Positive expiratory pressure physiotherapy for airway clearance in people with cystic fibrosis

Saved by the PEEP: Resolution of Complete Unilateral Lung Collapse Secondary to Mucus Plugging With Ventilator Technique

Bronchoscopy can be used to resolve respiratory failure caused by tenacious mucus plugs. However, emergent bronchoscopy to resolve mucus plugging is not always available in small rural hospitals around the country. We present a case in which increasing the positive end-expiratory pressure settings on the ventilator resulted in immediate improvement in patient oxygenation and imaging findings during a respiratory emergency caused by mucus plugging.

Positive expiratory pressure physiotherapy for airway clearance in people with cystic fibrosis

BACKGROUND

Chest physiotherapy is widely prescribed to assist the clearance of airway secretions in people with cystic fibrosis (CF). Positive expiratory pressure (PEP) devices provide back pressure to the airways during expiration. This may improve clearance by building up gas behind mucus via collateral ventilation and by temporarily increasing functional residual capacity. The developers of the PEP technique recommend using PEP with a mask in order to avoid air leaks via the upper airways and mouth. In addition, increasing forced residual capacity (FRC) has not been demonstrated using mouthpiece PEP. Given the widespread use of PEP devices, there is a need to determine the evidence for their effect. This is an update of a previously published review.

OBJECTIVES

To determine the effectiveness and acceptability of PEP devices compared to other forms of physiotherapy as a means of improving mucus clearance and other outcomes in people with CF.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register comprising of references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. The electronic database CINAHL was also searched from 1982 to 2017. Most recent search of the Group's CF Trials Register: 20 February 2019.

SELECTION CRITERIA

Randomised controlled studies in which PEP was compared with any other form of physiotherapy in people with CF. This included, postural drainage and percussion (PDPV), active cycle of breathing techniques (ACBT), oscillating PEP devices, thoracic oscillating devices, bilevel positive airway pressure (BiPaP) and exercise.

DATA COLLECTION AND ANALYSIS

Three authors independently applied the inclusion and exclusion criteria to publications, assessed the risk of bias of the included studies and assessed the quality of the evidence using the GRADE recommendations.

MAIN RESULTS

A total of 28 studies (involving 788 children and adults) were included in the review; 18 studies involving 296 participants were cross-over in design. Data were not published in sufficient detail in most of these studies to perform any meta-analysis. In 22 of the 28 studies the PEP technique was performed using a mask, in three of the studies a mouthpiece was used with nose clips and in three studies it was unclear whether a mask or mouthpiece was used. These studies compared PEP to ACBT, autogenic drainage (AD), oral oscillating PEP devices, high-frequency chest wall oscillation (HFCWO) and BiPaP and exercise. Forced expiratory volume in one second was the review's primary outcome and the most frequently reported outcome in the studies (24 studies, 716 participants). Single interventions or series of treatments that continued for up to three months demonstrated little or no difference in effect between PEP and other methods of airway clearance on this outcome (low- to moderate-quality evidence). However, long-term studies had equivocal or conflicting results regarding the effect on this outcome (low- to moderate-quality evidence). A second primary outcome was the number of respiratory exacerbations. There was a lower exacerbation rate in participants using PEP compared to other techniques when used with a mask for at least one year (five studies, 232 participants; moderate- to high-quality evidence). In one of the included studies which used PEP with a mouthpiece, it was reported (personal communication) that there was no difference in the number of respiratory exacerbations (66 participants, low-quality evidence). Participant preference was reported in 10 studies; and in all studies with an intervention period of at least one month, this was in favour of PEP. The results for the remaining outcome measures (including our third primary outcome of mucus clearance) were not examined or reported in sufficient detail to provide any high-quality evidence; only very low- to moderate-quality evidence was available for other outcomes. There was limited evidence reported on adverse events; these were measured in five studies, two of which found no events. In a study where infants performing either PEP or PDPV experienced some gastro-oesophageal reflux , this was more severe in the PDPV group (26 infants, low-quality evidence). In PEP versus oscillating PEP, adverse events were only reported in the flutter group (five participants complained of dizziness, which improved after further instructions on device use was provided) (22 participants, low-quality evidence). In PEP versus HFCWO, from one long-term high-quality study (107 participants) there was little or no difference in terms of number of adverse events; however, those in the PEP group had fewer adverse events related to the lower airways when compared to HFCWO (high-certainty evidence). Many studies had a risk of bias as they did not report how the randomisation sequence was either generated or concealed. Most studies reported the number of dropouts and also reported on all planned outcome measures.

