Lack of Relationship Between Functional and Perceived Quality of Life Outcomes Following Pulmonary Rehabilitation

Individuals with chronic obstructive pulmonary disease (COPD) have been shown to benefit from participation in pulmonary rehabilitation (PR) programs that include exercise training and education. Purpose: To examine the relationship between improvements in 6 minute walk distance and perceived quality of life in individuals with COPD following completion of a PR program. Methods: The records of 139 individuals completing a PR program (3 times a week for 8 weeks) were retrospectively examined. Prior to entry and upon completion of the program each individual completed a 6 minute walk test (6MWT), the SF-36 Health survey, and the UCSD Shortness of Breath Questionnaire (SOB). SF-36 results were analyzed according to 8 subscales [Physical Functioning (PF), Role Physical (RF), Bodily Pain (BP), General Health (GH), Vitality (V), Social Functioning (SF), Role Emotional (RE), and Mental Health (MH)]. Results: PR resulted in significant improvements in 6MWTdistance (Pre = 845 ± 37 ft, Post = 1127 ± 32 ft, p < 0.001), PF (p < 0.001), RF (p = 0.001), Vitality (p = 0.002), SF (p < 0.001), RE (p = 0.037), MH (p < 0.001) and SOB (Pre = 53 ± 2, Post = 47 ± 2, p < 0.001). The change in 6MWT distance was not related to changes in PF (r = 0.17), RF (r = 0.03), GH (r = 0.03), Vitality (r = −0.001), SF (r = 0.01), RE (r = 0.06), MH (r = −0.04) or SOB (r = 0.12). The magnitude of improvement in 6MWT distance (68%) was much greater than that observed in PF (15%), RF (16%), GH (6%), VT (18%), SF (20%), RE (14%), MH (14%), or SOB (8%). Conclusions: PR has a positive impact on 6 minute walk distance and perceived quality of life in individuals with COPD; however, changes in 6 minute walk distance appear to have no relationship to changes in perceived quality of life.     

Examination of the Six Minute Walk Test to Determine Functional Capacity in People with Chronic Heart Failure: A Systematic Review

Purpose: To evaluate the reliability and validity of the six-minute walk test (6MWT) with respect to its ability to predict functional capacity in patients with chronic heart failure. Methods: A systematic review was performed via 8 databases to assess relevant English language full-text articles published from January 1, 1980 to October 31, 2009. Participant characteristics, interventions, reliability, validity, and predictive value for each article with respect to functional capacity as defined by peak VO₂ levels were extracted and compared. Quality Assessment of Diagnostic Accuracy Studies (QUADAS) scores were determined for each study. Results: Fourteen studies met the selection criteria. Comparison of the studies investigating reliability shows that the 6MWT has good reproducibility. The 6MWT demonstrates moderate correlation with peak VO₂ levels, and ability to predict VO₂ (functional capacity) dependent on distance walked. Cut-off distances vary from 300 to 490 meters depending on the study; if total distance walked remains equal or less than these values, the 6MWT retains its strong predictive value. Conclusion: The 6MWT has good reliability, moderate validity, and a significant ability to predict functional capacity in patients with CHF who do not walk greater than 490 meters.Key Words: six-minute walk test, chronic heart failure, functional capacity, peak VO₂     

Exercise Training in Patients with Pulmonary Arterial Hypertension: A Case Report

