Search Results (5)

This study investigates the atomization process in Respimat^® Soft Mist^TM Inhalers (SMIs) using a validated Volume of Fluid (VOF)-to-Discrete Phase Model (DPM) to simulate the transition from colliding liquid jets to aerosolized droplets. Key parameters, including colliding jet inlet velocity, surface tension, and liquid viscosity, were systematically varied to analyze their impact on the atomization, i.e., aerosolized droplet size distributions. The VOF-to-DPM simulation results indicate that higher jet inlet velocities enhance ligament fragmentation, producing finer and more uniform droplets while reducing total atomized droplet mass. The relationship between surface tension and atomization performance in colliding jet atomization is not monotonic. Reducing surface tension plays a complex dual role in the atomization process. On the one hand, lower surface tension enhances the likelihood of liquid jet breakup into a liquid sheet, leading to the formation of smaller ligaments under the same airflow conditions and shear forces. This increases the probability of generating more secondary droplets. On the other hand, reduced surface tension also destabilizes the liquid surface shape, decreasing the formation of fine, high-sphericity droplets in regimes where surface tension is a dominant force. Viscosity also influences atomization through complex mechanisms, i.e., lower viscosity reduces resistance to ligament breakup but promotes droplet interactions and coalescence, while higher viscosity suppresses ligament fragmentation, generating larger droplets and reducing atomization efficiency. The validated VOF-to-DPM framework provides critical insights for enhancing the performance and efficiency of inhalation therapies. Future work will incorporate nozzle geometry, jet impingement angles, and surfactant effects to better understand and optimize the atomization process in SMIs, focusing on achieving preferred droplet size distributions and emitted doses for enhanced drug delivery efficiency in human respiratory systems. Full article

Background: Chronic obstructive pulmonary disease (COPD) mainly affects individuals aged 60 and older. The proper use of inhalers is crucial for managing COPD. This study aimed to evaluate the prevalence and factors affecting the appropriate use of inhalers among elderly patients with COPD. Methods: We enrolled 91 elderly patients with COPD admitted to the Department of Respiratory, University Medical Center HCMC between October 2020 and May 2021. Patients who were capable of using the inhaler would have their inhaler usage recorded through video footage. Two respiratory experts carefully analyzed 133 video-recorded demonstrations for evaluation purposes. Results: 18.7% of the patients demonstrated the correct inhaler technique. Pressurized metered dose inhaler (pMDI) and Turbuhaler had the lowest documented correct usage rates (11.9% and 10.0%, respectively). Two critical steps, namely “holding breath for about five seconds or as long as comfortable” and “breathing out gently,” were commonly performed incorrectly when using pMDI, Respimat, Breezhaler, or Turbuhaler. Multivariable logistic regression analysis showed that lower mMRC scores (AOR = 5.3, CI 1.1–25.5, p = 0.037) and receiving inhaler instruction within the past three months (AOR = 5.2, CI 1.3–20.1, p = 0.017) were associated with increased odds of using the inhaler correctly. Conclusions: Our study found that less than 20% of elderly patients with COPD use inhalers correctly. Common errors include inadequate breath-holding and gentle exhalation. mMRC scores and recent inhaler instruction were predictors of proper use. These findings can aid clinicians in improving inhaler management for elderly patients with COPD. Full article

