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Background While inhalation therapy efficacy hinges on attaining proper peak inspiratory flow rate (PIFR), the prevalence of inappropriate PIFR among patients with chronic obstructive pulmonary disease (COPD) remains unstudied in Korea. This study aimed to assess the prevalence of inappropriate PIFR, its correlation with COPD assessment test (CAT) scores, and factors associated with suboptimal PIFR. Methods We enrolled 108 patients with COPD who had been using the same inhaler for at least 1 year without exacerbations. PIFR was measured using an inspiratory flow meter (In-Check DIAL G16). Demographic, clinical, pulmonary function, and CAT score data were collected. Inappropriate was defined as PIFR 90 L/min for aerosol device users. Results The cohort comprised 87 (80.6%) men, mean age 71.0±8.5 years, with mean post-bronchodilator forced expiratory volume in 1 second of 69.1%±1.8% predicted. Twenty-nine (26.9%) used aerosol devices only, 76 (70.4%) used DPIs only, and three (2.8%) used both. Inappropriate PIFRs were found in 17.2% of aerosol device users, and 42.1% of DPI users. CAT scores were significantly higher in the inappropriate PIFR group than in the appropriate PIFR group (11.2±7.7 vs. 7.5±4.9, p=0.003). In DPI users, female, shorter height, lower body weight and maximal voluntary ventilation (MVV) were associated with inappropriate PIFR. Conclusion The prevalence of inappropriate PIFR among patients with COPD is 17.2% for aerosol device users, and 42.1% for DPI users. Suboptimal PIFR correlates with female gender, shorter stature, lower weight and MVV in DPI users.

Optimal peak inspiratory flow rate (PIFR) is required for effective drug delivery to distal airways when using dry powder inhalers (DPIs). This study aimed to examine the association between PIFR and hand grip strength (HGS) in stable COPD patients. A cross-sectional study was conducted. PIFR was measured using the In-check DIAL to assess for Accuhaler and Turbuhaler DPIs. HGS was measured using a handheld dynamometer. A PIFR of

Anti-inflammatory reliever (AIR) with or without regular maintenance delivered through Turbuhaler® has been widely recommended in the GINA strategy document. These patients are not prescribed with additional reliever inhalers, but dependent on Turbuhaler® during acute asthma episodes. The peak inspiratory flow rate (PIFR) is crucial in drug delivery from a dry powder inhaler (DPI) such as Turbuhaler®. Despite its increasing usage, there are some concerns that patients on Turbuhaler® are not able to achieve adequate PIFR during acute exacerbation of asthma. This study aimed to assess the PIFR at resistance settings that matched Turbuhaler® in patients with acute exacerbation of asthma. A six-month cross-sectional study was conducted at the Emergency Department (ED) of Hospital Sultanah Bahiyah and Hospital Kulim, Kedah, Malaysia. Adult patients diagnosed with mild to moderate acute exacerbations of asthma were recruited. The PIFRs were measured using the In-Check DIAL G16 that was set to simulate the resistance of Turbuhaler® (R3). The PIFRs were assessed before (pre) and after (post) the initial bronchodilator (BD) treatment at the ED. The minimal required PIFR was defined as flow rates ≥ 30 L/min while a PIFR of 60 L/min was considered as optimal. A total of 151 patients (81 females and 70 males) were recruited. The mean age was 37.5 years old with a range between 18 and 79 years old. The results showed that 98% (n = 148) of patients managed to achieve the minimal PIFR required for pre-BD. The mean PIFR pre-BD was 60 ± 18.5 L/min and post-BD was 70 ± 18.5 L/min. Furthermore, more than half (54%, n = 82) of the patients recorded PIFR ≥ 60 L/min during pre-BD, and about three-quarters (71%, n = 92) achieved PIFR ≥ 60 L/min post-BD. The PIFR showed a moderate correlation with peak expiratory flow rate (PEFR) (r = 0.55, 95% CI: 0.43–0.65, p < 0.001). The majority of patients with asthma in the present study were able to achieve sufficient PIFR from Turbuhaler® during mild to moderate acute exacerbations. [ABSTRACT FROM AUTHOR]

Dry powder inhalers are an effective yet costly COPD medication-delivery device. Patients must possess a minimum peak inspiratory flow rate (PIFR) for inhaled medication to be properly deposited into the lungs. Hospitalized palliative-care patients with diminished lung function due to advanced COPD may not possess the minimum PIFR (30 L/min) for adequate drug delivery. This study aims to quantify PIFR values for hospitalized palliative-care patients with advanced COPD to evaluate whether these patients meet the minimum PIFR requirements. Hospitalized patients ≥18 years old with a palliative-care consultation were eligible if they had a diagnosis of advanced COPD (GOLD C or D). Patients were excluded if they lacked decision-making capacity or had a positive COVID-19 test within the previous 90 days. Three PIFR values were recorded utilizing the In-CheckTM device, with the highest of the three PIFR attempts being utilized for statistical analysis. Eighteen patients were enrolled, and the mean of the highest PIFR readings was 72.5 L/min (±29 L/min). Post hoc analysis indicated 99.9% power when comparing the average best PIFR to the minimum PIFR (30 L/min) but only 51.4% power when compared to the optimal PIFR (60 L/min). This study found that palliative-care patients possess the minimum PIFR for DPI drug delivery. [ABSTRACT FROM AUTHOR]