Purpose: To describe the benefits of a feasible, outpatient exercise training program on exercise tolerance and health-related quality of life (HRQL) in individuals with pulmonary arterial hypertension (PAH). Methods: Case report on two subjects recruited from a tertiary care pulmonary hypertension clinic. Subject 1 was a 50-year-old male with idiopathic PAH. Subject 2 was a 54-year-old female with a 20+ year history of scleroderma and 6-year history of PAH. Both subjects underwent exercise training 3 times per week for 6 weeks using a cycle ergometer at workloads progressing from 50% to 80% of peak workload. Outcomes were assessed using cardiopulmonary exercise testing, six-minute walk test (6MWT), and HRQL using the Chronic Respiratory Disease Questionnaire (CRQ) and the Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR). Results: Both subjects made substantial improvements in oxygen consumption and workload at anaerobic threshold (improvements of 3.8 and 4.2 mL·kg⁻¹·min,⁻¹ 26 and 18 W, respectively) and 6MWT distance (from 496 to 586m and 416 to 517m, respectively). Only Subject 1 made substantial improvements in peak oxygen consumption (from 16.0 to 18.3 mL·kg⁻¹·min⁻¹and from 15.0 to 15.6 mL·kg⁻¹·min,⁻¹ respectively) and peak work rate (from 112 to 130W and 66 to 69W, respectively). Both subjects demonstrated improved HRQL. No adverse events were noted. CONCLUSIONS: A short and practical exercise training program can improve measures of workload, aerobic capacity, and HRQL in individuals with PAH with no adverse effects shown in these two case studies.Key Words: pulmonary arterial hypertension, exercise training     

Triangulating Clinically Meaningful Change in the Six-minute Walk Test in Individuals with Chronic Heart Failure: A Systematic Review

Purpose

The purpose of the present review was to use existing, published data to provide an estimate of the amount of change in six-minute walk test distance (Δ6MWT) that represents a clinically meaningful change in individuals with chronic heart failure (CHF).

Methods

The present review included two separate literature searches of the CINAHL and Medline databases for articles that: (1) reported the intraclass correlation coefficient (ICC) of the 6MWT in individuals with CHF, and (2) used the 6MWT along with either aerobic capacity or health-related quality of life (HRQL) as study endpoints in randomized controlled trials (RCTs) of exercise-based intervention for individuals with CHF. The ICCs were used to calculate the minimum detectable difference (MDD) at the 95% confidence interval for each included study. The Δ6MWT associated with aerobic capacity and HRQL within-group effect sizes for the intervention and control groups in each included RCT was analyzed using receiver operating characteristic (ROC) curves.

Results

Thirteen articles reported the ICC for the 6MWT. The mean (standard deviation) MDD calculated based on these data was 43.1(16.8) m. Eighteen RCTs measured the 6MWT and either aerobic capacity and/or HRQL. A Δ6MWT of 40–45 m was associated with at least moderate aerobic capacity and HRQL effect sizes in the intervention groups. The Δ6MWT thresholds that discriminated between intervention and control groups using ROC curves revealed the following sensitivity/specificity for the respective thresholds: 19 m, 94.4/83.3%, 32 m, 83.3/94.4%, and 48 m 44.4/100% (AUC = .935, p = .009, CI_95% .855, 1.015).

Conclusions

A Δ6MWT of approximately 45 m appears to exceed measurement error and be associated with significant changes in either aerobic capacity and/or HRQL.Key Words: heart failure, six-minute walk test, clinically meaningful change, minimum detectable difference     

Clinically Meaningful Change Estimates for the Six-Minute Walk Test and Daily Activity in Individuals With Chronic Heart Failure

Purpose

The purpose of the present pilot study was to provide a preliminary estimate of the minimum detectable difference (MDD) and minimum clinically important difference (MCID) of the six-minute walk test (6MWT) and daily activity in outpatients with chronic heart failure (CHF).

Methods

A convenience sample of 22 adults with stable New York Heart Association Functional Class II and III CHF performed two baseline 6MWTs separated by 30 minutes of rest. Subjects then wore a triaxial accelerometer for 7 days to monitor daily activity. After 7 weeks of usual care, subjects again wore the accelerometer for 7 days and then returned to the clinic to complete the Global Rating of Change Scale (GRS) with regard to their heart disease and perform another set of 6MWTs. For the 6MWT, the MDD was calculated using the two baseline 6MWT distances. For daily activity, the MDD was calculated using two methods: (1) day-to-day test-retest reliability during baseline monitoring, and (2) baseline to follow-up test-retest reliability in those who reported no change on the GRS. The MCID for the 6MWT and daily activity was calculated using the mean and 95% confidence interval (CI_95%) for those subjects who reported ‘improvement’ on the GRS.

