CF Airway Clearance Therapies Clinical Care Guidelines
Flume PA, Robinson KA, O'Sullivan BP, Finder JD, Vender RL, Willey-Courand DB, White TB, Marshall BC; Clinical Practice Guidelines for Pulmonary Therapies Committee. Cystic Fibrosis Pulmonary Guidelines: Airway Clearance Therapies. Respir Care. 2009;54(4):522-537.PMID: 19327189
Airway clearance therapy (ACT), the process of improving the efficacy of the mucociliary escalator as well as eliciting a cough, is at the center of chronic therapies necessary to maintain lung health in individuals affected by cystic fibrosis. Several different types of airway clearance devices and device-independent airway clearance techniques have been developed in recent decades. The purpose of the 2009 Cystic Fibrosis Foundation clinical practice guideline was to review and compare these devices and techniques, focusing on outcome measures such as sputum production and lung function. Airway clearance therapies that were evaluated included:
- Percussion and postural drainage (P&PD)
- Positive expiratory pressure (PEP) devices
- Active cycle of breathing technique (ACBT)
- Autogenic drainage (AD)
- Oscillatory PEP devices (OPEP)
- High-frequency chest compression (HFCC) devices
Overall, the committee recommended that all people with CF should perform airway clearance to maintain lung function and improve quality of life (level of evidence, fair; net benefit, moderate). After review of the available literature, no form of ACT was shown to be superior to another form of ACT. The committee went on to recommend that the choice of ACT be individualized to the patient, as patient-specific factors may make one form of ACT superior to another for the individual patient. Finally, the committee recommended aerobic exercise as an adjunctive therapy for airway clearance, as it has additional overall health benefits.
Purpose and Background
In CF, mucociliary clearance is impaired due to dehydration of the aqueous layer of the airway surface liquid as a direct result of the dysfunction of the cystic fibrosis transmembrane conductance regulator (CFTR) protein. Clinically, CFTR dysfunction results in decreased mucociliary clearance, airway obstruction, recurrent respiratory infections with neutrophil migration into airways, and an exuberant inflammatory response leading to damage to lung parenchyma over time.
ACT uses patient maneuvers or devices to improve mucociliary clearance and augment the cough. Many different forms of ACT have been advocated, and the purpose of this Cystic Fibrosis Foundation clinical practice guideline was to evaluate and compare ACTs to provide support for clinical decision making regarding specific therapies.
Methodology and Results
The committee initially met to identify ACTs that were believed to be most commonly used in clinical practice and for which there would be peer-reviewed literature available for evaluation. The two primary questions used for ACT assessment were:
- What is the efficacy of the ACT in comparison to no therapy at all?
- What is the efficacy of the therapy in comparison to the other therapies under review?
The following outcome measures were included in analysis:
- Sputum production
- Lung function
- Arterial oxygen saturation
- Exercise tolerance
- Pulmonary exacerbations
- Adverse events
- Quality of life measures
- Patient preferences
A systemic literature review was commissioned from Johns Hopkins University to identify all relevant literature. When possible, the recommendations were graded using the U.S. Preventative Services Task Force (USPSTF) grading definitions.
- Sputum production: The committee found evidence that P&PD and PEP therapy demonstrated greater sputum production compared to no therapy at all. In comparing sputum production with different ACTs, the committee found no difference between P&PD and PEP devices and no difference between P&PD and OPEP. In comparing sputum production between P&PD and HFCC, two trials favored HFCC and two trials showed no difference.
- Lung function: One study showed that P&PD significantly improved forced expiratory volume in the first second (FEV1) compared to no therapy over a short period. Another study comparing P&PD and PEP therapy found no difference in FEV1 over a four-week trial period. Although one study favored HFCC in comparison to P&PD in terms of effect on FEV1, another found no difference between these two therapies.
- Pulmonary exacerbations: The committee identified no studies that evaluated the effect of ACT vs no ACT on pulmonary exacerbations. In a study investigating the effect of aerobic exercise compared to no exercise program, no significant differences were identified between groups for number of hospitalizations or mean number of days hospitalized. There were no studies that showed that one ACT was superior to another in terms of its ability to reduce pulmonary exacerbations.
- Adverse events and mortality: Overall, there are few reports of adverse events with ACT, but the reports that do exist report hemoptysis and nausea. There are no reports evaluating the effects of ACT on mortality.
- Quality of life: Five studies were identified that evaluated quality of life and all evaluated the effects of exercise. Two studies showed improved quality of life in patients with an exercise program compared to no exercise program. One of these studies was a long-term, three-year study and the other was a short-term in-patient study over several weeks. One study involving inspiratory training reported lower anxiety and depression scores over an eight-week time period. One study compared P&PD and PEP therapy over a two-year period and found no difference in the Quality of Well-Being scale. There were no other reported comparisons for quality of life.
- Patient preference: Evaluating patient preference, four of six studies comparing P&PD to PEP found that patients preferred PEP. One study that evaluated P&PD and OPEP found that patients preferred OPEP. Another four-week study comparing HFCC and OPEP found that 50 percent of the participants preferred HFCC because they thought it was more efficacious.
|Recommendations||Evaluation of the Evidence|
|ACT is recommended for all patients with CF for clearance of sputum, augmentation of cough, maintenance of lung function, and improved quality of life.||Level of evidence: Fair
Net benefit: Moderate
|No ACT has been demonstrated to be superior to any other.||Level of evidence: Fair
|ACT choice should be individualized to the patient, as one form may be superior when considering factors such as age, patient preference, and individual history of adverse events.||Level of evidence: Fair
Grade of recommendation, consensus recommendation: B
|Aerobic exercise is recommended as an adjunctive therapy for airway clearance for all patients with CF, but is not a substitute for airway clearance.||Level of evidence: Fair
Net benefit: Moderate
Since the development of the original guidelines in 2009, several manuscripts relevant to ACT have been published. These manuscripts have not been reviewed or endorsed by the guidelines committee.
