Airway Caliber Research Articles

Mechanical effects of obesity on central and peripheral airway resistance in nonasthmatic early pubescent children.

In children, obesity typically reduces functional residual capacity (FRC), which reduces airway caliber and increases airway resistance. Whether these obesity-related changes in respiratory function can alter bronchodilator responsiveness is unknown. To investigate bronchodilator responsiveness in nonasthmatic children with and without obesity. Seventy nonasthmatic children, 8-12 years old, without (n = 19) and with (n = 51) obesity, completed spirometry, impulse oscillometry, and airway resistance measurements through plethysmography pre/post 360 µg of inhaled albuterol. FRC was assessed pre albuterol. A two-way analysis of variance determined the effects of obesity (group) and inhaled albuterol (pre-post) on outcome measures. FRC (%total lung capacity) was 16% lower in children with obesity compared with those without obesity. There was no significant group by pre-post albuterol interaction on any outcome variables. Albuterol inhalation reduced total, central and peripheral airway resistance and increased airway reactance (i.e., less negative) to a similar degree in children with and without obesity. In children with obesity, airway resistance was increased whether measured by impulse oscillometry or plethysmography. However, once airway resistance was adjusted for lung volumes (i.e., specific airway resistance or sRaw ), there were no differences between children with and without obesity. In addition, significant but moderate associations were detected between chest mass and FRC (r = -0.566; p < 0.001), FRC and total airway resistance (i.e., Raw ; r = -0.445; p < 0.001). In nonasthmatic early pubescent children, obesity increases total, central, and peripheral respiratory system resistance. However, the added respiratory system resistance and low lung volume breathing with obesity are not sufficient to reduce bronchodilator responsiveness.

Acute Effect of Bronchodilator on Intrathoracic Airway Wall Compliance in COPD Patients

PurposeIn patients with chronic obstructive pulmonary disease (COPD), bronchial responsiveness after acute administration of short acting bronchodilators is conventionally assessed by measuring the improvement of forced expiratory volume in the first second (FEV1) during a maximal forced expiratory maneuver. This study aimed to measure the variation of intrathoracic airway wall compliance (AWC) after acute administration of short acting beta-2 agonist in COPD patients since this might influence the final modification of airway caliber during maximal expiratory effort and the resulting bronchodilation as inferred by FEV1 changes.MethodsIn a group of 10 patients suffering from COPD, intrathoracic AWC was measured at middle (50% of Forced Vital Capacity (FVC) and low (75% of FVC) lung volumes using the interrupter method during forced expiratory maneuver in basal conditions and after acute inhalation of albuterol (salbutamol) (400 mcg by MDI). Ten healthy subjects were examined similarly as a control group.ResultsLower values of baseline intrathoracic AWC at both lung volumes were found in COPD patients (1.72 ± 0.20 ml/cmH2O and 1.08 ± 0.20 ml/cmH2O, respectively) as compared to controls (2.28 ± 0.27 ml/cmH2O and 1.44 ± 0.22 ml/cmH2O, respectively) (p < 0.001). In COPD patients, AWC increased significantly at both lung volumes after salbutamol, amounting to 1.81 ± 0.38 ml/cmH2O and 1.31 ± 0.39 ml/cmH2O, respectively (p < 0.01), but the relative change was not different from that observed in controls.ConclusionIn COPD patients, AWC is reduced compared to controls, but after bronchodilator, the intrathoracic airways become more compliant. The consequent increased collapsibility under high positive pleural pressure could limit the airway caliber improvement seen after bronchodilator, as assessed by the FEV1 changes during the forced expiratory maneuver, underestimating the effective bronchodilation achieved in these patients.

