Oscillating devices for airway clearance in people with cystic fibrosis

Effect of intrathoracic oscillations on pulmonary functions in children with cerebral palsy

Objectives

This study was aimed at investigating the effects of intrathoracic oscillations on pulmonary function in children with spastic quadriplegic cerebral palsy.

Methods

This study comprised 24 boys and girls 6-8 years of age with spastic quadriplegic cerebral palsy. According to the modified Ashworth scale, the degree of spasticity was 2 to 2+. The children were able to sit independently and follow instructions. The children were randomly divided into a study group and control group. A spirometer was used to examine each child before and after 6 weeks. Children in the control group received traditional chest physiotherapy (postural drainage and percussion), whereas children in the study group underwent quake device training. For 6 weeks, both groups received four sessions per week. After treatment, the results were collected. Paired t-test and independent-samples t-test were applied to compare the means for each group. p-values <0.05 were considered significant.

Results

The post-treatment results of forced expiratory volume at 1 s, peak expiratory flow, forced vital capacity, and the ratio of forced expiratory volume at 1 s to forced vital capacity demonstrated significant differences favoring the study group over the control group (p < 0.001, p < 0.001, p = 0.002, and p = 0.023, respectively).

Conclusion

Intrathoracic oscillations may improve pulmonary function in children with quadriplegic cerebral palsy.

Benefits of secretion clearance with high frequency percussive ventilation in tracheostomized critically ill patients: a pilot study

Clearance of secretions remains a challenge in ventilated patients. Despite high-frequency percussive ventilation (HFPV) showing benefits in patients with cystic fibrosis and neuromuscular disorders, very little is known about its effects on other patient categories. Therefore, we designed a physiological pilot study investigating the effects on lung aeration and gas exchange of short HFPV cycles in tracheostomized patients undergoing mechanical ventilation. Electrical impedance tomography (EIT) was recorded at baseline (T0) by a belt wrapped around the patient's chest, followed by the HFPV cycle lasting 10 min. EIT data was collected again after the HFPV cycle (T1) as well as after 1 h (T2) and 3 h (T3) from T0. Variation from baseline of end-expiratory lung impedance (∆EELI), tidal variation (TIV) and global inhomogeneity index (GI) were computed. Arterial blood was also taken for gas analysis. HFPV cycle significantly improved the ∆EELI at T1, T2 and T3 when compared to baseline (p < 0.05 for all comparisons). The ratio between arterial partial pressure and inspired fraction of oxygen (PaO₂/FiO₂) also increased after the treatment (p < 0.001 for all comparison) whereas TIV (p = 0.132) and GI (p = 0.114) remained unchanged. Short cycles of HFPV superimposed to mechanical ventilation promoted alveolar recruitment, as suggested by improved ∆EELI, and improved oxygenation in tracheostomized patients with high load of secretion.Trial Registration Prospectively registered on www.clinicaltrials.gov (NCT05200507; dated 6th January 2022).

Airway clearance physiotherapy and health-related quality of life in cystic fibrosis

OBJECTIVE

Airway clearance physiotherapy is recommended in cystic fibrosis, but limited evidence exists to suggest how much treatment is enough. As a secondary analysis of a prior study investigating the safety, efficacy, and participants' perceptions of a novel airway clearance technique, specific cough technique (SCT) compared to forced expiration technique (FET), we aimed to evaluate whether the intervention was associated with changes in health-related quality of life (HRQoL).

METHODS

We conducted randomised, controlled individual trials with six adults (N-of-1 RCTs). Each trial included eight weeks of treatment, twice a week, using saline inhalation in horizontal positions, one with SCT and one with FET, in random order. Efficacy was measured by sputum wet weight (g) after each session. Perceived usefulness and preference were self-reported at the end of the study. Lung function was assessed at baseline and at the end of study. HRQoL was measured using the Cystic Fibrosis Questionnaire-Revised (CFQ-R) at baseline (week 1) and at completion of the study (week 8). Individual HRQoL scores (0-100) were coded and analysed using CFQ-R Software Program, version 2.0.

