Physiology of Airﬂow Limitation in Emphysema

Abstract Study Objectives Determine if changes in K-complexes associated with sustained inspiratory airflow limitation (SIFL) during N2 sleep are associated with next-day vigilance and objective sleepiness. Methods Data from thirty subjects with moderate-to-severe obstructive sleep apnea who completed three in-lab polysomnograms: diagnostic, on therapeutic continuous positive airway pressure (CPAP), and on suboptimal CPAP (4 cmH2O below optimal titrated CPAP level) were analyzed. Four 20-min psychomotor vigilance tests (PVT) were performed after each PSG, every 2 h. Changes in the proportion of spontaneous K-complexes and spectral characteristics surrounding K-complexes were evaluated for K-complexes associated with both delta (∆SWAK), alpha (∆αK) frequencies. Results Suboptimal CPAP induced SIFL (14.7 (20.9) vs 2.9 (9.2); %total sleep time, p < 0.001) with a small increase in apnea–hypopnea index (AHI3A: 6.5 (7.7) vs 1.9 (2.3); p < 0.01) versus optimal CPAP. K-complex density (num./min of stage N2) was higher on suboptimal CPAP (0.97 ± 0.7 vs 0.65±0.5, #/min, mean ± SD, p < 0.01) above and beyond the effect of age, sex, AHI3A, and duration of SIFL. A decrease in ∆SWAK with suboptimal CPAP was associated with increased PVT lapses and explained 17% of additional variance in PVT lapses. Within-night during suboptimal CPAP K-complexes appeared to alternate between promoting sleep and as arousal surrogates. Electroencephalographic changes were not associated with objective sleepiness. Conclusions Sustained inspiratory airflow limitation is associated with altered K-complex morphology including the increased occurrence of K-complexes with bursts of alpha as arousal surrogates. These findings suggest that sustained inspiratory flow limitation may be associated with nonvisible sleep fragmentation and contribute to increased lapses in vigilance.

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Brain-derived Neurotrophic Factor in Platelets and Airflow Limitation in Asthma

American Journal of Respiratory and Critical Care Medicine ◽

10.1164/rccm.200406-758oc ◽

2005 ◽

Vol 171 (2) ◽

pp. 115-120 ◽

Cited By ~ 75

Author(s):

Marek Lommatzsch ◽

Katharina Schloetcke ◽

Jens Klotz ◽

Katharina Schuhbaeck ◽

Doerte Zingler ◽

...

Keyword(s):

Neurotrophic Factor ◽

Brain Derived Neurotrophic Factor ◽

Airflow Limitation

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COPD Guidelines in the Asia-Pacific Regions: Similarities and Differences

Diagnostics ◽

10.3390/diagnostics11071153 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1153

Author(s):

Shih-Lung Cheng ◽

Ching-Hsiung Lin

Keyword(s):

Chronic Obstructive Pulmonary Disease ◽

Pulmonary Disease ◽

Global Strategy ◽

Airflow Limitation ◽

Asia Pacific ◽

Pharmacologic Therapy ◽

Chronic Obstructive ◽

Obstructive Pulmonary Disease ◽

Country Level ◽

Similarities And Differences

Chronic obstructive pulmonary disease (COPD) is a preventable and treatable disease that is associated with significant morbidity and mortality, giving rise to an enormous social and economic burden. The Global Strategy for the Diagnosis, Management and Prevention of Chronic Obstructive Pulmonary Disease (GOLD) report is one of the most frequently used documents for managing COPD patients worldwide. A survey was conducted across country-level members of Asia-Pacific Society of Respiratory (APSR) for collecting an updated version of local COPD guidelines, which were implemented in each country. This is the first report to summarize the similarities and differences among the COPD guidelines across the Asia-Pacific region. The degree of airflow limitation, assessment of COPD severity, management, and pharmacologic therapy of stable COPD will be reviewed in this report.

