Comparisons between In-Check DIAL® and PF810® in evaluation and training inspiratory capacity for using dry powder inhalers.

BACKGROUND: Dry powder inhalers (DPIs) rely on both internal resistance and patients' inspiratory capacity for effective operation. Optimal inspiratory technique is crucial for DPI users. This study assessed the accuracy and repeatability of two available devices, PF810® and In-Check DIAL®, and analyzed their measurement errors and consistency in detecting inspiratory capacity. METHODS: The accuracy and repeatability of peak inspiratory flow (PIF) and forced inspiratory vital capacity (FIVC) against various internal resistances of the two devices were assessed using standard waveforms generated by a breathing simulator. The agreement of PIF measurements between the two devices in healthy volunteers and chronic obstructive pulmonary disease (COPD) patients was analyzed with the intraclass correlation coefficient and Bland-Altman graphical analysis. RESULTS: PF810® showed great accuracy and repeatability in measuring PIF, except for square waveforms at the lowest flow rate (20 L/min). In-Check DIAL® exhibited poor accuracy against high resistance levels. In scenarios with no resistance, In-Check DIAL® had significantly smaller measurement errors than PF810®, but larger errors against high resistance levels. The two devices showed excellent agreement (ICC > 0.80, P < 0.05), except for healthy volunteers against medium to high resistance (R3-R5) where the ICC was insignificant. Bland-Altman plots indicated small disagreements between the two devices for both healthy volunteers and COPD patients. CONCLUSIONS: In-Check DIAL® exhibited poor accuracy and larger measurement errors than PF810® when detecting PIFs against higher internal resistances. However, its good performance against lower internal resistances, along with its cost-effectiveness and convenience made it appropriate for primary care. PF810® showed good accuracy and repeatability and could detect additional parameters of inspiratory capacity beyond PIF, though required further studies to confirm its clinical benefits.

Prevalence of Critical Errors and Insufficient Peak Inspiratory Flow in Patients Hospitalized with COPD in a Department of General Internal Medicine: A Cross-Sectional Study.

Background: The suboptimal use of inhalers in the treatment of patients with chronic obstructive pulmonary disease (COPD) is probably a major but poorly documented problem in hospitalized patients. We aimed to describe the prevalence of misused inhalers among patients hospitalized with COPD in a department of general internal medicine. Methods: We conducted a monocentric cross-sectional study in consecutive patients with a diagnosis of COPD and hospitalized between August 2022 and April 2023 in the internal medicine division of Fribourg Hospital, Switzerland. Patients underwent an assessment of their inhaler technique and peak inspiratory flow (PIF) using the In-Check Dial G16®. The primary outcome was the prevalence of misused inhalers, defined as an inhaler used with a critical error and/or insufficient PIF. Secondary outcomes included the prevalence of inhalers unsuitable to patients' characteristics and of patients using at least one misused inhaler. Results: The study included 96 patients and 160 inhalers were assessed at admission. Among these inhalers, 111 (69.4%; 95% confidence interval [CI] 61.6-76.4) were misused; 105 (65.6%; 95% CI 57.7-72.9) due to the presence of a critical error in the inhalation technique and 22 (13.8%; 95% CI 8.8-20.1) due to insufficient PIF. Concerning the secondary outcome, 27 inhalers (16.9%) were unsuitable, and 79 patients (82.3%) used at least one misused inhaler. Conclusion: Among patients hospitalized with a diagnosis of COPD, two-thirds of inhalers were misused. Suboptimal use was mainly due to the presence of critical errors, but also to the presence of an insufficient PIF and unsuitable inhalers.

Prevalence and Factors Affecting the Optimal and Non-optimal Peak Inspiratory Flow Rate in Stable and Exacerbation Phases of Chronic Obstructive Pulmonary Disease and Bronchial Asthma in India.

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.

Changes in Peak Inspiratory Flow After Acute Bronchodilation: An Observational Study of Patients with Stable Chronic Obstructive Pulmonary Disease.

Introduction: 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. Materials and Methods: 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). Results: 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; r = 0.28 [p = 0.02]; r = 0.21 [p = 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. Conclusions: 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.