RESULTS

Patient-reported outcomes were completed by all subjects. Individual CFQ-R-Respiratory Symptoms Scores (CFQ-R-RSS) showed a positive change, meeting the minimal important difference (MID) ≥ 4 points in five participants and a negative change in one individual. A strong correlation (r = 0.94 (p<0.01) was found between total sputum weight (g) and the positive changes in CFQ-R-RSS, and between changes in lung function and CFQ-R-RSS (r = 0.84 (p = 0.04).

CONCLUSION

The airway clearance intervention was associated with clinically meaningful changes in patient-reported symptoms on the CFQ-R in the majority of the participants. This finding warrants further investigation regarding treatment, duration and frequency. A long-term study may reveal beneficial effects on other clinically meaningful endpoints, such as pulmonary exacerbations, high-resolution computed tomography scores and HRQoL.

TRIAL REGISTRATION

The study was registered in ClinicalTrials.gov, under the number NCT0 1266473.

Does the effect of comprehensive respiratory physiotherapy home-program differ in children with cystic fibrosis and non-cystic fibrosis bronchiectasis?

Bronchiectasis is a form of airway damage as a consequence of endobronchial infection and inflammation and may be present in different diseases. The underlying aetiologies include both cystic fibrosis (CF) and a group of non-cystic fibrosis diseases (NCFB) such as immunodeficiency, primary ciliary dyskinesia, or severe pulmonary infection. Although children with CF and non-cystic fibrosis bronchiectasis (NCFB) have many similar clinical features, their responses to exercise may be different. The aim of this study was to compare the efficacy of a comprehensive respiratory physiotherapy (CRP) home-program in children with CF and NCFB. Thirty children with CF and thirty children with NCFB were included in the study. Both groups performed the CRP home-program twice daily for 8 weeks. Pulmonary function, exercise capacity, and respiratory and peripheral muscle strength were assessed at baseline and after 8 weeks of training. Both groups experienced significant improvements in pulmonary function, exercise capacity, and respiratory and peripheral muscle strength (p < 0.001). Maximum expiratory pressure, exercise capacity, and peripheral muscle strength were further improved in NCFB group compared to CF (p < 0.05); however, there was a great variability in the improvements for each variable.

CONCLUSION

CRP is beneficial both for children with CF and NCFB and adherence to the program was high in both groups.

WHAT IS KNOWN

• Different physiotherapy approaches in the management of non-cystic fibrosis bronchiectasis have been based on the experience gained from the research studies performed in cystic fibrosis. • Although having similar pathophysiology, these two diseases show variation in some pulmonary and extrapulmonary features.

WHAT IS NEW

• The respiratory muscle strength and the efficacy of comprehensive respiratory physiotherapy have been compared for the first time in children with cystic fibrosis and non-cystic fibrosis bronchiectasis. • Comprehensive respiratory physiotherapy provides higher increases in children with non-cystic fibrosis bronchiectasis in exercise capacity and expiratory and peripheral muscle strength; however, there was a great variability in these improvements. Nevertheless, it can be concluded that both groups significantly benefited from the CRP program.

Physiotherapy for large airway collapse: an ABC approach

Large airway collapse (LAC) describes the phenomenon of excessive, abnormal, inward movement of the large airways (i.e. trachea and/or main bronchi and/or bronchus intermedius) occurring during the expiratory phase of the respiratory cycle. It is an increasingly well-recognised problem and a prevalent comorbidity in other chronic respiratory conditions (e.g. COPD and asthma). LAC is associated with pervasive respiratory features such as a barking cough, exertional dyspnoea and an increased propensity to lower respiratory tract infection. These symptoms are unpleasant, and patients are often limited in their daily life and their function. The pathophysiology of this condition impairs airway clearance and can cause breathlessness and exercise intolerance, due to a loss of airway patency during expiratory flow. Dysfunctional adaptations to breathing and coughing may further amplify symptoms. This article provides, for the first time, clinically focused physiotherapeutic intervention advice based on our understanding of the pathophysiology of LAC, to support conservative management. It uses the available evidence from LAC, transferable evidence from other conditions and knowledge based on clinical experience. It proposes a practical "ABC model" to ensure physiotherapy assessment and treatments are centred around optimising three key clinical areas: Airways, including airway clearance and cough; Breathing, including breathlessness and breathing pattern; and Capacity for exercise, including an assessment of functional exercise ability.

