Christine F. McDonald

Effect of palliative oxygen versus room air in relief of breathlessness in patients with refractory dyspnoea: a double-blind, randomised controlled trial

BACKGROUND Palliative oxygen therapy is widely used for treatment of dyspnoea in individuals with life-limiting illness who are ineligible for long-term oxygen therapy. We assessed the effectiveness of oxygen compared with room air delivered by nasal cannula for relief of breathlessness in this population of patients. METHODS Adults from outpatient clinics at nine sites in Australia, the USA, and the UK were eligible for enrolment in this double-blind, randomised controlled trial if they had life-limiting illness, refractory dyspnoea, and partial pressure of oxygen in arterial blood (PaO(2)) more than 7.3 kPa. Participants were randomly assigned in a 1:1 ratio by a central computer-generated system to receive oxygen or room air via a concentrator through a nasal cannula at 2 L per min for 7 days. Participants were instructed to use the concentrator for at least 15 h per day. The randomisation sequence was stratified by baseline PaO(2) with balanced blocks of four patients. The primary outcome measure was breathlessness (0-10 numerical rating scale [NRS]), measured twice a day (morning and evening). All randomised patients who completed an assessment were included in the primary analysis for that data point (no data were imputed). This study is registered, numbers NCT00327873 and ISRCTN67448752. FINDINGS 239 participants were randomly assigned to treatment (oxygen, n=120; room air, n=119). 112 (93%) patients assigned to receive oxygen and 99 (83%) assigned to receive room air completed all 7 days of assessments. From baseline to day 6, mean morning breathlessness changed by -0.9 points (95% CI -1.3 to -0.5) in patients assigned to receive oxygen and by -0.7 points (-1.2 to -0.2) in patients assigned to receive room air (p=0.504). Mean evening breathlessness changed by -0.3 points (-0.7 to 0.1) in the oxygen group and by -0.5 (-0.9 to -0.1) in the room air group (p=0.554). The frequency of side-effects did not differ between groups. Extreme drowsiness was reported by 12 (10%) of 116 patients assigned to receive oxygen compared with 14 (13%) of 108 patients assigned to receive room air. Two (2%) patients in the oxygen group reported extreme symptoms of nasal irritation compared with seven (6%) in the room air group. One patient reported an extremely troublesome nose bleed (oxygen group). INTERPRETATION Since oxygen delivered by a nasal cannula provides no additional symptomatic benefit for relief of refractory dyspnoea in patients with life-limiting illness compared with room air, less burdensome strategies should be considered after brief assessment of the effect of oxygen therapy on the individual patient. FUNDING US National Institutes of Health, Australian National Health and Medical Research Council, Duke Institute for Care at the End of Life, and Doris Duke Charitable Foundation.

Updating the minimal important difference for six-minute walk distance in patients with chronic obstructive pulmonary disease.

OBJECTIVE To establish the minimal important difference (MID) for the six-minute walk distance (6MWD) in persons with chronic obstructive pulmonary disease (COPD). DESIGN Analysis of data from an observational study using distribution- and anchor-based methods to determine the MID in 6MWD. SETTING Outpatient pulmonary rehabilitation program at 2 teaching hospitals. PARTICIPANTS Seventy-five patients with COPD (44 men) in a stable clinical state with mean age 70 years (SD 9 y), forced expiratory volume in one second 52% (SD 21%) predicted and baseline walking distance 359 meters (SD 104 m). INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Participants completed the six-minute walk test before and after a 7-week pulmonary rehabilitation program. Participants and clinicians completed a global rating of change score while blinded to the change in 6MWD. RESULTS The mean change in 6MWD in participants who reported themselves to be unchanged was 17.7 meters, compared with 60.2 meters in those who reported small change and 78.4 meters in those who reported substantial change (P=.004). Anchor-based methods identified an MID of 25 meters (95% confidence interval 20-61 m). There was excellent agreement with distribution-based methods (25.5-26.5m, kappa=.95). A change in 6MWD of 14% compared with baseline also represented a clinically important effect; this threshold was less sensitive than for absolute change (sensitivity .70 vs .85). CONCLUSIONS The MID for 6MWD in COPD is 25 meters. Absolute change in 6MWD is a more sensitive indicator than percentage change from baseline. These data support the use of 6MWD as a patient-important outcome in research and clinical practice.