Ultrafine particle exposure and biomarkers of effect on small airways in children

The small size and large surface area of ultrafine particles (UFP) enhance their ability to deposit in the lung periphery and their reactivity. The Ultrafine Particles from Traffic Emissions and Children's Health (UPTECH) cross-sectional study was conducted in 8–11-year-old schoolchildren attending 25 primary (elementary) schools, randomly selected from the Brisbane Metropolitan Area, Queensland, Australia. Main study findings outlined indirect evidence of distal airway deposition (raised C reactive protein) but as yet, there is no direct evidence in the literature of effects of UFP exposure on peripheral airway function. We present further UPTECH study data from two sensitive peripheral airway function tests, Oscillometry and Multiple Breath Nitrogen Washout (MBNW), performed in 577 and 627 children (88% and 96% of UPTECH study cohort) respectively: mean(SD) age 10.1(0.9) years, 46% male, with 50% atopy and 14% current asthma. Bayesian generalised linear mixed effects regression models were used to estimate the effect of UFP particle number count (PNC) exposure on key oscillometry (airway resistance, (Rrs), and reactance, (Xrs)) and MBNW (lung clearance index, (LCI) and functional residual capacity, (FRC)) indices. We adjusted for age, sex, and height, and potential confounders including socio-economic disadvantage, PM2.5 and NO2 exposure. All models contained an interaction term between UFP PNC exposure and atopy, allowing estimation of the effect of exposure on non-atopic and atopic students. Increasing UFP PNC was associated with greater lung stiffness as evidenced by a decrease in Xrs [mean (95% credible interval) −1.63 (−3.36 to −0.05)%] per 1000#.cm−3]. It was also associated with greater lung stiffness (decrease in Xrs) in atopic subjects across all models [mean change ranging from −2.06 to −2.40% per 1000#.cm−3]. A paradoxical positive effect was observed for Rrs across all models [mean change ranging from −1.55 to −1.70% per 1000#.cm−3] (decreases in Rrs indicating an increase in airway calibre), which was present for both atopic and non-atopic subjects. No effects on MBNW indices were observed. In conclusion, a modest detrimental effect of UFP on peripheral airway function among atopic subjects, as assessed by respiratory system reactance, was observed extending the main UPTECH study findings which reported a positive association with a biomarker for systemic inflammation, C-reactive protein (CRP). Further studies are warranted to explore the pathophysiological mechanisms underlying increased respiratory stiffness, and whether it persists through to adolescence and adulthood.

Air pollution exposure impairs lung function in infants.

AimTo assess associations between air pollution exposure and infant lung function.MethodsHealthy infants from Stockholm were recruited to two cohorts (n = 99 and n = 78). Infant spirometry included plethysmography and raised volume forced expiratory flows. In pooled analyses, lung function at ~6 months of age was related to time‐weighted average air pollution levels at residential addresses from birth until the lung function test. The pollutants included particulate matter with an aerodynamic diameter < 10 μm (PM10) or <2.5 μm and nitrogen dioxide.ResultsThere were significant inverse relations between air pollution exposure during infancy and forced expiratory volume at 0.5 s (FEV0.5) as well as forced vital capacity (FVC) for all pollutants. For example, the decline was 10.1 ml (95% confidence interval 1.3–18.8) and 10.3 ml (0.5–20.1) in FEV0.5 and FVC, respectively, for an interquartile increment of 5.3 μg/m3 in PM10. Corresponding associations for minute ventilation and functional residual capacity were 43.3 ml/min (−9.75–96.3) and 0.84 ml (−4.14–5.82).ConclusionsAir pollution exposure was associated with impaired infant lung function measures related to airway calibre and lung volume, suggesting that comparatively low levels of air pollution negatively affect lung function in early life.

Exercise‐induced Bronchoconstriction does not Change the Configuration of the Maximal Expiratory Flow‐Volume Curve in Adults with Asthma