Additive Manufacturing Interventions during the COVID-19 Pandemic: South Africa

Additive manufacturing (AM), also known as 3D printing, is considered a renaissance of the manufacturing industry. Its unique capability of manufacturing 3D objects with intricate geometrical configurations has been used to produce hospital equipment and personal protective equipment (PPE) in an attempt to curb the spread of the COVID-19 pandemic in South Africa. The technology has been used by different research units to produce ventilators, respirator face masks, oscillating respiratory devices, oxygen connectors, oxygen splitters, non-invasive ventilation helmets, reusable clinician PPE, visor frames for face shields, etc. Despite the efforts of the AM community in South Africa, COVID-19 infections have continued to increase in the country. It came to light that technological interventions (including AM) alone cannot prevent the spread of the virus without the corresponding adaptive behavioural changes, such as adhering to COVID-19 prevention protocols (washing of hands, social distancing, etc.). It could be postulated that the spread of COVID-19 can only be prevented by inter-marrying the technological interventions (AM) with adaptive behavioural changes.

Non-Pharmaceutical Techniques for Obstructive Airway Clearance Focusing on the Role of Oscillating Positive Expiratory Pressure (OPEP): A Narrative Review

Mucus secretion in the lungs is a natural process that protects the airways from inhaled insoluble particle accumulation by capture and removal via the mucociliary escalator. Diseases such as cystic fibrosis (CF) and associated bronchiectasis, as well as chronic obstructive pulmonary disease (COPD), result in mucus layer thickening, associated with high viscosity in CF, which can eventually lead to complete airway obstruction. These processes severely impair the delivery of inhaled medications to obstructed regions of the lungs, resulting in poorly controlled disease with associated increased morbidity and mortality. This narrative review article focuses on the use of non-pharmacological airway clearance therapies (ACTs) that promote mechanical movement from the obstructed airway. Particular attention is given to the evolving application of oscillating positive expiratory pressure (OPEP) therapy via a variety of devices. Advice is provided as to the features that appear to be the most effective at mucus mobilization.

Treatment of Pulmonary Disease of Cystic Fibrosis: A Comprehensive Review

Cystic fibrosis (CF) is a genetic disease that causes absence or dysfunction of a protein named transmembrane conductance regulatory protein (CFTR) that works as an anion channel. As a result, the secretions of the organs where CFTR is expressed are very viscous, so their functionality is altered. The main cause of morbidity is due to the involvement of the respiratory system as a result of recurrent respiratory infections by different pathogens. In recent decades, survival has been increasing, rising by around age 50. This is due to the monitoring of patients in multidisciplinary units, early diagnosis with neonatal screening, and advances in treatments. In this chapter, we will approach the different therapies used in CF for the treatment of symptoms, obstruction, inflammation, and infection. Moreover, we will discuss specific and personalized treatments to correct the defective gene and repair the altered protein CFTR. The obstacle for personalized CF treatment is to predict the drug response of patients due to genetic complexity and heterogeneity of uncommon mutations.

Performance Characteristics of Positive Expiratory Pressure Devices

BACKGROUND

Positive expiratory pressure (PEP) therapy imposes expiratory flow resistance to increase airway diameter and enhance mucus clearance. PEP is achieved several ways. Oscillatory PEP devices (OPEP) generate repeated occlusions that are known to reduce mucus viscosity. There are many marketed devices, but comparative performance is mostly unreported. The purpose of this study was to evaluate performance characteristics of many PEP/OPEP devices. For OPEP devices, we defined an optimal performance metric by creating an oscillation index that combines the OPEP performance characteristics.

