Technical performance analysis of different types of spirometers.

BACKGROUND: The spirometer is an important element in lung function examinations, and its accuracy is directly related to the accuracy of the results of these examinations and to the diagnosis and treatment of diseases. Our aim was to conduct a performance analysis of the detection techniques of differential pressure and ultrasonic portable spirometers commonly used in China. METHODS: A standard flow/volume simulator was used to analyze the performance (accuracy, repeatability, linearity, impedance, and so on) of portable spirometers, 4 imported and 6 domestic, based on 13 curves generated by different air sources in the ISO 26782:2009 standard. A Bland-Altman diagram was used to evaluate the consistency between the values measured by the spirometers and the simulator. RESULTS: The pass rates for accuracy, repeatability, linearity, and impedance for the 10 different portable spirometers were 50%, 100%, 70%, and 70%, respectively. Only 30% (3/10) of the spirometers-2 domestic and 1 imported-met all standards of quality and performance evaluation, while the rest were partially up to standard. In the consistency evaluation, only 3 spirometers were within both the consistency standard range and the acceptability range. CONCLUSION: The quality and performance of different types of portable spirometers commonly used in the clinic differ. The use of a standard flow/volume simulator is helpful for the standard evaluation of the technical performance of spirometers.

Vascular involvement in chronic thromboembolic pulmonary hypertension is associated with spirometry obstructive impairment.

BACKGROUND: Chronic thromboembolic pulmonary hypertension (CTEPH) is a type of pulmonary hypertension caused by persistent thromboembolism of the pulmonary arteries. In clinical practice, CTEPH patients often show obstructive ventilatory impairment, even in the absence of a smoking history. Recent reports imply a tendency for CTEPH patients to have a lower FEV1.0; however, the mechanism underlying obstructive impairment remains unknown. METHODS: We retrospectively analyzed CTEPH patients who underwent a pulmonary function test and respiratory impedance test to evaluate their exertional dyspnea during admission for right heart catheterization from January 2000 to December 2019. We excluded patients with a smoking history to rule out the effect of smoking on obstructive impairment. RESULTS: A total of 135 CTEPH patients were analyzed. The median FEV1.0/FVC was 76.0%, %FEV 1.0 had a negative correlation with the mean pulmonary artery pressure and pulmonary vascular resistance and the CT Angiogram (CTA) obstruction score. A multivariate regression analysis revealed that the CTA obstruction score was an independent factor of a lower %FEV1.0. In the 54 patients who underwent pulmonary endarterectomy, %FEV1.0 was improved in some cases and was not in some. Mean PAP largely decreased after PEA in the better %FEV1.0 improved cases, suggesting that vascular involvement in CTEPH could be associated with spirometry obstructive impairment. CONCLUSION: %FEV1.0 had a significant correlation with the CTA obstruction score. Obstructive impairment might have an etiological relationship with vascular involvement. Further investigations could shed new light on the etiology of CTEPH.

Safety of delivering bronchial thermoplasty in two treatment sessions.

BACKGROUND: Bronchial thermoplasty (BT) is a novel endoscopic therapy for severe asthma. Traditionally it is performed in three separate treatment sessions, targeting different portions of the lung, and each requires an anaesthetic and hospital admission. Compression of treatment into 2 sessions would present a more convenient alternative for patients. In this prospective observational study, the safety of compressing BT into two treatment sessions was compared with the traditional 3 treatment approach. METHODS: Sixteen patients meeting ERS/ATS criteria for severe asthma consented to participate in an accelerated treatment schedule (ABT), which treated the whole left lung followed by the right lung four weeks later. The short-term outcomes of these patients were compared with 37 patients treated with conventional BT scheduling (CBT). The outcome measures used to assess safety were (1) the requirement to remain in hospital beyond the electively planned 24-h admission and (2) the need for re-admission for any cause within of 30 days of treatment. RESULTS: The total number of radiofrequency activations delivered in the ABT group was similar to CBT (187 ± 21 vs 176 ± 40, p = 0.326). With ABT, 11 in 31 admissions (37.9%) required prolonged admission due to wheezing, compared to 5.4% with CBT (p = 0.0025). The mean hospital length of stay with ABT was 1.8 ± 1.3 days, compared to 1.1 ± 0.4 days (p < 0.001). ICU monitoring was required on 5 occasions with ABT (16.1%), compared to 0.9% with CBT (p = 0.002). Subgroup analysis demonstrated that females were more likely to require prolonged admission (OR 11.6, p = 0.0025). The 30-day hospital readmission rate was similar for both groups (6.4% vs 5.4%, p = 0.67). All patients made a complete recovery after treatment with similar outcomes at the 6-month follow-up reassessment. CONCLUSION: This study demonstrates that ABT results in greater short-term deterioration in lung function associated with a greater risk of prolonged hospital and ICU stay, predominantly affecting females. Therefore, in females, these risks need to be balanced against the convenience of fewer treatment sessions. In males, it may be an advantage to compress treatment.