Background: Dry powder inhalers (DPIs) require patients to impart sufficient energy through inhalation to ensure adequate dose emission, medication deaggregation, and resultant particle sizes suitable for lung deposition. There is an ongoing debate regarding the level of inspiratory effort, and therefore inspiratory flow rate, needed for optimal dose delivery from DPIs. Materials and Methods: The delivered dose (DD) and fine particle fraction (FPF) for each component of fluticasone furoate/umeclidinium/vilanterol (FF/UMEC/VI) 100/62.5/25 μg and FF/UMEC/VI 200/62.5/25 μg ELLIPTA DPIs were assessed at flow rates of 30, 60, and 90 L/min. Electronic lung (eLung) (eLung; an electronic breathing simulator) assessments were conducted to replicate inhalation profiles representing a wide range of inhalation parameters and inhaled volumes achieved by patients with chronic obstructive pulmonary disease (COPD) or asthma of all severity levels. Timing and duration of dose emission were assessed using a particle detector located at the entrance of an anatomical throat cast attached to the eLung. Results: During DD assessment, a mean of >80% of the nominal blister content (nbc) was emitted from the ELLIPTA DPI at all flow rates. In Next Generation Impactor assessments, the observed mean DD across flow rates for FF/UMEC/VI 100/62.5/25 μg ranged from 85.9% to 97.0% of nbc and 84.0% to 93.5% for FF/UMEC/VI 200/62.5/25 μg. In eLung assessments, 82.8% to 95.5% of nbc was delivered across the PIF range, 43.5 to 129.9 L/min (COPD), and 85.1% to 92.3% across the PIF range, 67.4 to 129.9 L/min (asthma). The FPF (mass <5 μm; % nbc) for each component was comparable across all flow rates and inhalation profiles. Dose emission timings indicated that near-complete dose emission occurs before reaching PIF. Conclusions: Dose delivery assessments across all flow rates and inhalation profiles indicate that patients with all severity levels of COPD or asthma can achieve the required inspiratory effort for efficient delivery of all components of FF/UMEC/VI from the ELLIPTA DPI. Dose emission profiles suggest rapid and near-complete dose delivery from the ELLIPTA DPI before reaching PIF. [ABSTRACT FROM AUTHOR]

Dry powder inhalers are an effective yet costly COPD medication-delivery device. Patients must possess a minimum peak inspiratory flow rate (PIFR) for inhaled medication to be properly deposited into the lungs. Hospitalized palliative-care patients with diminished lung function due to advanced COPD may not possess the minimum PIFR (30 L/min) for adequate drug delivery. This study aims to quantify PIFR values for hospitalized palliative-care patients with advanced COPD to evaluate whether these patients meet the minimum PIFR requirements. Hospitalized patients ≥18 years old with a palliative-care consultation were eligible if they had a diagnosis of advanced COPD (GOLD C or D). Patients were excluded if they lacked decision-making capacity or had a positive COVID-19 test within the previous 90 days. Three PIFR values were recorded utilizing the In-CheckTM device, with the highest of the three PIFR attempts being utilized for statistical analysis. Eighteen patients were enrolled, and the mean of the highest PIFR readings was 72.5 L/min (±29 L/min). Post hoc analysis indicated 99.9% power when comparing the average best PIFR to the minimum PIFR (30 L/min) but only 51.4% power when compared to the optimal PIFR (60 L/min). This study found that palliative-care patients possess the minimum PIFR for DPI drug delivery.