BackgroundSeveral indices of airflow and volume derived from the maximal expiratory flow volume (MEFV) curve are used to identify and diagnose the severity of respiratory disease. In addition to the objective measures of expiratory airflow and volume, the shape of the MEFV curve is thought to provide information on pulmonary (patho)physiology. In the asthmatic, the MEFV curve is often convex relative to the volume axis (“scooped”). This “scooped” curve is thought to indicate heterogeneous airway emptying during the forced exhalation. The effect of exercise‐induced airway narrowing on the shape of the MEFV curve is not known. The purpose of this study was to determine the effect of exercise‐induced bronchoconstriction (EIB) on the shape of the MEFV curve in asthmatic adults. We hypothesized that the slope‐ratio (SR) index, and thus the overall shape of the MEFV curve would not be affected by EIB.MethodsAdult male and female asthmatics (n=9; age, 26.8 ± 8.4 yrs; BMI, 27.4 ± 4.3 kg/m2) and non‐asthmatics (n=9; age, 25.4 ± 7.8 yrs; BMI, 21.9 ± 2.0 kg/m2) completed a high‐intensity cycle ergometry bout for six minutes at 85% of peak power. Maximal forced exhalations (MFE) were performed before exercise. Following exercise cessation, subjects remained on the ergometer and performed a MFE every two‐minutes for a total 20 minutes. In each MEFV curve, the SR index was calculated in 1% volume increments between 20% and 80% of the vital capacity. To calculate SR, the tangent and chord slope were generated at each point of interest, and the tangent slope was divided by the chord slope.ResultsPulmonary function at baseline was lower in asthmatics compared to the control group (FEV1% predicted, 84.9 ± 11.0 vs. 96.5 ± 12.2% in asthmatics vs. control, respectively; P&lt;0.05). In asthmatic subjects, post‐exercise nadir FEV1 decreased by 29.1 ± 13.7% from baseline (3.40 ± 0.74 to 2.47 ± 0.7 L for baseline and nadir, respectively; P&lt;0.001), whereas FEV1 did not change after exercise in control subjects (3.84 ± 0.9 to 3.70 ± 0.8 L for baseline and nadir, respectively). At all time points, the average SR between 20 and 80% of vital capacity was significantly larger in asthmatic than control subjects (1.49 ± 0.02 vs. 1.23 ± 0.02 [SD] for asthma vs. control; P&lt;0.005). However, in both control and asthmatic subjects, post‐exercise SR was not different from baseline at any time point. In asthmatic subjects, average SR between 20 and 80% of vital capacity was 1.49 ± 0.13 at baseline and averaged 1.49 ± 0.02 across all post‐exercise time points (range = 1.48 to 1.53).ConclusionIn this group of adults with asthma, EIB did not influence the SR index, indicating no change to the overall shape of the MEFV curve. Thus, these findings suggest that inhomogeneities in airway caliber and lung emptying are not magnified during an episode of EIB.

Combining low-frequency oscillometry and spirometry measurements in relation to asthma control and exacerbations in moderate-to-severe asthma

Combining low-frequency oscillometry and spirometry measurements in relation to asthma control and exacerbations in moderate-to-severe asthma

Changes in pharyngeal anatomy and apnea/hypopnea index after a mandibular advancement device

ObjectivesThis study aimed to evaluate the therapeutic effcacy of custom-made mandibular advancement devices (MAD) in the control of primary snoring and sleep apnea and to correlate with anatomical changes identified through imaging tests.MethodsPatients (n = 17) diagnosed with sleep apnea or primary snoring were included in this study and subsequently treated with MADs. Changes were assessed using a polysomnographic study (PSG), the Epworth Sleepiness Scale (ESS), and an imaging study with computed tomography scanning (CT). Studies were performed before and after the use of MAD. Anteroposterior measurements were taken in the sagittal plane at the hard palate, glottis, and supraglottic levels along the hard palate axis. Afterward, measurements were taken in the axial plane at the same levels along the hard palate axis.ResultsFrom the six recorded measurements, the airway caliber increased by five. However, these changes were significant only in two measurements (sagittal hard palate and axial supraglottic). Snoring was controlled in 16 of the 17 subjects. From these sixteen, 12 subjects had a correct opening of the airway at the hard palate level. Moreover, daytime sleepiness decreased in all subjects.DiscussionPresent results suggest that sagittal hard palate and axial supraglottic opening after use of MAD are mainly responsible for eliminating snoring and improve sleep apnea.