Effects of Medication Use on Small Airway Function and Airway Inflammation in Patients with Clinically Controlled Asthma.

OBJECTIVE: To observe effects of medication use on small airway function, airway inflammation and acute exacerbations in patients with clinically controlled asthma. METHODS: Forced expiratory flow over the middle half of the forced expiratory curve (FEF25%-75%), percentage of eosinophil, concentrations of eosinophil cationic protein (ECP) and interleukin (IL)-5 in induced sputum were assessed in patients with clinically controlled asthma who were given oral anti-inflammatory agents alone or in combination with inhaled therapy and inhaled therapy alone. Subsequently, acute exacerbations were compared between two groups during the 24-week follow-up period. RESULTS: FEF25%-75% in 43 patients with clinically controlled asthma given oral anti-inflammatory agents alone or in combination with inhaled therapy was significantly higher than that in 49 patients given inhaled therapy alone. Meanwhile, the percentage of eosinophils and levels of IL-5 and ECP in patients with clinically controlled asthma given oral anti-inflammatory agents alone or in combination with inhaled therapy were significantly lower than those in patients given inhaled therapy alone. Additionally, the patients with clinically controlled asthma given inhaled therapy were likely to have more acute exacerbation than the patients given oral anti-inflammatory agents alone or in combination with inhaled therapy during the 24-week follow-up period. CONCLUSION: Systemic anti-inflammatory agents may have a greater effect on parameters reflecting small airway patency and reducing acute exacerbations, presumably secondary to reduction in airway inflammation.

Comparative analysis of effectiveness of asthma control test-guided treatment versus usual care in patients with asthma from China.

OBJECTIVE: The present study compared the effectiveness of asthma control test (ACT)-guided treatment vs. usual care (UC) in patients with asthma from China. METHODS: This prospective, phase IV, multicenter, cluster-randomized, open-label 24-week study was conducted in China; patients were randomized to either ACT-guided treatment or UC group. The patients recorded peak expiratory flow, symptoms, and medication in a diary card every day and completed ACT at every clinic visit. For the UC group, patients completed ACT after the physician's treatment decision. RESULTS: In total, 83.6% patients (n = 443/530; ACT: n = 209, UC: n = 234) completed the study. A significantly higher proportion of patients (adjusted OR [95% CI]: 7.87 (1.29, 48.11; p = 0.027) responded to the treatment and had ACT total score ≥20 or demonstrated an improvement of >3 points in ACT total score in ≥1 post-baseline assessment in the ACT-guided treatment vs. UC group. A higher proportion of patients had an ACT total score ≥20 and an improvement of >3 points in ACT total score at Week 24 in the ACT-guided treatment vs. the UC group (adjusted OR (95% CI):2.28 (1.07, 4.85; p = 0.036). A significant difference (p = 0.005) in change from baseline in ACT total score was observed in ACT-guided treatment vs. UC group at Week 24. The mean annual exacerbation rate was similar in both the groups. CONCLUSIONS: ACT-guided treatment was more effective in achieving ACT total score ≥20 or showing an improvement of >3 points in the ACT total score and well tolerated compared with UC treatment in the 24-week treatment period. TRIAL REGISTRATION: Clinical trials.gov Identifier: NCT02868281, https://clinicaltrials.gov/; GlaxoSmithKline study ID: 201097, https://www.gsk-studyregister.com/.

