Dyspnea scales in the assessment of illiterate patients with chronic obstructive pulmonary disease

Effect and feasibility of non-linear periodized resistance training in people with COPD: study protocol for a randomized controlled trial

BACKGROUND

In people with chronic obstructive pulmonary disease (COPD), limb-muscle dysfunction is one of the most troublesome systemic manifestations of the disease, which at the functional level is evidenced by reduced strength and endurance of limb muscles. Improving limb-muscle function is an important therapeutic goal of COPD management, for which resistance training is recommended. However, current guidelines for resistance training in COPD mainly focus on improving muscle strength which only reflects one aspect of limb-muscle function and does not address the issue of reduced muscle endurance. The latter is of importance considering that the reduction in limb-muscle endurance often is greater than that of muscle weakness, and also, limb-muscle endurance seems to be closer related to walking capacity as well as arm function than to limb-muscle strength within this group of people. Thus, strategies targeting multiple aspects of the decreased muscle function are warranted to increase the possibility for an optimal effect for the individual patient. Periodized resistance training, which represents a planned variation of resistance training variables (i.e., volume, intensity, frequency, etc.), is one strategy that could be used to target limb-muscle strength as well as limb-muscle endurance within the same exercise regimen.

METHODS

This is an international, multicenter, randomized controlled trial comparing the effect and feasibility of non-linear periodized resistance training to traditional non-periodized resistance training in people with COPD. Primary outcomes are dynamic limb-muscle strength and endurance. Secondary outcomes include static limb-muscle strength and endurance, functional performance, quality of life, dyspnea, intramuscular adaptations as well as the proportion of responders. Feasibility of the training programs will be assessed and compared on attendance rate, duration, satisfaction, drop-outs as well as occurrence and severity of any adverse events.

DISCUSSION

The proposed trial will provide new knowledge to this research area by investigating and comparing the feasibility and effects of non-linear periodized resistance training compared to traditional non-periodized resistance training. If the former strategy produces larger physiological adaptations than non-periodized resistance training, this project may influence the prescription of resistance training in people with COPD.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT03518723 . Registered on 13 April 2018.

How well do patients and providers agree on the severity of dyspnea?

BACKGROUND

Understanding the severity of patients' dyspnea is critical to avoid under- or overtreatment of patients with acute cardiopulmonary conditions.

OBJECTIVE

To evaluate the agreement between dyspnea assessment by patients and healthcare providers and to explore which factors contribute to discordance in assessment.

DESIGN, SETTINGS AND PARTICIPANTS

Prospective study of patients hospitalized for acute cardiopulmonary diseases at an urban teaching hospital.

INTERVENTION AND MEASUREMENTS

A numerical rating scale (0-10) was used to assess dyspnea severity as perceived by patients and assessed by providers. Agreement was defined as a score within ±1 between patient and healthcare provider; differences of ≥2 points were considered over- or underestimations. The relationship between patient self-perceived dyspnea severity and provider rating was assessed using a weighted kappa coefficient.

RESULTS

Of the 138 patients enrolled, 33% had a diagnosis of heart failure, 30% chronic obstructive pulmonary disease, and 13% pneumonia; median age was 72 years, and 57% were women. In all, 96 patient-physician and 138 patient-nurses pairs were included in the study. The kappa coefficient for agreement was 0.11 (95% confidence interval [CI]: 0.01 to 0.21) between patients and physicians and 0.18 (95% CI: 0.12 to 0.24) between patients and nurses. Physicians underestimated patients' dyspnea 37.9% of the time and overestimated it 25.8% of the time, whereas nurses underestimated it 43.5% of the time and overestimated it 12.4% of the time. Admitting diagnosis was the only patient factor associated with discordance.

CONCLUSIONS

Agreement between patient perception of dyspnea and healthcare providers' assessment is low. Future studies should prospectively test whether routine assessment of dyspnea results in better patient outcomes. Journal of Hospital Medicine 2016;11:701-707. © 2016 Society of Hospital Medicine.

Effect of endurance training on expiratory flow limitation and dynamic hyperinflation in patients with stable chronic obstructive pulmonary disease

BACKGROUND

Expiratory flow limitation (EFL) is the primary pathophysiological hallmark of chronic obstructive pulmonary disease (COPD). However, the effect of lower-extremity endurance training alone on EFL in patients with COPD remains largely unknown.

AIM

This study aims to determine the effects of endurance training on EFL and dynamic hyperinflation in patients with stable COPD.