Martin Anderson,1 Kathryn Collison,2 M Bradley Drummond,3 Melanie Hamilton,4 Renu Jain,2 Neil Martin,5,6 Richard A Mularski,7 Mike Thomas,8 Chang-Qing Zhu,9 Gary T Ferguson10 1Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden; 2Respiratory Therapy Area, GSK, Research Triangle Park, NC, USA; 3Pulmonary and Critical Care Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; 4R&D, GSK, Ware, Hertfordshire, UK; 5Global Medical Affairs, GSK, Brentford, Middlesex, UK; 6Institute for Lung Health, University of Leicester, Leicester, Leicestershire, UK; 7Department of Pulmonary and Critical Care Medicine, Kaiser Permanente Northwest Center for Health Research, Portland, OR, USA; 8Primary Care Research, University of Southampton, Southampton, UK; 9Biostatistics, GSK, Stockley Park West, Uxbridge, Middlesex, UK; 10Pulmonary Research, Institute of Southeast Michigan, Farmington Hills, MI, USACorrespondence: Gary T FergusonPulmonary Research, Institute of Southeast Michigan, Farmington Hills, MI, USATel +1 248-478-6561Email garytferguson@msn.comBackground: The influence of peak inspiratory flow (PIF) on dose delivery from dry powder inhalers (DPIs) and association with treatment efficacy in patients with chronic obstructive pulmonary disease (COPD) has not been fully determined. In vitro studies have demonstrated adequate dose delivery through ELLIPTA DPI at PIF ≥ 30 L/min. This analysis of two clinical trials and a real-world population of COPD patients determined spirometric PIF distribution, and explored the relationship between PIF and outcomes in the trials.Methods: The replicate Phase IV, 12-week, randomized, double-blind 207608/207609 (NCT03478683/NCT03478696) trials evaluated fluticasone furoate/umeclidinium/vilanterol via ELLIPTA DPI versus budesonide/formoterol+tiotropium in COPD patients. This post hoc analysis assessed spirometric PIF distribution at screening and relationship between PIF and lung function outcomes in the pooled 207608/207609 population. Spirometric PIF distributions in a real-world population of COPD patients were evaluated by retrospective analysis of the Kaiser Permanente Northwest (KPNW) database to assess similarities between clinical trial and real-world populations.Results: A total of 1460 (207608/207609) and 3282 (KPNW) patients were included. There was considerable overlap between spirometric PIF distributions for both populations. Overall, 99.7% and 99.8% of the 207608/207609 and KPNW populations, respectively, reported spirometric PIF ≥ 50 L/min, estimated as equivalent to ELLIPTA PIFR ≥ 30 L/min. In the 207608/207609 combined analysis, there was no significant interaction between spirometric PIF and treatment for lung function endpoints, indicating treatment effect is independent of PIF.Conclusion: Nearly all COPD patients in the 207608/207609 and KPNW populations achieved spirometric PIF values estimated as equivalent to PIFR of ≥ 30 L/min through the ELLIPTA DPI. Lack of correlation between spirometric PIF at screening and treatment efficacy aligns with consistent dose performance from the ELLIPTA DPI across a wide range of PIFs, achieved by patients with COPD of all severities.Keywords: COPD, inhaled triple therapy, patient outcomes, real-world studies, peak inspiratory flow rate, DPI

Sohini Ghosh,1 Roy A Pleasants,2 Jill A Ohar,3 James F Donohue,1 M Bradley Drummond1 1Division of Pulmonary Diseases and Critical Medicine, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; 2Durham VA Medical Center, Durham, NC, USA; 3Department of Medicine, Section of Pulmonary, Critical Care, Allergy, and Immunology, School of Medicine, Wake Forest University, Winston-Salem, NC, USA Purpose: Adequate peak inspiratory flow rate (PIFR) is required for drug dispersion with dry powder inhalers (DPIs). Prevalence of PIFR discordance (suboptimal PIFR with prescribed inhalers) and factors influencing device-specific PIFR are unclear in COPD. The objective of this study was to determine the prevalence of PIFR discordance and associated clinical factors in a stable COPD population. Patients and methods: An observational, single-center, cohort study was conducted including 66 outpatients with COPD. PIFR was measured using the In-Check™ Dial with applied resistance of prescribed inhalers. Participants were defined as discordant if measured PIFR was Results: The median age of the COPD participants was 69.4 years, 92% were white and 47% were female. A total of 48% were using low–medium resistance DPIs (Diskus®/Ellipta®) and 76% used high-resistance DPI (Handihaler®). A total of 40% of COPD participants were discordant to prescribed inhalers. Female gender was the only factor consistently associated with lower PIFR. Shorter height was associated with reduced PIFR for low–medium resistance (r=0.44; P=0.01), but not high resistance (r=0.20; P=0.16). There was no correlation between PIFR by In-Check™ dial and PIFR measured by standard spirometer. Conclusion: PIFR is reduced in stable COPD patients, with female gender being the only factor consistently associated with reduced PIFR. Discordance with prescribed inhalers was seen in 40% of COPD patients, suggesting that many COPD patients do not generate adequate inspiratory force to overcome prescribed DPIs resistance in the course of normal use. Keywords: pulmonary disease, chronic obstructive, dry powder inhaler, peak inspiratory flow rate, drug delivery systems

Optimal peak inspiratory flow rate (PIFR) is crucial for inhalation therapy in patients with chronic obstructive pulmonary disease (COPD). However, little is known about the impact of PIFR-guided inhalation therapy on the clinical outcomes among patients with varying severities of COPD. A PIFR-guided inhalation therapy, including PIFR assessment and PIFR-guided inhaler education, was introduced in a pay-for-performance COPD management program in National Taiwan University Hospital. Among 383 COPD patients, there was significant reduction in incidence of severe acute exacerbation in the PIFR-guided inhalation therapy (PIFR group) than conventional inhaler education (control group) (11.9 vs. 21.1%, p = 0.019) during one-year follow-up. A multivariable Cox’s proportional-hazards analysis revealed that the PIFR-guided inhalation therapy was a significant, independent factor associated with the reduced risk of severe exacerbation (adjusted hazard ratio = 0.49, 95% confidence interval, 0.28–0.84, p = 0.011). Subgroup analysis found PIFR-guided inhalation therapy was more beneficial to patients with older age, short body stature, COPD stage 1&2, group C&D (frequent exacerbation phenotype), and using multiple inhalers. This study showed the PIFR-guided inhalation therapy significantly reduced the incidence of severe acute exacerbation than conventional inhaler education in patients with COPD. Careful PIFR-assessment and education would be crucial in the management of COPD.

