Suboptimal peak inspiratory flow rate in dry-powder inhaler users for chronic obstructive pulmonary disease in Korea.

BACKGROUND: A suboptimal peak inspiratory flow rate (PIFR) in dry-powder inhaler (DPI) users can lead to insufficient therapeutic effects in the treatment of chronic obstructive pulmonary disease (COPD). However, few data on the prevalence of and factors associated with suboptimal PIFR in Korean patients with COPD are available. METHODS: We conducted a cross-sectional study of patients with COPD who had been using DPIs for more than three months. PIFR was measured using an In-Check DIAL G16 device. Suboptimal PIFR was defined as below the resistance-matched threshold. Multivariable logistic regression analysis was used to determine factors associated with suboptimal PIFR. RESULTS: Of 444 DPI users with COPD, the rate of suboptimal PIFR was 22.0 % (98/444). In a multivariable analysis, significant factors associated with suboptimal PIFR were age (adjusted odds ratio [aOR] = 1.06 by 1-year increase; 95 % confidence interval [CI] = 1.02-1.09), male sex (aOR = 0.28; 95 % CI = 0.11-0.73), body mass index (BMI) (aOR = 0.91 by 1 kg/m2 increase; 95 % CI = 0.85-0.99), post-bronchodilator forced vital capacity (FVC) %pred (aOR = 0.97 by 1%pred increase; 95 % CI = 0.95-0.99), and In-Check DIAL R2-type inhaler [medium-low resistance] use (aOR = 3.70 compared with R1-type inhalers [low resistance]; 95 % CI = 2.03-7.03). CONCLUSIONS: In Korea, more than one-fifth of DPI users with COPD had a suboptimal PIFR. The factors associated with suboptimal PIFR were age, female gender, low BMI, low FVC, and R2-type inhaler use. Therefore, clinicians should carefully evaluate the possibility of suboptimal PIFR when prescribing DPIs.

A comparative study of dynamic lung hyperinflation and tidal volume to total lung capacity ratios during exercise in patients with chronic respiratory disease and healthy individuals.

BACKGROUND: Current measures of tidal volume/forced vital capacity (VT/FVC) and VT/inspiratory capacity (VT/IC) at peak exercise cannot differentiate restrictive from obstructive ventilation patterns. This study aimed to investigate the utility of VT/total lung capacity (VT/TLC) as a marker for dynamic lung hyperinflation (DH) in patients with chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD). METHODS: 267 subjects were screened: 23 ILD, 126 COPD, and 33 healthy individuals were enrolled. Lung function tests and cardiopulmonary exercise tests with repeated IC maneuver were conducted and compared at three exercise efforts: unloaded, middle of exercise, and peak exercise. RESULTS: During exercise, ILD patients demonstrated normal end-expiratory lung volume/TLC (EELV/TLC) ratios, but elevated end-inspiratory lung volume/TLC (EILV/TLC) ratios, except for peak exercise. COPD patients exhibited elevated ratios for both EELV/TLC and EILV/TLC during exercise with a larger EELV/TLC ratio compared to ILD patients at peak exercise (p < 0.05). The VT/TLC ratio distinguished ILD, COPD, and healthy controls at peak exercise (p < 0.05). A VT/TLC ratio of ≤ 0.22 or ≥ 0.30 indicated airflow obstruction with hyperinflation or normal lung expansion, respectively (AUC: 0.74 or 0.88). Furthermore, VT/TLC outperformed VT/FVC and VT/IC in differentiating lung expansion between ILD and COPD during exercise (all p < 0.05). CONCLUSION: Exercise-induced DH was absent in ILD patients but observed in COPD patients. Excessive lung expansion occurred in all patients during exercise, except for limited expansion in ILD at peak exercise probably due to specific lung properties. VT/TLC can distinguish between restrictive, obstructive, and normal ventilatory patterns.

Therapeutic Response to Single-Inhaler Triple Therapies in Moderate-to-Severe COPD.