AUTHORS' CONCLUSIONS

The evidence provided by this review is of variable quality, but suggests that all techniques and devices described may have a place in the clinical treatment of people with CF. Following meta-analyses of the effects of PEP versus other airway clearance techniques on lung function and patient preference, this Cochrane Review demonstrated that there was high-quality evidence that showed a significant reduction in pulmonary exacerbations when PEP using a mask was compared with HFCWO. It is important to note that airway clearance techniques should be individualised throughout life according to developmental stages, patient preferences, pulmonary symptoms and lung function. This also applies as conditions vary between baseline function and pulmonary exacerbations.

Positive expiratory pressure physiotherapy for airway clearance in people with cystic fibrosis

BACKGROUND

Chest physiotherapy is widely prescribed to assist the clearance of airway secretions in people with cystic fibrosis. Positive expiratory pressure (PEP) devices provide back pressure to the airways during expiration. This may improve clearance by building up gas behind mucus via collateral ventilation and by temporarily increasing functional residual capacity. Given the widespread use of PEP devices, there is a need to determine the evidence for their effect. This is an update of a previously published review.

OBJECTIVES

To determine the effectiveness and acceptability of PEP devices compared to other forms of physiotherapy as a means of improving mucus clearance and other outcomes in people with cystic fibrosis.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register comprising of references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. The electronic database CINAHL was also searched from 1982 to 2013.Most recent search of the Group's Cystic Fibrosis Trial Register: 02 December 2014.

SELECTION CRITERIA

Randomised controlled studies in which PEP was compared with any other form of physiotherapy in people with cystic fibrosis. This included, postural drainage and percussion, active cycle of breathing techniques, oscillating PEP devices, thoracic oscillating devices, bilevel positive airway pressure (BiPaP) and exercise. Studies also had to include one or more of the following outcomes: change in forced expiratory volume in one second; number of respiratory exacerbations; a direct measure of mucus clearance; weight of expectorated secretions; other pulmonary function parameters; a measure of exercise tolerance; ventilation scans; cost of intervention; and adherence to treatment.

DATA COLLECTION AND ANALYSIS

Three authors independently applied the inclusion and exclusion criteria to publications and assessed the risk of bias of the included studies.

MAIN RESULTS

A total of 26 studies (involving 733 participants) were included in the review. Eighteen studies involving 296 participants were cross-over in design. Data were not published in sufficient detail in most of these studies to perform any meta-analysis. These studies compared PEP to active cycle of breathing techniques (ACBT), autogenic drainage (AD), oral oscillating PEP devices, high frequency chest wall oscillation (HFCWO) and Bi level PEP devices (BiPaP) and exercise.Forced expiratory volume in one second was the review's primary outcome and the most frequently reported outcome in the studies. Single interventions or series of treatments that continued for up to three months demonstrated no significant difference in effect between PEP and other methods of airway clearance on this outcome. However, long-term studies had equivocal or conflicting results regarding the effect on this outcome. A second primary outcome was the number of respiratory exacerbations. There was a lower exacerbation rate in participants using PEP compared to other techniques when used with a mask for at least one year. Participant preference was reported in 10 studies; and in all studies with an intervention period of at least one month, this was in favour of PEP. The results for the remaining outcome measures were not examined or reported in sufficient detail to provide any high-level evidence. The only reported adverse event was in a study where infants performing either PEP or postural drainage with percussion experienced some gastro-oesophageal reflux. This was more severe in the postural drainage with percussion group. Many studies had a risk of bias as they did not report how the randomisation sequence was either generated or concealed. Most studies reported the number of dropouts and also reported on all planned outcome measures.