Optimal peak inspiratory flow rate (PIFR) is crucial for inhalation therapy in patients with chronic obstructive pulmonary disease (COPD). However, little is known about the impact of PIFR-guided inhalation therapy on the clinical outcomes among patients with varying severities of COPD. A PIFR-guided inhalation therapy, including PIFR assessment and PIFR-guided inhaler education, was introduced in a pay-for-performance COPD management program in National Taiwan University Hospital. Among 383 COPD patients, there was significant reduction in incidence of severe acute exacerbation in the PIFR-guided inhalation therapy (PIFR group) than conventional inhaler education (control group) (11.9 vs. 21.1%, p = 0.019) during one-year follow-up. A multivariable Cox's proportional-hazards analysis revealed that the PIFR-guided inhalation therapy was a significant, independent factor associated with the reduced risk of severe exacerbation (adjusted hazard ratio = 0.49, 95% confidence interval, 0.28–0.84, p = 0.011). Subgroup analysis found PIFR-guided inhalation therapy was more beneficial to patients with older age, short body stature, COPD stage 1&2, group C&D (frequent exacerbation phenotype), and using multiple inhalers. This study showed the PIFR-guided inhalation therapy significantly reduced the incidence of severe acute exacerbation than conventional inhaler education in patients with COPD. Careful PIFR-assessment and education would be crucial in the management of COPD. [ABSTRACT FROM AUTHOR]

Objectives: We aimed to assess the role of spirometry measures and Dyspnea Index (DI) in response to treatment of subglottic stenosis (SGS) and ability to predict need for surgery. We also assessed correlations between spirometry measures, DI, and physical SGS parameters. Methods: Thirty‐seven adult female SGS patients were prospectively enrolled. Spirometry data and DI were obtained at serial clinic visits; physical SGS parameters were obtained intraoperatively. PIFR, PEFR, EDI, FEV1/FVC, and DI were compared preoperatively to postoperatively for patients who underwent operative intervention. Spirometry data, DI, and physical SGS parameters were analyzed for correlations, and receiver operating characteristic (ROC) curves were created for spirometry measures and DI to determine optimal cutoffs for recommending surgery. Results: Means of all measured spirometry measures changed significantly from preoperative to postoperative visits (P <.05). Mean DIs changed significantly between preoperative (27.5, n = 13, SD = 8.6) and postoperative visits (8.6, n = 13, SD = 5.5, P < 5 × 10‐5). All Pearson correlations were negligible to moderate. The area under the curve (AUC) for peak inspiratory flow rate (PIFR) was 0.903 (95% CI, 0.832–0.974) with cutoff at 2.10 L/s; the AUC for DI was 0.874 (95% CI, 0.791–0.956) with cutoff between 22‐25; the AUC for peak expiratory flow rate (PEFR) was 0.806 (95% CI, 0.702–0.910) with cutoff at 2.5 L/s; all other ROC curves were less than good. Conclusion: PIFR, PEFR, EDI, FEV1/FVC, and DIs significantly improve after treatment for SGS. No strong correlations exist between spirometry measures, DI, and physical SGS parameters. PIFR was the most sensitive and specific for predicting timing of operative intervention in our cohort. Level of Evidence: 1b Laryngoscope, 2019 [ABSTRACT FROM AUTHOR]

Introduction: Chronic obstructive pulmonary disease (COPD) and bronchial asthma pose significant threats and challenges to global health care, emphasizing the need for precise inhaler therapies to overcome this burden. The optimal peak inspiratory flow rate (PIFR) is a crucial determinant for the right selection and effective use of an inhaler device. It also helps to improve the treatment effectiveness of obstructive airway diseases worldwide as it allows effective drug delivery to distal airways and lung parenchyma. It is used as a selection criterion by physicians around the world for selecting personalized inhaler devices., Objective: To find out the optimal and non-optimal PIFR prevalence and its influencing factors in stable and exacerbation phases of COPD and bronchial asthma in Tamil Nadu, India., Methodology: It is a single-center, observational, cross-sectional study conducted from February 2022 to August 2023. The patients who meet the diagnostic criteria specified by the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines for COPD and the Global Initiative for Asthma (GINA) guidelines for bronchial asthma are enrolled in our study. The PIFR was measured using a hand-held digital spirometry device, along with demographic data collection. Statistical analyses, including t-tests and chi-square tests, were performed using SPSS version 21 (IBM Corp., Armonk, NY)., Results: Gender, height, and disease severity significantly impacted the PIFR. Females, normal BMI individuals, and those with moderate disease severity exhibited higher optimal PIFR rates. Stable or exacerbation phases, disease, and smoking status do not influence either optimal or non-optimal PIFR. Notably, substantial differences in lung function parameters were observed between optimal (60-90 L/min) and non-optimal PIFR (insufficient: <30 L/min, suboptimal: 30-60 L/min, excessive: >90 L/min) groups, highlighting their impact on respiratory health., Conclusion: This study emphasizes the importance of personalized inhaler strategies, considering gender, height, and disease severity. Proper inhaler device selection, continuous monitoring of inhaler technique, and tailored inhaler education at every OPD visit are vital for optimizing effective COPD and bronchial asthma management and improving adherence to treatment., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2024, Murugaiya et al.)