Impact of 1h oral glucose tolerance test on the clinical status of adult cystic fibrosis patients over a 4-year period.

OBJECTIVE: To report the clinical profile associated with G60 and I60 over a 4-year prospective observational period in 2 large cohorts of adult patients with CF. METHODS: 319 patients were included (210 Canadian and 119 French) and classified according to their inclusion G60 (≥ or < 11.1 mmol/L) and the median inclusion I60 (≥ or < 24 mU/I). Forced expiratory volume in 1 second (FEV1), body mass index (BMI) were collected on OGTT days. Linear mixed regression models were used to assess the effect of G60 and I60. RESULTS: High G60 was not associated to a lower FEV1 at inclusion and the follow-up decline was not higher in the high G60 group (Coefficient [95% CI]: -3.4 [-7.4;0.6], p = 0.0995.). There was no significant association between BMI and G60. Patients with high I60 tended to have a higher mean BMI (+0.5 kg/m2 [0.0 to 1.1], p = 0.05) but no interaction over time was observed. CONCLUSIONS: High G60 is not associated with a lower lung function at inclusion nor its decline over a 4-year follow-up. High I60 is slightly associated to a higher weight at inclusion, but not with BMI evolution over time in adult patients.

Lung function changes in patients with chronic obstructive pulmonary disease (COPD) and asthma exposed to secondhand smoke in outdoor areas.

BACKGROUND: Further evidence is needed on the effects that short- and long-term exposure to secondhand smoke (SHS) have on the respiratory health of patients with lung disease. Within the TackSHS project we aimed to assess the acute respiratory effects in lung function that result from short-term SHS exposure among patients with asthma and chronic obstructive pulmonary disease (COPD). METHODS: The study design was an intervention trial with measurements before/after exposure to SHS in legal outdoor smoking areas. We studied patients with asthma or COPD from Czechia, Ireland, and Spain. Forced spirometry, peak flow and carbon monoxide (CO) measurements were performed pre- and 24 h post- exposure. RESULTS: Overall, 60 patients were studied, 30 with asthma, and 30 with COPD; 35 (58.3%) were female. There were no significant differences observed in exhaled CO between pre- and 24 h post-exposure neither in women (p = 0.210), nor in men (p = 0.169).A statistically significant decrease in forced vital capacity (FVC) was seen, overall, in asthma participants (p = 0.02) and in forced expiratory volume in the first second (FEV1), (p = 0.02), FVC (p = 0.04) and peak expiratory flow rate (PEFR) (p = 0.04) in female asthmatic participants. The observed decreases in respiratory measurements in COPD were not significant. There were no reported increases in symptoms, respiratory medication, or use of health services 24 h after the exposure. CONCLUSION: We conclude that acute, short-term SHS exposure had a statistically significant effect on spirometry in female asthma patients but did not significantly modify spirometric indices 24 h later in COPD patients.

Enhancing care for individuals with advanced cystic fibrosis lung disease.

While remarkable advances in cystic fibrosis (CF) care have led to improvements in survival and quality of life, many individuals with CF are living with advanced cystic fibrosis lung disease (ACFLD) and others will face continued disease progression and its associated complex treatments and choices. This review will provide a summary of recently published guidelines for ACFLD care and lung transplant referral and highlight ongoing work to enhance the care of those with ACFLD through improvements in medical and psychosocial care, palliative care, and care around lung transplantation.

Alveolar to arterial gas exchange during constant-load exercise in healthy active men and women.

