Intrapulmonary percussive ventilation improves lung function in cystic fibrosis patients chronically colonized with Pseudomonas aeruginosa: a pilot cross-over study

Clinical application of intrapulmonary percussive ventilation: A scoping review

Impaired respiratory function secondary to acute or chronic respiratory disease poses a significant clinical and healthcare burden. Intrapulmonary percussive ventilation (IPV) is used in various clinical settings to treat excessive airway secretions, pulmonary atelectasis, and impaired gas exchange. Despite IPV's wide use, there is a lack of clinical guidance on IPV application which may lead to inconsistency in clinical practice. This scoping review aimed to summarise the clinical application methods and dosage of IPV used by clinicians and researchers to provide guidance. A two-staged systematic search was conducted to retrieve studies that used IPV in inpatient and outpatient settings. MEDLINE, EMBASE, CINAHL, Scopus, and Google scholar were searched from January 1979 till 2022. Studies with patients aged ≥16 years and published in any language were included. Two reviewers independently screened the title and abstract, reviewed full text articles, and extracted data. Search yielded 514 studies. After removing duplicates and irrelevant studies, 25 studies with 905 participants met the inclusion criteria. This is the first scoping review to summarise IPV application methods and dosages from the available studies in intensive care unit (ICU), acute inpatient (non-ICU), and outpatient settings. Some variations in clinical applications and prescribed dosages of IPV were noted. Despite variations, common trends in clinical application and prescription of IPV dosages were observed and summarised to assist clinicians with IPV intervention. Although an evidence-based clinical guideline could not be provided, this review provides detailed information on IPV application and dosages in order to provide clinical guidance and lays a foundation towards developing a clinical practice guideline in the future.

Anti-Pseudomonas aeruginosa Vaccines and Therapies: An Assessment of Clinical Trials

Pseudomonas aeruginosa is a Gram-negative opportunistic pathogen that causes high morbidity and mortality in cystic fibrosis (CF) and immunocompromised patients, including patients with ventilator-associated pneumonia (VAP), severely burned patients, and patients with surgical wounds. Due to the intrinsic and extrinsic antibiotic resistance mechanisms, the ability to produce several cell-associated and extracellular virulence factors, and the capacity to adapt to several environmental conditions, eradicating P. aeruginosa within infected patients is difficult. Pseudomonas aeruginosa is one of the six multi-drug-resistant pathogens (ESKAPE) considered by the World Health Organization (WHO) as an entire group for which the development of novel antibiotics is urgently needed. In the United States (US) and within the last several years, P. aeruginosa caused 27% of deaths and approximately USD 767 million annually in health-care costs. Several P. aeruginosa therapies, including new antimicrobial agents, derivatives of existing antibiotics, novel antimicrobial agents such as bacteriophages and their chelators, potential vaccines targeting specific virulence factors, and immunotherapies have been developed. Within the last 2-3 decades, the efficacy of these different treatments was tested in clinical and preclinical trials. Despite these trials, no P. aeruginosa treatment is currently approved or available. In this review, we examined several of these clinicals, specifically those designed to combat P. aeruginosa infections in CF patients, patients with P. aeruginosa VAP, and P. aeruginosa-infected burn patients.

Can percussive intrapulmonary ventilation improve the efficacy of physiotherapy in children with cystic fibrosis?

Lung disease in cystic fibrosis (CF) is characterized by reduced mucociliary clearance, airway plugging, recurrent infections, and chronic pulmonary inflammation. Patients who are affected undergo daily respiratory physiotherapy to improve airway clearance. Intrapulmonary percussive ventilation (IPV) is a technique used in clinical practice, but it is not commonly used in CF patients. Evidence for various respiratory pathologies, particularly in children, is still lacking. We present the case of an 11-year-old boy with cystic fibrosis who did not respond to traditional respiratory physiotherapy techniques. We proposed and tested the use of IPV during hospitalization. In this case, the use of IPV in physiotherapy treatment reduced the need for intravenous antibiotics, hospitalization, and improved radiologic features. IPV can be used successfully in CF patients who are resistant to traditional physiotherapy techniques.

Demonstration of mucus simulant clearance in a Bench-Model using acoustic Field-Integrated Intrapulmonary Percussive ventilation

Intrapulmonary Percussive Ventilation (IPV) is a high-frequency airway clearance technique used to help in mucus transport for mechanically ventilated and unventilated patients. Despite the many years of usage, this technique does not provide clear evidence of its intended efficacy. This is mainly attributable to the lack of in vitro observations that show "mucokinesis" towards the direction of the mouth. In the current manuscript, we demonstrate and subsequently propose a mechanism that details the movement of a mucus simulant in the proximal (towards the mouthpiece) direction. Towards this end, a novel method utilizing a high-frequency acoustic field in addition to the conventional air pulsations brought forth by traditional IPV is proposed. Under these conditions, at certain parameter settings, it is shown that the simulant is broken down into much smaller parts and subsequently pushed in the upstream direction gradually over a period of half-hour.