Results

The MDD at the CI_95% for the 6MWT was 32.4 meters. The MCID for the 6MWT was 30.1 (CI_95% 20.8, 39.4) meters. The MDD for daily activity was 5,909 vector magnitude units (VMU·hr.⁻¹) The MCID for daily activity was 1,337 VMU·hr.⁻¹ There was good alignment of the MDD and MCID for the 6MWT, suggesting that clinically meaningful change is approximately 32 meters. However, the calculated MCID was substantially less than measurement error as represented by the MDD, indicating that the MCID was underestimated in this sample or that daily activity may be robust to change in overall disease status.Key Words: six-minute walk test, daily activity, heart failure, clinically meaningful change     

Inter-individual differences in the responses to aerobic exercise in Alzheimer’s disease: Findings from the FIT-AD trial

Background:Despite the strong evidence of aerobic exercise as a disease-modifying treatment for Alzheimer’s disease(AD)in animal models,its effects on cognition are inconsistent in human studies.A major contributor to these findings is inter-individual differences in the responses to aerobic exercise,which was well documented in the general population but not in those with AD.The purpose of this study was to examine inter-individual differences in aerobic fitness and cognitive responses to a 6-month aerobic exercise intervention in community-dwelling older adults with mild-to-moderate dementia due to AD.Methods:This study was a secondary analysis of the Effects of Aerobic Exercise for Treating Alzheimer’s Disease(FIT-AD)trial data.Aerobic fitness was measured by the shuttle walk test(SWT),the 6-min walk test(6MWT),and the maximal oxygen consumption(VO2max)test,and cognition by the AD Assessment Scale-Cognition(ADAS-Cog).Inter-individual differences were calculated as the differences in the standard deviation of 6-month change(SDR)in the SWT,6MWT,VO2max,and ADAS-Cog between the intervention and control groups.Results:Seventy-eight participants were included in this study(77.4±6.3 years old,mean±SD;15.7±2.8 years of education;41%were female).VO2max was available for 26 participants(77.7±7.1 years old;14.8±2.6 years of education;35%were female).The SDR was 37.0,121.1,1.7,and 2.3 for SWT,6MWT,VO2max,and ADAS-Cog,respectively.Conclusion:There are true inter-individual differences in aerobic fitness and cognitive responses to aerobic exercise in older adults with mild-tomoderate dementia due to AD.These inter-individual differences likely underline the inconsistent cognitive benefits in human studies.     

Improved Health-Related Quality of Life After Lung Volume Reduction Surgery and Pulmonary Rehabilitation

Purpose: It has been hypothesized that lung volume reduction surgery (LVRS) and pulmonary rehabilitation improve health-related quality of life (HRQOL). The purpose of this study was to test the hypothesis by examining the long-term functional consequences and general health status of patients with emphysema who have undergone LVRS and pulmonary rehabilitation. Methods: Forty-nine subjects with severe emphysema, aged 51 to 84 years old, post-LVRS and pulmonary rehabilitation participated in this study. Subjects reported changes in physical and mental domains on the Medical Outcomes Study 36-Item Short Form Health Survey (MOS SF-36) over 3 time periods: prior to surgery, 6 months postsurgery, and 18 months postsurgery. The population as a whole was studied and both gender and age were analyzed as subsets. Subjects participated in an intensive 2-week (10 daily sessions) pulmonary rehabilitation program following LVRS. Results: Subjects showed significant improvements in both the physical and mental component summaries at Time 2 (3 months post-LVRS through 6 months post-LVRS) and Time 3 (12 months post-LVRS through 18 months post-LVRS) when compared to Time 1 (pre-LVRS). On the mental component summary scale, subjects younger than 65 years old had significant improvement compared to subjects 65 years and older at Time 3 (P < .05). Women significantly improved more than men at Time 3 on the physical component summary scale (P < .05). Conclusions: Lung volume reduction surgery and 2 weeks (10 daily sessions) of intensive pulmonary rehabilitation appears to improve HRQOL in people with emphysema up to at least 18 months postsurgery. What these data further suggest is that even after declines in health, women can improve HRQOL later in life, and that greater focus should be given to the emotional needs of our older patients.Key Words: lung volume reduction surgery, rehabilitation, quality of life     

Can sit-to-stand muscle power explain the ability to perform functional tasks in adults with severe obesity?