Inappropriate Peak Inspiratory Flow Rate in the Patients with Stable Chronic Obstructive Pulmonary Disease in Korea.

Background: Inhalation therapy efficacy hinges on proper peak inspiratory flow rate (PIFR) attainment, yet 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 one 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 < 60L/min for dry power inhaler (DPI) users or > 90L/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 one second of 69.1 ± 1.8% predicted. Twenty-nine (26.9%) used aerosol devices, 76 (70.4%) used DPIs, 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 inappropriate PIFR group than 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 MVV (maximal voluntary ventilation) were associated with inappropriate PIFR. Conclusions: 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.

Exploring Indicators for Training Load Control in Young Swimmers: The Role of Inspiratory Spirometry Outcomes.

One of the most important implications of technology in swimming is to control training loads. Lactate control, video-analysis of the technique or the assessment of specific actions, i.e., the vertical jump, have helped to provide load adaptation indicators in swimmers in recent decades. However, these indicators have led to a longer application time, due to their indirect procedure and the need to analyze each variable. The aim of this study was to analyze whether inspiratory spirometry values can serve as a training load control tool in swimmers. Countermovement jump (CMJ), Inspiratory Force Index (S-INDEX) and Peak Inspiratory Flow (PIF) were evaluated with a load of 3 cm H2O before, during and after performing a swimming performance test (critical speed test: specific warming up, 400 m and 100 m freestyle). Positive correlations were found between S-INDEX and jump height after warm-up, after 400 m and at the end of 100 m (Spearman = 0.470, R2 = 0.280; Spearman = 0.508, R2 = 0.392; Spearman = 0.458, R2 = 0.359, p < 0.05, respectively). Moreover, positive correlations were also found between PIF and jump height at the same evaluated moments (Spearman = 0.461, R2 = 0.305; Spearman = 0.493, R2 = 0.386; Spearman = 0.454, R2 = 0.374, p < 0.05). Both the S-INDEX and the PIF could serve as useful tools for swimmer load control, allowing coaches to make more immediate decisions.

Effect on Physical Position of Peak Inspiratory Flow in Stable COPD: An Observational Study.

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 low­medium 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.

Exploration of quality criteria for the detection of peak inspiratory flow under different resistance conditions.

BACKGROUND: At present, robust quality criteria and methods for the assessment of Peak inspiratory flow meter performance are lacking. OBJECTIVE: A standard flow-volume simulator for quality control analyses of an inhalation assessment device was utilized with different simulated resistance levels in order to propose a quality testing method and associated standard for this device type. METHODS: A standard flow-volume simulator was utilized to assess the performance of an In-Check DIAL® (Device I) and an intelligent inhalation assessment device (Device P) at a fixed volume and flow rate. Indices used to evaluate these two instruments included repeatability, accuracy, linearity, and impedance. RESULTS: Both devices exhibited good repeatability (<± 3 L/min). The difference between test results and standard simulator values for Device P was less than ± 5 L/min at resistance level R1 but higher than ± 5 L/min at resistance levels R2-5, while Device I were greater than 5 L/min at all resistance levels. The relative error for Device P was <± 10% at resistance levels R1, R2, and R4, but > 10% at resistance levels R3 and R5. The relative error values for Device I at all five resistance levels were > 10%. Device P passed the linearity test at the R2 resistance level, while Device I partially passed the linearity test at all five resistance levels. CONCLUSION: Standard monitoring methods and standards provide a valuable approach to the more reliable clinical assessment and application of these instruments.

Consideration and Assessment of Patient Factors When Selecting an Inhaled Delivery System in COPD.