BACKGROUND: COPD is characterized by progressive and irreversible air flow limitations. Single-inhaler therapies (SITTs) incorporating an inhaled corticosteroid, a long-acting muscarinic antagonist, and a long-acting ß2-agonist have been shown to effectively alleviate symptoms and improve lung function. Fluticasone-furoate/umeclidinium/vilanterol (F/U/V) and budesonide/glycopyrronium/formoterol (B/G/F) are available as SITT in Japan. However, the clinical differences between these 2 combinations and the predictors of their proper use have not been established. This study aimed to identify the subject characteristics that could predict the effectiveness of inhaler therapy. METHODS: We assessed the pulmonary function test results of subjects with COPD before and one month after using F/U/V and B/G/F as SITT. Subjects with a difference of 100 mL or more in the FEV1 after treatment with pre-SITT were extracted and divided into the F/U/V effect and no-effect group and B/G/F effect and no-effect group to examine the factors associated with positive outcomes with each inhaler. RESULTS: F/U/V and B/G/F significantly improved the inspiratory capacity (IC), %IC, FVC, and %FEV1 when compared to pre-intervention values (P < .001, P = .001, P = .007, P = .009, respectively, for F/U/V; and P = .006, P = .008, P = .038, P = .005, respectively, for B/G/F). Factors associated with FEV1 improvement in F/U/V included lower %IC (odds ratio 0.97 [95% CI 0.94-0.99], P = .03) and a higher modified Medical Research Council (mMRC) dyspnea score (2.36 [1.27-4.70], P < .01). In addition, a higher %IC (1.03 [1.00-1.06], P = .02) and lower mMRC dyspnea score (0.55 [0.28-0.99], P = .041) were predictors for the effectiveness of B/G/F. CONCLUSIONS: Our results showed that SITT significantly improved the IC, %IC, FVC, and %FEV1 when compared to pre-intervention and that F/U/V was more effective in subjects with severe symptoms, whereas B/G/F was more effective in subjects with mild symptoms.

Physiological predictors of morbidity and mortality in COPD: the relative importance of reduced inspiratory capacity and inspiratory muscle strength.

Low resting inspiratory capacity (IC) and low maximal inspiratory pressure (MIP) have previously been linked to exertional dyspnea, exercise limitation, and poor survival in chronic obstructive pulmonary disease (COPD). The interaction and relative contributions of these two related variables to important clinical outcomes are unknown. The objective of the current study was to examine the interaction between resting IC and MIP (both % predicted), exertional dyspnea, exercise capacity, and long-term survival in patients with COPD. Two hundred and eighty-five patients with mild to advanced COPD completed standard lung function testing and a cycle cardiopulmonary exercise test. Multiple regression determined predictors of the exertional dyspnea-ventilation slope and peak oxygen uptake (V̇o2peak). Cox regression determined predictors of 10-year mortality. IC was associated with the dyspnea-ventilation slope (standardized ß = -0.42, P < 0.001), whereas MIP was excluded from the regression model (P = 0.918). IC and MIP were included in the final model to predict V̇o2peak. However, the standardized ß was greater for IC (0.43) than MIP (0.22). After adjusting for age, sex, body mass index, cardiovascular risk, airflow obstruction, and diffusing capacity, resting IC was independently associated with 10-year all-cause mortality (hazard ratio = 1.25, confidence interval5%-95% = 1.16-1.34, P < 0.001), whereas MIP was excluded from the final model (all P = 0.829). Low resting IC was consistently linked to heightened dyspnea intensity, low V̇o2peak, and worse survival in COPD even after accounting for airway obstruction, inspiratory muscle strength, and diffusing capacity. These results support the use of resting IC as an important physiological biomarker closely linked to key clinical outcomes in COPD.NEW & NOTEWORTHY To our knowledge, this study is the first to show an independent association between low resting inspiratory capacity (IC) and, severe exertional dyspnea, exercise limitation, and increased mortality risk, after accounting for the severity of airway obstruction, inspiratory muscle strength, and diffusing capacity. These results support the use of resting IC as an important independent physiological biomarker closely linked to key clinical outcomes in COPD.

A reappraisal of inspiratory capacity in chronic obstructive pulmonary disease: clinical correlates and role of long-acting muscarinic antagonists and long-acting ß2 agonists.

INTRODUCTION: In patients with chronic obstructive pulmonary disease (COPD), static and dynamic hyperinflation, together with expiratory flow limitation and gas exchange abnormalities, is one of the major causes of dyspnea, decreased exercise performance and ventilatory failure. An increase in functional residual capacity (FRC) is accompanied by a decrease in inspiratory capacity (IC), which is a volume readily available, repeatable, and simple to measure with any spirometer. Changes in IC and FRC after bronchodilation, contrary to changes in FEV1, have been closely associated with improvements in dyspnea and exercise performance. We systematically searched PubMed and Embase databases for clinical trials that assessed the effects of dual bronchodilation on inspiratory capacity in patients with COPD. AREAS COVERED: Despite their pivotal role in COPD, IC and static volumes have rarely been considered as primary outcomes in randomized clinical trials assessing the efficacy of bronchodilators. Available studies on dual bronchodilation have shown a significant and persistent positive impact on IC focusing mainly on patients with moderate-to-severe COPD, whereas dynamic hyperinflation is also present at milder disease stages. EXPERT OPINION: This narrative review discusses the pathophysiological and clinical importance of measuring IC in patients with COPD and how IC can be modified by maximizing bronchodilation combining long-acting muscarinic antagonists and long-acting ß2 agonists.