Short term improvement in exercise capacity and symptoms following exercise training in interstitial lung disease

Background: Interstitial lung disease (ILD) is characterised by exertional dyspnoea, exercise limitation and reduced quality of life. The role of exercise training in this diverse patient group is unclear. The aims of this study were to establish the safety of exercise training in ILD; its effects on exercise capacity, dyspnoea and quality of life; and whether patients with idiopathic pulmonary fibrosis (IPF) had similar responses to those with other types of ILD. Methods: 57 subjects with ILD (34 IPF) were randomised to receive 8 weeks of supervised exercise training or weekly telephone support. The 6 min walk distance (6MWD), incremental exercise test, modified Medical Research Council (MRC) dyspnoea score and Chronic Respiratory Disease Questionnaire (CRDQ) were performed at baseline, following intervention and at 6 months. Results: 80% of subjects completed the exercise programme and no adverse events were recorded. The 6MWD increased following training (mean difference to control 35 m, 95% CI 6 to 64 m). A significant reduction in MRC score was observed (0.7 points, 95% CI 0.1 to 1.3) along with improvements in dyspnoea (p = 0.04) and fatigue (p<0.01) on the CRDQ. There was no change in peak oxygen uptake; however, exercise training reduced heart rate at maximum isoworkload (p = 0.01). There were no significant differences in response between those with and without IPF. After 6 months there were no differences between the training and control group for any outcome variable. Conclusions: Exercise training improves exercise capacity and symptoms in patients with ILD, but these benefits are not sustained 6 months following intervention. Trial registration number: NCT00168285

Once-daily opioids for chronic dyspnea: a dose increment and pharmacovigilance study

CONTEXT Randomized controlled trials can answer questions of efficacy, but long-term pharmacovigilance studies generate complementary safety data. OBJECTIVES Level I evidence supports short-term efficacy of opioids in reducing chronic refractory dyspnea. This study aimed to determine the minimum effective once-daily dose of sustained-release morphine, and whether net clinical benefits are sustained safely. METHODS In a Phase II dose increment study, 10mg daily of sustained-release morphine was administered, and increased in nonresponders by 10mg daily each week to a maximum of 30 mg daily. The participant was withdrawn if there were unacceptable side effects or no response to maximum dose. If participants had a 10% improvement in dyspnea over their own baseline, they joined a long-term Phase IV effectiveness/safety study at that dose. Complying with Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines, response and side effects are described, with demographic and clinical characteristics of responders. RESULTS Eighty-three participants (53 males, mean age 75 years, 54% with chronic obstructive pulmonary disease) provided more than 30 patient-years of data. Fifty-two participants derived ≥ 10% benefit (on average 35% improvement over baseline), giving a response rate of 62% (number needed to treat of 1.6: number needed to harm 4.6); for 70%, this dose was 10mg/24h. Benefit was maintained at three months for 28 (33%) people. Ranking of breathlessness was reduced significantly (P<0.001), but constipation increased (P<0.001) despite laxatives. There were no episodes of respiratory depression or hospitalizations as a result of the sustained-release morphine. Overall, one in three people continued to derive benefit at three months. CONCLUSION Ten milligrams of sustained-release oral morphine once daily is safe and effective for most people who respond.

Exercise intervention to improve exercise capacity and health related quality of life for patients with Non-small cell lung cancer: A systematic review

CONTEXT The role of exercise intervention for patients with Non-small cell lung cancer (NSCLC) has not been systematically reviewed to date. OBJECTIVE To identify, evaluate and synthesize the evidence examining (1) the effect of exercise intervention on exercise capacity, health related quality of life (HRQoL), physical activity levels, cancer symptoms and mortality for patients with NSCLC; and (2) the safety and feasibility of exercise intervention for a population with NSCLC. DATA SOURCES A systematic review of articles using the electronic databases MEDLINE (1950-2010), CINAHL (1982-2010), EMBASE (1980-2010), TRIP (1997-2010), Science Direct (1994-2010), PubMed (1949-2010), Cochrane Library (2010), Expanded Academic ASAP (1994-2010), Meditext Informit (1995-2010), PEDRO (1999-2010) and DARE (2010). Additional studies were identified by manually cross referencing all full text reports and personal files were searched. No publication date restrictions were imposed. ELIGIBILITY CRITERIA FOR STUDY SELECTION: Randomised controlled trials (RCTs), case-control studies and case series assessing exercise intervention to improve exercise capacity, HRQoL, level of daily physical activity, cancer symptoms or mortality of patients with NSCLC were included. Only articles available in English and published in a peer reviewed journal were included. DATA EXTRACTION A data collection form was developed by one reviewer and data extracted. Data extraction was cross checked by a second reviewer. RESULTS AND DATA SYNTHESIS: 16 studies on 13 unique patient groups totalling 675 patients with NSCLC met the inclusion criteria. The majority of studies were case series (n=9) and two RCTs were included. Studies exercising participants pre-operatively reported improvements in exercise capacity but no change in HRQoL immediately post exercise intervention. Studies exercising participants post-treatment (surgery, chemotherapy or radiotherapy) demonstrated improvements in exercise capacity but conflicting results with respect to the impact on HRQoL immediately post exercise intervention. Heterogeneity among studies was observed and a meta-analysis was deemed inappropriate. PRISMA guidelines were followed in reporting this systematic review. CONCLUSION Exercise intervention for patients with NSCLC is safe before and after cancer treatment. Interventions pre-operatively or post-cancer treatment are associated with positive benefits on exercise capacity, symptoms and some domains of HRQoL. The majority of studies are small case series therefore results should be viewed with caution until larger RCTs are completed. Further research is required to establish the effect of exercise during and after cancer treatment and in the advanced stage of disease, the optimum type of exercise training and the optimum setting for delivery.

