Christian R. Osadnik

Australian and New Zealand Pulmonary Rehabilitation Guidelines

The aim of the Pulmonary Rehabilitation Guidelines (Guidelines) is to provide evidence‐based recommendations for the practice of pulmonary rehabilitation (PR) specific to Australian and New Zealand healthcare contexts.

Effect of “add-on” interventions on exercise training in individuals with COPD: a systematic review

The aim of this review was to identify the effectiveness of therapies added on to conventional exercise training to maximise exercise capacity in patients with chronic obstructive pulmonary disease (COPD). Electronic databases were searched, identifying trials comparing exercise training with exercise training plus “add-on” therapy. Outcomes included peak oxygen uptake (V′O2peak), work rate and incremental/endurance cycle and field walking tests. Individual trial effects on exercise capacity were extracted and collated into eight subgroups and pooled for meta-analysis. Sensitivity analyses were conducted to explore the stability of effect estimates across studies employing patient-centred designs and those deemed to be of “high” quality (PEDro score >5 out of 10). 74 studies (2506 subjects) met review inclusion criteria. Interventions spanned a broad scope of clinical practice and were most commonly evaluated via the 6-min walking distance and V′O2peak. Meta-analysis revealed few clinically relevant and statistically significant benefits of “add-on” therapies on exercise performance compared with exercise training. Benefits favouring “add-on” therapies were observed across six different interventions (additional exercise training, noninvasive ventilation, bronchodilator therapy, growth hormone, vitamin D and nutritional supplementation). The sensitivity analyses included considerably fewer studies, but revealed minimal differences to the primary analysis. The lack of systematic benefits of “add-on” interventions is a probable reflection of methodological limitations, such as “one size fits all” eligibility criteria, that are inherent in many of the included studies of “add-on” therapies. Future clarification regarding the exact value of such therapies may only arise from adequately powered, multicentre clinical trials of tailored interventions for carefully selected COPD patient subgroups defined according to distinct clinical phenotypes. Add-on modalities show mostly minimal additional benefits to exercise capacity after conventional training in COPD http://ow.ly/XABi4

The effect of positive expiratory pressure (PEP) therapy on symptoms, quality of life and incidence of re-exacerbation in patients with acute exacerbations of chronic obstructive pulmonary disease: a multicentre, randomised controlled trial

Background Positive expiratory pressure (PEP) is a technique used to enhance sputum clearance during acute exacerbations of chronic obstructive pulmonary disease (AECOPD). The impact of PEP therapy during acute exacerbations on clinically important outcomes is not clear. This study sought to determine the effect of PEP therapy on symptoms, quality of life and future exacerbations in patients with AECOPD. Methods 90 inpatients (58 men; mean age 68.6 years, FEV1 40.8% predicted) with AECOPD and sputum expectoration were randomised to receive usual care (including physical exercise)±PEP therapy. The Breathlessness, Cough and Sputum Scale (BCSS), St Georges Respiratory Questionnaire (SGRQ) and BODE index (Body mass index, airflow Obstruction, Dyspnoea, Exercise tolerance) were measured at discharge, 8 weeks and 6 months following discharge, and analysed via linear mixed models. Exacerbations and hospitalisations were recorded using home diaries. Results There were no significant between-group differences over time for BCSS score [mean (SE) at discharge 5.2 (0.4) vs 5.0 (0.4) for PEP and control group, respectively; p=0.978] or SGRQ total score [41.6 (2.6) vs 40.8 (2.8) at 8 weeks, p=0.872]. Dyspnoea improved more rapidly in the PEP group over the first 8 weeks (p=0.006), however these benefits were not observed at 6 months. Exacerbations (p=0.986) and hospitalisations (p=0.359) did not differ between groups. Conclusions We found no evidence that PEP therapy during AECOPD improves important short-term or long-term outcomes. There does not appear to be a routine role for PEP therapy in the management of such individuals.

Physiological responses during downhill walking: A new exercise modality for subjects with chronic obstructive pulmonary disease?

Skeletal muscle quadriceps low-frequency fatigue (LFF) during exercise promotes improvements in exercise capacity with exercise training. In healthy subjects, eccentric muscle work induced by downhill walking (DW) generates higher muscular stress, whilst metabolic cost is lower compared to level walking (LW). We investigated quadriceps LFF and metabolic cost of DW in patients with chronic obstructive pulmonary disease. Ten participants (67 ± 7 years, FEV1 51 ± 15% predicted) performed DW, DW carrying a load (DWL) of 10% body weight via vest and LW, in random order. Quadriceps potentiated twitch force (TWqpot) was assessed before and after each walk, and muscle damage was assessed before and 24 hours after each walk via serum creatine kinase (CK) levels. Ventilation (VE) and oxygen consumption (VO2) were measured via breath-by-breath analysis during each walk. DW and DWL resulted in a greater decrease in TWqpot (−30 ± 14 N in DW, p < 0.05; and −22 ± 16 N in DWL, p < 0.05) compared to LW (−3 ± 21 N, p > 0.05). CK levels only increased 24 hours following DW and DWL (p < 0.05). DW and DWL showed lower VE and VO2 than LW (p < 0.05). DW is associated with enhanced quadriceps LFF and lower cardiorespiratory costs than LW. The addition of a chest load to DW does not seem to enhance these effects.