Employing the Forced Oscillation Technique for the Assessment of Respiratory Mechanics in Adults

There is increasing interest in the use of the forced oscillation technique (FOT) or oscillometry to characterize respiratory mechanics in healthy and diseased individuals. FOT, a complementary method to traditional pulmonary function testing, utilizes a range of oscillatory frequencies superimposed on tidal breathing to measure the functional relationship between airway pressure and flow. This passive assessment provides an estimate of respiratory system resistance (Rrs) and reactance (Xrs) that reflect airway caliber and energy storage and dissipation, respectively. Despite the recent increase in popularity and updated Technical Standards, clinical adoption has been slow which relates, in part, to the lack of standardization regarding the acquisition and reporting of FOT data. The goal of this article is to address the lack of standardization across laboratories by providing a comprehensive written protocol for FOT and an accompanying video. To illustrate that this protocol can be utilized irrespective of a particular device, three separate FOT devices have been employed in the case examples and video demonstration. This effort is intended to standardize the use and interpretation of FOT, provide practical suggestions, as well as highlight future questions that need to be addressed.

Endoscopic Posterior Rotation Flap for Posterior Glottic Insufficiency.

Endoscopic Posterior Rotation Flap for Posterior Glottic Insufficiency.

Respiratory Dysfunction in Parkinson's Disease: Relation with Dysautonomia.

Background:Parkinson's disease (PD) is a neurodegenerative disease perceived as a motor disorder. It is most commonly associated with autonomic dysfunction, affecting multiple systems. This altered autonomic control might be reflected by a parallel change in the airway caliber of these patients.Aim:To correlate the pulmonary impairment in patients with Parkinson's disease with the underlying dysautonomia.Materials and Methods:A total of 30 patients with Parkinson's disease participated in the study. Heart rate (HR) variability was recorded for 5 min to assess the autonomic dysfunction, followed by impulse oscillometry (IOS) and spirometry. IOS being an effort independent technique uses sound waves at different frequencies (5–25 Hz) to measure the airway impedance.Results:There was a significant decrease in SDSD (6.60 (10.18–6.01) vs. 12.22 (13.95–11.30); P = 0.04), RMSSD (6.59 (10.17–5.50) vs. 12.20 (13.93–11.28); P = 0.04), and total power (315.8 (506.3–120.7) vs. 771.3 (799.0–643.6); P = 0.04) in stage II as compared to stage I. Resistance at 20 Hz (R20) was found to be positively correlated with SDSD (r = 0.40, P = 0.04), RMSSD (r = 0.40, P = 0.04), and HF (r = 0.41, P = 0.03).Conclusion:Amongst the PD population, any changes in the parasympathetic component (responsible for bronchoconstriction) due to the underlying dysautonomia might be reflected as increased airway resistance in the pulmonary system.

Mandibular Advancement Splint Therapy.

Mandibular advancement splint (MAS) therapy is the leading alternative to continuous positive airway pressure (CPAP) therapy for the treatment of obstructive sleep apnoea. A MAS is an oral appliance which advances the mandible in relation to the maxilla, thus increasing airway calibre and reducing collapsibility. Although it is less effective than CPAP in reducing the apnoea-hypopnoea index (AHI), it has demonstrated equivalence to CPAP in a number of key neurobehavioural and cardiovascular health outcomes, perhaps due to increased tolerability and patient adherence when compared to CPAP. However, response to MAS is variable, and reliable prediction tools for patients who respond best to MAS therapy have thus far been elusive; this is one of the key clinical barriers to wider uptake of MAS therapy. In addition, the most effective MAS devices are custom-made by a dentist specialising in the treatment of sleep disorders, which may present financial or accessibility barriers for some patients. MAS devices are generally well tolerated but may have side effects including temporomandibular joint (TMJ) dysfunction, hypersalivation, tooth pain and migration as well as occlusal changes. A patient-centred approach to treatment from a multidisciplinary team perspective is recommended. Evidence-based clinical practice points and areas of future research are summarised at the conclusion of the chapter.

This Month in Anesthesiology

This Month in Anesthesiology

To Investigate the Effect of Targeted Overdilation in Balloon-Expandable Stents.