Patients with Chronic Obstructive Pulmonary Disease Can Accurately Perform Home-Based Measurements of Inspiratory Capacity and Dynamic Hyperinflation.

Home-based lung function measurements can be used to capture day-to-day variations in symptoms in patients with chronic obstructive pulmonary disease (COPD). Although dynamic hyperinflation (DH) is clinically relevant, existing home-based measurements do not include its assessment. DH can be measured through inspiratory capacity (IC) measurements before and after metronome-paced tachypnea test (MPT). The goal of this study is to determine the accuracy of unsupervised home-based IC and DH measurements in COPD.Sixteen COPD patients performed IC and DH measurements during 4 home visits. Visit 1 was considered a training session. During all visits supervised and unsupervised IC at rest (ICREST) and after MPT (ICMPT) were measured. DH was calculated as the difference between ICREST and ICMPT, and as a percentage of ICREST. Bland-Altman analyses and ANOVA tests were performed to determine the effect of supervision and repeated measures over time.The biases between supervised and unsupervised ICREST, ICMPT, ΔIC and ΔIC% were 0.007 L, 0.007 L, 0 mL and -0.09% in the last visit, respectively. Limits of agreement of ICREST and ΔIC% decreased from ±0.261 mL to ±0.201 mL, and from ±13.84% to ±10.81% between visit 1 and 4, respectively. No significant effect of supervision or over time was found.After a robust training and a learning phase, COPD patients are able to perform IC measurements in an accurate manner in both rest and after MPT. This yield accurate assessment of DH, in an unsupervised home-based setting.

The role of inspiratory capacity and tidal flow in diagnosing exercise ventilatory limitation in Cystic Fibrosis.

BACKGROUND: Exercise ventilatory limitation conventionally defined by reduced breathing reserve (BR) may underestimate the effect of lung disease on exercise capacity in patients with mild to moderate obstructive lung diseases. OBJECTIVE: To investigate whether ventilatory limitation may be present despite a normal BR in Cystic Fibrosis (CF). METHODS: Twenty adult CF patients (age 16-58y) with a wide range of pulmonary obstruction severity completed a symptom-limited incremental exercise test on a cycle ergometer. Operating lung volumes were derived from inspiratory capacity (IC) measurement during exercise and exercise tidal flow volume loop analysis. RESULTS: six patients had a severe airway obstruction (FEV1<45% predicted) and conventional evidence of ventilatory limitation (low BR). Fourteen patients had mild to moderate-severe airway obstructive (FEV1 46-103% predicted), and a normal BR [12-62 L/min, BR% (17-40)]. However, dynamic respiratory mechanics demonstrated that even CF patients with mild to moderate-severe lung disease had clear evidence of ventilatory limitation during exercise. IC was decreased by (median) 580 ml (range 90-1180 ml) during exercise, indicating dynamic hyperinflation. Inspiratory reserve volume at peak exercise was 445 ml (241-1350 ml) indicating mechanical constraint on the respiratory system. The exercise tidal flow met or exceeded the expiratory boundary of the maximal flow volume loop over 72% of the expiratory volume (range 40-90%), indicating expiratory flow limitation. CONCLUSION: Reduced BR as a sole criterion underestimates ventilatory limitation during exercise in mild to moderate-severe CF patients. Assessment of dynamic respiratory mechanics during exercise revealed ventilatory limitation, present even in patients with mild obstruction.

Slow chest compression acutely reduces dynamic hyperinflation in people with chronic obstructive pulmonary disease: a randomized cross-over trial.

BACKGROUND: Strategies to minimize dynamic hyperinflation (DH) and dyspnea, such as slow chest compression (SCC), are relevant in people with chronic obstructive pulmonary disease (COPD). OBJECTIVES: To analyze the acute effects of SCC after exercise on DH and dyspnea in people with COPD and to identify responders to the technique. METHODS: This is a cross-over study with 40 patients. Two six-minute step tests (6MSTs) were performed followed by a one-minute application of SCC (6MSTSCC) or rest (6MSTCONTROL), at random. End-expiratory lung volume (EELV) and dyspnea were assessed. A difference ≥76 ml in ΔEELV between SCC and control characterized the responders. RESULTS: The performance in 6MSTSCC and 6MSTCONTROL were similar. There was a greater reduction in EELV after 6MSTSCC compared to 6MSTCONTROL (124 ± 193 ml vs. 174 ± 183 ml; p = .049), while there was no difference in change in dyspnea between the SCC and control groups. Twenty-one participants were SCC responders and had higher functional residual capacity [FRC: 5.36 ± 1.09 vs. 4.58 ± 0.94; p = .02; cutoff point: 4.56; sensitivity = 76%; specificity = 53%; AUC = 0.71 (95%CI: 0.54 to 0.87); p = .02]. CONCLUSION: SCC applied immediately after exercise reduced DH, but did not reduce dyspnea in people with COPD. The technique is beneficial only for some patients and FRC can help to identify them.