Because guidelines and strategies for pharmacologic treatment of COPD focus on specific classes of inhaled medications, there is an unmet need for information to guide health care professionals for selecting an inhaled medication delivery system that matches the unique characteristics of individual patients. This article provides guidance for selecting an inhaled medication delivery system based on three "key" patient factors: cognitive function, manual dexterity/strength, and peak inspiratory flow. In addition, information is provided about specific tests to assess these patient factors. Cognitive impairment with an estimated prevalence of 25% among patients with COPD adversely affects patients' ability to correctly use a handheld device. To our knowledge, the prevalence of impaired manual dexterity/strength has not been reported in those with COPD. However, 79% of patients with COPD have reported one or more physical impediments that could influence their ability to manipulate an inhaler device. The measurement of peak inspiratory flow against the simulated resistance (PIFr) of a dry powder inhaler establishes whether the patient has the inhalation ability for creating optimal turbulent energy within the device. A suboptimal PIFr for low to medium-high resistance dry powder inhalers has been reported in 19% to 84% of stable outpatients with COPD. Health care professionals should consider cognitive function, manual dexterity/strength, and PIFr in their patients with COPD when prescribing inhaled pharmacotherapy. Impairments in these patient factors are common among those with COPD and can affect the individual's competency and effectiveness of using inhaled medications delivered by handheld devices.

Effect of Chronic Obstructive Pulmonary Disease Severity on Inspiratory Flow Rates via Inhaler Devices.

INTRODUCTION: Chronic obstructive pulmonary disease (COPD) is a chronic respiratory disorder that affects millions of people worldwide and inhalation therapy is central to the symptomatic management of the disease. Therefore, knowledge of the minimum Peak inspiratory flow (PIF) requirements for specific inhalers especially dry powder inhalers (DPI's) is necessary when prescribing inhalation therapy. The purpose of this study is to assess the effect of COPD severity on PIF in patients with COPD. METHODOLOGY: A total of 150 subjects (75 patients with stable COPD, and 75 apparently healthy subjects) participated in the study. PIF was assessed using the In-check Inhaler Assessment Kit (manufactured by Clement Clarke International Ltd, Harlow, UK). Lung function was assessed by spirometry with subjects divided into four groups based on the severity of their airway obstruction using the GOLD criteria. The Modified Medical Research Council (MMRC) dyspnea scale was used to assess dyspnea severity. Exercise capacity was assessed using the 6-minute walk test. Statistical analysis was performed with SPSS 23.0 software. In all the statistical tests, a p value of <0.05 was considered significant. RESULTS: The mean age for the COPD patient and control population are 72.48 ± 8.01 and 70.69 ± 5.82 respectively. The control group had higher PIF than COPD group; however, only the clickhler and pMDI had statistically significant difference between the mean PIF of the patients compared with the control group. Generally, there was an observed trend of a decrease in mean PIF as the COPD stage progresses with a statistically significant difference observed for Easibreathe (F= 3.52, p= 0.019) and pressurized Metered dose inhaler (pMDI) (F= 4.26, p= 0.008). There was a significant positive correlation between FEV1%, FVC, Exercise capacity (6-minute walk distance) and PIF for Clickhaler, Autohaler, Easybreathe and pMDI. For pMDI, there was a statistically significant difference between means of PIF across the MMRC dyspnea scale with PIF decreasing with increasing severity of dyspnea (F= 2.85, p= 0.033). CONCLUSION: COPD patients have slightly lower PIF than controls. Poor exercise tolerance and lower spirometric pulmonary function parameters may contribute to low PIF.