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Alternative methods for assessing bronchodilator reversibility in chronic obstructive pulmonary disease

Thorax ◽

10.1136/thx.56.9.713 ◽

2001 ◽

Vol 56 (9) ◽

pp. 713-720

Author(s):

J Hadcroft ◽

P M A Calverley

Keyword(s):

Chronic Obstructive Pulmonary Disease ◽

Pulmonary Disease ◽

Lung Volume ◽

Tidal Flow ◽

Airflow Limitation ◽

Alternative Methods ◽

Chronic Obstructive ◽

Flow Limitation ◽

Inspiratory Capacity ◽

Obstructive Pulmonary Disease

BACKGROUNDBronchodilator reversibility testing is recommended in all patients with chronic obstructive pulmonary disease (COPD) but does not predict improvements in breathlessness or exercise performance. Two alternative ways of assessing lung mechanics—measurement of end expiratory lung volume (EELV) using the inspiratory capacity manoeuvre and application of negative expiratory pressure (NEP) during tidal breathing to detect tidal airflow limitation—do relate to the degree of breathlessness in COPD. Their usefulness as end points in bronchodilator reversibility testing has not been examined.METHODSWe studied 20 patients with clinically stable COPD (mean age 69.9 (1.5) years, 15 men, forced expiratory volume in one second (FEV1) 29.5 (1.6)% predicted) with tidal flow limitation as assessed by their maximum flow-volume loop. Spirometric parameters, slow vital capacity (SVC), inspiratory capacity (IC), and NEP were measured seated, before and after nebulised saline, and at intervals after 5 mg nebulised salbutamol and 500 μg nebulised ipratropium bromide. The patients attended twice and the treatment order was randomised.RESULTSMean FEV1, FVC, SVC, and IC were unchanged after saline but the degree of tidal flow limitation varied. FEV1 improved significantly after salbutamol and ipratropium (0.11 (0.02) l and 0.09 (0.02) l, respectively) as did the other lung volumes with further significant increases after the combination. Tidal volume and mean expiratory flow increased significantly after all bronchodilators but breathlessness fell significantly only after the combination treatment. The initial NEP score was unrelated to subsequent changes in lung volume.CONCLUSIONSNEP is not an appropriate measurement of acute bronchodilator responsiveness. Changes in IC were significantly larger than those in FEV1and may be more easily detected. However, our data showed no evidence for separation of “reversible” and “irreversible” groups whatever outcome measure was adopted.

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COPD Clinical Control: predictors and long-term follow-up of the CHAIN cohort

Respiratory Research ◽

10.1186/s12931-021-01633-y ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Myriam Calle Rubio ◽

◽

Juan Luis Rodriguez Hermosa ◽

Juan P. de Torres ◽

José María Marín ◽

...

Keyword(s):

Triple Therapy ◽

Clinical Status ◽

Airflow Limitation ◽

Psychological Status ◽

Prognostic Information ◽

Clinical Control ◽

All Cause Mortality ◽

Long Term Follow Up

Abstract Background Control in COPD is a dynamic concept that can reflect changes in patients’ clinical status that may have prognostic implications, but there is no information about changes in control status and its long-term consequences. Methods We classified 798 patients with COPD from the CHAIN cohort as controlled/uncontrolled at baseline and over 5 years. We describe the changes in control status in patients over long-term follow-up and analyze the factors that were associated with longitudinal control patterns and related survival using the Cox hazard analysis. Results 134 patients (16.8%) were considered persistently controlled, 248 (31.1%) persistently uncontrolled and 416 (52.1%) changed control status during follow-up. The variables significantly associated with persistent control were not requiring triple therapy at baseline and having a better quality of life. Annual changes in outcomes (health status, psychological status, airflow limitation) did not differ in patients, regardless of clinical control status. All-cause mortality was lower in persistently controlled patients (5.5% versus 19.1%, p = 0.001). The hazard ratio for all-cause mortality was 2.274 (95% CI 1.394–3.708; p = 0.001). Regarding pharmacological treatment, triple inhaled therapy was the most common option in persistently uncontrolled patients (72.2%). Patients with persistent disease control more frequently used bronchodilators for monotherapy (53%) at recruitment, although by the end of the follow-up period, 20% had scaled up their treatment, with triple therapy being the most frequent therapeutic pattern. Conclusions The evaluation of COPD control status provides relevant prognostic information on survival. There is important variability in clinical control status and only a small proportion of the patients had persistently good control. Changes in the treatment pattern may be relevant in the longitudinal pattern of COPD clinical control. Further studies in other populations should validate our results. Trial registration: Clinical Trials.gov: identifier NCT01122758.

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Ventilatory defects and treatable traits in very elderly patients

Science Progress ◽

10.1177/00368504211013171 ◽

2021 ◽

Vol 104 (2) ◽

pp. 003685042110131

Author(s):

João Gaspar-Marques ◽

Teresa Palmeiro ◽

Iolanda Caires ◽

Paula Leiria Pinto ◽

Nuno Neuparth ◽

...