Effect of Six-Minute Walk Test and Incremental Exercise on Inspiratory Capacity, Ventilatory Constraints, Breathlessness and Exercise Performance in Sedentary Male Smokers without Airway Obstruction.

We investigated physiological responses and exercise capacity in sedentary young smokers during sub-maximal and maximal test and its impact on dyspnea and exercise intolerance. Fifty sedentary male smokers and non-smokers (age: 24 ± 1 years., weight: 71 ± 9 kg, height: 177.3 ± 4.8 cm, body mass index: 22.6 ± 2.5 kg/m2) underwent two visits with pulmonary function tests, breathing pattern, and inspiratory capacity measurement at rest and during sub-maximal and maximal exercise. Smokers show reduced exercise capacity during six minutes walk test (6-MWT) with decreased walked distance (p < 0.001) and inspiratory capacity (p < 0.05). During cardiopulmonary exercise test (CPET), smokers had higher minute ventilation VE for a given submaximal intensity (p < 0.05) and lower minute ventilation at maximal exercise (p < 0.001). End expiratory lung volume was significantly lower in sedentary smokers at rest (p < 0.05), at ventilatory threshold during exercise (p < 0.05), but not during peak exercise. End inspiratory lung volume was significantly lower in smokers at rest (p < 0.05) and ventilatory threshold (p < 0.05). Cigarette smoking alters lung function during submaximal and maximal exercise. This alteration is manifested by the development of dynamic hyperinflation contributing to exercise capacity limitation.

[Effectiveness and safety evaluation of a cough stimulation device in early postoperative respiratory rehabilitation in cardiac surgery patients]. / Otsenka effektivnosti i bezopasnosti apparatnoi stimulyatsii kashlya pri rannei posleoperatsionnoi respiratornoi reabilitatsii u kardiokhirurgicheskikh patsientov.

Postoperative respiratory complications in cardiac surgery patients occur in 22-30% of cases, mostly associated with ineffective cough and evacuation of bronchial secretion. OBJECTIVE: To evaluate the effectiveness and safety of cough stimulation using the mechanical in- and exsufflator in the early postoperative period in cardiac surgery patients. MATERIAL AND METHODS: The study included 37 patients; mean age was 57±12.3 years. Inclusion criteria: age over 18 years; post-extubation spontaneous breathing; fully conscious and cooperative; adequate gas exchange with oxygen therapy; adequate pain control (2 points or less on 10-point visual analogue scale). Exclusion criteria: need for re-intubation and mechanical ventilation; noninvasive mask ventilation; high-flow oxygen therapy; acute cerebrovascular event; uncontrolled bleeding; heart failure (inotropic score over 10); shock; need of extracorporeal blood purification; neuromuscular disease; pneumothorax, hydro- or hemothorax. Cough stimulation was performed using the mechanical in- and exsufflator Comfort Cough Plus («Seoil Pacific Corporation¼, Republic of Korea). The device provides cough stimulation after high-frequency vibrations transmitted through a special vest and lung tissue recruiting by changing the airways pressure of the gas mixture, delivered through the anesthesia face mask. RESULTS: Cough stimulation device use was associated with an increase in the cough effectiveness; the number of patients with productive cough increased 8-fold, from 4 (10.8%) to 32 (86.4%), p=0.0000. The increase of blood oxygen saturation (SpO2) on room air from 92% to 96% (p=0.000001) and inspiratory capacity (IC) from 750 mL to 1200 mL (p=0.000002) was observed. The number of patients with IC of 1200-1500 mL increased 3-fold, and those with an IC over 1500 mL increased 2.6-fold. The proportion of patients with low oxygenation (SpO2 less than 92%) decreased 5-fold after the procedure (p=0.0011). Good tolerability and no side effects of the procedure were noted in all patients. CONCLUSION: Impaired sputum expectoration early after cardiac surgery is observed in most patients and may cause low oxygenation. The main effects of the cough stimulation device were improvement of sputum expectoration and an increase in oxygenation. An increase in blood oxygen saturation and inspiratory capacity after a single procedure with this device was demonstrated. It resulted in a significantly decreased proportion of patients with respiratory insufficiency. No adverse effects of the procedure were observed.