INTRODUCTION: La bronchopneumopathie chronique obstructive (BPCO) est un trouble respiratoire chronique qui touche des millions de personnes dans le monde et la thérapie par inhalation est essentielle à la gestion symptomatique de la maladie. Par conséquent, il est nécessaire de connaître les exigences minimales en matière de débit inspiratoire de pointe (DIP) pour certains inhalateurs, en particulier les inhalateurs de poudre sèche (IPS), lors de la prescription d'un traitement par inhalation. L'objectif de cette étude est d'évaluer l'effet de la gravité de la BPCO sur le débit de pointe inspiratoire chez les patients atteints de BPCO. MÉTHODOLOGIES: Un total de 150 sujets (75 patients atteints de BPCO stable et 75 sujets apparemment sains) ont participé à l'étude. Le PIF a été évalué à l'aide du kit d'évaluation In-check Inhaler (fabriqué par Clement Clarke International Ltd, Harlow, UK). La fonction pulmonaire a été évaluée par spirométrie, les sujets étant répartis en quatre groupes en fonction de la gravité de l'obstruction des voies respiratoires selon les critères GOLD. L'échelle de dyspnée modifiée du Medical Research Council (MMRC) a été utilisée pour évaluer la sévérité de la dyspnée. La capacité d'exercice a été évaluée à l'aide du test de marche de 6 minutes. L'analyse statistique a été réalisée avec le logiciel SPSS 23.0. Dans tous les tests statistiques, une valeur p de <0,05 a été considérée comme significative. RÉSULTATS: L'âge moyen des patients atteints de BPCO et de la population de contrôle est respectivement de 72,48 ± 8,01 et 70,69 ± 5,82. Le groupe de contrôle avait un PIF plus élevé que le groupe BPCO; cependant, seuls le clickhler et le pMDI présentaient une différence statistiquement significative entre le PIF moyen des patients et celui du groupe de contrôle. D'une manière générale, on a observé une tendance à la diminution du FRP moyen au fur et à mesure de l'évolution de la BPCO, avec une différence statistiquement significative pour l'Easibreathe (F= 3,52, p= 0,019) et l'aérosol-doseur pressurisé (pMDI) (F= 4,26, p= 0,008). Il existe une corrélation positive significative entre le VEMS, la CVF, la capacité d'exercice (distance de marche de 6 minutes) et le PIF pour Clickhaler, Autohaler, Easybreathe et pMDI. Pour le pMDI, il y avait une différence statistiquement significative entre les moyennes de PIF sur l'échelle de dyspnée du MMRC, le PIF diminuant avec l'augmentation de la sévérité de la dyspnée (F= 2,85, p= 0,033). CONCLUSION: Les patients atteints de BPCO ont un PIF légèrement inférieur à celui des témoins. Une mauvaise tolérance à l'exercice et des paramètres spirométriques de la fonction pulmonaire plus faibles peuvent contribuer à la faiblesse du PIF. Mots clés: Maladie pulmonaire obstructive chronique, Inhalateurs de poudre sèche, Débit inspiratoire de pointe, Aérosol-doseur pressurisé.

Evaluation of Peak Inspiratory Flow Rate in Hospitalized Palliative Care Patients with COPD.

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.

Riesgo de Retención de Secreciones en Pacientes con Ventilación Mecánica Invasiva / Risk of Retention of Secretions in Patients with Invasive Mechanical Ventilation

Introducción. Los pacientes conectados a ventilación mecánica invasiva pueden presentar complicaciones respiratorias, donde la retención de secreciones es una de las más frecuentes. El drenaje y eliminación de las secreciones depende entre otras variables de los flujos respiratorios generados, donde una diferencia absoluta entre el flujo espiratorio máximo (FEM) y flujo inspiratorio máximo (FIM) menor a 17 L•min-1 o una relación FIM/FEM mayor a 0.9 favorecerían la retención de secreciones. Sin embargo, falta por determinar los flujos respiratorios resultantes y la proporción de pacientes con riesgo de retención de secreciones según estos parámetros. Objetivo. Determinar los flujos respiratorios durante la ventilación mecánica invasiva y la proporción de pacientes que se encuentra en riesgo de retención de secreciones. Métodos. Estudio descriptivo transversal desarrollado en la Unidad de Paciente Crítico Médico-Quirúrgico del "Hospital Clínico de la Red de Salud UC-CHRISTUS". Se incluyeron pacientes adultos intubados y conectados a ventilación mecánica, en quienes se determinó los flujos respiratorios resultantes y se estimó la diferencia absoluta FEM-FIM, la relación FIM/FEM y la proporción de pacientes con riesgo de retención de secreciones. Resultados. Se incluyeron 100 pacientes, 45% presentaba entre sus diagnósticos patología respiratoria. La mediana de la diferencia absoluta entre FEM y FIM fue de 6 L•min-1 (-5 - 14.5) y la mediana de la tasa FIM/FEM de 0.87 (0.7 - 1.13). Un 84% presentó una diferencia absoluta entre FEM y FIM menor a 17 L•min-1, mientras que el 46% presentó una relación FIM/FEM mayor a 0.9. Conclusión. Una alta proporción de pacientes conectados a ventilación mecánica presenta riesgo de retención de secreciones independiente de la presencia o ausencia de patología respiratoria. Se requieren futuras investigaciones para evaluar el impacto de este criterio sobre complicaciones respiratorias.