Small changes in six-minute walk distance are important in diffuse parenchymal lung disease

UNLABELLED The aim of this study was to determine the minimal important difference for the six-minute walk distance in people with diffuse parenchymal lung disease. METHODS Forty-eight subjects (24 idiopathic pulmonary fibrosis) undertook the six-minute walk test before and after an 8-week exercise program. The minimal important difference was calculated using a distribution-based and an anchor-based method. A global rating of change scale was used as the external criterion to judge patients as clinically unchanged or changed. RESULTS The mean change in six-minute walk distance in improved subjects was 50.0 m, compared to 4.0 m in unchanged subjects and a reduction of 64.3 m in those classified as worse (p<0.001). The receiver operating characteristic curve indicated a cut-off value for meaningful change of 30.5 m (area under the curve 0.89, 95% confidence interval 0.81-0.98) whilst the standard error of the mean method indicated a value of 33 m. Similar values were obtained when only subjects with idiopathic pulmonary fibrosis were included (29 and 34 m, respectively). CONCLUSIONS Small differences in six-minute walk distance, in the range 29-34 m, may be clinically significant for people with diffuse parenchymal lung disease.

The Interplay between the Effects of Lifetime Asthma, Smoking, and Atopy on Fixed Airflow Obstruction in Middle Age

RATIONALE The contribution by asthma to the development of fixed airflow obstruction (AO) and the nature of its effect combined with active smoking and atopy remain unclear. OBJECTIVES To investigate the prevalence and relative influence of lifetime asthma, active smoking, and atopy on fixed AO in middle age. METHODS The population-based Tasmanian Longitudinal Health Study cohort born in 1961 (n = 8,583) and studied with prebronchodilator spirometry in 1968 was retraced (n = 7,312) and resurveyed (n = 5,729 responses) from 2002 to 2005. A sample enriched for asthma and chronic bronchitis underwent a further questionnaire, pre- and post-bronchodilator spirometry (n = 1,389), skin prick testing, lung volumes, and diffusing capacity measurements. Prevalence estimates were reweighted for sampling fractions. Multiple linear and logistic regression were used to assess the relevant associations. MEASUREMENTS AND MAIN RESULTS Main effects and interactions between lifetime asthma, active smoking, and atopy as they relate to fixed AO were measured. The prevalence of fixed AO was 6.0% (95% confidence interval [CI], 4.5-7.5%). Its association with early-onset current clinical asthma was equivalent to a 33 pack-year history of smoking (odds ratio, 3.7; 95% CI, 1.5-9.3; P = 0.005), compared with a 24 pack-year history for late-onset current clinical asthma (odds ratio, 2.6; 95% CI, 1.03-6.5; P = 0.042). An interaction (multiplicative effect) was present between asthma and active smoking as it relates to the ratio of post-bronchodilator FEV(1)/FVC, but only among those with atopic sensitization. CONCLUSIONS Active smoking and current clinical asthma both contribute substantially to fixed AO in middle age, especially among those with atopy. The interaction between these factors provides another compelling reason for atopic individuals with current asthma who smoke to quit.

A randomised trial of domiciliary, ambulatory oxygen in patients with COPD and dyspnoea but without resting hypoxaemia