Effects of Tiotropium/Olodaterol on Activity-Related Breathlessness, Exercise Endurance and Physical Activity in Patients with COPD: Narrative Review with Meta-/Pooled Analyses.

One of the most debilitating symptoms of chronic obstructive pulmonary disease (COPD) is breathlessness, which leads to avoidance of physical activities in daily living and hastens clinical deterioration. Treatment of patients with COPD with inhaled long-acting muscarinic antagonist (LAMA)/long-acting ß2-agonist (LABA) combination therapy improves airflow limitation, reduces breathlessness compared with LAMA or LABA monotherapies, and improves health status and quality of life. A large clinical trial programme focusing on the effects of tiotropium/olodaterol combination therapy demonstrated that this LAMA/LABA combination improves lung function and reduces hyperinflation (assessed by serial inspiratory capacity measurements) compared with either tiotropium alone or placebo in patients with COPD. Tiotropium/olodaterol also increases exercise endurance capacity and improves patient perception of the intensity of breathlessness compared with placebo. In this narrative review, we focus on the relationship between improving symptoms during activity, the ability to remain active in daily life and how this may impact quality of life. We consider the benefits of therapy optimisation by means of dual bronchodilation with tiotropium/olodaterol, and present new data from meta-analyses/pooled analyses showing that tiotropium/olodaterol improves inspiratory capacity compared with placebo and tiotropium and improves exercise endurance time compared with placebo after 6 weeks of treatment. We also discuss the importance of taking a holistic approach to improving physical activity, including pulmonary rehabilitation and exercise programmes in parallel with bronchodilator therapy and psychological programmes to support behaviour change.

Induction of dynamic hyperinflation by expiratory resistance breathing in healthy subjects - an efficacy and safety study.

NEW FINDINGS: What is the central question of this study? The study aimed to establish a novel model to study the chronic obstructive pulmonary disease (COPD)-related cardiopulmonary effects of dynamic hyperinflation in healthy subjects. What is the main finding and its importance? A model of expiratory resistance breathing (ERB) was established in which dynamic hyperinflation was induced in healthy subjects, expressed both by lung volumes and intrathoracic pressures. ERB outperformed existing methods and represents an efficacious model to study cardiopulmonary mechanics of dynamic hyperinflation without potentially confounding factors as present in COPD. ABSTRACT: Dynamic hyperinflation (DH) determines symptoms and prognosis of chronic obstructive pulmonary disease (COPD). The induction of DH is used to study cardiopulmonary mechanics in healthy subjects without COPD-related confounders like inflammation, hypoxic vasoconstriction and rarefication of pulmonary vasculature. Metronome-paced tachypnoea (MPT) has proven effective in inducing DH in healthy subjects, but does not account for airflow limitation. We aimed to establish a novel model incorporating airflow limitation by combining tachypnoea with an expiratory airway stenosis. We investigated this expiratory resistance breathing (ERB) model in 14 healthy subjects using different stenosis diameters to assess a dose-response relationship. Via cross-over design, we compared ERB to MPT in a random sequence. DH was quantified by inspiratory capacity (IC, litres) and intrinsic positive end-expiratory pressure (PEEPi, cmH2 O). ERB induced a stepwise decreasing IC (means (95% CI): tidal breathing: 3.66 (3.45-3.88), ERB 3 mm: 3.33 (1.75-4.91), 2 mm: 2.05 (0.76-3.34), 1.5 mm: 0.73 (0.12-1.58) litres) and increasing PEEPi (tidal breathing: 0.70 (0.50-0.80), ERB 3 mm: 11.1 (7.0-15.2), 2 mm: 22.3 (17.1-27.6), 1.5 mm: 33.4 (3.40-63) cmH2 O). All three MPT patterns increased PEEPi, but to a far lesser extent than ERB. No adverse events during ERB were noted. In conclusion, ERB was proven to be a safe and efficacious model for the induction of DH and might be used for the investigation of cardiopulmonary interaction in healthy subjects.

Evaluation of Dynamic Respiratory Mechanical Abnormalities During Conventional CPET.