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 but it has previously been shown to be an effective treatment option for those who are seeking techniques to support and promote independence.  However, at a time where the trajectory and demographics of the disease are changing, 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 ongoing trials registers (02 February 2021). Date of most recent search of the Cochrane Cystic Fibrosis Trials Register: 06 July 2021.

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 three authors. The authors assessed the quality of the evidence using the GRADE system. The authors contacted seven teams of investigators for further information pertinent to their published studies.

MAIN RESULTS

Searches retrieved 64 references to 37 individual studies, of which eight (n = 212) were eligible for inclusion. One study was of parallel design with the remaining seven being cross-over in design; participant numbers ranged from 4 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 two studies received treatment whilst 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 certainty 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 eight 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. Seven of the eight 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, intravenous antibiotics and pseudomonas gene expression. 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, particularly in an era where treatment options are changing rapidly. 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.

Rehabilitation programs for patients with COronaVIrus Disease 2019: consensus statements of Taiwan Academy of Cardiovascular and Pulmonary Rehabilitation

The COronaVIrus Disease 2019 (COVID-19), which developed into a pandemic in 2020, has become a major healthcare challenge for governments and healthcare workers worldwide. Despite several medical treatment protocols having been established, a comprehensive rehabilitation program that can promote functional recovery is still frequently ignored. An online consensus meeting of an expert panel comprising members of the Taiwan Academy of Cardiovascular and Pulmonary Rehabilitation was held to provide recommendations for rehabilitation protocols in each of the five COVID-19 stages, namely (1) outpatients with mild disease and no risk factors, (2) outpatients with mild disease and epidemiological risk factors, (3) hospitalized patients with moderate to severe disease, (4) ventilator-supported patients with clear cognitive function, and (5) ventilator-supported patients with impaired cognitive function. Apart from medications and life support care, a proper rehabilitation protocol that facilitates recovery from COVID-19 needs to be established and emphasized in clinical practice.

Outcome measures for airway clearance techniques in children with chronic obstructive lung diseases: a systematic review

BACKGROUND

Airway clearance techniques (ACTs) are an important aspect of the treatment of children with chronic obstructive lung diseases. Unfortunately, a sound evidence base is lacking and airway clearance strategies are largely based on clinical expertise. One of the reasons for the limited evidence is the lack of appropriate outcome measures specifically related to the effectiveness of ACTs. This review discusses all outcome measures applied in previous research in the pediatric population to provide a baseline for future studies.

DATA SOURCES

A systematic literature search was performed in PubMed, Web of Science and EMBASE databases. Search terms included chronic obstructive lung diseases and ACTs.

STUDY SELECTION

Studies were independently selected by the investigators according to the eligibility criteria. After screening, 49 articles remained for further analysis.

RESULTS AND CONCLUSIONS

Data are summarized according to the type of outcome measure. 48 (98%) studies performed pulmonary function tests, 19 (39%) assessed expectorated sputum, 10 (20%) parameters related to disease exacerbation, 8 (16%) oxygenation, 8 (16%) patient-reported outcomes, 5 (10%) exercise capacity and 5 (10%) applied imaging techniques. The synthesis of results showed a high discrepancy between studies due to differences in study design, population and the application of techniques. Since no 'gold standard' method could be identified, a combination of different outcome measures is recommended to gain a better understanding and to identify the potential effects of ACTs. An overview of important considerations has been provided to assist researchers in their choice of outcomes in future studies.

Oscillating devices 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. Oscillating devices generate intra- or extra-thoracic oscillations orally or external to the chest wall. Internally they create variable resistances within the airways, generating controlled oscillating positive pressure which mobilises mucus. Extra-thoracic oscillations are generated by forces outside the respiratory system, e.g. high frequency chest wall oscillation. This is an update of a previously published review.

OBJECTIVES

To identify whether oscillatory devices, oral or chest wall, are effective for mucociliary clearance and whether they are equivalent or superior to other forms of airway clearance in the successful management of secretions in people with cystic fibrosis.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register comprising references identified from comprehensive electronic database searches and hand searches of relevant journals and abstract books of conference proceedings. Latest search of the Cystic Fibrosis Trials Register: 29 July 2019. In addition we searched the trials databases ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform. Latest search of trials databases: 15 August 2019.

SELECTION CRITERIA

Randomised controlled studies and controlled clinical studies of oscillating devices compared with any other form of physiotherapy in people with cystic fibrosis. Single-treatment interventions (therapy technique used only once in the comparison) were excluded.

DATA COLLECTION AND ANALYSIS

Two authors independently applied the inclusion criteria to publications, assessed the quality of the included studies and assessed the evidence using GRADE.