Background. Patients connected to invasive mechanical ventilation may develop respiratory complications, where retention of secretions is one of the most frequent. The drainage and elimination of the secretions depend on other variables of the respiratory flows generated, where an absolute difference between the peak expiratory flow (PEF) and peak inspiratory flow (PIF) less than 17 L•min-1 or a PIF/PEF ratio greater than 0.9 would favor secretion retention. However, it is necessary to determine the respiratory flows and the proportion of patients, with and without respiratory pathology, with a risk of secretions retention according to these parameters. Objective. Determine respiratory flows during connection to invasive mechanical ventilation and the proportion of patients with and without respiratory pathology at risk of secretions retention. Methods. A descriptive cross-sectional study was conducted in the Medical-Surgical Intensive Care Unit of the "Hospital Clínico de la Red de Salud UC-CHRISTUS". Intubated adult patients connected to mechanical ventilation were included, in whom the respiratory flows were assessed, and the absolute PEF-PIF difference, PIF/PEF ratio, and the proportion of patients with a risk of secretions retention were determined. Results. 100 patients were included, of which 45% presented among their diagnoses acute or chronic respiratory pathology. For the total number of patients, the median of the absolute difference between PEF and PIF was 6 L•min-1 (-5 - 14.5), and the median of the PIF/PEF ratio of 0.87 (0.7 - 1.13). Of the total of patients, 84% presented an absolute difference between PEF and PIF less than 17 L• min-1, while 46% presented a PIF/PEF ratio greater than 0.9. Conclusion. Considering the absolute difference between PEF-PIF and the PIF/PEF ratio, many patients present a risk of secretions retention. However, whether this is associated with severe respiratory complications in patients connected to invasive mechanical ventilation should be clarified in future research.

Determinants of Suboptimal Peak Inspiratory Flow Rates among Patients with Chronic Obstructive Pulmonary Disease in Southwest, Nigeria.

BACKGROUND: Inhalational therapy is the cornerstone in the management of chronic obstructive pulmonary disease (COPD) patients. Patients' peak inspiratory flow impacts effective dry powder inhaler (DPI) delivery and management outcome. OBJECTIVE: This study assessed peak inspiratory flow rates (PIFR) and determined the factors associated with suboptimal inspiratory flow rates among COPD patients. METHODS: A descriptive cross-sectional study was conducted among 60 participants (30 stable COPD patients and 30 age-and-sex matched controls). Socio-demographic characteristics was obtained and spirometry was done for all participants. PIFR assessment was done using the In-Check Dial Meter and was categorized as suboptimal (< 60L/min) or optimal (≥ 60L/min). P values less than 0.05 were taken as statistically significant. RESULTS: Mean age of the COPD patients and healthy controls were both 67.8 ± 10.3 years, with 53.3% being females. Post-bronchodilation FEV 1/FVC% for COPD patients was 54.15 ± 11.27%. The mean PIFR among COPD patients was significantly lower than that of healthy controls, in all DPIs simulated, especially for Clickhaler (46.2±13.4 vs 60.5±11.4L/min, p<0.001). A significant proportion of COPD patients had suboptimal PIFR, in the simulated resistances against Clickhaler and Turbuhaler (70% vs 80%; p<0.001). Older age, shorter height and low BMI were associated with suboptimal PIFR among COPD patients. However, independent predictors of suboptimal PIFR were BMI, PEFR, FEV1% and FVC%. CONCLUSION: Suboptimal PIFR was found in a significant number of COPD patients when compared with healthy respondents. Routine assessment using In-Check Dial meter should be done to determine the suitability of dry powder inhalers for patients with COPD.