Inadequate hyperventilation and inefficient alveolar to arterial gas exchange are gas exchange challenges that can limit capacity and cause exercise-induced arterial hypoxaemia (EIAH). This work evaluated if the prevalence of gas exchange inefficiencies, defined as AaDO2>25 mmHg, PaCO2>38 mmHg, and/or ΔPaO2>-10 mmHg at any point during constant-load exercise in healthy, active, but not highly trained, individuals suggested an innate sex difference that would make females more susceptible to EIAH. Sixty-four healthy, active males and females completed 18-min of cycling exercise (moderate and vigorous intensity, 9 min/stage). Arterial blood gases were measured at rest and every 3-min during exercise, while constantly assessing gas exchange. Both sexes demonstrated similar levels of AaDO2 widening until the final 3 min of vigorous exercise, where females demonstrated a trend for greater widening than males (16.3±6.2 mmHg vs. 19.1±6.0 mmHg, p=0.07). Males demonstrated a blunted ventilatory response to moderate exercise with higher PaCO2 (38.5±2.6 vs. 36.5±2.4, p=0.002) and a lower ventilation when corrected for workload (0.42±0.1 vs. 0.48±0.1, p=0.002). No significant arterial hypoxaemia occurred, but in 6 M and 5 F SaO2 dropped by ≥2%. There was no difference in prevalence of pulmonary gas exchange inefficiencies between sexes, but the type of inefficiency was influenced by sex.Abbreviations: AaDO2: alveolar-arterial oxygen difference; BP: blood pressure; EIAH: exercise-induced arterial hypoxaemia; F: females; HR: heart rate; M: males; Q: cardiac output; PaCO2: arterial partial pressure of carbon dioxide; PaO2: arterial partial pressure of oxygen; ΔPaO2: change in arterial partial pressure of oxygen; PAO2: alveolar partial pressure of oxygen; RPE: rating of perceived exertion; SaO2: arterial oxygen saturation; VE: ventilation; VE/VCO2: ventilatory equivalent for carbon dioxide; VO2PEAK: peak oxygen consumption; WMAX: workload maximum.

Respiratory muscle training for cystic fibrosis.

BACKGROUND: Cystic fibrosis is the most common autosomal recessive disease in white populations, and causes respiratory dysfunction in the majority of individuals. Numerous types of respiratory muscle training to improve respiratory function and health-related quality of life in people with cystic fibrosis have been reported in the literature. Hence a systematic review of the literature is needed to establish the effectiveness of respiratory muscle training (either inspiratory or expiratory muscle training) on clinical outcomes in cystic fibrosis. This is an update of a previously published review. OBJECTIVES: To determine the effectiveness of respiratory muscle training on clinical 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. Date of most recent search: 11 June 2020. A hand search of the Journal of Cystic Fibrosis and Pediatric Pulmonology was performed, along with an electronic search of online trial databases. Date of most recent search: 05 October 2020. SELECTION CRITERIA: Randomised controlled studies comparing respiratory muscle training with a control group in people with cystic fibrosis. DATA COLLECTION AND ANALYSIS: Review authors independently selected articles for inclusion, evaluated the methodological quality of the studies, and extracted data. Additional information was sought from trial authors where necessary. The quality of the evidence was assessed using the GRADE system. MAIN RESULTS: Authors identified 20 studies, of which 10 studies with 238 participants met the review's inclusion criteria. There was wide variation in the methodological and written quality of the included studies. Four of the 10 included studies were published as abstracts only and lacked concise details, thus limiting the information available. Eight studies were parallel studies and two of a cross-over design. Respiratory muscle training interventions varied dramatically, with frequency, intensity and duration ranging from thrice weekly to twice daily, 20% to 80% of maximal effort, and 10 to 30 minutes, respectively. Participant numbers ranged from 11 to 39 participants in the included studies; five studies were in adults only, one in children only and four in a combination of children and adults. No differences between treatment and control were reported in the primary outcome of pulmonary function (forced expiratory volume in one second and forced vital capacity) or postural stability (very low-quality evidence). Although no change was reported in exercise capacity as assessed by the maximum rate of oxygen use and distance completed in a six minute walk test, a 10% improvement in exercise duration was found when working at 60% of maximal effort in one study (n = 20) (very low-quality evidence). In a further study (n = 18), when working at 80% of maximal effort, health-related quality of life improved in the mastery and emotion domains (very low-quality evidence). With regards to the review's secondary outcomes, one study (n = 11) found a change in intramural pressure, functional residual capacity and maximal inspiratory pressure following training (very low-quality evidence). Another study (n=36) reported improvements in maximal inspiratory pressure following training (P < 0.001) (very low-quality evidence). A further study (n = 22) reported that respiratory muscle endurance was longer in the training group (P < 0.01). No studies reported significant differences on any other secondary outcomes. Meta-analyses could not be performed due to a lack of consistency and insufficient detail in reported outcome measures. AUTHORS' CONCLUSIONS: There is insufficient evidence to suggest whether this intervention is beneficial or not. Healthcare practitioners should consider the use of respiratory muscle training on a case-by-case basis. Further research of reputable methodological quality is needed to determine the effectiveness of respiratory muscle training in people with cystic fibrosis. Researchers should consider the following clinical outcomes in future studies; respiratory muscle function, pulmonary function, exercise capacity, hospital admissions, and health-related quality of life. Sensory-perceptual changes, such as respiratory effort sensation (e.g. rating of perceived breathlessness) and peripheral effort sensation (e.g. rating of perceived exertion) may also help to elucidate mechanisms underpinning the effectiveness of respiratory muscle training.