METHODS

PEP devices (TheraPEP, EzPAP, VersaPAP, Resistex, AccuPEP, AccuPAP, and Threshold PEP) and OPEP devices (Acapella DH, Acapella DM, Acapella Choice, ShurClear, Aerobika, VibraPEP, vPEP, and PocketPEP with and without the Oxyjet attachment) were tested by adjusting simulated expiratory flow from 5 L/min to 30 L/min in increments of 5 L/min using a standard flow meter.

RESULTS

All devices showed varying performance characteristics. As expiratory flow increased, mean PEP increased for most devices. The TheraPEP showed a mean PEP of 13 cm H₂O across all settings. For OPEP devices, there was a major difference between pressure and flow waveforms. The Acapella DH, ShurClear, and Aerobika showed the highest flow amplitude, flow frequency, and oscillation index.

CONCLUSIONS

PEP devices behaved similarly and as expected, with increased pressure with increased flow (flow resistors) or flow independence (threshold resistors). There was much greater variation in the performance of the OPEP devices. A higher oscillation index indicates better mechanical performance characteristics. Many devices have similar characteristics. However, the devices with the highest oscillation index have the highest flow amplitude and frequency, which may indicate better clinical performance.

The effect of vibrating positive expiratory pressure therapy on refractory Mycoplasma pneumoniae pneumonia prognosis in children

BACKGROUND

It is well documented that vibration techniques and positive expiratory pressure (PEP) can improve airway clearance, however, few clinical trials have studied the efficacy of vibrating PEP therapy on refractory Mycoplasma pneumoniae (M. pneumoniae) pneumonia (RMPP) in children. This study aimed to explore using vibrating PEP therapy in children with RMPP.

METHODS

Sixty participants in the remission stage of RMPP were recruited into this randomized study and divided into two groups. The Acapella group (n=30) used the Acapella^® Choice twice daily for 2 months to clear their airways. The control group (n=30) used traditional chest percussion or postural drainage to mediate sputum expectoration. The groups administered their respective treatments at home and were followed up weekly. Participants kept a record of their treatment and condition in a daily log. The primary outcome of this study was the resolution of chest images, and the secondary outcome was the sputum period.

RESULTS

There was no significant difference in sex or age distribution between the two groups. There were no significant differences at baseline between the groups in the location of their lesions (P=0.11). After 2 months of treatment, there was a better resolution of chest images in the Acapella group (P=0.00) compared with the control group. Additionally, the mean sputum period was significantly shorter for the Acapella group than for the control group (Acapella: 7.97±1.54 days; control: 11.90±1.64 days; P=0.00).

CONCLUSIONS

Vibrating PEP therapy is an effective therapy for children with RMPP, both in airway clearance and the resolution of lung abnormalities.

Investigating outcome measures for assessing airway clearance techniques in adults with cystic fibrosis: protocol of a single-centre randomised controlled crossover trial

Introduction

Airway clearance techniques (ACTs) are a gold standard of cystic fibrosis management; however, the majority of research evidence for their efficacy is of low standard; often attributed to the lack of sensitivity from outcome measures (OMs) used historically. This randomised controlled trial (RCT) investigates these standard OMs (sputum weight, forced expiratory volume in 1 s) and new OMs (electrical impedance tomography (EIT), multiple breath washout (MBW) and impulse oscillometry (IOS)) to determine the most useful measures of ACT.

Methods and analysis

This is a single-centre RCT with crossover design. Participants perform MBW, IOS and spirometry, and then are randomised to either rest or supervised ACT lasting 30–60 min. MBW, IOS and spirometry are repeated immediately afterwards. EIT and sputum are collected during rest/ACT. On a separate day, the OMs are performed with the other intervention. Primary endpoint is difference in change in OMs before and after ACT/rest. Sample size was calculated with 80% power and significance of 5% for each OM (target n=64).

