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Oscillating devices for airway clearance in people with cystic fibrosis
Accepted Manuscript Oscillating devices for airway clearance in people with cystic fibrosis L. Morrison, S. Milroy PII: DOI: Reference:
S1526-0542(17)30069-6 http://dx.doi.org/10.1016/j.prrv.2017.07.001 YPRRV 1230
To appear in:
Paediatric Respiratory Reviews
Received Date: Accepted Date:
5 July 2017 5 July 2017
Please cite this article as: L. Morrison, S. Milroy, Oscillating devices for airway clearance in people with cystic fibrosis, Paediatric Respiratory Reviews (2017), doi: http://dx.doi.org/10.1016/j.prrv.2017.07.001
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Oscillating devices for airway clearance in people with cystic fibrosis Morrison L1, Milroy S1. 1 West of Scotland Adult CF Unit, Queen Elizabeth University Hospital, Glasgow, UK Why is it important to do this Cochrane review 1? Cystic fibrosis (CF) is a common inherited life-limiting genetic disorder in which mucus hypersecretion within the airways leads to airway obstruction and mucus plugging2. Airway damage and the progressive loss of respiratory function is a consequence of persistent infection and inflammation within the lungs 3,4. As respiratory infections are the most common cause of morbidity and mortality, chest physiotherapy in the form of breathing exercises or adjunctive devices is the mainstay of therapies to keep the lungs as free from mucus as possible. What comparisons were made in this review? This review considered the use of oscillation and oscillatory devices for airway clearance and the consequent impact these have on the individual with CF, in particular when compared with other recognised forms of airway clearance. The primary outcomes investigated were respiratory function parameters; secondary outcomes considered sputum volume/weight, patient preference, frequency of exacerbations, oxygen saturations, exercise tolerance and quality of life (QoL). Two review authors independently searched relevant databases, extracted data, and assessed the risk of bias of included studies in accordance with the Cochrane risk of bias tool. What did we find? The review included 35 studies (randomised controlled trials (RCTs) and quasiRCTs) with 1138 people with CF aged between 4 and 63 years of age. One third of these were published only as abstracts, thus limiting the amount of information available for the meta-analysis. We considered few studies to be of relatively high methodological quality and therefore at a low risk of bias. Since airway clearance requires the application of a technique or the inclusion of a device, it was not possible to blind the participants to the interventions; however, in nine studies there was evidence that researchers collecting respiratory function data or sputum samples or performing other relevant testing were blinded to the intervention. Oscillatory devices, both oral and chest wall, for airway clearance were compared with another recognised airway clearance technique either as a single technique (e.g. oscillation versus active cycle of breathing technique (ACBT)) or in conjunction with another recognised airway clearance technique (e.g. oscillation and ACBT
versus ACBT alone). Interventions of variable duration were considered; however, single-treatment episodes were not considered. Intra-thoracic oscillations are generated orally and created using variable resistances within the airways producing controlled oscillating positive pressure which mobilises respiratory secretions. Exhalation through these devices generates both oscillations of positive pressure in the airways and repeated accelerations of expiratory airflow that have been shown to result in improved sputum clearance5. The devices considered were Flutter, Quake, Cornet, Acapella and intermittent percussive ventilator (IPV). Extra-thoracic oscillations are generated by forces external to the respiratory system, e.g. high frequency chest wall oscillation (HFCWO)6. External chest wall oscillations are applied using an inflatable vest attached to a machine which vibrates at a variable frequencies and intensities as set by the operator to ensure the individual's comfort and associated concordance. The literature reviewed was representative of the airway clearance techniques used in the management of CF. There was a lack of long-term studies with few being of greater than three months in duration. Short-term studies, despite demonstrating improved sputum clearance, did not demonstrate preservation of respiratory function, decreased morbidity or show an improved QoL7. Oscillatory devices can be effective in clearing secretions, but despite evidence showing improvement in sputum volume (Figure 1), there is no statistically significant evidence to suggest that these devices are superior to other physiotherapy techniques when respiratory function is the primary outcome in the short term (Figure 2). Participant satisfaction was reported in 15 studies but this was also not specifically in favour of an oscillating device, with some participants preferring breathing techniques or techniques used prior to the study. One study8 demonstrated an increase in the frequency of exacerbations requiring antibiotics whilst using an oscillating device compared to positive expiratory pressure (PEP); evidence such as this may have significant resource implications.
