Inspiratory Flow Research Articles

Successful Use of Easyhaler® Dry Powder Inhaler in Patients with Chronic Obstructive Pulmonary Disease; Analysis of Peak Inspiratory Flow from Three Clinical Trials.

There is increasing pressure to use environmentally friendly dry powder inhalers (DPI) instead of pressurized metered-dose inhalers (pMDI). However, correct inhalation technique is needed for effective inhaler therapy, and there is persistent concern whether patients with chronic obstructive pulmonary disease (COPD) can generate sufficient inspiratory effort to use DPIs successfully. The aims of this study were to find clinical predictors for peak inspiratory flow rate (PIF) and to assess whether patients with COPD had difficulties in generating sufficient PIF with a high resistance DPI. Pooled data of 246 patients with COPD from previous clinical trials was analyzed to find possible predictors of PIF via the DPI Easyhaler (PIFEH) and to assess the proportion of patients able to achieve an inhalation flow rate of 30 l/min, which is needed to use the Easyhaler successfully. The mean PIF was 56.9l/min and 99% (243/246) of the study patients achieved a PIF ≥ 30l/min. A low PIF was associated with female gender and lower forced expiratory volume in 1s (FEV1), but the association was weak and a statistical model including both only accounted for 18% of the variation seen in PIFEH. Based on our results, impaired expiratory lung function or patient characteristics do not predict patients' ability to use DPIs in COPD; 99% of the patients generated sufficient PIFEH for successful dose delivery. Considering the targets for sustainability in health care, this should be addressed as DPIs are a potential option for most patients when choosing the right inhaler for the patient. Two of three included trials were registered under numbers NCT04147572 and NCT01424137. Third trial preceded registration platforms and therefore, was not registered.

Effect of Sildenafil in Neonates with Persistent Pulmonary Hypertension: An Interventional Study

Introduction: Persistent Pulmonary Hypertension of the Newborn (PPHN) reflects a disruption of the normal perinatal circulatory transition and is characterised by high pulmonary artery pressure. Inhaled Nitric Oxide (iNO) is considered the mainstay of treatment for PPHN. However, many developing and resource limited countries do not have access to such expensive therapy. Therefore, sildenafil, due to its easy availability and low cost, becomes the most commonly used drug in the management of PPHN in such settings. Aim: To study the treatment response and outcomes of neonates who received sildenafil for the management of PPHN. Materials and Methods: The present hospital-based prospective interventional study was conducted in the Neonatal Intensive Care Unit (NICU), BJ Medical College, Civil Hospital, Ahmedabad, Gujarat, between May 1, 2020, and April 30, 2021. Study was conducted on neonates with meconium aspiration syndrome and/or severe birth asphyxia admitted to the NICU. A total of 48 neonates with Two Dimensional (2D) echocardiography-proven PPHN were enrolled. Baseline clinical parameters including heart rate, respiratory rate, preductal and postductal Saturation of Peripheral Oxygen (SpO2), Oxygenation Index (OI), Saturation Oxygen Distending Pressure Index (SOPI), and Non Invasive Blood Pressure (NIBP) were monitored every six hours. Neonates who were on invasive/ non invasive ventilation had their Fraction of Inspired Oxygen (FiO2), Positive End Expiratory Pressure (PEEP), Peak Inspiratory Pressure (PIP), respiratory rate and flow rate monitored every six hours. Data were statistically analysed using Analysis of Variance (ANOVA) test. Results: During the study period, a total of 1080 neonates were admitted with meconium aspiration syndrome and/or severe birth asphyxia, out of which 48 neonates showed findings suggestive of PPHN on 2D echocardiography. A statistically significant improvement in oxygenation after sildenafil treatment was indicated by a significant reduction in OI from 35.3±8.6 to 13.2±2.1 (p-value<0.001), a reduction in SOPI from 3.6±0.3 to 1.5±0.2 (p-value<0.001), a reduction in FiO2 (%) from 94.6±8.19 to 24.2±4.5 (p-value<0.001), an increase in Partial pressure of oxygen (PaO2) (mmHg) from 52±5.6 to 72±3.4 (p-value<0.001), and an increase in SpO2 (%) from 83.5±8.6 to 93.5±5.1 (p-value<0.001). Conclusion: The findings of the present study suggest that oral sildenafil can be successfully used to improve oxygenation in patients with PPHN, especially in a resource limited setting where facilities like Extracorporeal Membrane Oxygenation (ECMO) and iNO are not available, as demonstrated in the present study.