Background: We examined the effect of physical position on peak inspiratory flow (PIF) in patients with chronic obstructive pulmonary disease (COPD) using dry-powder inhalers (DPIs) with low‑medium internal resistance (R2) and/or high internal resistance (R5)., Methods: This prospective study in stable, ambulatory patients with spirometry-confirmed COPD evaluated the effect of 3 physical positions on maximal PIF achieved. Participants had PIFs of 30-90L/min (R5) or 60-90L/min (R2 DPIs) using the In-Check™ DIAL. PIF was measured in triplicate randomly in 3 positions that patients might be in while using their inhaler (standing, sitting, and semi-upright [supine position with the head of the bed at 45°, neck flexed forward]) against prescribed DPI resistance (R2/R5/both). Correlations between PIF and percentage decline in PIF between positions and differences in participant characteristics with >10% versus ≤10% PIF decline standing to semi-upright were calculated., Results: A total of 76 participants (mean age, 65.2 years) had positional measurements; 59% reported seated DPI use at home. The mean (standard deviation) PIF standing, sitting, and semi-upright was 80.7 (13.4), 77.8 (14.3), and 74.0 (14.5) L/min, respectively, for R2 and 51.1 (9.52), 48.6 (9.84), and 45.8 (7.69) L/min, respectively, for R5 DPIs. PIF semi-upright was significantly lower than sitting and standing (R2; P < 0.0001) and standing (R5; P = 0.002). Approximately half of the participants had >10% decline in PIF from standing to semi-upright. Patient characteristics exceeding the 0.10 absolute standardized difference threshold with the decline in PIF for both the R2 and R5 DPIs were waist-to-hip ratio, modified Medical Research Council dyspnea score, and postbronchodilator percentage predicted forced vital capacity and PIF by spirometry., Conclusions: PIF was significantly affected by physical position regardless of DPI resistance. PIF was highest when standing and lowest when semi-upright. We recommend that patients with COPD stand while using an R2 or R5 DPI. Where unfeasible, the position should be sitting rather than semi-upright. ClinicalTrials.gov identifier NCT04168775., (JCOPDF © 2024.)

Objectives: For dry powder inhalers, the airflow properties in the airways could affect the deposition of inhaled particles; the flow patterns vary inherently between patients. This paper provides an evaluation of the effects of six airflow patterns on the behaviour of inhaled particles, as determined by using numerical simulations. Methods: Constant‐velocity and unsteady inhalation flows were employed. The unsteady inhalation flow was set as an inhalation curve with a peak inspiratory flow rate. Under a constant flow of 28.3 l/min, the total flow rates were calculated to confirm the validity of the numerical simulation. The effects of different inhalation patterns on the particle behaviour in a realistic human airway model were revealed via numerical simulation. Key findings: Different flow rates affected the behaviour and deposition of the inhaled particles. Under an inhalation flow pattern, different airflow tendencies were observed between the right and left bronchi. Particle deposition in the airways was promoted by a vortex following terminal‐velocity‐like breath‐holding. The inhalation flow pattern affected the behaviour and deposition of inhaled particles in the airway. Conclusions: Our results indicated that particle deposition in a realistic human airway model was promoted by a vortex formation following the terminal‐velocity‐like breath‐holding. Moreover, the inhalation flow pattern significantly influenced the behaviour and deposition of inhaled particles in the airways. Additionally, the effect of flow patterns on the particle deposition in each airway position was quantitatively evaluated by numerical simulations for a realistic human airway model. [ABSTRACT FROM AUTHOR]

Theerasuk Kawamatawong, Supattra Khiawwan, Prapaporn Pornsuriyasak Division of Pulmonary and Critical Care Medicine, Department of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand Background: Inhaler device technique is a common cause of treatment failure in patients with asthma and chronic obstructive pulmonary disease. Dry powder inhaler (DPI) requires optimal peak inspiratory flow rate (PIFR) for drug delivery. Low PIFR generation is common in the elderly. Patient lung function and intrinsic inhaler resistance are factors for determining generated PIFR and drug delivery from DPI. Objectives: We aimed to identify the PIFR of the older (aged >60 years) and the younger (aged ≤60 years) patients with obstructive airway diseases for the different inhaler devices (Turbuhaler® and Accuhaler). Patients and methods: A cross-sectional study was conducted from January to December 2014. Patients with obstructive airway diseases were recruited. Spirometry was performed. PIFR was measured by using an In-Check DIAL device. Individual PIFR values for each inhaler device were obtained for three consecutive measurements and then averaged. Results: A total of 139 patients diagnosed with obstructive lung diseases (asthma, n = 109; chronic obstructive pulmonary disease, n = 30) were recruited. Of these, 71 patients (51%) were >60 years. The PIFR generated by the patients who were ≤60 years for nonresistance mode was not different from that generated by those aged >60 years (115.0 ± 15.2 L/min vs 115.4 ± 13.3 L/ min, p = 0.86). Regarding the DPI, PIFR generated from the older group was significantly lower than that generated from the younger group for Turbuhaler (72.5 ± 18.8 L/min vs 82.4 ± 21.1 L/min, p = 0.01), but the PIFR generated was not significantly different between the older and the younger groups for the Accuhaler (93.8 ± 22.9 L/min vs 99.4 ± 24.2 L/min, p = 0.86). The low peak expiratory flow rate and PIFR from spirometry were associated with the suboptimal PIFR measured by using In-Check DIAL. Discussion: Optimal PIFR is critical for DPI use in the elderly; appropriate DPI selection is essential for management. In-Check DIAL may be useful for detecting inhaler device problem among the elderly. Conclusion: Lower PIFR generated from Turbuhaler was noted in patients with airway diseases who were older than 60 years, when compared to the younger patients. Keywords: elderly, obstructive airway diseases, peak inspiratory flow rate, dry powder inhaler