AUTHORS' CONCLUSIONS

Following meta-analyses of the effects of PEP versus other airway clearance techniques on lung function and patient preference, this Cochrane review demonstrated that there was a significant reduction in pulmonary exacerbations in people using PEP compared to those using HFCWO in the study where exacerbation rate was a primary outcome measure. It is important to note, however, that there may be individual preferences with respect to airway clearance techniques and that each patient needs to be considered individually for the selection of their optimal treatment regimen in the short and long term, throughout life, as circumstances including developmental stages, pulmonary symptoms and lung function change over time. This also applies as conditions vary between baseline function and pulmonary exacerbations.However, meta-analysis in this Cochrane review has shown a significant reduction in pulmonary exacerbations in people using PEP in the few studies where exacerbation rate was a primary outcome measure.

The effects of oscillating positive expiratory pressure therapy in adults with stable non-cystic fibrosis bronchiectasis: A systematic review

Airway clearance techniques (ACTs) are recommended for patients with stable non-cystic fibrosis (non-CF) bronchiectasis, but the efficacy of oscillating positive expiratory pressure (PEP) therapy compared to other techniques has not been reviewed. A systematic review of studies was conducted in stable patients comparing the effect of oscillating PEP therapy to other ACTs or a control condition. Data were extracted related to sputum expectoration, lung function, gas exchange, quality of life (QOL), symptoms, and exacerbation rate. Seven studies were included with a total of 146 patients, with a mean (SD) PEDro score of 7(1). Oscillating PEP therapy enhanced sputum expectoration compared to no treatment, but has equivalent benefits as the active cycle of breathing technique with gravity-assisted drainage (mean difference [95% CI] -2.8 g [-8.8 to 3.2 g]). Oscillating PEP has a similar effect as other ACTs on dynamic lung volumes, gas exchange and breathlessness. Use of oscillating PEP improved disease-specific QOL (p < 0.001) and cough-related QOL (p < 0.002) compared to no treatment but did not reduce exacerbation rate. In conclusion, in stable non-CF bronchiectasis, oscillating PEP therapy is associated with improvement in sputum expectoration and QOL compared to no treatment. Compared to other ACTs, the effect upon sputum expectoration, lung function, gas exchange, and symptoms are equivalent.

What is the best airway clearance technique in cystic fibrosis?

The global development of airway clearance techniques (ACTs) for cystic fibrosis (CF) and corresponding research spans over four decades. Five Cochrane reviews synthesising the evidence from a plethora of early short and medium term studies have not uncovered any superior method. Four recent long term RCT studies exposed fundamental shortcomings in the standard RCT trial design and the insensitivity of FEV1 in physiotherapy studies. Strong patient preference, lack of blinding and the requirement for effortful and demanding participation over long intervals will continue to derail efforts to find the best ACT for CF, unless they are addressed in future clinical trials.

Problems and solutions: Accounts by parents and children of adhering to chest physiotherapy for cystic fibrosis

PURPOSE

Although chest physiotherapy is central to the management of cystic fibrosis (CF), adherence among children is problematic. This study explores accounts by parents and children of the difficulties of adhering to chest physiotherapy for cystic fibrosis, and identifies strategies used by families to overcome these.

METHODS

A qualitative study based on in-depth interviews with 32 children with a diagnosis of cystic fibrosis aged 7 - 17 years, and with 31 parents.

