Helen Seale

Balance is impaired in people with chronic obstructive pulmonary disease

BACKGROUND It has recently been suggested that people with chronic obstructive pulmonary disease have an increased risk of falls. Although falls risk is multifactorial, impaired balance may contribute. The primary aim of this study was to compare balance between people with and without chronic obstructive pulmonary disease and the secondary aim was to determine if balance deteriorates when respiratory demand is increased by upper limb exercise. METHODS Twelve people with chronic obstructive pulmonary disease and 12 healthy control subjects participated in this study. Participants stood on a force plate to record centre of pressure displacement during a range of conditions that challenge balance. Lumbar spine and hip motion were measured with inclinometers. Balance trials were performed before and after participation in upper limb exercise that increased respiratory demand in those with chronic obstructive pulmonary disease. FINDINGS People with chronic obstructive pulmonary disease had increased mediolateral centre of pressure displacement and increased angular motion of the hip compared to healthy controls. Mediolateral centre of pressure displacement was further increased in people with chronic obstructive pulmonary disease following exercise, but unchanged in controls. Anteroposterior centre of pressure displacement did not differ between groups. INTERPRETATION People with chronic obstructive pulmonary disease have reduced control of balance in the mediolateral direction. This may contribute to an increased risk of falls in this population.

Predictive Utility of the 6-Minute Walk Distance on Survival in Patients Awaiting Lung Transplantation

BACKGROUND The 6-minute walk distance (6MWD) is a widely used clinical indicator of exercise capacity. Although used as part of the assessment process in determining a candidates suitability for lung transplantation (LT), the literature describing the impact of the 6MWD in predicting survival on LT waiting lists is limited. This study aimed to determine the hazard function associated with the 6MWD, and its utility relative to other prognostic variables. METHODS A retrospective chart review was conducted on 163 patients who were listed for single or double LT, and either survived to transplant or died while on the waiting list. A Cox regression for survival analysis, stratified by diagnostic group, was conducted utilizing the 6MWD, demographic variables and measures of cardiopulmonary function. RESULTS The 6MWD proved to be the only significant covariate in the Cox regression for survival analysis (p < 0.001), with all other variables eliminated as non-significant. Furthermore, there was a protective effect for each unit increase in the 6MWD [Exp (B) = 0.994, 95% confidence interval 0.990 to 0.997]. CONCLUSIONS This research demonstrates that the 6MWD is useful for stratifying patients on the LT waiting list by identifying those patients with a significantly higher risk of mortality.

Static balance is affected following an exercise task in chronic obstructive pulmonary disease.

PURPOSE To investigate balance following a submaximal exercise task (6-minute walk test [6MWT]) in patients with chronic obstructive pulmonary disease (COPD). METHODS A consecutive sample of 19 patients with COPD from an institutional pulmonary rehabilitation program served as participants. The following measures were recorded before and following a 6MWT: (1) timed-up and go (TUG) test, (2) step-up test, and (3) quiet standing for 30 seconds with eyes open and closed in a narrow and semi-tandem stance. Displacement of the body at the level of the waist was recorded using a swaymeter. Data were analyzed using a linear mixed model. RESULTS In the semi-tandem stance with eyes closed post-6MWT, increases in total sway (165.9 mm vs 240.0 mm, P = .043) and mediolateral sway (45.8 mm vs 66.6 mm, P = .011) were found in comparison with pre-6MWT measures. The exercise task did not affect the TUG test performance (8.3 seconds vs 9.0 seconds, P = .213), number of steps completed during the step-up test (10 vs 10, P = .233), or sway during the semi-tandem stance with eyes open; narrow base, eyes open or closed (P > .05). Conclusions A submaximal exercise task in patients with COPD affects balance during static standing tasks in the absence of visual input. This may have implications for functional performance following exercise in patients with chronic respiratory disease.