Ethics and dissemination

Ethics approval was gained from the London–Chelsea Research Ethics Committee (reference 16/LO/0995, project ID 154635). Dissemination will involve scientific conference presentation and publication in a peer-reviewed journal.

Trial registration numbers

ISRCTN11220163 and NCT02721498.

Airway clearance techniques for cystic fibrosis: an overview of Cochrane systematic reviews

BACKGROUND

Cystic fibrosis is a life-limiting genetic condition in which thick mucus builds up in the lungs, leading to infections, inflammation, and eventually, deterioration in lung function. To clear their lungs of mucus, people with cystic fibrosis perform airway clearance techniques daily. There are various airway clearance techniques, which differ in terms of the need for assistance or equipment, and cost.

OBJECTIVES

To summarise the evidence from Cochrane Reviews on the effectiveness and safety of various airway clearance techniques in people with cystic fibrosis.

METHODS

For this overview, we included Cochrane Reviews of randomised or quasi-randomised controlled trials (including cross-over trials) that evaluated an airway clearance technique (conventional chest physiotherapy, positive expiratory pressure (PEP) therapy, high-pressure PEP therapy, active cycle of breathing techniques, autogenic drainage, airway oscillating devices, external high frequency chest compression devices and exercise) in people with cystic fibrosis.We searched the Cochrane Database of Systematic Reviews on 29 November 2018.Two review authors independently evaluated reviews for eligibility. One review author extracted data from included reviews and a second author checked the data for accuracy. Two review authors independently graded the quality of reviews using the ROBIS tool. We used the GRADE approach for assessing the overall strength of the evidence for each primary outcome (forced expiratory volume in one second (FEV1), individual preference and quality of life).

MAIN RESULTS

We included six Cochrane Reviews, one of which compared any type of chest physiotherapy with no chest physiotherapy or coughing alone and the remaining five reviews included head-to-head comparisons of different airway clearance techniques. All the reviews were considered to have a low risk of bias. However, the individual trials included in the reviews often did not report sufficient information to adequately assess risk of bias. Many trials did not sufficiently report on outcome measures and had a high risk of reporting bias.We are unable to draw definitive conclusions for comparisons of airway clearance techniques in terms of FEV1, except for reporting no difference between PEP therapy and oscillating devices after six months of treatment, mean difference -1.43% predicted (95% confidence interval -5.72 to 2.87); the quality of the body of evidence was graded as moderate. The quality of the body of evidence comparing different airway clearance techniques for other outcomes was either low or very low.

AUTHORS' CONCLUSIONS

There is little evidence to support the use of one airway clearance technique over another. People with cystic fibrosis should choose the airway clearance technique that best meets their needs, after considering comfort, convenience, flexibility, practicality, cost, or some other factor. More long-term, high-quality randomised controlled trials comparing airway clearance techniques among people with cystic fibrosis are needed.

Chest physiotherapy for pneumonia in children

BACKGROUND

Pneumonia is a lung infection that causes more deaths in children aged under five years than any other single cause. Chest physiotherapy is widely used as adjuvant treatment for pneumonia. Physiotherapy is thought to help remove inflammatory exudates, tracheobronchial secretions, and airway obstructions, and reduce airway resistance to improve breathing and enhance gas exchange. This is an update of a review published in 2013.

OBJECTIVES

To assess the effectiveness of chest physiotherapy with regard to time until clinical resolution in children (from birth to 18 years) of either gender with any type of pneumonia.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 1), which includes the Cochrane Acute Respiratory Infections Group Specialised Register, MEDLINE (22 February 2018), Embase (22 February 2018), CINAHL (22 February 2018), LILACS (22 February 2018), Web of Science (22 February 2018), and PEDro (22 February 2018). We also searched clinical trials registers (ClinicalTrials.gov and WHO ICTRP) to identify planned, ongoing, and unpublished trials.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared any type of chest physiotherapy with no chest physiotherapy for children with pneumonia.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. The primary outcomes of interest were mortality, duration of hospital stay, and time to clinical resolution. We used Review Manager 5 software to analyse data and GRADE to assess the quality of the evidence for each outcome.