Individual wearable air purifier protects against pollen, house dust mite, and cat allergens: Report from anallergen exposure chamber.

Evaluation of a new individual wearable air purifier (Respiray Wear A+) for birch pollen, house dust mite (HDM), and cat-allergic rhinoconjunctivitis (ARC) patients in a standardized allergen exposure chamber (AEC). Eligible allergic patients were exposed to birch pollen, HDM raw material, and cat allergen in an AEC for 60 minutes without (V1) and with (V3) the use of the Respiray device. Nasal, ocular, bronchial, and other symptoms were rated by the patients every 10 minutes, and their wellbeing, peak nasal inspiratory flow (PNIF), and lung function parameters were assessed every 30 minutes. The primary endpoint was the change in the median of the total symptom score (TSS) at V3 compared to V1 at 60 minutes of exposure. The secondary endpoints consisted of the total nasal symptom score (TNSS) and total eye symptom score (TESS). 23 patients with birch pollen allergy, 37 patients with HDM allergy, and 41 patients with cat allergy were included in the analysis. Significant reduced symptom scores of ~49% were observed when using Respiray Wea A+ under birch pollen exposure (p<0.05) in the primary endpoint TSS (V3 2.43 compared to V1 4.78). An 48% reduction of symptoms was seen in TSS in case of HDM exposure (V3 3.59; V1 6.92, (t-test: p<0.01)) and the highest reduction of TSS (60%) under Respiray A+ using cat allergens (V3 2.95, V1 7.44, (t-test p<0.01) after 60 minutes of exposure. The personal wellbeing revealed clinically meaningful improvements over time in all three studies which manifested in a lower symptom increase during the final allergen exposures. The individual wearable air purifier Respiray Wear A+ protects significantly against airborne pollen, HDM, and cat allergens and may be a very useful device for avoiding indoor allergens in a new way.

Correlations among visual analog scales, total nasal symptom scores, and peak nasal inspiratory flow in children with perennial allergic rhinitis

Correlations among visual analog scales, total nasal symptom scores, and peak nasal inspiratory flow in children with perennial allergic rhinitis

Peak nasal inspiratory flow in the assessment of nasal airway obstruction

Nasal congestion is one of the most common complaints in otolaryngology practice and can significantly impact the quality of life for patients. Objective and subjective assessments provide different information, but objective assessment of nasal obstruction is crucial for accurate diagnosis and appropriate treatment. This review demonstrates that peak nasal inspiratory flow (PNIF) is a reproducible and reliable measure of objective nasal patency. It is inexpensive, easy to use, suitable for serial measurements, and can be applied to patients of different age groups. PNIF is recommended for use in every outpatient clinic that treats patients with nasal congestion. To summarize the data on the application of PNIF in diagnosing conditions of the nasal airways. Publications (articles and relevant abstracts) available in the PubMed and eLibrary databases were analyzed. PNIF offers an objective and non-invasive assessment of nasal airflow, aiding in diagnosis, therapy monitoring, and preoperative planning. Further research, standardization, and establishment of normative data will enhance the informative value of peak nasal inspiratory flow in assessing nasal obstruction.

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

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). 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. 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. 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.

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.

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. 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. 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. 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.

Comparative Analysis of Peak Inspiratory Flow Rate at Discharge and Three-month Follow-up in Severe Acute Exacerbation of COPD Patients using Metered Dose Inhalers versus Dry Powder Inhalers: A Prospective Observational Study