This study examined the relationship between sit-to-stand (STS) power and physical function in adults with severe obesity. Thirty-eight adults (age: 44 ± 12 years; body mass index [BMI]: 45.2 ± 7.8 kg/m²) completed evaluations of STS power, strength and functional performance. STS power was measured with a wearable inertial sensor, strength was assessed with the isometric mid-thigh pull, and function was measured with the timed up-and-go (TUG), six-minute walk test (6MWT) and 30-s chair STS. Power and strength (normalised to body mass) entered regression models in addition to age, gender, BMI and physical activity (daily step count). Power displayed large univariate associations with TUG (r = 0.50) and 30-s chair STS (r = 0.67), and a moderate association with 6MWT (r = 0.49). Forward stepwise regression revealed that power independently contributed to TUG (β = ?0.40, p = 0.010), 30-s chair STS (β = 0.67, p < 0.001) and 6MWT performance (β = 0.27, p = 0.007). Power also appeared to be a superior determinant of function compared with strength. Power generated via the STS transfer largely underpins the ability to perform functional tasks in adults with severe obesity, although intervention studies are required to investigate a potentially causal relationship.     

Outcomes of an Education and Exercise Program for Adults with Type 2 Diabetes,and Comorbidities that Limit their Mobility: A Preliminary Project Report

Purpose: Some adults with type 2 diabetes mellitus (T2DM) have comorbidities and mobility impairments that limit their exercise capacity. In consideration of this, we developed and piloted a program called Active Steps for Diabetes for people with T2DM, comorbidities, and mobility impairments. The purpose of this paper was to report outcomes for the pilot program. Methods: Active Steps for Diabetes, an 8-week program, included instruction on diabetes self-care andgroup and home exercise programs. Twenty-two females (62.7 ± 6.1yrs) with T2DM and self-reported mobility impairments completed the program. Six participants used a walking aid. Outcome measures included two risk factors for coronary artery disease [daily physical activity and body mass index (BMI)], cardiovascular fitness (6-minute walk distance), and knowledge of diabetes-specific exercise guidelines. A two-way repeated measures ANOVA was used to compare outcomes before and after the program and between participants who did and did not use a walking aid. Results: Active Steps for Diabetes was effective in increasing daily physical activity in both groups of subjects (walking aid group: 2.6 days/week [95% confidence interval (CI) = 2.1 to 3.3]; no walking aid group: 1.9 days/week [95% CI=1.2 to 2.5]). This was accompanied by increases in 6-minute walk distances (walking aid group: 54.0 m [95% CI = 36.4 to 71.6]; no walking aid group: 62.6 m [95% CI=55.7 to 69.4]). Changes in BMI were not significant (walking aid group: −0.4 [95% CI = −1.2 to 0.4]; no walking aid group: −.24[95% CI = −.91 to .44]). Increases in knowledge of diabetes-specific exercise guidelines were observed in both groups (walking aid group: 18.8% [95% CI = 11.3 to 26.4]; no walking aid group: 19.3% [95% CI = 16.1 to 22.5]). Discussion:: Physical inactivity and low cardiovascular fitness are predictors of CAD morbidity and mortality in adults with T2DM. This pilot program suggests that a model for diabetes education, incorporating exercise programs developed by a physical therapist, may increase physical activity, improve endurance, and thereby potentially reduce CAD risk in people with T2DM and mobility impairments from comorbidities.Key Words: type 2 diabetes, physical activity     