METHODS

This was a prospective, single-blinded, non-randomised controlled 12-week study recruiting Chinese patients with stable COPD in an endurance training group (n = 15) or a control group (n = 13). Before and at the end of the study, we measured the EFL, pulmonary function, peak inspiratory flow (PIF) and maximum inspiratory pressure (MIP); moreover, the patients underwent a constant work rate exercise test in which Borg dyspnoea scale, tidal breathing flow volume curves and inspiratory capacity (IC) were determined every other minute.

RESULTS

Exercise training significantly improved the exercise endurance time (7.00 ± 3.05 vs 18.13 ± 6.44 min, P < 0.001), MIP (69.49 ± 16.03 vs 80.18 ± 15.97 cmH2 O, P < 0.001) and PIF (3.96 ± 1.01 vs 4.51 ± 1.13 L/s, P = 0.014), but not EFL (3.33 ± 0.49 vs 3.40 ± 0.51, P = 0.334). Subjects on training had decreased breathing frequency (26.26 ± 7.13 vs 23.15 ± 5.34 breaths/min, P = 0.002), minute ventilation (30.28 ± 7.52 vs 26.85 ± 4.17 L, P = 0.013), tidal peak expiratory flow (1.53 ± 0.22 vs 1.32 ± 0.20 L/s, P = 0.006), mean expiratory flow (0.87 ± 0.19 vs 0.68 ± 0.15 L/s, P = 0.011) and Borg dyspnoea score (7.20 ± 1.15 vs 3.93 ± 1.39, P < 0.001), as well as increased IC (1.50 ± 0.34 vs 1.67 ± 0.45 L, P = 0.002), expiratory time (1.47 ± 0.62 vs 1.72 ± 0.62 s, P = 0.004) and inspiratory flow reserve (2.05 ± 1.10 vs 2.95 ± 1.19 L/s, P = 0.002) at isotime. These changes were not observed in the control group.

CONCLUSION

Endurance training may benefit stable COPD patients in improving exercise endurance, inspiratory muscle strength, ventilatory requirements, exercise-induced hyperinflation and exertional dyspnoea.

Muscular and functional effects of partitioning exercising muscle mass in patients with chronic obstructive pulmonary disease - a study protocol for a randomized controlled trial

BACKGROUND

Low-load, high-repetitive single-limb resistance training may increase limb muscle function and functional exercise capacity in patients with chronic obstructive pulmonary disease (COPD) while minimizing the occurrence of limiting exertional symptoms. Whether high-repetitive single-limb resistance training would perform better than high-repetitive two-limb resistance training is unknown. In addition, the mechanisms underlying possible benefits of high-repetitive resistance training has not been investigated. The aims of this study are to compare single versus two-limb high-repetitive resistance training in patients with COPD and to investigate mechanisms of action of these training modalities.

METHODS/DESIGN

This trial is a prospective, assessor-blind, randomized controlled trial. The participants are patients with stable severe to very severe COPD who are older than 40 years of age and healthy controls. The intervention is single-limb, high-repetitive, resistance training with elastic bands, three times/week for 8 weeks. The control is two-limb high-repetitive resistance training with elastic bands, three times/week for 8 weeks. The primary outcomes is change in the 6-min walking distance after 8 weeks of single-limb or two-limb high-repetitive resistance training. The secondary outcomes are changes in limb muscle strength and endurance capacity, key protein involved in quadriceps anabolic/catabolic signalization, fiber-type distribution and capillarization, subjective dyspnea and muscle fatigue, muscle oxygenation, cardiorespiratory demand and health-related quality-of-life after 8 weeks of single-limb or two-limb high-repetitive resistance training. The acute effects of single-limb versus two-limb high-repetitive resistance training on contractile fatigue, exercise stimulus (the product of number of repetition and load), subjective dyspnea and muscle fatigue, muscle oxygenation, and cardiorespiratory demand during upper and lower limb exercises will also be investigated in patients with COPD and healthy controls. Randomization will be performed using a random number generator by a person independent of the recruitment process, using 1:1 allocation to the intervention and the control group using random block sizes.

BLINDING

All outcome assessors will be blinded to group assignment.

DISCUSSION

The results of this project will provide important information to help developing and implementing customized exercise training programs for patients with COPD.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT02283580 Registration date: 4 November 2014. First participant randomized: 10 November 2014.

Assessing the effect of high-repetitive single limb exercises (HRSLE) on exercise capacity and quality of life in patients with chronic obstructive pulmonary disease (COPD): study protocol for randomized controlled trial

Background

Single-limb knee extension exercises have been found to be effective at improving lower extremity exercise capacity in patients with chronic obstructive pulmonary disease (COPD). Since the positive local physiological effects of exercise training only occur in the engaged muscle(s), should upper extremity muscles also be included to determine the effect of single limb exercises in COPD patients.