Introduction: Patients discharged following hospitalisation for Acute Exacerbation of Chronic Obstructive Pulmonary Disease (AECOPD) are prescribed Metered Dose Inhalers (MDI), Dry Powder Inhalers (DPI), or nebulisers. Drug dispersion from the inhaler and deposition in the lung depends on Peak Inspiratory Flow Rate (PIFR) among other factors. A low PIFR results in suboptimal drug delivery and is a risk factor for readmission. Aim: To estimate PIFR at discharge following AECOPD, assess the type of inhalers prescribed at discharge, and estimate the mean change in PIFR at three months follow-up in patients using MDI and DPI. Materials and Methods: A prospective observational study was conducted at a tertiary care hospital, Goa Medical College, Goa, India on 138 patients over 15 months from November 2018 to February 2020. A sample size of 138 was calculated, and the study duration was 15 months. Patients admitted with AECOPD were enrolled in the study after obtaining informed consent. At discharge, baseline characteristics and co-morbidities were recorded, and PIFR was measured using an in-check dial peak inspiratory flow meter without resistance. Inhalers prescribed by the treating physician were verified and checked for errors. PIFR was measured at three months of follow-up. Optimal PIFR was defined as PIFR of ≥60 L/min. Statistical analysis was performed using the Statistical Package for Social Science Programs (SPSS) version 24.0 (IBM Corp, SPSS Inc, Chicago, IL). A paired t-test assessed the change in PIFR at discharge and three months follow-up, and Pearson’s correlation test was used to assess the correlation between continuous variables. Results: Total 138 were enrolled with a mean age of 69.8±7.5 years, 87 (63%) were males. The mean PIFR at discharge was 58.9±24.7 L/min. 85 (61.6%) had suboptimal PIFR and were older {71.9±7.8 versus 66.3±5.6, p-value=0.01}. A total of 59 (69.4%) with suboptimal PIFR received MDI. At three months, the suboptimal PIFR group receiving MDI showed a mean change in PIFR of 18.6±7.7, p-value&lt;0.001 while with DPI mean change was -3.8±6.3, p-value=0.005. Conclusion: 61.6% had suboptimal PIFR at discharge following hospitalisation with AECOPD. Patients with suboptimal PIFR receiving MDI showed improvement in PIFR at three months, while those with suboptimal PIFR using DPI showed significant deterioration. Identifying patients with suboptimal PIFR will aid appropriate prescription of inhaler devices.

Quantitative assessment of dysphagia in myasthenia gravis.

Objective Dysphagia is a common and disabling symptom in patients with myasthenia gravis (MG). Moreover, it is caused by muscle weakness or fatigability in the pharynx, swallowing, and respiration discoordination. The current study aimed to establish a novel method for evaluating swallowing difficulty in patients with MG. Methods The ventilation patterns and submental surface electromyography (sEMG) activity of the swallowing reflex were simultaneously recorded for 10 min during the continuous infusion of distilled water (150 mL/h) into the pharynx in 10 patients with MG and 22 healthy controls. Moreover, we assessed excessive expiratory flows, clusters of excessive expiratory flows, high-inspiratory flows, and prolonged EMG patterns. Results Patients with MG who presented with dysphagia had abnormal excessive expiratory flows, clusters of excessive expiratory flows, high inspiratory flows, and prolonged EMG patterns compared to healthy controls (all p <0.05). Among these parameters, the incidence of an excessive expiratory flow, cluster of excessive expiratory flows, and prolonged EMG pattern significantly improved after treatment (p <0.05). Conclusion Based on this study, the respiratory patterns and submental sEMG are likely to reflect the severity of pharyngeal muscle weakness/fatigability and thus can be used as a quantitative parameter for dysphagia in patients with MG.

Assessment of inhalation exposure to microplastic particles when disposable masks are repeatedly used

Wearing masks to prevent infectious diseases, especially during the COVID-19 pandemic, is common. However, concerns arise about inhalation exposure to microplastics (MPs) when disposable masks are improperly reused. In this study, we assessed whether disposable masks release inhalable MPs when reused in simulated wearing conditions. All experiments were conducted using a controlled test chamber setup with a constant inspiratory flow. Commercially available medical masks with a three-layer material, composition comprising polypropylene (PP in the outer and middle layers) and polyethylene (PE in the inner layer), were used as the test material. Brand-new masks with and without hand rubbing, as well as reused medical masks, were tested. Physical properties (number, size, and shape) and chemical composition (polymers) were identified using various analytical techniques such as fluorescence staining, fluorescence microscopy, and micro-Fourier Transform Infrared Spectroscopy (μFTIR). Scanning Electron Microscopy (SEM) was used to scrutinize the surface structure of reused masks across different layers, elucidating the mechanism behind the MP generation. The findings revealed that brand-new masks subjected to hand rubbing exhibited a higher cumulative count of MPs, averaging approximately 1.5 times more than those without hand rubbing. Fragments remained the predominant shape across all selected size classes among the released MPs from reused masks, primarily through a physical abrasion mechanism, accounting for >90 % of the total MPs. The numbers of PE particles were higher than PP particles, indicating that the inner layer of the mask contributed more inhalable MPs than the middle and outer layers combined. The released MPs from reused masks reached their peak after 8 h of wearing. This implies that regularly replacing masks serves as a preventive measure and mitigates associated health risks of inhalation exposure to MPs.