不同方式运动对慢性阻塞性肺疾病患者肺功能及生存质量影响的Meta分析

目的:评价有氧运动、抗阻运动、瑜伽、传统健身功法4种不同运动对慢性阻塞性肺疾病(chronic obstructive pulmonary disease,COPD)患者的影响,从肺功能、6 min步行实验(6 minutes walk test,6MWT)、生存质量3方面,分析比较不同运动方式对慢性阻塞性肺疾病患者肺功能及生存质量的改善效果,有针对性的在慢性阻塞性肺疾病的预防和管理方面提供合理建议和科学依据。方法:建立纳入和排除标准,通过检索PubMed、Web of Science、Embase、Cochrane Library、中国知网(CNKI)、万方等文献数据库,收集运动对慢性阻塞性肺疾病干预的随机对照试验(randomized controlled trial,RCT),运用Revman5.3软件和Stata16.0软件对所纳入文献的结局指标进行分析。结果:共纳入23篇文献,包括1440例受试者,其中实验组719人,对照组721人。Meta分析结果显示,与对照组相比,运动锻炼能够提高COPD患者第1 s用力呼吸容积(forced expiratory volume in the first second,FEV1)(SMD=0.51,95%CI:0.19,0.83,P=0.002)、用力肺活量(forced vital capacity,FVC)(SMD=0.78,95%CI:0.08,1.47,P=0.03)、第1 s用力呼气容积与用力肺活量比值FEV1/FVC(SMD=0.51,95%CI:0.18,1.10,P=0.007)和第1 s用力呼气容积占预计值百分比FEV1/%(SMD=0.35,95%CI:0.10,0.60,P=0.006),延长了6 min步行距离6MWT(SMD=0.49,95%CI:0.33,0.65,P≤0.0001),降低患者呼吸困难指数,提高了生存质量(SMD=-0.59,95%CI:-0.87,-0.31,P≤0.0001)。传统健身功法和有氧运动对COPD患者肺功能、6MWT及生存质量的改善效果更好,抗阻运动和瑜伽虽然在6 min步行距离的加长和生存质量的提高方面效果显著,但在与慢性阻塞性肺疾病最密切相关的肺功能方面的改善效果并不明显。结论:有氧运动、抗阻运动、瑜伽和传统健身功法都对慢性阻塞性肺疾病有一定的预防和改善效果,对肺功能、6MWT及生存质量有明显的改善作用,且传统健身功法和有氧运动的改善效果更全面。     

Effects of an unsupervised pedometer-based physical activity program on daily steps of adults with moderate to severe asthma: a randomized controlled trial

Supervised exercise has shown benefits for subjects with asthma, but little is known about the effectiveness of unsupervised physical activity on this population. We investigated the effects of a 12-week unsupervised pedometer-based physical activity program on daily steps and on clinical and psychological parameters of adults with asthma. Clinically stable adults with moderate to severe asthma were encouraged to take daily 30-minute walks and were randomized to pedometer and control groups. The pedometer group received pedometers and individualized daily step targets. Changes in daily steps (average of steps taken during six consecutive days), six-minute walk test (6MWT), health-related quality of life, asthma control and anxiety and depression levels were assessed 12 weeks after intervention and 24–28 weeks after randomization. Thirty-seven participants were recruited and 30 completed the intervention. At 12 weeks, the groups differed significantly in daily steps (adjusted average difference, 2488 steps; 95% confidence interval [CI], 803 to 4172; p = 0.005) and in the 6MWT (adjusted average difference, 21.9 m; 95% CI, 6.6 to 37.3; p = 0.006). These differences were not significant 24–28 weeks after randomization. The program was effective in increasing daily steps of adults with moderate to severe asthma 12 weeks after intervention.     

6-Minute Walk Test Performance in Young Children who are Normal Weight and Overweight

PURPOSE

The primary purpose of this study was to investigate 6-minute walk test (6MWT) performance in young children who were normal weight (NW) and overweight (OW).

METHODS

Seventy children, 5-9 years of age, participated in this study. The 6MWT was performed on an indoor walkway. Heart rate (HR), blood pressure (BP), and oxygen saturation (SaO₂) were measured. A self-reported physical activity questionnaire was completed by a parent/guardian. Data were analyzed with independent t tests, ANOVA, correlation analyses, and logistic regression.