Keyword(s):

Cognitive Impairment ◽

Elderly Patients ◽

Elderly Care ◽

Airflow Limitation ◽

The Novel ◽

Z Score ◽

Very Elderly ◽

Chronic Respiratory Diseases ◽

Novel Association ◽

Peripheral Pulse

Though the approach used to classify chronic respiratory diseases is changing to a treatable-traits (TT) approach, data regarding very elderly patients is lacking. The objectives of this study were to assess TT frequency in very elderly patients and to study the link between extrapulmonary TT and ventilatory defects. Individuals (≥75 years) residing in elderly care centres answered a standardised questionnaire, underwent spirometry, atopy and fractional exhaled nitric oxide assessments and had their blood pressure and peripheral pulse oximetry measured. Pulmonary, extrapulmonary and behavioural TT were evaluated. Outcome variables were an airflow limitation (post-bronchodilator z-score FEV1/FVC<−1.64) and a restrictive spirometry pattern (z-score FEV1/FVC ≥ +1.64 and z-score FVC<−1.64). Seventy-two percent of the individuals who took part in the study ( n = 234) were women, and the median age of participants was 86 (IQR: 7.4). At least one pulmonary TT was identified in 105 (44.9%) individuals. The most frequent extrapulmonary TTs were: persistent systemic inflammation (47.0%), anaemia (34.4%), depression (32.5%) and obesity (27.4). Airflow limitation was exclusively associated with smoking (OR 5.03; 95% CI 1.56–16.22). A restrictive spirometry pattern was associated with cognitive impairment (OR: 3.89; 95% CI: 1.55–9.79). A high frequency of various TTs was found. The novel association between a restrictive spirometry pattern and cognitive impairment highlights the urgency of clinical research on this vulnerable age group.

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Reversible airflow limitation in adults with respiratory infection

European Respiratory Journal ◽

10.1183/09031936.94.07071239 ◽

1994 ◽

Vol 7 (7) ◽

pp. 1239-1245 ◽

Cited By ~ 32

Author(s):

H. Melbye ◽

J. Kongerud ◽

L. Vorland

Keyword(s):

Respiratory Infection ◽

Airflow Limitation

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How different are COPD-specific patient reported outcomes, health status, dyspnoea and respiratory symptoms? An observational study in a working population

BMJ Open ◽

10.1136/bmjopen-2018-025132 ◽

2019 ◽

Vol 9 (7) ◽

pp. e025132 ◽

Cited By ~ 2

Author(s):

Koichi Nishimura ◽

Toru Oga ◽

Kazuhito Nakayasu ◽

Miyoko Ogasawara ◽

Yoshinori Hasegawa ◽

...

Keyword(s):

Health Status ◽

Respiratory Symptoms ◽

Smoking Status ◽

Fixed Ratio ◽

Airflow Limitation ◽

Chronic Obstructive ◽

Working Population ◽

Specific Patient ◽

Patient Reported ◽

D 12

ObjectivesWe hypothesised that chronic obstructive pulmonary disease (COPD)-specific health status measured by the COPD assessment test (CAT), respiratory symptoms by the evaluating respiratory symptoms in COPD (E-RS) and dyspnoea by Dyspnoea-12 (D-12) are independently based on specific conceptual frameworks and are not interchangeable. We aimed to discover whether health status, dyspnoea or respiratory symptoms could be related to smoking status and airflow limitation in a working population.DesignThis is an observational, cross-sectional study.Participants1566 healthy industrial workers were analysed.ResultsRelationships between D-12, CAT and E-RS total were statistically significant but weak (Spearman’s correlation coefficient=0.274 to 0.446). In 646 healthy non-smoking subjects, as the reference scores for healthy non-smoking subjects, that is, upper threshold, the bootstrap 95th percentile values were 1.00 for D-12, 9.88 for CAT and 4.44 for E-RS. Of the 1566 workers, 85 (5.4%) were diagnosed with COPD using the fixed ratio of the forced expiratory volume in one second/forced vital capacity <0.7, and 34 (2.2%) using the lower limit of normal. The CAT and E-RS total were significantly worse in non-COPD smokers and subjects with COPD than non-COPD never smokers, although the D-12 was not as sensitive. There were no significant differences between non-COPD smokers and subjects with COPD on any of the measures.ConclusionsAssessment of health status and respiratory symptoms would be preferable to dyspnoea in view of smoking status and airflow limitation in a working population. However, these patient-reported measures were inadequate in differentiating between smokers and subjects with COPD identified by spirometry.

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