IMPLICATIONS FOR PRACTICE AND RESEARCH More adequately-powered long-term RCTs are necessary; outcomes measured should include frequency of exacerbations, individual preference, adherence to therapy and general satisfaction with treatment. Additional evidence is needed to evaluate whether oscillating devices combined with other forms of airway clearance, which is becoming more commonplace, is efficacious in people with CF. There may also be a requirement to consider the cost implication of devices over other forms of equally advantageous airway clearance techniques. Individual preference is a significant factor when introducing airway clearance techniques or therapy adjuncts and this can vary at different stages of the disease
process. It would appear no single treatment technique is suitable for everyone and physiotherapists supporting patients should be well-educated in all aspects of airway clearance and associated adjunctive techniques. This would enable the appropriate selection and inclusion of airway clearance techniques or devices into the management of the individual. As there is no appreciable difference between the devices or therapies for airway clearance, the healthcare provider should consider a cost-benefit analysis for their individual patients based on financial burdens and possible insurance cover where appropriate. In particular, where the frequency of exacerbations was shown to increase whilst using the Vest® compared to PEP7, this may have significant resource implications. Individual preference and acknowledgement of personal health beliefs are also important, as is ageappropriateness of the therapy techniques, which may have a considerable impact on concordance with therapies suggested or offered. Many of the studies included QoL scales and satisfaction questionnaires; however, few incorporated measures of adherence. When there is no marker of superiority between airway clearance techniques, it may be prudent to include time to next exacerbation, frequency of exacerbations, individual preference, adherence to therapy and general satisfaction with treatment as potential outcome measures in further studies of these techniques. As a consequence of adherence to therapy, we may then see improvements in other parameters such as exercise tolerance and respiratory function.
References 1. Morrison L, Milroy S. Oscillating devices for airway clearance in people with cystic fibrosis. Cochrane Database of Systematic Reviews 2017, Issue 5. Art. No.: CD006842. DOI: 10.1002/14651858.CD006842.pub4. 2. Zach MS. Lung disease in cystic fibrosis - an updated concept. Pediatric Pulmonology 1990;8(3):188-202. 3. Cantin A. Cystic fibrosis lung inflammation: early, sustained, and severe. American Journal of Respiratory and Critical Care Medicine 1995;151(4):93941 4. Konstan MW, Berger M. Current understanding of the inflammatory process in cystic fibrosis: onset and etiology. Pediatric Pulomonolgy 1997;24(2):137-42. 5. Rogers D, Doull IJM. Physiological principles of airway clearance techniques used in the physiotherapy management of cystic fibrosis. Current Paediatrics 2005;15(3):233-8. 6. Warwick WJ, Wielnski CI. Matched pair comparison of manual chest physical therapy (CPT) and the thairapy bronchial drainage vest (ThBVD) system. Pediatric Pulmonology 1990;9 Suppl 5:177. 7. Varekojis SM, Douce FH, Flucke RL, Filbrun DA, Tice JS, McCoy KS, et al. A comparison of the therapeutic effectiveness of and preference for postural drainage and percussion, intrapulmonary percussive ventilation, and high-
frequency chest wall compression in hospitalized cystic fibrosis patients. Respiratory Care 2003;48(1):24-8. 8. McIlwaine MP, Alarie N, Davidson GF, Lands LC, Ratjen F, Milner R, et al. Long-term multicentre randomised controlled study of high frequency chest wall oscillation versus positive expiratory pressure mask in cystic fibrosis. Thorax 2013;68(8):746-51.