RESULTS

The systolic BP values were higher in the children who were OW compared with their NW peers (resting mean 104.1 (8.9) mmHg vs. 97.5 (7.8) mmHg, P < 0.05; post-6WMT: mean 118.4 (10.78) mmHg vs. 109.9 (9.1) mmHg, P < 0.05). The SaO₂ values were lower in the children who were OW compared to their NW counterparts (resting: mean 97.2 (1.1) % vs. 98.0 (1.0) %, P < 0.05; post-6WMT: mean 96.8 (1.0) % vs. 97.7 (1.0) %, P < 0.05).

CONCLUSIONS

The children who were OW had higher systolic BP and lower SaO₂ levels at rest and post-6WMT. More research is needed to determine if these differences contribute to children who are OW having difficulty performing exercise.Key Words: obesity, children, exercise capacity     

Temporal trends in 6-minute walking distance for older Japanese adults between 1998 and 2017

BackgroundThe 6-minute walking distance (6MWD) is an excellent measure of both functional endurance and health. The primary aim of this study was to estimate temporal trends in 6MWD for older Japanese adults between 1998 and 2017; the secondary aim was to estimate concurrent trends in body size (i.e., height and mass) and self-reported participation in exercise/sport.MethodsAdults aged 65–79 years were included. Annual nationally representative 6MWD data (n = 103,505) for the entire period were obtained from the Japanese Ministry of Education, Culture, Sports, Science and Technology. Temporal trends in means (and relative frequencies) were estimated at the gender–age level by best-fitting sample-weighted linear/polynomial regression models, with national trends estimated by a post-stratified population-weighting procedure. Temporal trends in distributional variability were estimated as the ratio of coefficients of variation.ResultsBetween 1998 and 2017 there was a steady, moderate improvement in mean 6MWD (absolute = 45 m (95% confidence interval (95%CI): 43–47); percent = 8.0% (95%CI: 7.6%–8.4%); effect size = 0.51 (95%CI: 0.48–0.54)). Gender- and age-related temporal differences in means were negligible. Variability in 6MWD declined substantially (ratio of coefficients of variation = 0.89, 95%CI: 0.87–0.92), with declines larger for women compared to men, and for 75–79-year-olds compared to 65–74-year-olds. Correspondingly, there were moderate and negligible increases in mean height and mass, respectively, and negligible increases in the percentage who participated in exercise/sport at least 3 days per week and at least 30 min per session.ConclusionThere has been a steady, moderate improvement in mean 6MWD for older Japanese adults since 1998, which is suggestive of corresponding improvements in both functional endurance and health. The substantial decline in variability indicates that the temporal improvement in mean 6MWD was not uniform across the distribution. Trends in 6MWD are probably influenced by corresponding trends in body size and/or participation in exercise/sport.     

太极拳运动对中老年人运动耐力及肺功能影响分析

通过对太极拳逆腹式呼吸和健步走腹式顺式呼吸的对比,并与未参加锻炼的普通人群对照,从6min步行实验（6MWT）、血氧饱和度（Sa）、肺功能角度探讨太极拳运动对中老年人运动耐力及肺功能的改善与提高情况,为太极拳健身功能提供一定的理论依据.     

不同锻炼方式对中老年心脏功能影响的实验研究

运用二次台阶实验方法,对参加12周不同项目锻炼方式的529名中老年人心功能能力进行测试。研究表明,传统体育和慢跑快走锻炼方式对提高中、老年男子和中年女子的心功能能力效果显著。同时球类项目锻炼方式,不仅对提高中年男子心功能能力有显著效果,同样也对提高老年人的心功能能力有非常显著的效果。有氧体操锻炼方式对中、老年女子心功能能力的提高均有显著效果。     

Classification of Physical Activity Cut-Points and the Estimation of Energy Expenditure During Walking Using the GT3X+ Accelerometer in Overweight and Obese Adults