PurposeBalloon-expandable stents are commonly used for the treatment of tracheobronchial strictures. We routinely perform targeted overdilation of these stents 1–2mm on initial deployment to prevent stent migration or allow foreshortening to target airway caliber; however, specific data on the effect of targeted overdilation is unknown.Patients and MethodsWe used three iCAST stents (6×22mm, 7×22mm, and 10×38mm) to perform the study. We had two sets of each size to average our results. Targeted overdilation was accomplished with Merit Elation balloons.ResultsThe 6 × 22 and 7 × 22 stent OD increased from 6 to 11.4mm and 7 to 11.6mm. The 10 × 38 stent demonstrated minimal OD change with overdilation (OD change of 10.4 to 12.2mm). All stents demonstrated significant foreshortening with overdilation (20.2 to 5.65mm, 19.4 to 6mm, and 30.9 to 10.2mm for 6 × 22, 7 × 22, and 10 × 38, respectively). The breakpoint was seen at near twice the stated stent OD (13.5mm, 15mm, and 15mm with 6 × 22, 7 × 22 and 10 × 38, respectively).ConclusionWe have demonstrated that iCAST stents can increase their OD with subsequent foreshortening during targeted overdilation. This data can help facilitate decisions when selecting a particular iCAST stent for a specific airway application. Additionally, we have highlighted that balloon inflation diameter does not correspond to the actual stent OD during deployment. We believe that this data offers practical information for end-users of this stent type and additional data will be needed to corroborate our findings.

Altered responses of end-expiratory lung volume and upper airway patency to body posture in diet-induced obese mice.

ObjectiveAlthough both obesity and body posture are important factors affecting end‐expiratory lung volume (EELV) and upper airway patency, the influence of those factors on EELV and the association between EELV and upper airway calibers are still unknown in mice. This study examined such interaction effects in obese mice to test the hypothesis that obese mice have decreased EELV accompanied by structural alterations of the upper airway.MethodsA high‐resolution in vivo micro‐computed tomography was utilized to scan anesthetized lean and diet‐induced obese mice in the prone and supine positions, followed by quantifying lung volume and analyzing upper airway morphology.ResultsThere was a statistically significant interaction between the effects of body weight and posture on both EELV (p = 0.0049, η 2 = 0.1041) and upper airway calibers (p = 0.0215, η 2 = 0.6304). In lean mice, EELV in the prone position was significantly larger than in the supine position (prone EELV = 193.22 ± 9.10 µl vs. supine EELV = 176.01 ± 10.91 µl; p = 0.0072), whereas obese mice did not have such an improvement in EELV in the prone position (prone EELV = 174.37 ± 20.23 µl vs. supine EELV = 183.39 ± 17.49 µl; p = 0.0981) and tended to have a smaller upper airway when EELV was low based on Spearman's correlation analysis.ConclusionsThese data indicate that obesity is an important factor compromising both EELV and upper airway calibers in a posture‐dependent manner even in mice, which should be taken into consideration in future studies regarding upper airway collapse and lung mechanical properties using mice.

VIP/PACAP signaling as an alternative target during hyperoxic exposure in preterm newborns.

The use of oxygen therapy (high doses of oxygen - hyperoxia) in the treatment of premature infants results in their survival. However, it also results in a high incidence of chronic lung disease known as bronchopulmonary dysplasia, a disease in which airway hyper-responsiveness and pulmonary hypertension are well known as consequences. In our previous studies, we have shown that hyperoxia causes airway hyper-reactivity, characterized by an increased constrictive and impaired airway smooth muscle relaxation due to a reduced release of relaxant molecules such as nitric oxide, measured under in vivo and in vitro conditions (extra- and intrapulmonary) airways. In addition, the relaxation pathway of the vasoactive intestinal peptide (VIP) and/or pituitary adenylate cyclase activating peptide (PACAP) is another part of this system that plays an important role in the airway caliber. Peptide, which activates VIP cyclase and pituitary adenylate cyclase, has prolonged airway smooth muscle activity. It has long been known that VIP inhibits airway smooth muscle cell proliferation in a mouse model of asthma, but there is no data about its role in the regulation of airway and tracheal smooth muscle contractility during hyperoxic exposure of preterm newborns.

