriodicalId":14940,"journal":{"name":"Journal of Aerosol Medicine and Pulmonary Drug Delivery","volume":" ","pages":"157-165"},"PeriodicalIF":2.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141070652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nebulizers.","authors":"James B Fink, Kevin W Stapleton","doi":"10.1089/jamp.2024.29110.jbf","DOIUrl":"10.1089/jamp.2024.29110.jbf","url":null,"abstract":"<p><p>Nebulizers generate aerosols from liquid-based solutions and suspensions. Nebulizers are particularly well suited to delivering larger doses of medication than is practical with inhalers and are used with a broad range of liquid formulations. When the same drug is available in liquid or inhaler form, nebulizers are applicable for use with patients who will not or cannot reliably use a pressurized metered-dosed inhaler (pMDI) or dry powder inhaler (DPI) due to poor lung function, hand-breath coordination, cognitive abilities (e.g., infants, elderly) or device preference. In a nebulizer, liquid medication is placed in a reservoir and fed to an aerosol generator to produce the droplets. A series of tubes and channels direct the aerosol to the patient via an interface such as mouthpiece, mask, tent, nasal prongs or artificial airway. All nebulizers contain these basic parts, although the technology and design used can vary widely and can result in significant difference in ergonomics, directions for use, and performance. While many types of nebulizers have been described, the three categories of modern clinical nebulizers include: (1) pneumatic jet nebulizers (JN); (2) ultrasonic nebulizers (USN); and (3) vibrating mesh nebulizers (VMN). Nebulizers are also described in terms of their reservoir size. Small volume nebulizers (SVNs), most commonly used for medical aerosol therapy, can hold 5 to 20 mL of medication and may be jet, ultrasonic, or mesh nebulizers. Large volume nebulizers, typically jet or ultrasonic nebulizers, hold up to 200 mL and may be used for either bland aerosol therapy or continuous drug administration.</p>","PeriodicalId":14940,"journal":{"name":"Journal of Aerosol Medicine and Pulmonary Drug Delivery","volume":" ","pages":"140-156"},"PeriodicalIF":2.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140850699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantifying Exhaled Particles in Healthy Humans During Various Respiratory Activities Under Realistic Conditions.","authors":"Katharina Schwarz, Nadja Struß, Liudmila Banari, Jens M Hohlfeld","doi":"10.1089/jamp.2022.0076","DOIUrl":"10.1089/jamp.2022.0076","url":null,"abstract":"<p><p><b><i>Background:</i></b> Quantitatively collecting and characterizing exhaled aerosols is vital for infection risk assessment, but the entire droplet size spectrum has often been neglected. We analyzed particle number and size distribution of healthy participants in various respiratory activities, considering inter-individual variability, and deployed a simplified far-field model to inform on infection risks. <b><i>Methods:</i></b> Participants repeated the same respiratory activities on two visits. Particles were collected using an airtight extraction helmet supplied with High Efficiency Particulate Air (HEPA) filtered air. The sampling volume flow was transported to two particle counters covering the small and large particle spectrum. The applied simple mass balance model included respiratory activity, viral load, room size, and air exchange rates. <b><i>Results:</i></b> Thirty participants completed the study. The major fraction of the number-based size distribution was <5 μm in all respiratory activities. In contrast, the major fraction of the volume-based size distribution was 2-12 μm in tidal breathing, but >60 μm in all other activities. Aerosol volume flow was lowest in tidal breathing, 10-fold higher in quiet/normal speaking, deep breathing, coughing, and 100-fold higher in loud speaking/singing. Intra-individual reproducibility was high. Between participants, aerosol volume flow varied by two orders of magnitude in droplets <80 μm, and three orders of magnitude in droplets >80 μm. Simple model calculations not accounting for potential particle size-dependent differences in viral load and infection-related differences were used to model airborne pathogen concentrations. <b><i>Conclusions:</i></b> Quantitative analysis of exhaled aerosols for the entire droplet size spectrum as well as the variability in aerosol emission between individuals provides information that can support infection research. Clinical Trial Registration number: NCT04771585.</p>","PeriodicalId":14940,"journal":{"name":"Journal of Aerosol Medicine and Pulmonary Drug Delivery","volume":" ","pages":"51-63"},"PeriodicalIF":3.4,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139569809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}