Rationale: Dry powder inhalers (DPIs) are prescribed after hospitalization for acute exacerbation of COPD (AECOPD). Peak inspiratory flow (PIF) affects DPI delivery.Objectives: To study the impact of PIF on readmission after hospitalization for AECOPD.Methods: A retrospective analysis of hospitalized patients, enrolled in an AECOPD care plan, was performed. Data analyzed included PIF, age, sex, length of stay, Charlson Comorbidity Index, COPD Assessment Test score, modified Medical Research Council score, percent predicted FEV1, FVC, and inspiratory capacity. A PIF equal to and less than 60 L/min was defined as suboptimal (sPIF). Outcome measures included 30- and 90-day COPD and all-cause readmissions, and days to next COPD and all-cause readmissions.Results: Of the 123 subjects, 52% (n = 64) had sPIF. They had greater COPD Assessment Test scores (29.1 ± 5.9 vs. 25.3 ± 8.7; P = 0.0073), rates of 90-day COPD readmissions (28.1 vs. 13.6%; P = 0.048), fewer median days to COPD (63.5 [interquartile range (IQR), 21-89.8] vs. 144 [IQR, 66-218]; P = 0.002) and all-cause readmissions (65.5 [IQR, 24.3-107.3] vs. 101 [IQR, 54.5-205.5]; P = 0.009). PIF was the only variable (P = 0.041) that predicted days to COPD readmission in a multivariate model incorporating age, sex, percent predicted FEV1, Charlson Comorbidity Index, and inspiratory flow group. In a group of patients with sPIF (n = 22), all-cause and COPD 30- and 90-day readmission rates were significantly lower for those discharged with nebulizer compared with DPI therapy.Conclusions: sPIF is common during AECOPD and predicts all-cause and COPD readmissions. Patients with sPIF may benefit from nebulized therapies. We recommend checking PIF in patients hospitalized for AECOPD for selection of delivery devices. [ABSTRACT FROM AUTHOR]

Background: Inhaler device technique is a common cause of treatment failure in patients with asthma and chronic obstructive pulmonary disease. Dry powder inhaler (DPI) requires optimal peak inspiratory flow rate (PIFR) for drug delivery. Low PIFR generation is common in the elderly. Patient lung function and intrinsic inhaler resistance are factors for determining generated PIFR and drug delivery from DPI. Objectives: We aimed to identify the PIFR of the older (aged >60 years) and the younger (aged ≤60 years) patients with obstructive airway diseases for the different inhaler devices (Turbuhaler® and Accuhaler). Patients and methods: A cross-sectional study was conducted from January to December 2014. Patients with obstructive airway diseases were recruited. Spirometry was performed. PIFR was measured by using an In-Check DIAL device. Individual PIFR values for each inhaler device were obtained for three consecutive measurements and then averaged. Results: A total of 139 patients diagnosed with obstructive lung diseases (asthma, n = 109; chronic obstructive pulmonary disease, n = 30) were recruited. Of these, 71 patients (51%) were >60 years. The PIFR generated by the patients who were ≤60 years for nonresistance mode was not different from that generated by those aged >60 years (115.0 ± 15.2 L/min vs 115.4 ± 13.3 L/ min, p = 0.86). Regarding the DPI, PIFR generated from the older group was significantly lower than that generated from the younger group for Turbuhaler (72.5 ± 18.8 L/min vs 82.4 ± 21.1 L/min, p = 0.01), but the PIFR generated was not significantly different between the older and the younger groups for the Accuhaler (93.8 ± 22.9 L/min vs 99.4 ± 24.2 L/min, p = 0.86). The low peak expiratory flow rate and PIFR from spirometry were associated with the suboptimal PIFR measured by using In-Check DIAL. Discussion: Optimal PIFR is critical for DPI use in the elderly; appropriate DPI selection is essential for management. In-Check DIAL may be useful for detecting inhaler device problem among the elderly. Conclusion: Lower PIFR generated from Turbuhaler was noted in patients with airway diseases who were older than 60 years, when compared to the younger patients. [ABSTRACT FROM AUTHOR]