Positive Expiratory Pressure via Mask Does Not Improve Ventilation Inhomogeneity More than Huffing and Coughing in Individuals with Stable Chronic Obstructive Pulmonary Disease and Chronic Sputum Expectoration

Background: Positive expiratory pressure (PEP) has been used to promote airway clearance in individuals with chronic obstructive pulmonary disease (COPD) for many years; however, its mechanism of action and benefits are unclear. Previous authors have suggested that PEP improves collateral ventilation via changes in lung volumes. Objectives: It was the aim of this study to determine whether PEP improves ventilation inhomogeneity more than controlled huffing and coughing in individuals with stable COPD. Methods: Twelve participants with COPD (mean forced expiratory volume in 1 s 45% predicted) and chronic sputum expectoration performed PEP therapy (10-20 cm H2O) or controlled huffing and coughing in random order on alternate study days with a 48-hour washout. Measures of acinar and conductive airway ventilation (Sacin, Scond), lung volumes, spirometry and sputum wet weight were recorded before, immediately after and 90 min following treatment. Ease of expectoration [visual analogue scale (VAS)] and oxyhaemoglobin saturation were assessed immediately following treatment. Results: There were no significant differences between the effect of either test condition at any time point for any test parameter. Mean Sacin immediately following PEP and control conditions was 0.465 and 0.438 litre-1, respectively (p = 0.45 for comparison between conditions) and mean Scond was 0.042 and 0.039 litre-1 (p = 0.55). PEP therapy did not significantly enhance total mean sputum expectoration compared to controlled huffing and coughing (7.06 vs. 6.15 g; p = 0.51) and did not improve ease of expectoration (VAS PEP 4.8 cm vs. control 4.1 cm; p = 0.53). Conclusion: Any therapeutic benefits of PEP in individuals with COPD and chronic sputum expectoration are unlikely to be mediated by improvements in ventilation or lung volumes.

Principles of rehabilitation and reactivation.

Skeletal muscle dysfunction and physical inactivity are two clinically important features of a wide range of acute and chronic respiratory conditions. Optimisation of both of these features is important in order to improve physical function, prevent clinical deterioration and maximise community participation. One of the most potent and evidence-based interventions to address these physical deficits is pulmonary rehabilitation (PR). Whilst the majority of PR research has been conducted in patients with chronic obstructive pulmonary disease, there is widespread recognition that PR can benefit many other respiratory patient groups. These include patients with interstitial lung diseases, asthma, pulmonary hypertension, pre-/post-lung surgery (e.g. lung cancer, transplantation) and cystic fibrosis to name a few. Exercise training must be appropriately prescribed by a skilled healthcare professional with comprehensive knowledge of the pathology and physiology of these conditions, as well as a sound understanding of the exercise physiology and core principles of exercise prescription, monitoring and progression. It has also become increasingly recognised that people with respiratory conditions, particularly those with chronic disease, are considerably less active than those of good health. PR should therefore aim to induce behavioural change to facilitate the adoption and maintenance of an active lifestyle. In addition, PR should pay attention to the psychological well-being of patients and self-management of their lung disease in all its aspects. To that end, multidisciplinary individualised programs should be offered. This review sets the scene of PR principles for a series of papers that will focus on specific diseases other than chronic obstructive pulmonary disease where rehabilitation may offer a clinically important aspect of care over and above conventional pharmacological treatment.