Methods/design

Trial design: a prospective, assessor-blind, block randomized controlled, parallel-group multicenter trial. Participants: stage II-IV COPD patients, > 40 years of age, ex-smokers, with stable medical treatment will be included starting May 2011. Recruitment at three locations in Sweden. Interventions: 1) high-repetitive single limb exercise (HRSLE) training with elastic bands, 60 minutes, three times/week for 8 weeks combined with four sessions of 60 minutes patient education, or 2) the same patient education alone. Outcomes: Primary: determine the effects of HRSLE on local muscle endurance capacity (measured as meters walked during 6-minute walk test and rings moved on 6-minute ring and pegboard test) and quality of life (measured as change on the Swedish version of the Chronic Respiratory Disease Questionnaire). Secondary: effects on maximal strength, muscular endurance, dyspnea, self-efficacy, anxiety and depression. The relationship between changes in health-related variables and changes in exercise capacity, sex-related differences in training effects, feasibility of the program, strategies to determine adequate starting resistance and provide accurate resistance for each involved movement and the relationship between muscle fatigue and dyspnea in the different exercise tests will also be analyzed. Randomization: performed by a person independent of the recruitment process and using a computer random number generator. Stratification by center and gender with a 1:1 allocation to the intervention or control using random block sizes. Blinding: all outcome assessors will be blinded to group assignment.

Discussion

The results of this project will contribute to increase the body of knowledge regarding COPD and HRSLE.

Trial registration

ClinicalTrials.gov Identifier: NCT01354067. Registration date: 2011-05-11. First participant randomized: 2011-09-02

Exhaled breath condensate 8-isoprostane, clinical parameters, radiological indices and airway inflammation in COPD

BACKGROUND

Exhaled breath condensate (EBC) 8-isoprostane levels were found increased in chronic obstructive pulmonary disease. However, the relation between EBC 8-isoprostane and parameters which have a known predictive value in COPD, remains vastly unknown, and so does subsequently its clinical value.

OBJECTIVES

To investigate the relationship between 8-isoprostane level in EBC and clinical parameters, radiological indices and airway inflammation in COPD patients.

MATERIALS AND METHODS

We studied 18 COPD patients (all ex-smokers) and 12 healthy controls (5 ex-smokers and 7 never-smokers). All patients underwent clinical evaluation, sputum induction, high-resolution computed tomography (HRCT) of the thorax and EBC 8-isoprostane measurement. 8-Isoprostane levels were correlated with markers that reflect disease severity, such as dyspnea severity, FEV(1) (%pred), emphysema changes and bronchiectasis in HRCT. Emphysema was quantified as the percentage of lung area with attenuation values < -950 Hounsfield units.

RESULTS

8-Isoprostane levels were significantly elevated in EBC of patients with COPD [mean (SE) 18.1 (2) vs. 5.6 (0.7) pg/ml, p = 0.0001], irrespective of lung function impairment. 8-Isoprostane levels were correlated with emphysema score in HRCT (r(2) = 0.43, p = 0.001) as well as with Medical Research Council dyspnea scale score (rho = 0.61, p = 0.005).

CONCLUSION

Our findings suggest that EBC 8-isoprostane levels may reflect the extension of lung emphysema in COPD patients. In this respect, further investigation is required in order to evaluate the possible role of EBC 8-isoprostane in assessing disease progress in COPD patients.

Exacerbations and lung function decline in COPD: New insights in current and ex-smokers

AIM

To investigate whether there is a significant relationship between an increased frequency of exacerbations and the rate of forced expiratory volume in 1s (FEV(1)) decline in COPD patients. METHODS-MEASUREMENTS: About 102 COPD patients (44 smokers, 58 ex-smokers) participated in a 3-year prospective study. Exacerbations were identified as worsening of patient's respiratory symptoms as recorded on diary cards. Spirometry was performed every 6 months. The effect of frequent exacerbations on lung function was investigated using random effects models.

RESULTS

The median (mean(95% CI)) annual exacerbation rate was 2.85 (3.1 (2.7-3.6)). Patients with an annual exacerbation rate over the median rate had significantly lower baseline post-bronchodilation FEV(1)(%pred), higher MRC dyspnoea score and chronic cough compared to patients who had an annual exacerbation rate less than the median. The average annual rate of FEV(1)(%pred), adjusted for smoking decline (DeltaFEV(1)), was found significantly increased in frequent compared to infrequent exacerbators (P=0.017). The highest DeltaFEV(1) was observed in smokers frequent exacerbators and a significant interaction between exacerbation frequency and DeltaFEV(1) was also observed in ex-smokers.