Background: Inhaler therapy plays a crucial role in controlling respiratory symptoms in patients with chronic obstructive pulmonary disease (COPD). Incorrect or partially correct use of inhaler devices causes many chronic obstructive pulmonary disease (COPD) patients to continue to have respiratory symptoms due to poor drug deposition in the airways as a result of poor inhaler technique, leading to increased healthcare costs due to exacerbations and multiple emergency room presentations. Choosing the right inhaler device for each individual patient is a bigger challenge for doctors and chronic obstructive pulmonary disease (COPD) patients. The type of inhaler device and the correct inhaler technique depends on the control of symptoms in chronic obstructive pulmonary disease (COPD). Physicians treating patients with chronic obstructive pulmonary disease (COPD) play a central role in educating patients about the correct use of inhalation devices. The steps for the correct use of inhalation devices should be taught to patients by doctors in the presence of the family so that if the patient has difficulties handling the device correctly, the family can support them. Methods: Our analysis included 200 subjects divided into two groups—recommended group (RG) and chosen group (CG)—and aimed primarily to identify the behaviour of chronic obstructive pulmonary disease (COPD) patients when faced with deciding which type of inhaler device is most suitable for them. The two groups were monitored three times during the 12-month follow-up period. Monitoring required the physical presence of the patient at the investigating physician’s office. The study included patients who were smokers, ex-smokers, and/or with significant exposure to occupational pollutants, aged over 40 years diagnosed with chronic obstructive pulmonary disease (COPD), risk group B and C according to the GOLD guideline staging, and on inhaled ICS+LABA treatment, although they had an indication for LAMA+LABA dual bronchodilation treatment. Patients presented for consultation on their own initiative for residual respiratory symptoms under background treatment with ICS+LABA. The investigating pulmonologist who offered consultations to all scheduled patients, on the occasion of the consultation, also checked the inclusion and exclusion criteria. If the patient did not meet the study entry criteria, they were assessed and received the appropriate treatment, and if the study entry criteria were met, the patient signed the consent and followed the steps recommended by the investigating pulmonologist. As a result, patient entry into the study was randomised 1:1, meaning that the first patient was recommended the inhaler device by the doctor and the next patient entered into the study was left to decide for themselves which type of device was most suitable for them. In both groups, the percentage of patients who had a different choice of inhaler device from that of their doctor was statistically significant. Results: Compliance to treatment at T12 was found to be low, but compared to results previously published on compliance, in our analysis, compliance was higher and the only reasons identified as responsible for the better results were related to the selection of the target groups and the regular assessments, where, in addition to reviewing the inhaler technique, patients were encouraged to continue treatment, thus creating a strong bond between patient and doctor. Conclusions: Our analysis revealed that empowering patients by involving them in the inhaler selection process increases adherence to inhaler treatment, reduces the number of mistakes in inhaler use of the inhaler device, and implicitly the number of exacerbations. Full article

Albeit inhalation therapy is the cornerstone in chronic obstructive pulmonary disease (COPD) treatment, inhaler technique is rarely evaluated, and training materials are often insufficient. In this single-center study, we aimed to evaluate the effectiveness of a teaching session complemented by a flyer on inhaler technique in COPD patients and to evaluate the perceived quality of the flyer. A total of 30 participants with stable COPD who had never used a soft mist inhaler before (Respimat^®, Boehringer Ingelheim) received a brief teaching session on proper inhaler technique complemented by a flyer (visit 1). The teaching intervention was completed by a pulmonologist. Epidemiological and clinical characteristics of COPD were collected by a questionnaire, and the ability to properly handle the inhaler was assessed. After 14 days, inhaler handling was re-evaluated, and patients were asked to rate the flyer (visit 2). After the initial training, proper inhaler handling was achieved in 80.0% of patients. Inhaler proficiency was maintained after 14 days (83.0% of the patients used the Respimat^® correctly, p-value > 0.99). The flyer was considered at least good by 27 patients (90.0%). This study indicated that the administration of an educational intervention resulted in persistent good competence in inhaler technique at a 14-day follow-up. Full article

Respimat^®Soft Mist^TM is a newly developed spray inhaler. Different from traditional nebulizers, metered-dose inhalers, and dry powder inhalers, this new type of inhaler can produce aerosols with long duration, relatively slow speed, and a high content of fine particles. Investigating the effect of the key geometric parameters of the device on the atomization is of great significance for generic product development and inhaler optimization. In this paper, a laser high-speed camera experimental platform is built, and important parameters such as the geometric pattern and particle size distribution of the Respimat^®Soft Mist^TM are measured. Computational fluid dynamics (CFD) and the volume of fluid method coupled with the Shear Stress Transport (SST) k-ω turbulence model are applied to simulate the key geometric parameters of the device. The effects of geometric parameters on the spray velocity distribution and geometric pattern are obtained. The angle of flow collision, the sphere size of the central divider and the length and width of the flow channel show significant impacts on the spray atomization. Full article