Figure 1: FEV₁ post-intervention [% predicted]
Figure 2: FEV₁ change from baseline [% predicted]
S1526-0542(17)30069-6 http://dx.doi.org/10.1016/j.prrv.2017.07.001 YPRRV 1230
To appear in:
Paediatric Respiratory Reviews
Received Date: Accepted Date:
5 July 2017 5 July 2017
Please cite this article as: L. Morrison, S. Milroy, Oscillating devices for airway clearance in people with cystic fibrosis, Paediatric Respiratory Reviews (2017), doi: http://dx.doi.org/10.1016/j.prrv.2017.07.001
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Oscillating devices for airway clearance in people with cystic fibrosis Morrison L1, Milroy S1. 1 West of Scotland Adult CF Unit, Queen Elizabeth University Hospital, Glasgow, UK Why is it important to do this Cochrane review 1? Cystic fibrosis (CF) is a common inherited life-limiting genetic disorder in which mucus hypersecretion within the airways leads to airway obstruction and mucus plugging2. Airway damage and the progressive loss of respiratory function is a consequence of persistent infection and inflammation within the lungs 3,4. As respiratory infections are the most common cause of morbidity and mortality, chest physiotherapy in the form of breathing exercises or adjunctive devices is the mainstay of therapies to keep the lungs as free from mucus as possible. What comparisons were made in this review? This review considered the use of oscillation and oscillatory devices for airway clearance and the consequent impact these have on the individual with CF, in particular when compared with other recognised forms of airway clearance. The primary outcomes investigated were respiratory function parameters; secondary outcomes considered sputum volume/weight, patient preference, frequency of exacerbations, oxygen saturations, exercise tolerance and quality of life (QoL). Two review authors independently searched relevant databases, extracted data, and assessed the risk of bias of included studies in accordance with the Cochrane risk of bias tool. What did we find? The review included 35 studies (randomised controlled trials (RCTs) and quasiRCTs) with 1138 people with CF aged between 4 and 63 years of age. One third of these were published only as abstracts, thus limiting the amount of information available for the meta-analysis. We considered few studies to be of relatively high methodological quality and therefore at a low risk of bias. Since airway clearance requires the application of a technique or the inclusion of a device, it was not possible to blind the participants to the interventions; however, in nine studies there was evidence that researchers collecting respiratory function data or sputum samples or performing other relevant testing were blinded to the intervention. Oscillatory devices, both oral and chest wall, for airway clearance were compared with another recognised airway clearance technique either as a single technique (e.g. oscillation versus active cycle of breathing technique (ACBT)) or in conjunction with another recognised airway clearance technique (e.g. oscillation and ACBT
versus ACBT alone). Interventions of variable duration were considered; however, single-treatment episodes were not considered. Intra-thoracic oscillations are generated orally and created using variable resistances within the airways producing controlled oscillating positive pressure which mobilises respiratory secretions. Exhalation through these devices generates both oscillations of positive pressure in the airways and repeated accelerations of expiratory airflow that have been shown to result in improved sputum clearance5. The devices considered were Flutter, Quake, Cornet, Acapella and intermittent percussive ventilator (IPV). Extra-thoracic oscillations are generated by forces external to the respiratory system, e.g. high frequency chest wall oscillation (HFCWO)6. External chest wall oscillations are applied using an inflatable vest attached to a machine which vibrates at a variable frequencies and intensities as set by the operator to ensure the individual's comfort and associated concordance. The literature reviewed was representative of the airway clearance techniques used in the management of CF. There was a lack of long-term studies with few being of greater than three months in duration. Short-term studies, despite demonstrating improved sputum clearance, did not demonstrate preservation of respiratory function, decreased morbidity or show an improved QoL7. Oscillatory devices can be effective in clearing secretions, but despite evidence showing improvement in sputum volume (Figure 1), there is no statistically significant evidence to suggest that these devices are superior to other physiotherapy techniques when respiratory function is the primary outcome in the short term (Figure 2). Participant satisfaction was reported in 15 studies but this was also not specifically in favour of an oscillating device, with some participants preferring breathing techniques or techniques used prior to the study. One study8 demonstrated an increase in the frequency of exacerbations requiring antibiotics whilst using an oscillating device compared to positive expiratory pressure (PEP); evidence such as this may have significant resource implications.