CONCLUSIONS

Our findings suggest that an increased frequency of exacerbations is significantly associated with FEV(1) decline even in ex-smokers. Thus, smoking and frequent exacerbations may have both negative impact on lung function. Smoking cessation and prevention of exacerbations should be a major target in COPD.

Verbal numerical scales are as reliable and sensitive as visual analog scales for rating dyspnea in young and older subjects

This study compared the use of a simple verbal 0-10 numerical rating scale (verbal NRS) and a visual analog scale (VAS) for the rating of dyspnea during exercise in a group of young and older subjects. Twelve younger (32+/-9 yr) and 12 older (71+/-7 yr) subjects used either the verbal NRS or the VAS in a randomised fashion to rate dyspnea during 60 s of uphill treadmill walking (range 5.6-8.8 km h(-1)) performed at either a low (17% grade) or high workload (26% grade) and then during recovery. Rating scales were evaluated twice on separate days (day 1 and day 2) at each workload. While the verbal NRS scores proved to be reliable throughout exercise and recovery, VAS scores were significantly (p<0.05) lower on day 2 during the low workload test (younger group) and the high workload test (older group). Verbal NRS ratings were consistently greater than VAS ratings at both workloads (p<0.001) for both young and older groups. The intra-class correlation coefficients for rating peak dyspnea using either the VAS or verbal NRS were consistently lower for the older subjects (range: r=0.54-0.67) than the younger subjects (range: r=0.70-0.86). Overall, subjects preferred the verbal NRS to the VAS. These results suggest that the verbal NRS compares favourably with the VAS for rating dyspnea during exercise without mask or mouthpiece. However, when rating peak dyspnea both scales appear less reliable when used by the older compared to young subjects.

Dyspnea assessment and adverse events during sputum induction in COPD

Background

The inhalation of normal or hypertonic saline during sputum induction (SI) may act as an indirect bronchoconstrictive stimulus leading to dyspnea and lung function deterioration. Our aim was to assess dyspnea and adverse events in COPD patients who undergo SI following a safety protocol.

Methods

Sputum was induced by normal and hypertonic (4.5%) saline solution in 65 patients with COPD of varying severity. In order to minimize saline-induced bronchoconstriction a protocol based on the European Respiratory Society sputum induction Task group report was followed. Dyspnea change was scored using the Borg scale and lung function was assessed by spirometry and oximetry.

Results

Borg score changes [median(IQR) 1.5(0–2)] were observed during SI in 40 subjects; 16 patients required temporary discontinuation of the procedure due to dyspnea-general discomfort and 2 did not complete the session due to dyspnea-wheezing. The change in Borg dyspnea score was significantly correlated with oxygen saturation and heart rate changes and with discontinuation of the procedure due to undesired symptoms. 19 subjects presented an hyperresponsive reaction (decline>20% from baseline FEV₁). No significant correlation between Borg changes and FEV₁decline was found. Patients with advanced COPD presented significantly greater Borg and oxygen saturation changes than patients with less severe disease (p = 0.02 and p = 0.001, respectively). Baseline FEV₁, oxygen saturation and 6MWT demonstrated significant diagnostic values in distinguishing subjects who develop an adverse physiologic reaction during the procedure.

Conclusion

COPD patients undergoing SI following a safety protocol do not experience major adverse events. Dyspnea and oxygen desaturation is more likely to occur in patients with disease in advanced stages, leading to short discontinuation or less frequently to termination of the procedure. Baseline FEV₁, oxygen saturation and 6MWT may have a prognostic value for the development of these adverse events and might be useful to be evaluated in advance.

Effects of mandibular advancement on brain activation during inspiratory loading in healthy subjects: a functional magnetic resonance imaging study

Oral appliances have been a popular treatment option for subjects with obstructive sleep apnea. However, little information is available on how brain activation induced by respiratory challenge is modulated by mandibular advancement with these appliances. We hypothesized that the brain activation caused by respiratory stress may be alleviated by mandibular advancement. Respiratory stress was induced in 12 healthy subjects by resistive inspiratory loading. The effects of mandibular advancement during resistive inspiratory loading were assessed subjectively by using a visual analog scale. These effects were also evaluated objectively by using blood oxygenation level-dependent functional magnetic resonance imaging. The score for the visual analog scale significantly decreased with mandibular advancement. Cortical deactivation, in association with mandibular advancement, was localized to several specific regions, including the left cingulate gyrus and the bilateral prefrontal cortexes. These regions are known to be involved in respiratory control. Our results suggest that mandibular advancement with an oral appliance appears to be useful for reducing respiratory stress, based on both subjective and neuronal criteria.