Background: The efficacy of drug delivery from inhalers is very much dependent on the user's peak inspiratory flow rate (PIFR). Current methods to measure PIFR in inhalers are based on subjective checklists. There is a lack of methods currently available to objectively remotely monitor PIFR in pressurized metered dose inhalers (pMDIs) and dry powder inhalers (DPIs). In this study, for the first time, non-contact acoustic methods were employed to estimate PIFR through three commonly used inhalers (Diskus™ DPI, Turbuhaler™ DPI, and Evohaler™ pMDI) with the aim of applying these methods to remotely monitor inhaler inhalation technique in future clinical applications. Methods: Each inhaler was placed inside an airtight container connected to a spirometer to measure PIFR. A high quality microphone was placed 5 cm from the mouthpiece of the inhalers to record inhalation sounds. Over 2000 inhaler inhalation sounds were recorded from 11 healthy participants. A range of temporal and spectral acoustic features from the inhalation sounds were correlated with PIFR. The variation of acoustic features and the repeatability of the inhalation acoustic spectral profile were investigated to further characterize inhaler inhalation sounds and to determine the reliability of acoustics to estimate PIFR. Results: All acoustic features were significantly correlated with PIFR ( p < 0.001). The mean power of the inhalation sound generated the most consistent correlation across all inhalers [ R2 = 0.77 (Diskus™), R2 = 0.7 (Turbuhaler™), R2 = 0.75 (Evohaler™)]. Acoustic features generated low variation and the spectral profile of inhalation sounds was repeatable regardless of flow rate, suggesting that acoustic methods are a reliable method of estimating PIFR. Conclusions: The methods presented in this study may be employed in a wearable monitoring device in future applications to measure inhaler PIFR. Objective monitoring of PIFR in inhalers may help patients improve their inhaler inhalation technique and therefore may be of significant clinical benefit to both patients and clinicians. [ABSTRACT FROM AUTHOR]

Introduction: There has been an active discussion on the sustainability of inhaler therapy in respiratory diseases, and it has cast a shadow on pMDIs which rely on propellant with high global warming potential (GWP). DPIs offer a lower GWP and effective alternative, but there has been concern whether all patients can generate sufficient inspiratory effort to disperse the drug. This review focuses on airflow resistance of DPIs and its clinical relevance., Areas Covered: For this narrative review, we searched the literature for studies comparing flow patterns with different devices. We also included a section on clinical trials comparing reliever administration with DPI, pMDI with spacer, and nebulizer during exacerbation., Expert Opinion: The evidence supports the efficacy of DPIs irrespective of respiratory condition or age of the patient even during acute exacerbations. Air flow resistance does not limit the use of DPIs and the patients were able to generate sufficient inspiratory flow rate with almost any device studied. None of 16 identified clinical trials comparing reliever administration via DPIs to other types of devices during exacerbation or bronchial challenge showed statistically significant difference between the device types in FEV1 recovery. DPIs performed as well as other types of inhaler devices even during asthma or COPD exacerbation.

Background: A peak inspiratory flow rate (PIFR) of < 60 L/min against the internal resistance (resist) of a dry powder inhaler (DPI) may limit the ability of a patient with chronic obstructive pulmonary disease (COPD) to achieve bronchodilation. The hypothesis was that lung function would be higher with a beta-agonist inhaled via nebulization compared with dry powder in patients with COPD who exhibit a PIFRresist of < 60 L/min against the Diskus®. Methods: This study was randomized, single-blind, and crossover with spirometry and inspiratory capacity (IC) measured at 15, 30, and 120 min post treatment. The efficacy of arformoterol aerosol solution (15 μg/2mL) via nebulizer was compared with salmeterol dry powder (50 μg) via Diskus. The primary outcome was the change in lung function from baseline at 2 hr as these two inhaled beta-agonists have the similar peak bronchodilator effect as measured by forced expiratory volume in 1 sec (FEV1). Results: Twenty patients (15 females/5 males) with postalbuterol FEV1 of 0.83 ± 0.31 L (38 ± 12% predicted) and PIFRresist of 53 ± 5 L/min completed the study. At 15 min, improvements in FEV1, forced vital capacity (FVC), and IC were significantly higher with arformoterol than with salmeterol. At 2 hr, changes in FVC and IC, but not FEV1, were significantly higher with arformoterol. At visit 3, patient preference was similar for salmeterol Diskus (n=8) and arformoterol solution (n=7), whereas five patients reported no preference. Conclusions: At peak effect (2 hr), volumeresponseswere greater with arfomoterol via nebulizer comparedwith dry powder salmeterol in patients with COPD who had a PIFRresist of < 60 L/min. Bronchodilator therapy via nebulization should be considered in patients with COPD who have a suboptimal PIFRresist against a particular DPI. [ABSTRACT FROM AUTHOR]

Background: Dry powder inhalers (DPI) are alternative devices for delivering medication for treatment of asthma. The amount of drug delivery to the lungs is directly influenced by peak inspiratory flow rate (PIFR). A minimum PIFR of −30 L/min is needed for the Turbuhaler and Accuhaler. Methods: In order to evaluate the sensitivity of the Turbutester and Accuhaler tester in detecting the minimum and optimum PIFR for the Turbuhaler and Accuhaler in asthmatic children, PIFR was measured using the In-Check Dial through the internal resistance of the Turbuhaler and Accuhaler and compared according to the child's ability to make a whistle sound via both testers. Results: A total of 259 asthmatic children were studied: 20 pre-school children, aged 5–6 years; 174 school-age children, aged 7–12 years; and 65 adolescents, aged 13–18 years. The sensitivity of the Turbutester and Accuhaler tester to detect optimum PIFR were 98.40% and 97.2%, respectively. In the comparison among age groups, the sensitivity of the Accuhaler tester to detect optimum or minimum PIFR for the Accuhaler was 95%, 97.7% and 95.4%, respectively. The sensitivity of the Turbutester to detect optimum PIFR for the Turbuhaler was 94.4%, 98.8% and 98.5%, respectively. The sensitivity of the Turbutester to detect minimum PIFR for the Turbuhaler was 94.7%, 100% and 100%, respectively. There were no significant differences in percentage of having optimum or minimum PIFR among asthma severity and current device usage in all age groups. Conclusions: Most children aged at least 5 years could generate enough PIFR to use dry powder inhaler devices. Both the Turbutester and Accuhaler tester were found to have high sensitivity in detecting optimum and minimum required PIFR. [ABSTRACT FROM AUTHOR]

