An acute exacerbation of a chronic obstructive pulmonary disease is an important event to both the individual and the health service, it is well established that an exacerbation has a deleterious effect upon lung function, health related quality of life, and mortality. We also know that hospitalisation for an exacerbation and subsequent readmission has a significant impact on the trajectory of the disease . An exacerbation is characterised by an increase in breathlessness, sputum production and cough. It would seem that there is an important role for the respiratory physiotherapist to apply airways clearance techniques and enhance recovery of the individual.
There are several airway clearance techniques that are available, and the application of these techniques has been surveyed previously in a number of countries as acknowledged by the authors of a paper in this issue ; Osadnik et al. describe the application of airways clearance techniques (ACT) techniques in Australia. Interestingly it appears that the most popular techniques applied by respiratory physiotherapists during the time of an acute exacerbation are physical exercise, the forced expiratory technique followed by the active cycle of breathing. The evidence for any ACT in the literature is not overwhelming. This survey is particularly interesting in light of the recent study of chest physiotherapy at the time of an acute exacerbation conducted in the UK . This study was a fully powered randomised controlled study to identify the benefit of chest physiotherapy to facilitate airways clearance during an acute exacerbation of COPD. The MATREX study was a well conducted trial that failed to identify the value of manual chest physiotherapy techniques in terms of health related quality of life, exacerbation frequency or readmissions. Although rather curiously, despite lack of clinical benefit there appeared to be a marginal cost effectiveness benefit associated with the intervention. In a sub group analysis the authors of the MATREX study, also failed to report any clinical benefit in those with documented sputum production. Perhaps it might be timely to reassess practice in the UK?
Over and above reporting treatment choices, Osadnik's paper  reflects on a number of interesting findings. The application of evidence in treatment choice appeared to be lacking, this was echoed in a UK paper reported by Agostini who surveyed physiotherapists’ choice of technique after thoracic surgery . In the former paper only 23% of those surveyed expressed a view that would probably best reflect the outcome of the recent Cochrane review , suggesting that the benefits are marginal and further well conducted randomised controls are required. 21% of those surveyed felt that the evidence strongly supported their interventions. The distribution of these responses did not vary across grades of seniority, judged by years working. Despite this uniformity in response the propensity for ACT's was greater in physiotherapists with less than 5 years experience compared to those with more than 5 years experience, in was not clear what drove a reduced application in more senior physiotherapists, perhaps personal experience rather than experimental data.
One of the most interesting finding of this survey was the use of physical exercise, indeed 89% of respondents confirmed that it was either ‘very often/always or often prescribed’. What the authors have not been able to unravel is whether the therapeutic value of the physical exercise is associated with anticipated increased sputum clearance, for which there is a very limited evidence base or whether there is a perceived additional benefit of an in-patient rehabilitation programme. Furthermore we have no indication whether the physical exercise was accurately monitored and prescribed or whether the therapist was simply advising the patients to be ‘more active’. A more formal prescription of exercise has been speculated to be of value within the pulmonary rehabilitation community. Whilst conceptually of benefit, in terms of preventing the documented decline in peripheral muscle strength  we have little evidence to established exercise as an effective intervention during this time, a fully powered randomised controlled trial is required. The limited evidence to date has supported the use of resistance training as opposed to aerobic training, to avoid aggravating ventilatory distress associated with an acute exacerbation . There is some tantalising data to suggest that those individuals who improve their physical activity after an acute exacerbation are less likely to be readmitted within a short period of time after discharge, compared to those who do not see any improvement in physical activity . There are several gaps in our knowledge around physical activity and acute exacerbations, intuitively is would seem important to encourage physical activity – perhaps the physiotherapists in Australia should be considered leaders in the field, although the dissociation between practice and evidence is always cause for concern.
Respiratory physiotherapy during an acute exacerbation – evidence versus practice. Physiotherapy - June 2013 (Vol. 99, Issue 2, Pages 93-94, DOI: 10.1016/j.physio.2013.01.002) Sally Singh