This study establishes tri-axial activity count (AC) cut-points for the GT3X+ accelerometer to classify physical activity intensity in overweight and obese adults. Further, we examined the accuracy of established and novel energy expenditure (EE) prediction equations based on AC and other metrics. Part 1: Twenty overweight or obese adults completed a 30 minute incremental treadmill walking protocol. Heart rate (HR), EE, and AC were measured using the GT3X+ accelerometer. Part 2: Ten overweight and obese adults conducted a self-paced external walk during which EE, AC, and HR were measured. Established equations (Freedson et al., 1998; Sasaki et al., 2011) overestimated EE by 40% and 31%, respectively (p < .01). Novel gender-specific prediction equations provided good estimates of EE during treadmill and outdoor walking (standard error of the estimate = .91 and .65, respectively). We propose new cut-points and prediction equations to estimate EE using the GT3X+ tri-axial accelerometer in overweight and obese adults.     

Impaired pulmonary and cardiac function after maximal exercise

The cardiopulmonary response to maximal rowing exercise of short duration was studied in six healthy well-trained oarsmen. The lung diffusing capacity for carbon monoxide was significantly decreased below the pre-exercise value for 2.5 days post-exercise (P less than 0.05). Residual volume (RV) showed a significantly increased value at 30 min of recovery (P less than 0.01) with no change in total lung capacity. There was no significant change in transthoracic electrical impedance following exercise but a decrease may have been masked by the increased RV. The changes in the pulmonary parameters may reflect the occurrence of a transient interstitial lung oedema. Exercise-induced bronchoconstriction may be a part of the cardiopulmonary response as peak expiratory flow rate (PEFR) was significantly reduced at 30 min of recovery. The reason for the increase in pulmonary extravascular water volume may be a marked distension of the lung capillaries due to increased blood volume in the lungs and as a consequence increased vascular permeability. The changes may also be caused by impaired myocardial contractility indicated by a split impedance dZ/dt waveform, not previously described in healthy persons, which occurred in all six subjects immediately following exercise.     

Lung Volume Reduction Surgery and Pulmonary Rehabilitation Improve Exercise Capacity and Reduce Dyspnea During Functional Activities in People with Emphysema

Purpose: The purpose of this study was to examine the therapeutic effects of lung volume reduction surgery (LVRS) and pulmonary rehabilitation on levels of dyspnea during functional activities in patients with diffuse emphysema. Methods: Fifteen subjects who had undergone LVRS participated in this study. A visual analog scale (VAS) Activity Dyspnea Scales (VADS) measurement tool developed for this study was determined reliable in 10 subjects. The VADS was used to assess changes in dyspnea with functional activity in 10 subjects prior to and following the interventions of LVRS and pulmonary rehabilitation. Results: Results of this study indicate that LVRS followed by pulmonary rehabilitation significantly reduces levels of dyspnea during functional activities. Conclusion: The VADS developed for this study is a valid and reliable method of assessing changes in levels of dyspnea during functional activities in the LVRS population.Key Words: breathlessness, functional capacity     

Inspiratory Muscle Training in Patients with Heart Failure: A Systematic Review

Purpose

The purpose of this review was to assess the quality of evidence on inspiratory muscle training (IMT) in patients with heart failure and to provide an overview on subject selection, training protocols, and outcome achieved with IMT.

Methods

Literature search was first performed via the PubMed database, and additional references were identified from the Scopus citation index. Articles of the review type and of clinical trials published in English were included. Quality of the articles was assessed using Sackett''s levels of evidence and rigor of methodology was assessed using PEDro (Physiotherapy Evidence Database) criteria for randomized controlled trials and the Downs & Black tool for cohort studies.

Results

Twelve articles of clinical trials were included. Typical training protocols involved daily training with intensity greater than 30% of maximal inspiratory pressure (PImax), duration of 20 to 30 minutes (continuous or incremental) and using a pressure threshold muscle trainer. The effect sizes of PImax, walk test distance, and dyspnea were moderate to large across these studies. Effects on quality of life scores were inconsistent.

Conclusion

Inspiratory muscle training is beneficial for improving respiratory muscle strength, functional capacity, and dyspnea in patients with stable heart failure and respiratory muscle weakness.Key Words: inspiratory muscle training, heart failure, maximal inspiratory pressure