- In 2014, a Cochrane review of OPEP for airway clearance in CF found no clear evidence that oscillation was more or less effective than other forms of physiotherapy (Morrison 2017).
- In 2013, a randomized controlled multi-center trial of 12 CF centers in Canada compared HFCC and PEP over a one-year period and found no significant difference in lung function, health-related quality of life scores, or patient satisfaction, but a significant difference favoring PEP was found in terms of fewer exacerbations and longer time to first exacerbation (McIlwaine 2013). This finding may have clinical significance when considering the contribution of exacerbations to the rate of decline of lung function in CF patients (Goss 2013).
- A review by Walsh and colleagues serves as a recent review of ACT used in the pediatric population (Walsh 2011).
- Rand and colleagues provide an ACT review, which includes medications used with ACT. This allows clinicians to individualize an ACT plan for each patient (Rand 2013).
- The 2009 guidelines did not evaluate concurrent use of noninvasive ventilation (NIV) along with ACT for inpatient therapy. This has been addressed in a small study by Dwyer, et al. (Dwyer 2015) in which the authors found a significant improvement in FEV1 in the NIV cohort. A 2016 Cochrane review did not find sufficient evidence to support or reject active cycle of breathing techniques compared to any other form of ACT (McKoy 2016).
Airway clearance therapy represents a long-standing and important part of CF care. In the 2009 guidelines, several questions were identified as needing further research:
- When should airway clearance be initiated? With the majority of CF patients diagnosed by newborn screening, there has been some impetus to initiate ACT early in the first year of life, as evidence suggests that airway inflammation and obstruction exist in this age group (Pillarisetti 2011). This evidence is still in line with the recommendation in the 2009 guidelines that ACT should be started in the first few months of life.
- How should the clinician choose an ACT for a patient? While there is still no published evidence in regard to this question, the principles of personalized medicine apply. Decisions regarding patient-specific ACT should still focus on age, severity of disease, the patient's ability to perform specific maneuvers, and patient preference.
- What is the optimal method of performing each of the ACTs? There remains a paucity of research in regard to this question, and thus this remains an area of need for research.
- Who should educate the patient on ACT? Although there is no published literature in regard to this question, ACT continues to be taught by experienced providers in CF centers in both the inpatient and outpatient settings. Incorporation of trained respiratory therapists into the CF team will increase the opportunity to educate patients about the various ACT modalities available and their correct usage.
- How should we evaluate new methods of airway clearance? ACT literature continues to lack controlled, long-term studies that have been powered to adequately compare therapies. Individuals with CF are living longer and with less morbidity. As a result, future studies need to focus on objective ways to evaluate individual responses to ACT. Newer surrogate markers of lung function may prove beneficial in this area.
Relevant manuscripts published after the original guidelines are listed below. These manuscripts have not been reviewed or endorsed by the guidelines committee.
- Morrison L, Agnew J. Oscillating devices for airway clearance in people with cystic fibrosis. Cochrane Database Syst Rev. 2017 May 4;5:CD006842. doi: 10.1002/14651858.CD006842.pub4. PMID: 25038719.
- McIlwaine MP, Alarie N, Davidson GF, Lands LC, Ratjen F, Milner R, Owen B, Agnew JL. Long-term multicentre randomised controlled study of high frequency chest wall oscillation versus positive expiratory pressure mask in cystic fibrosis. Thorax. 2013 Aug;68(8):746-51.PMID: 23407019.
- Goss CH, Burns JL. Exacerbations in cystic fibrosis. 1: Epidemiology and pathogenesis. Thorax. 2013 Aug;68(8):746-51. Epub 2013 Feb 13.PMID: 17387214.
- Walsh BK, Hood K, Merritt G. Pediatric airway maintenance and clearance in the acute care setting: how to stay out of trouble. Respir Care. 2011 Sep;56(9):1424-40.PMID: 21944689.
- Rand S, Hill L, Prasad SA. Physiotherapy in cystic fibrosis: optimising techniques to improve outcomes. Paediatr Respir Rev. 2013 Dec;14(4):263-9. Epub 2012 Nov 4.PMID: 24209461.
- Dwyer TJ, Robbins L, Kelly P, Piper AJ, Bell SC, Bye PT. Non-invasive ventilation used as an adjunct to airway clearance treatments improves lung function during an acute exacerbation of cystic fibrosis: a randomised trial. J Physiother. 2015 Jul;61(3):142-7. Epub 2015 Jun 18.PMID: 26096013.
- McKoy NA, Wilson LM, Saldanha IJ, Odelola OA, Robinson KA. Active cycle of breathing technique for cystic fibrosis. Cochrane Database Syst Rev. 2016 Jul 5;7:CD007862. doi: 10.1002/14651858.CD007862.pub4.PMID: 27378490.
- Pillarisetti N, Williamson E, Linnane B, Skoric B, Robertson CF, Robinson P, Massie J, Hall GL, Sly P, Stick S, Ranganathan S, Australian Respiratory Early Surveillance Team for Cystic Fibrosis (AREST CF). Infection, inflammation, and lung function decline in infants with cystic fibrosis. Am J Respir Crit Care Med. 2011 Jul 1;184(1):75-81. Epub 2011 Apr 14.PMID: 21493738.
This executive summary was prepared by:
Michael Glenn O'Connor, MD (Monroe Carell Jr. Children's Hospital at Vanderbilt) and Brian P. O'Sullivan, MD (Geisel School of Medicine at Dartmouth)
The guidelines were published in April 2009, they were reviewed in July 2021 and it was determined that no update is needed at this time.