CONTEXTE: Le traitement par inhalation est la pierre angulaire de la prise en charge des patients atteints de bronchopneumopathie chronique obstructive (BPCO). Le débit inspiratoire de pointe des patients a une incidence sur l'efficacité de l'inhalateur de poudre sèche et sur les résultats de la prise en charge. OBJECTIF DE L'ÉTUDE: Cette étude a évalué les débits inspiratoires de pointe et déterminé les facteurs associés aux débits inspiratoires sousoptimaux chez les patients atteints de BPCO. MÉTHODES: Une étude transversale descriptive a été menée auprès de 60 participants (30 patients atteints de BPCO stable et 30 témoins appariés selon l'âge et le sexe). Les caractéristiques socio-démographiques ont été recueillies et une spirométrie a été effectuée pour tous les participants. L'évaluation du PIFR a été réalisée à l'aide du Dial Meter In-Check et a été catégorisée comme suboptimale (< 60L/min) ou optimale (≥ 60L/min). Les valeurs P inférieures à 0,05 ont été considérées comme statistiquement significatives. RÉSULTATS: L'âge moyen des patients atteints de BPCO et des témoins sains était de 67,8 ± 10,3 ans, avec 53,3 % de femmes. Le pourcentage de VEMS/FVC après bronchodilatation chez les patients atteints de BPCO était de 54,15 ± 11,27 %. Le PIFR moyen des patients atteints de BPCO était significativement plus faible que celui des témoins sains, pour tous les DPI simulés, en particulier pour le Clickhaler (46,2±13,4 vs 60,5±11,4L/min, p<0,001). Une proportion significative de patients atteints de BPCO avait un PIFR sous-optimal, dans les résistances simulées contre Clickhaler et Turbuhaler (70% vs 80% ; p<0.001). L'âge avancé, la petite taille et un faible IMC étaient associés à une PIFR sous-optimale chez les patients atteints de BPCO. Cependant, les prédicteurs indépendants du PIFR suboptimal étaient l'IMC, le DEP, le VEMS et la CVF. CONCLUSION: Un nombre significatif de patients atteints de BPCO présente un PIFR sous-optimal par rapport aux personnes interrogées en bonne santé. Une évaluation de routine à l'aide de l'appareil de mesure In-Check Dial devrait être effectuée pour déterminer si les inhalateurs de poudre sèche conviennent aux patients atteints de BPCO. Mots clés: Inhalateur de poudre sèche, Débit inspiratoire maximal, Fonction pulmonaire.

The effects of flow settings during high-flow nasal cannula support for adult subjects: a systematic review.

BACKGROUND: During high-flow nasal cannula (HFNC) therapy, flow plays a crucial role in the physiological effects. However, there is no consensus on the initial flow settings and subsequent titration. Thus, we aimed to systematically synthesize the effects of flows during HFNC treatment. METHODS: In this systematic review, two investigators independently searched PubMed, Embase, Web of Science, Scopus, and Cochrane for in vitro and in vivo studies investigating the effects of flows in HFNC treatment published in English before July 10, 2022. We excluded studies that investigated the pediatric population (< 18 years) or used only one flow. Two investigators independently extracted the data and assessed the risk of bias. The study protocol was prospectively registered with PROSPERO, CRD42022345419. RESULTS: In total, 32,543 studies were identified, and 44 were included. In vitro studies evaluated the effects of flow settings on the fraction of inspired oxygen (FIO2), positive end-expiratory pressure, and carbon dioxide (CO2) washout. These effects are flow-dependent and are maximized when the flow exceeds the patient peak inspiratory flow, which varies between patients and disease conditions. In vivo studies report that higher flows result in improved oxygenation and dead space washout and can reduce work of breathing. Higher flows also lead to alveolar overdistention in non-dependent lung regions and patient discomfort. The impact of flows on different patients is largely heterogeneous. INTERPRETATION: Individualizing flow settings during HFNC treatment is necessary, and titrating flow based on clinical findings like oxygenation, respiratory rates, ROX index, and patient comfort is a pragmatic way forward.

High inhaler resistance does not limit successful inspiratory maneuver among patients with asthma or COPD.

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.

Computational fluid dynamics model of laryngotracheal stenosis and correlation to pulmonary function measures.

3D models of airway lumens were created from CT scans of 19 patients with laryngotracheal stenosis. Computational fluid dynamics (CFD) simulations were completed for each, and results were compared to measured peak inspiratory flow rate, grade of lumen constriction, and measures of airway geometry. Results demonstrate flow resistance and shear stress correlate with degree of lumen constriction and absolute cross-sectional area as well as flow rate. Flow recirculation depends on airway constriction but does not vary with flow rate. Resistance and wall shear stress did not correlate well with functional measures. Flow recirculation did differ between subjects with higher functional measures and subjects with lower functional measures. This analysis provides mathematical models to predict airway resistance, wall shear stress, and flow reversal according lumen constriction and inspiratory flow rate. It suggests aerodynamic factors such as flow recirculation play a role in differences in functional performance between patients with similar airway measures.