Background Patients with chronic obstructive pulmonary disease (COPD) who are not severely hypoxaemic at rest may experience significant breathlessness on exertion, and ambulatory oxygen is often prescribed in this circumstance despite a lack of conclusive evidence for benefit. This study aimed to determine whether such patients benefit from domiciliary ambulatory oxygen and, if so, which factors may be associated with benefit. Methods This was a 12 week, parallel, double-blinded, randomised, placebo-controlled trial of cylinder air versus cylinder oxygen, provided at 6 l/min intranasally, for use during any activity provoking breathlessness. Patients underwent baseline measurements of arterial blood gases and lung function. Outcome measures assessed dyspnoea, health-related quality of life, mood disturbance, functional status and cylinder utilisation. Data were analysed on an intention-to-treat basis, p≤0.05. Results 143 subjects (44 female), mean±SD age 71.8±9.8 years, forced expiratory volume in 1 s (FEV1)1.16±0.51 lites, Pao2 9.5±1.1 kPa (71.4±8.5 mm Hg) were randomised, including 50 patients with exertional desaturation to ≤88%. No significant differences in any outcome were found between groups receiving air or oxygen. Statistically significant but clinically small improvements in dyspnoea and depression were observed in the whole study group over the 12 weeks of the study. Conclusion In breathless patients with COPD who do not have severe resting hypoxaemia, domiciliary ambulatory oxygen confers no benefits in terms of dyspnoea, quality of life or function. Exertional desaturation is not predictive of outcome. Intranasal gas (either air or oxygen) may provide a placebo benefit. Clinical trial number ACTRN12605000457640.

Low physical activity levels and functional decline in individuals with lung cancer

OBJECTIVES Physical activity has been infrequently measured objectively in non-small cell lung cancer (NSCLC). We aimed to investigate levels of physical activity, functional and patient reported outcomes at diagnosis and over six months in participants with recently diagnosed NSCLC and compare results with both physical activity guidelines and outcomes of similar-aged healthy individuals. METHODS This prospective observational study assessed 50 individuals from three Australian tertiary hospitals with stage I-IIIB NSCLC at diagnosis, then 10 weeks and six months later. Thirty five healthy individuals without cancer were assessed once. Outcome measures included tri-axial accelerometery (number of steps per day), six minute walk distance (6MWD), muscle strength and questionnaires including health-related quality of life (HRQoL). RESULTS Individuals with NSCLC were engaged in significantly less physical activity than similar-aged healthy individuals, with 60% not meeting physical activity guidelines. At diagnosis they had worse quadriceps strength, nutritional status and HRQoL. Over six months, participants with NSCLC experienced decline in self-reported physical activity, 6MWD and muscle strength, and worsening symptoms. CONCLUSION At diagnosis individuals with NSCLC engage in less physical activity, are weaker and more depressed than healthy individuals and their self-reported physical activity declines over six months. Future studies are required to investigate the efficacy of interventions to increase physical activity.

Distinguishing adult-onset asthma from COPD: a review and a new approach.

Adult-onset asthma and chronic obstructive pulmonary disease (COPD) are major public health burdens. This review presents a comprehensive synopsis of their epidemiology, pathophysiology, and clinical presentations; describes how they can be distinguished; and considers both established and proposed new approaches to their management. Both adult-onset asthma and COPD are complex diseases arising from gene–environment interactions. Early life exposures such as childhood infections, smoke, obesity, and allergy influence adult-onset asthma. While the established environmental risk factors for COPD are adult tobacco and biomass smoke, there is emerging evidence that some childhood exposures such as maternal smoking and infections may cause COPD. Asthma has been characterized predominantly by Type 2 helper T cell (Th2) cytokine-mediated eosinophilic airway inflammation associated with airway hyperresponsiveness. In established COPD, the inflammatory cell infiltrate in small airways comprises predominantly neutrophils and cytotoxic T cells (CD8 positive lymphocytes). Parenchymal destruction (emphysema) in COPD is associated with loss of lung tissue elasticity, and small airways collapse during exhalation. The precise definition of chronic airflow limitation is affected by age; a fixed cut-off of forced expiratory volume in 1 second/forced vital capacity leads to overdiagnosis of COPD in the elderly. Traditional approaches to distinguishing between asthma and COPD have highlighted age of onset, variability of symptoms, reversibility of airflow limitation, and atopy. Each of these is associated with error due to overlap and convergence of clinical characteristics. The management of chronic stable asthma and COPD is similarly convergent. New approaches to the management of obstructive airway diseases in adults have been proposed based on inflammometry and also multidimensional assessment, which focuses on the four domains of the airways, comorbidity, self-management, and risk factors. Short-acting beta-agonists provide effective symptom relief in airway diseases. Inhalers combining a long-acting beta-agonist and corticosteroid are now widely used for both asthma and COPD. Written action plans are a cornerstone of asthma management although evidence for self-management in COPD is less compelling. The current management of chronic asthma in adults is based on achieving and maintaining control through step-up and step-down approaches, but further trials of back-titration in COPD are required before a similar approach can be endorsed. Long-acting inhaled anticholinergic medications are particularly useful in COPD. Other distinctive features of management include pulmonary rehabilitation, home oxygen, and end of life care.