MAIN RESULTS

We included three new RCTs for this update, for a total of six included RCTs involving 559 children aged from 29 days to 12 years with pneumonia who were treated as inpatients. Pneumonia severity was described as moderate in one trial, severe in two trials, and was not stated in three trials. The studies assessed five different interventions: effects of conventional chest physiotherapy (3 studies, 211 children), positive expiratory pressure (1 study, 72 children), continuous positive airway pressure (CPAP) (1 study, 94 children), bubble CPAP (bCPAP) (1 study, 225 children), and assisted autogenic drainage (1 studies, 29 children). The included studies were conducted in Bangladesh, Brazil, China, Egypt, and South Africa. The studies were overall at low risk of bias. Blinding of participants was not possible in most studies, but we considered that the outcomes were unlikely to be influenced by the lack of blinding.All included studies evaluated mortality. However, three studies assessed mortality as an outcome, and only one study of bCPAP reported that deaths occurred. Three deaths occurred in children in the physiotherapy group (N = 79) and 20 deaths in children in the control group (N = 146) (risk ratio (RR) 0.28, 95% confidence interval (CI) 0.08 to 0.90; 559 children; low-quality evidence). It is uncertain whether chest physiotherapy techniques (bCPAP, assisted autogenic drainage, and conventional chest physiotherapy) reduced hospital stay duration (days) (mean difference (MD) 0.10, 95% CI -0.56 to 0.76; 4 studies; low-quality evidence).There was variation among clinical parameters used to define clinical resolution. Two small studies found no difference in resolution of fever between children in the physiotherapy (conventional chest physiotherapy and assisted autogenic drainage) and control groups. Of five studies that considered peripheral oxygen saturation levels, only two reported that use of chest physiotherapy (CPAP and conventional chest physiotherapy) showed a greater improvement in peripheral oxygen saturation levels. However, it was unclear whether respiratory rate (breaths/min) improved after conventional chest physiotherapy (MD -2.25, 95% CI -5.17 to 0.68; 2 studies, 122 children; low-quality evidence). Two studies assessed adverse events (number of events), but only one study reported any events (RR 1.28, 95% CI 0.98 to 1.67; 2 studies, 254 children; low-quality evidence).

AUTHORS' CONCLUSIONS

We could draw no reliable conclusions concerning the use of chest physiotherapy for children with pneumonia due to the small number of included trials with differing study characteristics and statistical presentation of data. Future studies should consider the following key points: appropriate sample size with adequate power to detect expected differences, standardisation of chest physiotherapy techniques, appropriate outcomes (such as duration of leukocytosis, and airway clearance), and adverse effects.

Acute effects of combined exercise and oscillatory positive expiratory pressure therapy on sputum properties and lung diffusing capacity in cystic fibrosis: a randomized, controlled, crossover trial

Background

Regular airway clearance by chest physiotherapy and/or exercise is critical to lung health in cystic fibrosis (CF). Combination of cycling exercise and chest physiotherapy using the Flutter® device on sputum properties has not yet been investigated.

Methods

This prospective, randomized crossover study compared a single bout of continuous cycling exercise at moderate intensity (experiment A, control condition) vs a combination of interval cycling exercise plus Flutter® (experiment B). Sputum properties (viscoelasticity, yield stress, solids content, spinnability, and ease of sputum expectoration), pulmonary diffusing capacity for nitric oxide (DLNO) and carbon monoxide (DLCO) were assessed at rest, directly and 45 min post-exercise (recovery) at 2 consecutive visits. Primary outcome was change in sputum viscoelasticity (G’, storage modulus; G”, loss modulus) over a broad frequency range (0.1–100 rad.s^− 1).