Assessment of the ventilatory response to exercise is important in evaluating mechanisms of dyspnea and exercise intolerance in chronic cardiopulmonary diseases. The characteristic mechanical derangements that occur during exercise in chronic respiratory conditions have previously been determined in seminal studies using esophageal catheter pressure-derived measurements. In this brief review, we examine the emerging role and clinical utility of conventional assessment of dynamic respiratory mechanics during exercise testing. Thus, we provide a physiologic rationale for measuring operating lung volumes, breathing pattern, and flow-volume loops during exercise. We consider standardization of inspiratory capacity-derived measurements and their practical implementation in clinical laboratories. We examine the evidence that this iterative approach allows greater refinement in evaluation of ventilatory limitation during exercise than traditional assessments of breathing reserve. We appraise the available data on the reproducibility and responsiveness of this methodology. In particular, we review inspiratory capacity measurement and derived operating lung volumes during exercise. We demonstrate, using recent published data, how systematic evaluation of dynamic mechanical constraints, together with breathing pattern analysis, can provide valuable insights into the nature and extent of physiological impairment contributing to exercise intolerance in individuals with common chronic obstructive and restrictive respiratory disorders.

Dyspnea During Night-Time and at Early Morning in Patients with Stable COPD is Associated with Supine Tidal Expiratory Flow Limitation.

Rationale: Patients with chronic obstructive pulmonary disorder (COPD) complain of various COPD-related symptoms with different daily frequencies. During the night-time and at early morning, dyspnea is often reported and may predict an increased risk of COPD exacerbation and hospitalization and all-cause mortality. The aim of the study was to assess the underlying mechanisms of this symptom, seeking functional biomarkers of its occurrence. Methods: Stable COPD patients with moderate-to-severe airflow obstruction and without confounding comorbidities underwent extensive baseline function respiratory tests. Spirometry, maximal flow-volume curves, lung volumes, and lung diffusion capacity parameters were obtained. Inspiratory capacity was also measured both in seated and supine positions. Forced oscillation technique (FOT) and negative expiratory pressure (NEP) method were used to establish the presence of tidal expiratory flow limitation (EFL) during recumbency. Questionnaires for recording COPD-related symptoms were administered. Sleep-related disturbances reported by the patients were also registered. Results: Forty-two consecutive COPD patients aged 65±9 completed the protocol. They were divided, according to the absence (NFL) or presence (FL) of supine EFL, in NFL group (n=17) and FL group (n=25). FL COPD patients had more severe airflow obstruction (FEV1= 46.4±19.4 vs 65.1±12.5% pred., p<0.01) and they showed no increase of supine IC in contrast with NFL COPD patients (ΔIC= 0.080±0.18 vs 0.390±0.28 L, p<0.01). Dyspnea either during night-time and at early morning was significantly more reported in FL COPD patients than in NFL COPD patients (p<0.05) and in those with less than 10% increase in supine IC (p<0.05). Conclusion: Supine EFL is frequently associated with both night-time and early morning dyspnea, suggesting that the development of recumbent dynamic pulmonary hyperinflation, heralded by the lack of increment of IC in supine position, is a pivotal mechanism of this symptom. No or trivial increase in supine IC may indicate the occurrence of dyspnea under these conditions.

Metronome-Paced Incremental Hyperventilation May Predict Exercise Tolerance and Dyspnea as a Surrogate for Dynamic Lung Hyperinflation During Exercise.

Background: Dynamic lung hyperinflation (DLH) has been evaluated based on decreased inspiratory capacity (IC) during exercise load. However, this is not routinely done in clinical practice. We have developed a convenient method of metronome-paced incremental hyperventilation (MPIH) and reported its usefulness. In the present study, we compared these two methods for evaluating DLH and examined whether our MPIH method can be used to predict DLH during exercise. Methods: DLH was measured by MPIH and constant load exercise (CLE) in 35 patients with stable COPD. DLH was defined as the most decreased IC (IClowest) and the most decreases in IC from IC at rest (-IClowest), and we compared between these two methods. Results: The IClowest in CLE and the -IClowest in MPIH were significantly lower in emphysema-dominant COPD than in emphysema-nondominant COPD. Both IClowest and -IClowest showed significant correlations between the two methods (r = 0.67, p < 0.01 and r = 0.44, p < 0.01, respectively). The endurance time of CLE was significantly correlated with IClowest following MPIH (r = 0.62, p < 0.01) but not with that obtained by the CLE method. Furthermore, the IClowest of MPIH was more significantly correlated with endurance time in emphysema-dominant COPD. Weak but significant correlations between the -IClowest obtained by each method and maximum modified Borg scale were observed (MPIH: r = 0.38, p = 0.02; CLE: r = 0.37, p = 0.03). Conclusion: The MPIH method may be a convenient method to predict exercise tolerance and dyspnea as a clinically useful synergic screening surrogate for DLH during exercise.

The effects of decreased inspiratory capacity on postural stability during backward reach.