IMPLICATIONS FOR PRACTICE AND RESEARCH More adequately-powered long-term RCTs are necessary; outcomes measured should include frequency of exacerbations, individual preference, adherence to therapy and general satisfaction with treatment. Additional evidence is needed to evaluate whether oscillating devices combined with other forms of airway clearance, which is becoming more commonplace, is efficacious in people with CF. There may also be a requirement to consider the cost implication of devices over other forms of equally advantageous airway clearance techniques. Individual preference is a significant factor when introducing airway clearance techniques or therapy adjuncts and this can vary at different stages of the disease
process. It would appear no single treatment technique is suitable for everyone and physiotherapists supporting patients should be well-educated in all aspects of airway clearance and associated adjunctive techniques. This would enable the appropriate selection and inclusion of airway clearance techniques or devices into the management of the individual. As there is no appreciable difference between the devices or therapies for airway clearance, the healthcare provider should consider a cost-benefit analysis for their individual patients based on financial burdens and possible insurance cover where appropriate. In particular, where the frequency of exacerbations was shown to increase whilst using the Vest® compared to PEP7, this may have significant resource implications. Individual preference and acknowledgement of personal health beliefs are also important, as is ageappropriateness of the therapy techniques, which may have a considerable impact on concordance with therapies suggested or offered. Many of the studies included QoL scales and satisfaction questionnaires; however, few incorporated measures of adherence. When there is no marker of superiority between airway clearance techniques, it may be prudent to include time to next exacerbation, frequency of exacerbations, individual preference, adherence to therapy and general satisfaction with treatment as potential outcome measures in further studies of these techniques. As a consequence of adherence to therapy, we may then see improvements in other parameters such as exercise tolerance and respiratory function.
References 1. Morrison L, Milroy S. Oscillating devices for airway clearance in people with cystic fibrosis. Cochrane Database of Systematic Reviews 2017, Issue 5. Art. No.: CD006842. DOI: 10.1002/14651858.CD006842.pub4. 2. Zach MS. Lung disease in cystic fibrosis - an updated concept. Pediatric Pulmonology 1990;8(3):188-202. 3. Cantin A. Cystic fibrosis lung inflammation: early, sustained, and severe. American Journal of Respiratory and Critical Care Medicine 1995;151(4):93941 4. Konstan MW, Berger M. Current understanding of the inflammatory process in cystic fibrosis: onset and etiology. Pediatric Pulomonolgy 1997;24(2):137-42. 5. Rogers D, Doull IJM. Physiological principles of airway clearance techniques used in the physiotherapy management of cystic fibrosis. Current Paediatrics 2005;15(3):233-8. 6. Warwick WJ, Wielnski CI. Matched pair comparison of manual chest physical therapy (CPT) and the thairapy bronchial drainage vest (ThBVD) system. Pediatric Pulmonology 1990;9 Suppl 5:177. 7. Varekojis SM, Douce FH, Flucke RL, Filbrun DA, Tice JS, McCoy KS, et al. A comparison of the therapeutic effectiveness of and preference for postural drainage and percussion, intrapulmonary percussive ventilation, and high-
frequency chest wall compression in hospitalized cystic fibrosis patients. Respiratory Care 2003;48(1):24-8. 8. McIlwaine MP, Alarie N, Davidson GF, Lands LC, Ratjen F, Milner R, et al. Long-term multicentre randomised controlled study of high frequency chest wall oscillation versus positive expiratory pressure mask in cystic fibrosis. Thorax 2013;68(8):746-51.
Figure 1: FEV₁ post-intervention [% predicted]
Figure 2: FEV₁ change from baseline [% predicted]