Toxic Particles Deposition in the Human Respiratory Tract under Natural Inspiratory Flow

Toxic particle (PM2.5) deposition in the human respiratory tract is investigated under natural inspiratory flow. The flow physics of nostrils is asymmetric, and its effect on particle deposition needs prompt attention. An ideal 3-D CT-scan-based geometrical model of the human respiratory tract is re-constructed from the nasal cavity to the 7th generation bronchi. The pulsatile numerical simulation is performed with light (10 L/min) and moderate (40 L/min) inspiratory flow. The Lagrangian method is adopted to compute particle deposition fraction (DPF) in the airways. The suspended particle mass of 300 µg/m3 (poor air quality) (dp = 2.5 µm in diameter) is released from the inlet of airways at every time interval (∆t). The results revealed that the pattern of particle transportation is not similar in both the bronchus and particle hot spots are constituted in the airways. Findings guide optimal targeted drug delivery and the assessment of ventilation illness under hazardous exposure in distinct populations.

Does mixing inhaler devices lead to unchecked inhaler technique errors in patients with COPD? Findings from the cross-sectional observational MISMATCH study

BackgroundPatients with chronic obstructive pulmonary disease (COPD) may be prescribed multiple inhalers that require different techniques for optimal performance. Mixing devices has been associated with poorer COPD outcomes suggesting that...

In-Line Aerosol Therapy via Nasal Cannula during Adult and Paediatric Normal, Obstructive, and Restrictive Breathing.

High-flow nasal oxygen therapy is being increasingly adopted in intensive and home care settings. The concurrent delivery of aerosolised therapeutics allows for the targeted treatment of respiratory illnesses. This study examined in-line aerosol therapy via a nasal cannula to simulated adult and paediatric models with healthy, obstructive and restrictive lung types. The Aerogen Solo vibrating mesh nebuliser was used in combination with the InspiredTM O2FLO high-flow therapy system. Representative adult and paediatric head models were connected to a breathing simulator, which replicated several different states of lung health. The aerosol delivery was quantified at the tracheal level using UV-spectrophotometry. Testing was performed at a range of supplemental gas flow rates applicable to both models. Positive end-expiratory pressure was measured pre-, during and post-nebulisation. The increases in supplemental gas flow rates resulted in a decrease in aerosol delivery, irrespective of lung health. Large tidal volumes and extended inspiratory phases were associated with the greatest aerosol delivery. Gas flow to inspiratory flow ratios of 0.29-0.5 were found to be optimum for aerosol delivery. To enhance aerosol delivery to patients receiving high-flow nasal oxygen therapy, respiratory therapists should keep supplemental gas-flow rates below the inspiratory flow of the patient.

Long-term effects of maxillary skeletal expander treatment on functional breathing.

: To investigate the long-term effects of maxillary skeletal expander (MSE) treatment on functional breathing. measures of breathing, the peak nasal inspiratory flow (PNIF), and peak oral inspiratory flow (POIF), and subjective measures of breathing, the visual analog scale (VAS) and nasal obstruction symptom evaluation (NOSE) survey, were used to investigate the long-term effects of MSE in functional breathing. Seventeen patients, mean age 19.4 ± 3.9 years treated at the UCLA Orthodontics Clinic were assessed on their functional breathing at 3 timepoints: pre-expansion (T0), post-expansion (T1), and post-orthodontic treatment (T2). : Immediately after expansion (T1), all the objective functional breathing values were significantly increased in comparison to T0 (P < 0.05). The VAS total, VAS right and VAS left were significantly lower at T1 in comparison to T0 (P < 0.05). At 26.8 ± 3.9 months after MSE expansion (T2), PNIF total, PNIF right, PNIF left, and POIF were significantly higher when compared to T0 (P < 0.05). Also, VAS total, VAS right and VAS left were significantly lower at T2 when compared to T0 (P < 0.05). Additionally, there was a positive correlation between PNIF and the magnitude of expansion at anterior nasal spine and zygomaticomaxillary point (ZMA). There was a positive correlation between total VAS and the magnitude of expansion at the ZMA. There were no significant changes for the NOSE subjective breathing measurement at all time comparisons. : Overall, MSE treatment produces an increased objective and subjective airway improvement that continues to remain stable in the long-term post expansion.