Inhaled Dual Phosphodiesterase 3/4 Inhibitors for the Treatment of Patients with COPD: A Short Review.

Current pharmacological treatments for chronic obstructive pulmonary disease (COPD) are mostly limited to inhaled bronchodilators and corticosteroids. Azithromycin can contribute to exacerbation prevention. Roflumilast, a phosphodiesterase (PDE) 4 inhibitor administered orally, also prevents exacerbations in selected patients with chronic bronchitis, recurrent exacerbations, severe airflow limitation and concomitant therapy with long-acting inhaled bronchodilators. This outcome likely results from anti-inflammatory effects since PDE4 is expressed by all inflammatory cell types involved in COPD. The use of this agent is, however, limited by side-effects, particularly nausea and diarrhea. To address remaining unmet needs and enrich therapeutic options for patients with COPD, inhaled dual PDE3/4 inhibitors have been developed, with the aim of enhancing bronchodilation through PDE3 inhibition and modulating inflammation and mucus production though PDE4 inhibition, thus producing a potentially synergistic effect on airway calibre. Experimental preclinical data confirmed these effects in vitro and in animal models. At present, RPL554/ensifentrine is the only agent of this family in clinical development. It decreases sputum markers of both neutrophilic and eosinophilic inflammation in patients with COPD. Clinical Phase II trials confirmed its bronchodilator effect and demonstrated clinically meaningful symptom relief and quality of life improvements in these patients. The safety profile appears satisfactory, with less effects on heart rate and blood pressure than salbutamol and no other side effect. Altogether, these data suggest that ensifentrine could have a role in COPD management, especially in addition to inhaled long-acting bronchodilators with or without corticosteroids since experimental studies suggest potentiation of ensifentrine effects by these agents. However, results from ongoing and future Phase III studies are needed to confirm both beneficial effects and favourable safety profile on a larger scale and assess other outcomes including exacerbations, lung function decline, comorbidities and mortality.

Low-frequency Intrapulmonary Percussive Ventilation Increases Aerosol Penetration in a 2-Compartment Physical Model of Fibrotic Lung Disease

In patients with fibrotic pulmonary disease such as idiopathic pulmonary fibrosis (IPF), inhaled aerosols deposit mostly in the les affected region of the lung, resulting in suboptimal pharmacokinetics of airway-delivered treatments. Refinement of aerosol delivery technique requires new models to simulate the major alterations of lung physiology associated with IPF, i.e. heterogeneously reduced lung compliance and increased airway caliber. A novel physical model of the respiratory system was constructed to simulate aerosol drug delivery in spontaneously breathing (negative pressure ventilation) IPF patients. The model comprises upper (Alberta idealized throat) and lower airway (plastic tubing) models and branches into two compartments (Michigan lung model) which differ in compliance and caliber of conducting airway. Aerosol penetration and deposition (using NaF as a model aerosol) in the model was studied in different conditions. The model was able to reproduce the heterogeneous, compliance-dependent reduction in ventilation and aerosol penetration seen in the fibrotic lung regions in IPF. Addition of intrapulmonary percussive ventilation (IPV) induces a 2-3 fold increase in aerosol penetration in the low-complaince/high airway caliber compartment of the model, demonstrating the responsiveness of the model to therapeutic intervention. Thanks to the model, we observed that reduced compliance of target lung regions is a critical determinant of aerosol penetration, and thus presumably of aerosol deposition. This finding underscores the need for techniques specifically tailored to enhance delivery of inhaled aerosols to low compliance regions of lungs. Low-frequency IPV (≤ 3 Hz) pulses may represent an attractive option to increase aerosol deposition in fibrotic lung regions.