Results

15 adults with CF (FEV₁range 24–94% predicted) completed all experiments. No consistent differences between experiments were observed for G’ and G” and other sputum properties, except for ease of sputum expectoration during recovery favoring experiment A. DLNO, DLCO, alveolar volume (V_A) and pulmonary capillary blood volume (V_cap) increased during experiment A, while DLCO and V_cap increased during experiment B (all P < 0.05). We found no differences in absolute changes in pulmonary diffusing capacity and its components between experiments, except a higher V_A immediately post-exercise favoring experiment A (P = 0.032).

Conclusions

The additional use of the Flutter® to moderate intensity interval cycling exercise has no measurable effect on the viscoelastic properties of sputum compared to moderate intensity continuous cycling alone. Elevations in diffusing capacity represent an acute exercise-induced effect not sustained post-exercise.

Trial registration

ClinicalTrials.gov; No.: NCT02750722; URL: clinical.trials.gov; Registration date: April 25th, 2016.

Electronic supplementary material

The online version of this article (10.1186/s12890-018-0661-1) contains supplementary material, which is available to authorized users.

Standard (head-down tilt) versus modified (without head-down tilt) postural drainage in infants and young children with cystic fibrosis

BACKGROUND

Postural drainage is used primarily in infants with cystic fibrosis from diagnosis up to the moment when they are mature enough to actively participate in self-administered treatments. However, there is a risk of gastroesophageal reflux associated with this technique.This is an update of a review published in 2015.

OBJECTIVES

To compare the effects of standard postural drainage (15º to 45º head-down tilt) with modified postural drainage (15º to 30º head-up tilt) with regard to gastroesophageal reflux in infants and young children up to six years old with cystic fibrosis in terms of safety and efficacy.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Cystic Fibrosis Trials Register. We also searched the reference lists of relevant articles and reviews. Additional searches were conducted on ClinicalTrials.gov and on the WHO International Clinical Trials Registry Platform for any planned, ongoing and unpublished studies.The date of the most recent literature searches: 19 June 2017.

SELECTION CRITERIA

We included randomised controlled studies that compared two postural drainage regimens (standard and modified postural drainage) with regard to gastroesophageal reflux in infants and young children (up to and including six years old) with cystic fibrosis.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Two review authors independently identified studies for inclusion, extracted outcome data and assessed risk of bias. We resolved disagreements by consensus or by involving a third review author. We contacted study authors to obtain missing or additional information. The quality of the evidence was assessed using GRADE.

MAIN RESULTS

Two studies, involving a total of 40 participants, were eligible for inclusion in the review. We included no new studies in the 2018 update. The included studies were different in terms of the age of participants, the angle of tilt, the reported outcomes, the number of sessions and the study duration. The following outcomes were measured: appearance or exacerbation of gastroesophageal reflux episodes; percentage of peripheral oxygen saturation; number of exacerbations of upper respiratory tract symptoms; number of days on antibiotics for acute exacerbations; chest X-ray scores; and pulmonary function tests. One study reported that postural drainage with a 20° head-down position did not appear to exacerbate gastroesophageal reflux. However, the majority of the reflux episodes in this study reached the upper oesophagus (moderate-quality evidence). The second included study reported that modified postural drainage (30° head-up tilt) was associated with fewer number of gastroesophageal reflux episodes and fewer respiratory complications than standard postural drainage (30° head-down tilt) (moderate-quality evidence). The included studies had an overall low risk of bias. One included study was funded by the Sydney Children's Hospital Foundation and the other by the Royal Children's Hospital Research Foundation and Physiotherapy Research Foundation of Australia. Data were not able to be pooled by meta-analysis due to differences in the statistical presentation of the data.