Can patients achieve sufficient peak inspiratory flow rate (PIFR) with Turbuhaler® during acute exacerbation of asthma?

INTRODUCTION: 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. OBJECTIVE: This study aimed to assess the PIFR at resistance settings that matched Turbuhaler® in patients with acute exacerbation of asthma. METHODOLOGY: 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. RESULTS: 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). CONCLUSION: The majority of patients with asthma in the present study were able to achieve sufficient PIFR from Turbuhaler® during mild to moderate acute exacerbations.

In Vitro Drug Delivery of a Fixed-Dose Combination of Fluticasone Furoate/Umeclidinium/Vilanterol from a Dry Powder Inhaler.

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.

Effect of the Inspiratory Method and Timing of Voluntary Cough on Peak Cough Flow.

OBJECTIVE: To define the effect of the inspiratory method and cough timing on peak cough flow (PCF). METHODS: We investigated the effect of measurement conditions on PCF in healthy subjects (n=10). We then compared obstructive and restrictive pulmonary diseases (n=20) to assess for similar results in respiratory diseases. The PCF was measured under four conditions: before coughing, without maneuver 1 or with maneuver 2 a temporary respiratory pause (4-6 seconds) after rapid inspiration, and without maneuver 3 or with maneuver 4 a temporary respiratory pause after slow inspiration. After the measurements were completed, the PCF between the four conditions was compared for each subject group, and the effect size was calculated. RESULTS: PCF of maneuvers 1 and 3 were significantly higher than maneuver 4 in healthy subjects (476.34±102.05 L/min and 463.44±107.14 L/min vs. 429.54±116.83 L/min, p<0.01 and p<0.05, respectively) and patients with restrictive pulmonary disease (381.96±145.31 L/min, 354.60±157.36 L/min vs. 296.94±137.49 L/min, p<0.01 and p<0.05, respectively). In obstructive pulmonary disease, maneuver 1 was significantly higher than maneuver 4 (327.42±154.73 L/min vs. 279.48±141.10 L/min, p<0.05). The largest effect sizes were shown by maneuvers 4 and 1. CONCLUSION: PCF depends on changes in inspiratory speed before coughing and on temporary respiratory pauses after maximal inspiration. It will become necessary to unify the measurement methods for coughing strength and present appropriate coughing methods.

Verifying Efficacy of Self-Inhalation Training for Velopharyngeal Dysfunction.

Velopharyngeal closure in healthy adults during different tasksObjective: Velopharyngeal dysfunction causes not only resonance problems (so-called "hypernasality") but also dysphagia, particularly in the elderly. In our previous study, we developed a new inhaling training method to objectively improve velopharyngeal function using the measurement of peak inspiratory flow (PIF) rate, which was effective in all patients. In this study, we clarify the degree of velopharyngeal closure to determine the efficacy of our training to improve the closure mechanism. METHODS: Three healthy volunteers performed tasks in a magnetic resonance imaging (MRI) gantry in the supine position. To confirm velopharyngeal function, volunteers were first asked to distinguish the difference in the velum position between the production of a nonnasal (sustained phonation /shi:/) and a nasal (sustained phonation /n:/) sound. They were then asked to inhale forcefully through the mouth from an empty 500-mL plastic bottle. For comparison, volunteers performed exhaling forcefully, then inhaling and exhaling softly, through a straw. Each task was performed for 30 s, and the MRI images were obtained in sagittal sections. RESULTS: Inhaling forcefully from an empty plastic bottle created the strongest velopharyngeal closure between the posterior surface of the velum (soft palate) and the posterior pharyngeal wall in all volunteers. CONCLUSION: The results of our MRI study supported our training method. Using inhalation through a PIF meter or from a plastic bottle to create resistance strengthens particularly the levator veli palatini muscle for velopharyngeal closure, which may be useful in patients with other acquired velopharyngeal dysfunctions including physiological aging. Also, anyone anywhere can train with plastic bottles.