RESULTS

Physiotherapy was frequently described as restrictive, threatening to identity and boring, giving rise to feelings of unfairness, inequality, 'difference', and social stigma. Motivation to adhere was influenced by perceptions of effectiveness that depended on external signs evident during or after the physiotherapy. Motivation was enhanced where parents and children visualized the accumulation of mucus. Some parents had developed distraction techniques that improved the experience of chest physiotherapy but had few opportunities to share these with other parents.

CONCLUSION

The experience of physiotherapy is problematic to some parents and children. Furthermore, motivation to overcome these problems may be undermined by perceptions of ineffectiveness. Distraction techniques that change the value that the child places on the time spent doing physiotherapy and that reduces their perception of its duration may improve experience and adherence. The potential of visualization techniques to promote adherence should be investigated further.

Comparison of High-Frequency Chest Wall Oscillation With Differing Waveforms for Airway Clearance in Cystic Fibrosis

BACKGROUND

High-frequency chest wall oscillation (HFCWO) is commonly used by cystic fibrosis (CF) patients for airway clearance. The primary objective of this study was to determine whether the use of a newer HFCWO device that generates oscillations with a triangular waveform results in greater sputum production than a commonly used device that generates oscillations with a sine waveform.

METHODS

This was a controlled, randomized, double-blind, crossover study. Fifteen clinically stable, adult CF patients participated. Patients performed airway clearance with each device once and at matched oscillation frequencies and pressures. All sputum produced during each session was collected. Patients completed pulmonary function tests before and after each session, and rated the comfort of the two devices.

RESULTS

Mean sputum wet and dry weight produced during sine waveform and triangular waveform HFCWO sessions did not differ (p = 0.11 and p = 0.2, respectively). Mean changes in FEV(1) and FVC following HFCWO therapy were also comparable (p = 0.21 and p = 0.56, respectively). However, there was a significant reduction in air trapping by residual volume/total lung capacity ratio following triangular waveform HFCWO (p = 0.01). In addition, in vitro cough transportability was 10.6% greater following therapy with the triangular waveform device (p = 0.05). Patients perceived the two devices as equally comfortable (p = 0.8).

CONCLUSIONS

Single-session sputum production is comparable with sine and triangular waveform HFCWO devices. Longer term comparisons are needed to determine whether sustained use of the devices results in clinically important differences in outcomes.

Nonpharmacologic airway clearance therapies: ACCP evidence-based clinical practice guidelines

BACKGROUND

Airway clearance may be impaired in disorders associated with abnormal cough mechanics, altered mucus rheology, altered mucociliary clearance, or structural airway defects. A variety of interventions are used to enhance airway clearance with the goal of improving lung mechanics and gas exchange, and preventing atelectasis and infection.

METHOD

A formal systematic review of nonpharmacologic protussive therapies was performed and constitutes the basis for this section of the guideline. In addition, the articles reviewed were found using the same methodology but were not limited to those that focused only on cough as a symptom. The MEDLINE database was searched for this review and consisted of studies published in the English language between 1960 and April 2004. The search terms used were "chest physiotherapy," "forced expiratory technique," "positive expiratory pressure," "high frequency chest compression," "insufflation," and "exsufflation."

RESULTS

In general, studies of nonpharmacologic methods of improving cough clearance are limited by methodological constraints, and most were conducted only in patients with cystic fibrosis. Chest physiotherapy, including postural drainage, chest wall percussion and vibration, and a forced expiration technique (called huffing), increase airway clearance as assessed by sputum characteristics (ie, volume, weight, and viscosity) and clearance of the radioaerosol from the lung, but the long-term efficacy of these techniques compared with unassisted cough alone is unknown. Other devices that allow patients to achieve the same benefits derived from chest physiotherapy without the assistance of a caregiver appear to be as effective as chest physiotherapy in increasing sputum production.

CONCLUSIONS

Some nonpharmacologic therapies are effective in increasing sputum production, but their long-term efficacy in improving outcomes compared with unassisted cough alone is unknown.