Effectiveness of expiratory flow acceleration in patients with Parkinson's disease and swallowing deficiency: A preliminary study.

OBJECTIVES: Parkinson's disease (PD) causes dysfunction both to swallowing and to the cough mechanism. Oropharyngeal dysphagia is the main cause of pneumonia, due to silent aspiration of food and saliva. Pneumonia is the leading cause of death in PD. Different strategies exist to reduce the risk of inhalation and associated lung infections, but evidence of their efficacy is still unclear. The aim of this preliminary study was to investigate if adding an expiratory flow acceleration (EFA®) technique to standard therapy (ST) for dysphagia can reduce the incidence of bronchopulmonary infections and improve quality of life, respiratory function parameters, cough, and airways encumbrance perception. MATERIALS AND METHODS: Twenty-five patients with PD were randomized to two groups: ST vs. ST + EFA. Patients were re-assessed at 30, 180 and 360 days from start of treatment. The primary outcome was the incidence of respiratory exacerbations together with quality of life score (PDQ-39). Secondary outcomes were changes in respiratory function tests, cough capacity (CPEF), perceived health status (Euro-QOL-VAS), cough, and upper airways encumbrance perception evaluated by visual numeric scale (VNS). RESULTS: Twenty patients concluded the study (10 each group). Albeit the difference was not significant, less respiratory infections, symptoms, hospital admissions and medical visits were found in the study group. Furthermore, there was a significant difference in cough effectiveness measured with the peak cough expiratory flow (PCEF) and other spirometry parameters (FEV1, FVC), and also in specific and generic health-related quality of life measures (PDQ-39, Euro-QoL-VAS). CONCLUSION: The results of this preliminary study support the use of EFA® technology in Parkinson's patients with dysphagia to reduce the risk of respiratory complications. Nevertheless, further studies are needed in a larger, more representative sample to definitively confirm the usefulness of this technique in PD patients.

Reduction of peak expiratory flow after a 5-meter dive with extreme exertion.

The effects of physically exerting scuba dives on the airways are expected to affect the respiratory system and therefore the spirometric flow indices directly after surfacing. After on-air open-sea dives, the flow indices were examined with standard spirometry (maximal forced expiration) within 10 minutes pre- and post-dive. Twenty volunteers, age 49 ± 14 years (m ± SD) equipped with a dive computer to record the dive profile, cylinder pressures and water temperature (27°C), as well as a heart rate monitor, performed 5-meter dives of 27 minutes at maximal swimming velocity (v). Mean pulmonary ventilation (PV) was 48 ± 10 ambient L/minute (aL.min-1). Mean v was 34 ± 6 meters/minute and mean heart rate 143 beats per minute, about 80% of the on-land theoretical maximum. None of the flow variables changed except a decrease of 7.1% ± 8.3 (p=0.001) of the peak expiratory flow (PEF), pre-dive of 11.2 ± 2.7 L/minute. A likely major cause of the reduction of PEF is expiratory muscle fatigue. A small contribution of subclinical pulmonary edema cannot be excluded. The inhalation of dry air and the cooling of the airways are expected to affect PEF minimally. Although the change is normally clinically irrelevant, during emergency it may be of importance.

Composite endpoints in COPD: clinically important deterioration in the UPLIFT trial.