[Purpose] The purpose of this study is to investigate the effect of decreased inspiratory capacity on the backward reach distance in healthy young individuals, as patients with chronic obstructive pulmonary disease have a high risk of falling. [Participants and Methods] Thirteen healthy volunteers (age, 19.2 ± 0.4 years: mean ± SD) participated in this study. We recorded the backward reach distance at the resting expiration level and at two different inspiratory capacity levels: -1/3 and -2/3 of inspiratory capacity, when the air is inhaled at resting expiration level. We assessed the backward reach distance for each inspiratory capacity, using one-way repeated measures analysis of variance and post-hoc analysis. [Results] We found that inspiratory capacity has a significant effect on backward reach distance. The backward reach distance was significantly decreased in participants with a -2/3 inspiratory capacity, compared with the backward reach distance in participants with a resting expiration level. [Conclusion] Patients with lung volume fractionation and decreased inspiratory capacity lack postural stability during backward reach. Therefore, the link between decreased inspiratory capacity and loss of balance in patients with chronic obstructive pulmonary disease may, in part, be due to decreased postural stability, and the resulting tendency to plan movements, which create a loss of balance.

Efectos del tratamiento con quimioterapia y radioterapia concomitante sobre los volúmenes pulmonares en mujeres con cáncer de mama en Talca, Chile / Effects of concurrent chemotherapy and radiotherapy on lung volumes in women with breast cancer living in Talca, Chile

Resumen Introducción. El cáncer de mama (CM) es la enfermedad crónica no transmisible más frecuente y letal en mujeres. La información disponible sobre el impacto de sus diversos tratamientos en el sistema respiratorio es controversial. Objetivo. Determinar el efecto del tratamiento con quimioterapia y radioterapia concomitante en los volúmenes pulmonares de un grupo de mujeres con CM en Talca, Chile. Materiales y métodos. Estudio de casos y controles. La muestra (n=22) se dividió en dos grupos: control (n = 11) y con CM (n = 11). Para medir la capacidad vital forzada, los volúmenes pulmonares y la resistencia de las vías aéreas, se usó la prueba de pletismografía corporal. Para determinar la normalidad de los datos, se usó la prueba Shapiro-Wilks y, según sus resultados, se utilizó la prueba de t-Student o la de U de Mann-Whitney; se consideró un nivel de significancia de p<0.05. Resultados. Los flujos ventilatorios no presentaron diferencias significativas entre los dos grupos, mientras que los volúmenes pulmonares en el grupo con CM experimentaron una disminución significativa en las variables capacidad inspiratoria (CI) y volumen residual (VR) (p<0.05). Conclusión. Las mujeres con CM y que fueron tratadas con quimioterapia y radioterapia concomitante experimentaron una disminución en su CI y su VR en comparación con el grupo control, lo que podría impactar su calidad de vida.

Abstract Introduction: Breast cancer (BC) is the most frequent and lethal chronic non-communicable disease in women, and available information on the impact that the different treatments for BC have on the respiratory system is controversial. Objective: To determine the effect of concurrent chemotherapy and radiotherapy on lung volumes in a group of women with BC living in Talca, Chile. Material and methods: Case-control study. The sample (n=22) was divided into two groups: control (n=11) and BC (n=11). A whole body plethysmography test was used to measure participants' forced vital capacity, lung volumes, and airway resistance. The Shapiro-Wilks test was used to determine the normality of data, and, according to the result of this test, the Student's t test or the Mann-Whitney U test were used. A significance level of p<0.05 was considered. Results: Ventilatory flows showed no significant differences between both groups, while lung volumes in the BC group experienced a significant decrease in the inspiratory capacity (IC) and residual volume (RV) variables (p<0.05). Conclusion: Compared to the CG, the women with BC who received concurrent chemotherapy and radiotherapy experienced a reduction of their IC and RV, which could affect their quality of life.

Absence of dynamic hyperinflation during exhaustive exercise in severe COPD reflects submaximal IC maneuvers rather than a nonhyperinflator phenotype.