Clinical issues of mucus accumulation in COPD

Dear editor We wish to thank Ramos et al for presenting a succinct and up-to-date synthesis of the evidence relating to the important issue of mucus hypersecretion in COPD.1 The authors highlight the association of mucus hypersecretion with poor outcomes, including increased risk of exacerbations, hospitalization and mortality. These associations have led to interest in the potential benefits of mucus clearance techniques in COPD. As Ramos et al1 point out, although the physiological rationale for airway clearance techniques (ACTs) in COPD is strong, clinical efficacy has historically been difficult to establish, perhaps due to the variety of techniques and outcomes that have been employed in small studies. We have recently synthesized this body of evidence in a Cochrane systematic review of ACTs for individuals with COPD. The review demonstrated ACTs are safe and meta-analysis showed they confer small beneficial effects on a limited range of important clinical outcomes, such as the need for and duration of ventilatory assistance during an acute exacerbation of COPD (AECOPD).2 We agree with Ramos et al1 that ACTs based upon positive expiratory pressure (or PEP) appear to be physiologically suited to addressing the underlying pathophysiology and mechanics of the lungs in individuals affected by COPD. This is supported by non-significant trends of improved efficacy of PEP-based ACTs over other types of ACTs,2 and was the premise of our multicentre, randomized controlled trial (n=92) investigating the effect of PEP compared to usual care consisting of no ACTs in patients with AECOPD.3 However, this study demonstrated a clear lack of benefit in a range of important clinical outcomes, including self-reported symptom severity, both in the short-term and long-term. The lack of impact of ACTs on significant outcomes in COPD is now emerging consistently in the literature, such as the important investigation by Cross et al4 of manual chest physical therapy (percussions and vibrations) in 526 inpatients with AECOPD. A theme of these new investigations is the importance of outcome choice. Much of the existing literature in the area of ACTs in COPD is founded on outcomes such as forced expiratory volume or measures of sputum clearance. These may be intuitively useful and relatively simple to obtain, however measures of lung function correlate poorly with more relevant patient-centered outcomes5 and measures of sputum clearance are fraught with limitations regarding their interpretation. Both are no longer considered useful indicators of ACT success.6 Future investigations in this area should address whether ACTs can modify the important adverse outcomes associated with mucus hypersecretion, as outlined in the review of Ramos et al.1 We would like to add our voice to the growing call for high quality research into the clinically challenging dilemma of diagnosing and managing coexistent COPD (or chronic bronchitis) with bronchiectasis. Although radiological evidence of bronchiectasis is present in a significant proportion of people with COPD, defining the dominant condition in cases of established or severe co-existing disease poses a challenge, as does determination of the ideal pharmacological and non-pharmacological management for this “combined” phenotype.

Peripheral muscle training in patients with chronic obstructive pulmonary disease: novel approaches and recent advances

ABSTRACT Introduction: Pulmonary rehabilitation is one of the most effective non-pharmacological management options for individuals with chronic obstructive pulmonary disease (COPD). Exercise training is the cornerstone of pulmonary rehabilitation, however considerable variability exists regarding the way it is delivered across the world. It is widely accepted that efforts should be made to tailor specific therapeutic approaches to individuals’ needs. This applies as much to respiratory medicine as it does to respiratory rehabilitation. Areas covered: This narrative review examines the emerging literature evaluating advancements of exercise training modalities targeting peripheral muscle function in people with COPD. It aims to highlight practical considerations regarding the delivery key evidence regarding clinical effectiveness, as well as highlight some of the and evaluation of their effectiveness to inform clinical practice. Expert commentary: Although novel therapies may offer advantages over more ‘traditional’ training methods under specific circumstances, challenges regarding the potential impact upon clinical rehabilitation, the identification of the best candidates for such therapy and access to equipment may pose realistic barriers to their more widespread clinical implementation. Future directions regarding the ways in which these barriers could be overcome will be discussed, including identification of the key research priorities to optimize evidence-based practice in this area.

Validity and reliability of strain gauge measurement of volitional quadriceps force in patients with COPD

This study investigated the validity and reliability of fixed strain gauge measurements of isometric quadriceps force in patients with chronic obstructive pulmonary disease (COPD). A total cohort of 138 patients with COPD were assessed. To determine validity, maximal volitional quadriceps force was evaluated during isometric maximal voluntary contraction (MVC) manoeuvre via a fixed strain gauge dynamometer and compared to (a) potentiated non-volitional quadriceps force obtained via magnetic stimulation of the femoral nerve (twitch (Tw); n = 92) and (b) volitional computerized dynamometry (Biodex; n = 46) and analysed via correlation coefficients. Test–retest and absolute reliability were determined via calculations of intra-class correlation coefficients (ICCs), smallest real differences (SRDs) and standard errors of measurement (SEMs). For this, MVC recordings in each device were performed across two test sessions separated by a period of 7 days (n = 46). Strain gauge measures of MVC demonstrated very large correlation with Tw and Biodex results (r = 0.86 and 0.88, respectively, both p < 0.0001). ICC, SEM and SRD were numerically comparable between strain gauge and Biodex devices (ICC = 0.96 vs. 0.93; SEM = 8.50 vs. 10.54 N·m and SRD = 23.59 vs. 29.22 N·m, respectively). The results support that strain gauge measures of quadriceps force are valid and reliable in patients with COPD.

Targeting obesity in COPD through allied health therapies

See article, page 875