Inhaled triple therapy and airway hyperresponsiveness in persistent asthma

Adding a long-acting muscarinic antagonist (LAMA) is recommended in the guidelines for a patient with asthma not controlled on inhaled corticosteroid (ICS)/long-acting β-agonist (LABA). The change in forced expiratory volume in 1 second (FEV1) resulting from the addition of LAMA to ICS/LABA may be relatively small or less than the minimal clinically important difference, and as such, improved airway caliber is not the primary mechanism for a reduction in exacerbations with LAMA therapy. 1 Lipworth B.J. Emerging role of long acting muscarinic antagonists for asthma. Br J Clin Pharmacol. 2014; 77: 55-62 Crossref PubMed Scopus (33) Google Scholar Exacerbations are, in part, determined by the effects on airway hyperresponsiveness (AHR) in which a LAMA might be expected to confer additional airway smooth muscle–stabilizing effects when added to ICS/LABA. 2 Currie G.P. Jackson C.M. Ogston S.A. Lipworth B.J. Airway-stabilizing effect of long-acting beta2-agonists as add-on therapy to inhaled corticosteroids. Qjm. 2003; 96: 435-440 Crossref PubMed Scopus (23) Google Scholar Aside from effects on airway smooth muscle, there may be neuronal and paracrine actions of LAMAs that may reduce exacerbations. 1 Lipworth B.J. Emerging role of long acting muscarinic antagonists for asthma. Br J Clin Pharmacol. 2014; 77: 55-62 Crossref PubMed Scopus (33) Google Scholar Indirect challenge tests with agents such as mannitol are thought to be more physiological than direct agents such as histamine or methacholine in that they better reflect the underlying inflammation status as opposed to the function of airway smooth muscle alone. 3 Nair P. Martin J.G. Cockcroft D.C. et al. Airway hyperresponsiveness in asthma: measurement and clinical relevance. J Allergy Clin Immunol Pract. 2017; 5: 649-659.e2 Abstract Full Text Full Text PDF PubMed Scopus (52) Google Scholar

Asthma in elderly is characterized by increased sputum neutrophils, lower airway caliber variability and air trapping

BackgroundElderly asthmatics represent an important group that is often excluded from clinical studies. In this study we wanted to present characteristics of asthmatics older than 70 years old as compared to younger patients.MethodsWe conducted a retrospective analysis on a series of 758 asthmatics subdivided in three groups: lower than 40, between 40 and 70 and older than 70. All the patients who had a successful sputum induction were included in the study.ResultsOlder patients had a higher Body Mass Index, had less active smokers and were more often treated with Long Acting anti-Muscarinic Agents. We found a significant increase in sputum neutrophil counts with ageing. There was no significant difference in blood inflammatory cell counts whatever the age group. Forced expiratory volume in one second (FEV1) and FEV1/FVC values were significantly lower in elderly who had lower bronchial hyperresponsiveness and signs of air trapping. We found a lower occurrence of the allergic component in advanced ages. Asthmatics older than 70 years old had later onset of the disease and a significant longer disease duration.ConclusionOur study highlights that asthmatics older than 70 years old have higher bronchial neutrophilic inflammation, a poorer lung function, signs of air trapping and lower airway variability. The role of immunosenescence inducing chronic low-grade inflammation in this asthma subtype remains to be elucidated.

Correlation of Body Mass Index, Mean Arterial Pressure with Peak Expiratory Flow Rate in Healthy Individuals- A Descriptive Study

Introduction: Modern lifestyle has resulted in an increased prevalence of cardiovascular and respiratory diseases along with being overweight. An interaction between the three factors has also been demonstrated. Aim: The study aimed to assess the relationship of Body Mass Index (BMI), Mean Arterial Pressure (MAP) and Peak Expiratory Flow Rate (PEFR) in healthy individuals. Materials and Methods: This cross-sectional, observational study was done in the Department of Physiology, KGMU, Lucknow from 30 July 2019 to 30 July 2020. Forty healthy individuals, aged 18-35 years were assessed for height, weight, blood pressure and spirometric parameter of PEFR. PEFR was chosen as it was a reliable representative of airways functioning. PEFR reflects proximal airway calibre changes which might be due to effect of airway geometry. A correlation test was run to test the relation between BMI and PEFR and MAP and PEFR. Results: A weak correlation (r=-0.136) was noted between BMI and PEFR indicating that as BMI increased, PEFR compromised. A linear correlation was observed between MAP and PEFR. Conclusion: The present study confirms a weak association of BMI and MAP with PEFR.