Background: The recently released handheld In-Check device can be used to measure the peak inspiratory flow rate (PIF) of patients and is reportedly useful in determining whether the PIF is sufficient for using inhaler devices. In this study, we evaluated the effects of instructions for the use of the device and of the device type based on measurements of the PIF in asthma. Objectives: One hundred and thirty-five asthmatic patients who used a fluticasone propionate Diskus (FP-DK) or a budesonide Turbuhaler (BUD-TH) were studied. Methods: The PIF was measured by the In-Check device. For patients without a sufficient PIF of 50 l/min, instructions for the use of the device were given, and the device was changed to hydrofluoroalkan-beclomethasone dipropionate (HFA-BDP). Results: A significant correlation between the PIF and peak expiratory flow rate (p < 0.0001) was found. In 10 patients in whom the PIF did not increase to >50 l/min after instructions, the device was changed to HFA-BDP, which resulted in significant improvements in lung function in terms of the forced expiratory volume in 1 s (p = 0.018), peak expiratory flow (p = 0.038) and the maximum expiratory flow rates at 50% (p = 0.018) and 25% (p = 0.011). Conclusions: Measurement of the PIF by the In-Check device is useful in the clinical management of asthma, to provide an appropriate device so as to improve lung function. Copyright © 2009 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

There has been a long-standing debate regarding the adequacy of airflow rates used in respirator certification testing and whether these test flow rates underestimate actual values. This study investigated breath by breath inspiratory peak flow rate, minute ventilation, and instantaneous flow rates of eight young, healthy volunteers walking on a treadmill at 80-85% of maximal aerobic capacity until exhaustion while wearing an air-purifying respirator with one of eight combinations of inhalation and exhalation resistance. An analysis of variance was performed to identify differences among the eight conditions. Scheffe's post hoc analysis indicated which means differed. The group of conditions with the highest average value for each parameter was identified and considered to represent a worst-case scenario. Data was reported for these conditions. A Gaussian distribution was fit to the data and the 99.9% probability levels determined. The 99.9% probability level for the peak and instantaneous flow rates were 374 L/min and 336 L/min, respectively. The minute ventilation distribution was not Gaussian. Less than 1% of the recorded minute ventilations exceeded 135 L/min. Instantaneous flow rates exceeded the National Institute for Occupational Safety and Health's respirator test standards of 64, 85, and 100 L/min constant flow 91%, 87%, and 82% of the time, respectively. The recorded minute ventilations exceeded the 40 L/min minute ventilation test standard (for tests with a sinusoidal flow pattern) 100% of the time. This study showed that young, healthy respirator wearers generated peak flow rates, minute ventilations, and instantaneous flow rates that consistently exceeded current test standards. Their flow rates should be higher than those of a respirator wearer performing occupational work and could be considered upper limits. Testing respirators and respirator cartridges using a sinusoidal breathing pattern with a minute ventilation of 135 L/min (peak flow rate approximately 424 L/min) would encompass 99% of the recorded minute ventilations and 99.9% of the predicted peak and instantaneous flow rates from this study and would more accurately reflect human respiration during strenuous exercise. [ABSTRACT FROM AUTHOR]

Protection afforded by a respirator filter depends on many factors, among them chemical or biological agent and flow rate. Filtration mechanisms, such as chemical adsorption, depend on sufficient residence time for the filter media to extract noxious agents from the airstream. Consequently, filter efficiency depends on inspiratory air velocities, among other factors. Filter designs account for this by adjusting bed depth and cross-sectional area to anticipated flow rates. Many military and commercial filters are designed and tested at 32–40 L/min. The present study investigated respiratory demand while U.S. Marines (n=32) completed operationally relevant tasks in chemical protective ensembles, including M-40 masks and C2A1 filters. Respiratory demand greatly exceeded current test conditions during the most arduous tasks: minute ventilation=96.4±18.9 L/min (mean±SD) with a maximum of 131.7 L/min observed in one subject. Mean peak inspiratory flow rate (PIF) reached 238.7±34.0 L/min with maximum PIF often exceeding 300 L/min (maximum observed value=356.3 L/min). The observed respiratory demand was consistent with data reported in previous laboratory studies of very heavy workloads. This study is among the few to report on respiratory demand while subjects perform operationally relevant tasking in chemical protective ensembles. The results indicate that military and industrial filters will probably encounter higher flow rates than previously anticipated during heavy exertion. [ABSTRACT FROM AUTHOR]