Muscle Stretching Technique Increases Vital Capacity and Range of Motion in Patients With Chronic Obstructive Pulmonary Disease

OBJECTIVES To determine if a specific hold and relax stretching technique was capable of (1) reversing the effect of tight chest wall muscles by increasing chest expansion, vital capacity, and shoulder range of motion and (2) decreasing perceived dyspnea and respiratory rate in persons with chronic obstructive pulmonary disease (COPD). DESIGN Double-blind crossover trial. SETTING A physiotherapy department at a major metropolitan hospital. PARTICIPANTS Fourteen stable patients with COPD who had recently completed a pulmonary rehabilitation program were enrolled, with 10 patients completing the study. INTERVENTION A hold and relax stretching technique of the pectoralis major and a sham technique each for 2 days. MAIN OUTCOME MEASURES The primary outcome measure was vital capacity (VC), with secondary outcome measures being perceived dyspnea, axillary (ACE) and xiphisternal chest expansion (XCE), right and left shoulder horizontal extension, and respiratory rate. RESULTS The hold and relax technique to the pectoralis major compared with the sham technique produced significant effects on VC (P<.01), and right (P<.01) and left (P<.05) upper-limb range of motion. There was no significant effect on ACE, XCE, perceived dyspnea, or respiratory rate. There was no order effect for either technique. CONCLUSIONS The hold and relax technique produces short-term benefits in patients with COPD and should be investigated further.

Endothelin receptor antagonists are an effective long term treatment option in pulmonary arterial hypertension associated with congenital heart disease with or without trisomy 21.

INTRODUCTION Traditionally, treatment options for patients with pulmonary arterial hypertension associated with congenital heart disease (PAH-CHD) are limited. Bosentan has been shown to improve pulmonary haemodynamics and exercise tolerance short term but long term clinical studies are lacking. AIM To report long term efficacy and safety data with endothelin receptor antagonists (ERA) in patients with PAH associated CHD. METHODS Prospective, open label, uncontrolled, single centre study of 53 patients (33 females, 17 Trisomy 21, mean age 34 ± 12 years) prescribed ERA (48 bosentan, 5 sitaxentan) from 2003 to August 2009. Outcome measurements of oxygen saturation (SaO2), WHO functional class, 6-minute walk test distance (6MWD) and adverse events were analysed. RESULTS Mean duration of therapy was 15 ± 13 months in 53 patients with CHD. Four patients failed ERA, seven died (five progressive RHF) and one delisted from transplantation. No abnormal liver transaminases occurred on bosentan, with one case on sitaxentan. After 3, 6, 12, 18 and 24 months of treatment a significant improvement was seen in WHO functional class (mean 3.15 vs 2.8 vs 2.5 vs 2.5 vs 2.4 vs 2.4; p<0.01) and 6MWD (344 ± 18 vs 392 ± 17 vs 411 ± 17 vs 420 ± 17 vs 442 ± 18 vs 417 ± 23: p<0.0005, p<0.01) compared with baseline. The Trisomy 21 and PAH-CHD showed a significant improvement in 6MWD at 6 and 12 months (263 ± 24 vs 348 ± 29 vs 360 ± 32, p<0.01, p<0.05) respectively. No changes in SaO2, BNP, RV or LV function were demonstrated during follow-up. CONCLUSION This large single centre study demonstrates that endothelin receptor antagonism is an effective and safe treatment in PAH associated CHD with or without Trisomy 21. The improvements in exercise tolerance are similar to reported benefits in other forms of PAH.

Impaired exercise capacity after lung transplantation is related to delayed recovery of muscle strength.

Lung transplant recipients report reduced exercise capacity despite satisfactory graft function. We analysed changes in lung function, six‐min walk distance (6MWD), and quadriceps strength in the first 26‐wk post‐transplant and examined what factors predict 6MWD recovery. All lung transplant recipients at a single institution between June 2007 and January 2011 were considered for inclusion. Lung function, 6MWD, and quadriceps strength corrected for body weight (QS%) were recorded pre‐ and two‐, six‐, 13‐, and 26‐wk post‐transplant. Fifty recipients, of mean (±SD) age 42 (±13) yr, were studied. Mean FEV1% and 6MWD improved from 26.4% to 88.9% and from 397 to 549 m at 26 wk, respectively (both p < 0.001). QS% declined in the first two wk but had improved to above pre‐transplant levels by 26 wk (p = 0.027). On multivariate analysis (n = 35), lower pre‐transplant exercise capacity and greater recovery in muscle strength explained most of the improvement in exercise capacity. Delayed recovery of exercise capacity after lung transplantation is unrelated to delay in improvement in graft function, but occurs secondary to the slow recovery of muscle strength. Our findings show that additional controlled trials are needed to better understand the influence of exercise rehabilitation on improvement in exercise capacity post‐transplantation.