Mechanically assisted cough strategies: user perspectives and cough flows in children with neurodisability.

Mechanical insufflation-exsufflation (MI-E) is used to augment cough in children with neurodisability. We aimed to determine the user comfort and cough flows during three MI-E strategies, and to predict factors associated with improved comfort and cough flows. This multicentre, crossover trial was done at four regional hospitals in Norway. Children with neurodisability using MI-E long term via mask were enrolled. In randomised order, they tested three MI-E setting strategies (in-/exsufflation pressure (cmH2O)/in (In)- versus exsufflation (Ex) time): 1) "A-symmetric" (±50/In=Ex); 2) "B-asymmetric" (+25- +30)/-40, In>Ex); and 3) "C-personalised", as set by their therapist. The primary outcomes were user-reported comfort on a visual analogue scale (VAS) (0=maximum comfort) and peak cough flows (PCF) (L·min-1) measured by a pneumotachograph in the MI-E circuit. We recruited 74 children median (IQR) age 8.1 (4.4-13.8) years, range 0.6-17.9, and analysed 218 MI-E sequences. The mean±sd VAS comfort scores were 4.7±2.96, 2.9±2.44 and 3.2±2.46 for strategies A, B and C, respectively (A versus B and C, p<0.001). The mean±sd PCF registered during strategies A, B and C were 203±46.87, 166±46.05 and 171±49.74 L·min-1, respectively (A versus B and C, p<0.001). Using low inspiratory flow predicted improved comfort. Age and unassisted cough flows increased exsufflation flows. An asymmetric or personalised MI-E strategy resulted in better comfort scores, but lower PCF than a symmetric approach utilising high pressures. All three strategies generated cough flows above therapeutic thresholds and were rated as slightly to moderately uncomfortable.

Effect of Body Weight on Response to Nasal Glucocorticoid Treatment in Allergic Rhinitis.

Allergic rhinitis is among the most common chronic diseases in the world. Obesity can lead to a chronic systemic inflammatory process. In this study, we evaluated the effects of body weight on the response to treatment of allergic rhinitis with nasal corticosteroids. Two groups of patients diagnosed with allergic rhinitis were compared: one composed of obese patients and one composed of normal weight patients. Nasal endoscopy, peak nasal inspiratory flow, quality of life, the VAS, SNOT22, and NOSE-5 questionnaires, and the concentration of nasal cytokines (INF-γ, TNF-ᾳ, IL-4, IL-5, IL-6, and IL-10) through nasal brushing were evaluated before and after treatment with 400 mcg/day nasal beclomethasone. No differences were identified between the groups in nasal endoscopy, peak nasal inspiratory flow, the VAS, SNOT22, and NOSE-5 questionnaires, or in the cytokines INF-γ, TNF-ᾳ, IL-4, IL-5, IL-6, and IL-10 prior to nasal corticosteroid treatment. Both groups showed improvement in the VAS, SNOT-22, and NOSE-5 questionnaires and an increase in peak nasal inspiratory volumes after treatment. In the eutrophic group, there was an increase in INF-γ and IL-5 after treatment. When comparing the variation in cytokines before and after treatment between groups, IL-10 was the cytokine that showed altered behavior dependent on weight. Obesity did not seem to impact nasal symptoms and physiology and presented a similar clinical response to treatment with nasal corticosteroids to normal weight patients. However, obese patients had an impaired anti-inflammatory response during treatment with nasal corticosteroids.

The placebo effect in randomized-controlled trials of medical treatments for chronic rhinosinusitis: A systematic review and meta-analysis.