BACKGROUND: Assessments of lung function, exacerbations and health status are common measures of chronic obstructive pulmonary disease (COPD) progression and treatment response in clinical trials. We hypothesised that a composite endpoint could more holistically assess clinically important deterioration (CID) in a COPD clinical trial setting. METHODS: A composite endpoint was tested in a post hoc analysis of 5652 patients with Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2-4 COPD from the 4-year UPLIFT study. Patients received tiotropium 18 µg or placebo. RESULTS: The composite endpoint included time to first confirmed decrease in trough forced expiratory volume in 1 s (FEV1) ≥100 mL, confirmed increase in St. George's Respiratory Questionnaire (SGRQ) total score ≥ 4 units, or moderate/severe exacerbation. Most patients (> 80%) experienced CID, with similar incidence among GOLD subgroups. Most confirmed trough FEV1 (74.6-81.6%) and SGRQ (72.3-78.1%) deteriorations were sustained across the study and in all GOLD subgroups. Patients with CID more frequently experienced subsequent exacerbation (hazard ratio [HR] 1.79; 95% confidence interval [CI] 1.67, 1.92) or death (HR 1.21; 95% CI 1.06, 1.39) by Month 6. CID was responsive to bronchodilator treatment. CONCLUSIONS: Composite endpoints provide additional information on COPD progression and treatment effects in clinical trials. TRIAL REGISTRATION: ClinicalTrials.gov NCT00144339 .

Sociodemographic factors, current asthma and lung function in an urban child population.

BACKGROUND: We aimed to assess which sociodemographic factors are associated with current asthma and indicators of lung function in 10-year-old children. METHODS: We analysed data of 5237 children (Mean age: 9.7, SD: 0.3) from the Generation R Study (2012-2016), a population-based cohort study in the Netherlands. Indicators of sociodemographic factors included parental educational level, net household income, financial difficulties, parental employment status and child ethnic background. Current asthma (yes/no) was defined as ever doctor-diagnosed-asthma combined with wheezing symptoms or asthma-medication use in the past 12 months. Lung function was measured by spirometry and included forced expiratory volume in 1 second (FEV1 ), forced vital capacity (FVC), FEV1 /FVC, and forced expiratory flow after exhaling 75% of FVC (FEF75 ). Within-study sex-, height- and age-adjusted lung function measurements' z-scores were converted. RESULTS: After adjustment for all sociodemographic factors, an independent association was observed between ethnic background with current asthma and lung function. Compared with children with a Dutch background, children with a nonwestern ethnic background had a higher odds of having current asthma (OR: 1.61, 95% CI: 1.02, 2.53), lower FVC z-score (-0.25, 95% CI: -0.35, -0.14), higher FEV1 /FVC z-score (0.26, 95% CI: 0.14, 0.37) and higher FEF75% z-score (0.15, 95% CI: 0.04, 0.25). CONCLUSIONS: Among 10-year-old children, ethnic background was associated with current asthma and lung function after adjusting for a wide range of sociodemographic factors. No associations were found between socioeconomic status indicators and current asthma. Explanations for these associations such as language barriers, suboptimal care or pathophysiological differences require further investigation.

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.

Dibutyl Phthalate Augments Allergen-induced Lung Function Decline and Alters Human Airway Immunology. A Randomized Crossover Study.

Rationale: Phthalates are a group of chemicals used in common commercial products. Epidemiological studies suggest that phthalate exposure is associated with development or worsening of allergic diseases such as asthma. However, effects of dibutyl phthalate (DBP) or other phthalates found in high concentrations in indoor air have never been examined in allergic individuals in a controlled exposure setting.Objectives: To investigate the airway effects in humans caused by inhalation of a known concentration of a single phthalate, DBP.Methods: In a randomized crossover study, 16 allergen-sensitized participants were exposed to control air or DBP for 3 hours in an environmental chamber followed immediately by an allergen inhalation challenge. Bronchoalveolar wash and lavage were obtained 24 hours after exposure. Lung function, early allergic response, airway responsiveness, inflammation, immune mediators, and immune cell phenotypes were assessed after DBP exposure.Measurements and Main Results: DBP exposure increased the early allergic response (21.4% decline in FEV1 area under the curve, P = 0.03). Airway responsiveness was increased by 48.1% after DBP exposure in participants without baseline hyperresponsiveness (P = 0.01). DBP increased the recruitment of BAL total macrophages by 4.6% (P = 0.07), whereas the M2 macrophage phenotype increased by 46.9% (P = 0.04). Airway immune mediator levels were modestly affected by DBP.Conclusions: DBP exposure augmented allergen-induced lung function decline, particularly in those without baseline hyperresponsiveness, and exhibited immunomodulatory effects in the airways of allergic individuals. This is the first controlled human exposure study providing biological evidence for phthalate-induced effects in the airways.Clinical trial registered with www.clinicaltrials.gov (NCT02688478).