MAIN RESULTS

The searches identified 82 studies (330 references); 39 studies (total of 1114 participants) met the inclusion criteria. Studies varied in duration from up to one week to one year; 20 of the studies were cross-over in design. The studies also varied in type of intervention and the outcomes measured, data were not published in sufficient detail in most of these studies, so meta-analysis was limited. Few studies were considered to have a low risk of bias in any domain. It is not possible to blind participants and clinicians to physiotherapy interventions, but 13 studies did blind the outcome assessors. The quality of the evidence across all comparisons ranged from low to very low. Forced expiratory volume in one second was the most frequently measured outcome and while many of the studies reported an improvement in those people using a vibrating device compared to before the study, there were few differences when comparing the different devices to each other or to other airway clearance techniques. One study identified an increase in frequency of exacerbations requiring antibiotics whilst using high frequency chest wall oscillation when compared to positive expiratory pressure (low-quality evidence). There were some small but significant changes in secondary outcome variables such as sputum volume or weight, but not wholly in favour of oscillating devices and due to the low- or very low-quality evidence, it is not clear whether these were due to the particular intervention. Participant satisfaction was reported in 13 studies but again with low- or very low-quality evidence and not consistently in favour of an oscillating device, as some participants preferred breathing techniques or techniques used prior to the study interventions. The results for the remaining outcome measures were not examined or reported in sufficient detail to provide any high-level evidence.

AUTHORS' CONCLUSIONS

There was no clear evidence that oscillation was a more or less effective intervention overall than other forms of physiotherapy; furthermore there was no evidence that one device is superior to another. The findings from one study showing an increase in frequency of exacerbations requiring antibiotics whilst using an oscillating device compared to positive expiratory pressure may have significant resource implications. More adequately-powered long-term randomised controlled trials are necessary and outcomes measured should include frequency of exacerbations, individual preference, adherence to therapy and general satisfaction with treatment. Increased adherence to therapy may then lead to improvements in other parameters, such as exercise tolerance and respiratory function. Additional evidence is needed to evaluate whether oscillating devices combined with other forms of airway clearance is efficacious in people with cystic fibrosis.There may also be a requirement to consider the cost implication of devices over other forms of equally advantageous airway clearance techniques. Using the GRADE method to assess the quality of the evidence, we judged this to be low or very low quality, which suggests that further research is very likely to have an impact on confidence in any estimate of effect generated by future interventions.

The effects of high-frequency chest compression on end-tidal CO2

INTRODUCTION

High-frequency chest compression (HFCC) is used for airway clearance, but may have other effects. We sought to determine if HFCC provides augmented ventilation.

METHODS

During treatment, capnometry was measured with the HFCC vest set to 6-20 Hz. End-tidal CO₂ (etCO₂ ) was compared using generalized estimating equations.

RESULTS

Twenty-four measurements were obtained from 15 subjects with mean age 15.2 ± 2.5 years and forced expiratory volume in one second (FEV₁ ) % predicted 70 ± 23. EtCO₂ decreased with HFCC at 6 Hz when compared with baseline (P < .001), with small changes with increasing oscillation frequency. Change in etCO₂ was not predicted by FEV₁ , body mass index, age, or sex.

CONCLUSIONS

While HFCC has been shown to be a suitable method of airway clearance, investigators have failed to demonstrate differences between techniques. Assessment of these methodologies will become important as new airway clearance devices are proposed. Other outcome measures (besides FEV₁ ) may be needed to assess effects of airway clearance, and we propose that physiologic measures might be one such measure which deserves further exploration.

Cystic fibrosis year in review 2018, part 2

Cystic fibrosis (CF) research and case reports were robust in the year 2018. This report summarizes publications related the multisystem effects of CF, pulmonary exacerbations, new and expanded therapies other than cystic fibrosis transmembrane conductance regulator modulator studies, and patient-reported priorities and outcomes.

Controlling chronic Pseudomonas aeruginosa infections by strategically interfering with the sensory function of SagS

The hybrid sensor SagS plays a central role in the formation of Pseudomonas aeruginosa biofilms, by enabling the switch from the planktonic to the biofilm mode of growth and by facilitating the transition of biofilm cells to a highly tolerant state. In this study, we examined the importance of the SagS key amino acid residues associated with biofilm formation (L154) and antibiotic tolerance (D105) in P. aeruginosa virulence. Recombinant P. aeruginosa ΔsagS and ΔsagS chromosomally expressing wild-type sagS, or its two variants D105A and L154A, were tested for their potential to form biofilms and cause virulence in plants and mouse models of acute and chronic pneumonia. Although mutation of sagS did not alter P. aeruginosa virulence during acute infections, a significant difference in pathogenicity of sagS mutants was observed during chronic infections, with the L154A variant showing reduced bacterial loads in the chronic pneumonia model, while interference with the D105 residue enhanced the susceptibility of P. aeruginosa biofilms during tobramycin treatment. Our findings suggest that interference with the biofilm or tolerance regulatory circuits of SagS affects P. aeruginosa pathogenicity in chronic but not acute infections, and reveal SagS to be a promising new target to treat P. aeruginosa biofilm infections.