Approximately 20% of chronic obstructive pulmonary disease (COPD) patients have been considered to have a "nonhyperinflator phenotype." However, this judgment depends on patients making a fully maximal inspiratory capacity (IC) maneuver at rest, since the IC during exercise is compared with this baseline measurement. We hypothesized that IC maneuvers at rest are sometimes submaximal and tested this hypothesis by measuring IC and associated neural respiratory drive at rest and during inhalation of CO2 and exercise in patients with COPD. Twenty-six COPD patients [age 66 ± 6 yr, mean forced expiratory volume in 1 s (FEV1) 40 ± 11% predicted] and 39 healthy subjects (age 39 ± 14 yr, FEV1 98 ± 12% predicted) were studied. IC and the diaphragm electromyogram (EMGdi) associated with it (EMGdi-IC) and forced inspiratory vital capacity (FIVC) and its corresponding EMGdi (EMGdi-FIVC) were measured during inhalation of 8% CO2 (8% CO2-92% O2) and room air. Incremental exhaustive cycle ergometer exercise was also performed in both patients with COPD and healthy subjects. IC, EMGdi-IC, FIVC, and EMGdi-FIVC during breathing 8% CO2 were significantly greater than those during breathing room air in both patients with COPD and healthy subjects (all P < 0.001). EMGdi-IC in patients with COPD constantly increased during exercise from 145 ± 40 µV at rest to 185 ± 52 µV at the end of exercise but change in IC was variable. Neural respiratory drive and its relevant IC increased during hypercapnia. Exercise-related hypercapnia in patients with COPD raises neural respiratory drives, which compensate for IC reduction, leading to underestimation of dynamic hyperinflation measured by IC at rest breathing room air.NEW & NOTEWORTHY Inspiratory capacity measured during hypercapnia is higher than that during eucapnia. Thus total lung capacity is not always be achieved by a standard inspiratory capacity maneuver, leading to risk of underestimation of dynamic hyperinflation in patients with severe chronic obstructive pulmonary disease after exhaustive exercise.

Incentive spirometry inspiratory capacity changes and predictors after open heart surgery: a 5-day prospective study

@#Introduction: Incentive spirometry (IS) is commonly used for increasing postoperative IS inspiratory capacity (ISIC) after open heart surgery (OHS). However, little is known about the serial changes in ISIC and their predictive factors. Objective: The aim of this study is to identify the postoperative ISIC changes relative to preoperative ISIC after OHS, and determine their predictors, including patient characteristics factors and IS performance parameters such as inspiration volumes (ISv) and frequencies (ISf). Methods: This is a prospective study with blinding procedures involving 95 OHS patients, aged 52.8±11.5 years, whose ISIC was measured preoperatively (PreopISIC) until fifth postoperative day (POD), while ISv and ISf monitored with an electronic device from POD1-POD4. Regression models were used to identify predictors of POD1 ISIC, POD2- POD5 ISIC increments, and the odds of attaining PreopISIC by POD5. Results: The ISIC reduced to 41% on POD1, increasing thereafter to 57%, 75%, 91%, and 106% from POD2-POD5 respectively. Higher PreopISIC (B=-0.01) significantly predicted lower POD1 ISIC, and, together with hyperlipedemia (B=11.52), which significantly predicted higher POD1 ISIC, explained 13% of variance. ISv at relative percentages of PreopISIC from POD1-POD4 (BPOD1=0.60, BPOD2=0.56, BPOD3=0.49, BPOD4=0.50) significantly predicted ISIC of subsequent PODs with variances at 23%, 24%, 17% and 25% respectively, but no association was elicited for ISf. IS performance findings facilitated proposal of a postoperative IS therapy target guideline. Higher ISv (B=0.05) also increased odds of patients recovering to preoperative ISIC on POD5 while higher PreopISIC (B=- 0.002), pain (B=-0.72) and being of Indian race (B=-1.73) decreased its odds. Conclusion: ISv appears integral to IS therapy efficacy after OHS and the proposed therapy targets need further verification through randomized controlled trials.

Bronchodilators for hyperinflation in COPD associated with biomass smoke: clinical trial.

Introduction: The efficacy of long-acting bronchodilators for COPD associated with biomass (BE-COPD) has not been properly evaluated. Objective: To determine the acute effect of indacaterol (IND) 150 µg q.d and tiotropium (TIO) 18 µg q.d. on lung hyperinflation, walking distance (WD) and dyspnea during the six-minute walking test (6MWT) in moderate BE-COPD at 30, 60 and 240 mins post-drug administration. Design: Randomized, controlled, open-level, crossover noninferiority clinical trial. Forty-two women with BE-COPD were randomly assigned to a bronchodilator sequence: IND-TIO or vice versa. Results: There were statistically significant changes over time in inspiratory capacity (IC) (p<0.0001), FEV1 (p<0.0001) and FVC (p<0.0001) when IND was used. When TIO was administered, an increase over all time periods was observed only for FEV1 (p<0.0001) and FVC (p<0.0001), whereas for IC an increase was observed only at 30 mins and 24 hrs after TIO administration. We did not find clinically significant increases in WD and dyspnea after the administration of both bronchodilators. Conclusion: Both IND and TIO showed significant and fast onset improvement in hyperinflation. Therefore, either of them may be recommended as a first line of treatment for COPD associated with BE-COPD.