AUTHORS' CONCLUSIONS

The limited evidence regarding the comparison between the two regimens of postural drainage is still weak due to the small number of included studies, the small number of participants assessed, the inability to perform any meta-analyses and some methodological issues with the studies. However, it may be inferred that the use of a postural regimen with a 30° head-up tilt is associated with a lower number of gastroesophageal reflux episodes and fewer respiratory complications in the long term. The 20° head-down postural drainage position was not found to be significantly different from the 20° head-up tilt modified position. Nevertheless, the fact that the majority of reflux episodes reached the upper oesophagus should make physiotherapists carefully consider their treatment strategy. We do not envisage that there will be any new trials undertaken that will affect the conclusions of this review; therefore, we do not plan to update this review.

Autogenic drainage for airway clearance in cystic fibrosis

BACKGROUND

Autogenic drainage is an airway clearance technique that was developed by Jean Chevaillier in 1967. The technique is characterised by breathing control using expiratory airflow to mobilise secretions from smaller to larger airways. Secretions are cleared independently by adjusting the depth and speed of respiration in a sequence of controlled breathing techniques during exhalation. The technique requires training, concentration and effort from the individual. It is important to systematically review the evidence demonstrating that autogenic drainage is an effective intervention for people with cystic fibrosis.

OBJECTIVES

To compare the clinical effectiveness of autogenic drainage in people with cystic fibrosis with other physiotherapy airway clearance techniques.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. We also searched the reference lists of relevant articles and reviews, as well as two trials registers (31 August 2017).Dtae of most recent search of the Cochrane Cystic Fibrosis Trials Register: 25 September 2017.

SELECTION CRITERIA

We identified randomised and quasi-randomised controlled studies comparing autogenic drainage to another airway clearance technique or no therapy in people with cystic fibrosis for at least two treatment sessions.

DATA COLLECTION AND ANALYSIS

Data extraction and assessments of risk of bias were independently performed by two authors. The authors assessed the quality of the evidence using the GRADE system. The authors contacted two investigators for further information pertinent to their published studies.

MAIN RESULTS

Searches retrieved 35 references to 21 individual studies, of which seven (n = 208) were eligible for inclusion. One study was of parallel design with the remaining six being cross-over in design; participant numbers ranged from 17 to 75. The total study duration varied between four days and two years. The age of participants ranged between seven and 63 years with a wide range of disease severity reported. Six studies enrolled participants who were clinically stable, whilst participants in one study had been hospitalised with an infective exacerbation. All studies compared autogenic drainage to one (or more) other recognised airway clearance technique. Exercise is commonly used as an alternative therapy by people with cystic fibrosis; however, there were no studies identified comparing exercise with autogenic drainage.The quality of the evidence was generally low or very low. The main reasons for downgrading the level of evidence were the frequent use of a cross-over design, outcome reporting bias and the inability to blind participants.The review's primary outcome, forced expiratory volume in one second, was the most common outcome measured and was reported by all seven studies; only three studies reported on quality of life (also a primary outcome of the review). One study reported on adverse events and described a decrease in oxygen saturation levels whilst performing active cycle of breathing techniques, but not with autogenic drainage. Six of the seven included studies measured forced vital capacity and three of the studies used mid peak expiratory flow (per cent predicted) as an outcome. Six studies reported sputum weight. Less commonly used outcomes included oxygen saturation levels, personal preference, hospital admissions or intravenous antibiotics. There were no statistically significant differences found between any of the techniques used with respect to the outcomes measured except when autogenic drainage was described as being the preferred technique of the participants in one study over postural drainage and percussion.

AUTHORS' CONCLUSIONS

Autogenic drainage is a challenging technique that requires commitment from the individual. As such, this intervention merits systematic review to ensure its effectiveness for people with cystic fibrosis. From the studies assessed, autogenic drainage was not found to be superior to any other form of airway clearance technique. Larger studies are required to better evaluate autogenic drainage in comparison to other airway clearance techniques in view of the relatively small number of participants in this review and the complex study designs. The studies recruited a range of participants and were not powered to assess non-inferiority. The varied length and design of the studies made the analysis of pooled data challenging.