The placebo effect observed in clinical trials evaluating medical treatments for chronic rhinosinusitis (CRS) is not well understood. This systematic review and meta-analysis sought to characterize the placebo effect present within CRS outcomes. A systematic review of PubMed, Scopus, and Cumulated Index in Nursing and Allied Health Nursing (CINAHL) was performed. Randomized controlled trials (RCTs) evaluating medical treatments for CRS versus placebo were included. We assessed patient-reported (sino-nasal outcome test 22 [SNOT-22], nasal obstruction, sense of smell, nasal obstruction visual analogue score [VAS], sense of smell VAS, anterior rhinorrhea, and postnasal drip) and objective (Lund-Mackay Computed tomography (CT) score, peak nasal inspiratory flow [PNIF], nasal polyp scores, 40-item Smell Identification Test, serum IgE, and blood eosinophil levels) outcomes. Twenty-one RCTs were included, comprising 1437 patients (mean age 49.2 years). Biologics were the most common treatment investigated (n=9). Eleven studies administered background steroids along with placebo. Following placebo administration, multiple patient-reported outcomes significantly decreased, including SNOT-22 (mean difference -9.49, 95% confidence interval [CI] [-11.26, -7.73]), nasal obstruction (-0.33 [-0.54, -0.13]), sense of smell (-0.22 [-0.33, -0.11]), nasal obstruction VAS (-2.47 [-2.87, -2.06]), and loss of smell VAS (-2.31 [-4.14, -0.47]) scores. For objective measures, significant changes occurred in Lund-Mackay CT score (-0.82, [-1.48, -0.16]) and PNIF (4.70, [4.76, 24.64]) with placebo. Placebo arms had the greatest impact when no background medications were used. Placebo treatments have a statistically and potentially clinically significant effect on patient-reported and some objective CRS outcomes. Further investigation is required to fully understand placebo effect, which could improve assessment of RCTs and impact patient care.

Hypopharyngeal geometry impact on air-induced loads on the supraglottis

Exercise-induced laryngeal obstruction (EILO) describes paradoxical laryngeal closure during inspiration at high-intensity exercise. It is hypothesised that during intense activity, the air-induced loads on supraglottic walls overcome their internal stiffness, leading to the obstruction. Recent investigations have revealed that the air-induced loads on the supraglottic walls vary nonlinearly with increasing flow rate. It is, however, unclear whether certain geometric configurations of the hypopharynx and larynx may contribute to the predisposition to EILO. This study investigates the influence of hypopharyngeal and laryngeal geometry on upper respiratory tract airflow and air-induced forces. A computational fluid dynamics model is developed to study airflow through larynx. Four real, adult upper respiratory tracts with variable configurations are considered. Two steady, uniform inspiratory flow rates of 60 L/min and 180 L/min are considered. The analysis shows that geometries with a space lateral to the epiglottis (EpiS) and piriform fossae (PF) directs the hypopharyngeal and supraglottic pressure field to remain positive and increase with the flow rate. In geometries with EpiS and PF, pressure differential occurs around the aryepiglottic fold producing a net inward force over the region. The three-fold increase in flow rate induces near ten-fold increases in force over the region which may facilitate the closure. It is concluded that hypopharyngeal anatomy, particularly the piriform fossae, play a significant role in the obstruction of the supraglottic airway and should be considered in research and clinical assessment of EILO.

The role of peak inspiratory flow in the selection of inhalation therapy in patients with chronic obstructive pulmonary disease

Pharmacotherapy for chronic obstructive pulmonary disease (COPD) primarily relies on inhalation therapy. The choice of an appropriate inhalation device is of particular importance as it impacts the frequency of device use errors, patient adherence to treatment, and overall treatment effectiveness. Peak inspiratory flow (PIF) represents the maximum air flow rate generated by a patient during inhalation and is measured in liters per minute. Dry powder inhalers (DPIs) possess internal device resistance that patients must overcome to activate the device. Measuring PIF is an integral component of optimizing COPD therapy when utilizing dry powder inhalers (DPIs). For most DPIs, an optimal PIF value is considered to be no less than 60 L/min, while with a PIF of less than 30 L/min, the medication can’t reach the lower airways. At the same time, the clinical effectiveness of the use of DPI at values of PIF from 30 L/min to 60 L/min may be insufficient, therefore, it is necessary to take into account the value of PIF for the selection of basic COPD therapy. Given the lack of portable fluometers among doctors in real clinical practice, it is important to identify risk factors for suboptimal PIF in patients with COPD. Patients with emphysema, pulmonary hyperinflation, elderly, female, short height, obesity and comorbidity are at risk for insufficient PIF value for further effective use of DPI.This review provides essential information about the role of inspiratory flow for the effective use of DPIs, presents methods for its measurement, discusses predictors of suboptimal PIF, and offers recommendations for selecting inhalation devices for COPD patients based on PIF values.

Chinese expert consensus on standardized inhaler device application in stable chronic airway diseases (2023)

Chinese expert consensus on standardized inhaler device application in stable chronic airway diseases (2023)