Prognostic value of respiratory index in haemodynamically stable patients with acute pulmonary embolism: The Respiratory Index model study.

BACKGROUND: Current strategies for prognostic stratification in haemodynamically stable patients with acute pulmonary embolism require improvement. The aims of this study in haemodynamically stable patients with acute pulmonary embolism were (a) to evaluate the prognostic value of a novel respiratory index (oxygen saturation in air to respiratory rate ratio) and (b) to derive a risk model which includes the respiratory index and evaluate its value in predicting 30-day mortality. METHODS: Prospective cohorts of haemodynamically stable patients with acute pulmonary embolism were merged to a collaborative database that served to create two subsequent derivation and validation cohorts based on a temporal criterion. The study outcome was 30-day all-cause death. RESULTS: Thirty-day all-cause death occurred in 7.5% and in 6.9% of patients in the derivation and validation cohorts (each composed of 319 patients). In the derivation cohort, the respiratory index (odds ratio 0.66, 95% confidence interval 0.48-0.90) and simplified Pulmonary Embolism Severity Index (odds ratio 9.16, 95% confidence interval 1.22-68.89) were predictors of 30-day mortality. The cut-off value of the respiratory index ⩽3.8 was identified to best predict 30-day all-cause death (15.4% vs 5.0%, odds ratio 2.94, 95% confidence interval 1.22-7.11). The respiratory index ⩽3.8 was combined with the simplified Pulmonary Embolism Severity Index to create the Respiratory Index model that showed a good discriminatory power in the derivation (c-statistic 0.703, 95% confidence interval 0.60-0.80) and in the validation cohort (c-statistic 0.838, 95% confidence interval 0.768-0.907). CONCLUSION: In hemodynamically stable patients with acute pulmonary embolism, the respiratory index was an independent predictor of 30-day all-cause death. The Respiratory Index model which includes the simplified Pulmonary Embolism Severity Index and the respiratory index, provides a good risk stratification of haemodynamically stable patients with acute pulmonary embolism.

Evaluating the FEV1/FVC ratio in the lower range of normality as a marker of worse clinical outcomes in asthmatic subjects without airway obstruction.

BACKGROUND: We should continually improve tools for evaluating asthma. The aim of this study was to evaluate whether the FEV1/FVC ratio in the lower range of normality is associated with worse outcomes in asthmatics without airway obstruction. METHODS: We screened asthmatics at eight clinics. Subjects answered the Asthma Control Questionnaire and underwent spirometry. We assigned individuals without airway obstruction in three groups according to the post bronchodilator FEV1/FVC ratio: lower range of normality, intermediary range of normality and upper range of normality. Asthma outcomes were hospital admission due to asthma during the preceding year, non-controlled asthma symptoms and moderate-high inhaled maintenance therapy need. RESULTS: In subjects from six to 18 years old, the rate of hospital admission was higher in the group with FEV1/FVC ratio in the lower range of normality as compared with the other two groups but the frequency of non-controlled symptoms of asthma and moderate-high dose of inhaled maintenance therapy need was similar. From 19 to 59 years old, the rate of moderate-high inhaled maintenance therapy need was higher in the group with FEV1/FVC ratio in the lower range of normality as compared with the other two groups, but the frequency of hospital admissions and non-controlled symptoms of asthma was similar. Above 59 years old, there was no difference in clinical asthma outcomes between lung function groups. CONCLUSIONS: FEV1/FVC ratio in the lower range of normality is a marker of worse clinical outcomes in asthmatics without airway obstruction.