Metabolic disease and participant age are independent predictors of response to pulmonary rehabilitation.

PURPOSE: The study aims were (1) to determine whether baseline measures—including the Body Mass Index, Airflow Obstruction, Dyspnea, and Exercise Capacity (BODE) index; Age, Dyspnea, and Airflow Obstruction (ADO) index; physical activity; comorbidities (cardiac, metabolic, or musculoskeletal disease); and the number of hospitalizations over the previous 12 months—can predict responders in 6-minute walk distance (6MWD) following pulmonary rehabilitation (PR) and (2) to determine whether different methods in defining improvement in 6MWD affected identifying responders to PR. METHODS: All participants with chronic obstructive pulmonary disease who attended PR at our institution between 2004 and 2009 were evaluated. A participant was classified as a responder with improvement in 6MWD (≥25 m or ≥2 SD of this dataset coefficient of repeatability). RESULTS: A total of 203 participants (mean age, 68.2 ± 8.7 years; mean predicted forced expiratory volume in 1 second, 52.5 ± 22.4%) were analyzed. One hundred twenty participants (59.1%) had a comorbidity categorized as cardiac, metabolic, or musculoskeletal disease. The binary logistic regression models showed that younger participants (P ⩽ .015) and, when using the coefficient of repeatability method (≥60.9 m), participants with metabolic disease (P = .040) were the only independent predictors of response. No other measure, including participant BODE or ADO index scores, contributed to either model. CONCLUSION: Identifying responders in exercise capacity following PR remains difficult, with only age and participants with metabolic disease identified as independent predictors.

Serious adverse events during a 6-min walk test in patients with pulmonary hypertension

The 6-min walk test (6MWT) is well standardised and, as per current guidelines, is deemed safe to perform in a range of patients [1]. In pulmonary arterial hypertension (PAH), 6-min walk distance (6MWD) is an important predictor of mortality and morbidity [2]. Moreover, changes in the 6MWD have been the primary end-point of most pivotal randomised controlled trials that have assessed the clinical response to specific pharmacological therapies in PAH [2]. The first ever reported cases of serious adverse events during the 6MWT in patients with pulmonary hypertension http://ow.ly/FdVp8

Six minute walking test

The six-minute walking test (6MWT) is a commonly used objective measure of functional exercise capacity in individuals with moderately severe impairment. (non-author abstract)

Exercise cardiac MRI-derived right ventriculo-arterial coupling ratio detects early right ventricular maladaptation in PAH.

Exercise intolerance and right ventricular (RV) dysfunction are cardinal features of pulmonary arterial hypertension (PAH). Despite the significantly elevated afterload, patients rarely experience symptoms at rest until the late stages of the disease. Recent data suggest that the ability of the right ventricle to adapt to increased afterload is an important determinant of exercise capacity and outcome in PAH [1]. RV ejection fraction (RVEF) has been demonstrated to predict outcome [2]. There is also growing evidence that a noninvasively derived right ventriculo-arterial coupling ratio (VACR) may provide important prognostic information [3]. However, it remains unclear to what extent RV contractility is impaired during exercise and which metric best describes ventricular functional adaptation to afterload in PAH. We aimed to evaluate and compare the effects of submaximal exercise on RV systolic function and VACR in PAH and healthy subjects using cardiac magnetic resonance (MRI). We also examined and compared VACR and cardiopulmonary exercise test (CPET) in estimating the severity of disease. In well-compensated PAH, early RV maladaptation is best captured by changes in SV/ESV at exercise by cardiac MRI http://ow.ly/MyEi302UUeL