Chest wall dynamics during voluntary and induced cough in healthy volunteers

Sensorimotor Cough Dysfunction in Cerebellar Ataxias

Cerebellar ataxias are neurological conditions with a high prevalence of aspiration pneumonia and dysphagia. Recent research shows that sensorimotor cough dysfunction is associated with airway invasion and dysphagia in other neurological conditions and may increase the risk of pneumonia. Therefore, this study aimed to characterize sensorimotor cough function and its relationship with ataxia severity. Thirty-seven participants with cerebellar ataxia completed voluntary and/or reflex cough testing. Ataxia severity was assessed using the Scale for the Assessment and Rating of Ataxia (SARA). Linear multilevel models revealed voluntary cough peak expiratory flow rate (PEFR) estimates of 2.61 L/s and cough expired volume (CEV) estimates of 0.52 L. Reflex PEFR (1.82 L/s) and CEV (0.34 L) estimates were lower than voluntary PEFR and CEV estimates. Variability was higher for reflex PEFR (15.74% coefficient of variation [CoV]) than voluntary PEFR (12.13% CoV). 46% of participants generated at least two, two-cough responses following presentations of reflex cough stimuli. There was a small inverse relationship between ataxia severity and voluntary PEFR (β = -0.05, 95% CI: -0.09 - -0.01 L) and ataxia severity and voluntary CEV (β = -0.01, 95% CI: -0.02 - -0.004 L/s). Relationships between reflex cough motor outcomes (PEFR β = 0.03, 95% CI: -0.007-0.07 L/s; CEV β = 0.007, 95% CI: -0.004-0.02 L) and ataxia severity were not statistically robust. Results indicate that voluntary and reflex cough sensorimotor dysfunction is present in cerebellar ataxias and that increased severity of ataxia symptoms may impact voluntary cough function.

Non-brachycephalic dogs with stertor have higher nasopharyngeal collapsibility compared with dogs without stertor and foramen lacerum level is ideal for evaluating nasopharyngeal collapse on dynamic CT

Stertor, a clinical sign associated with obstructive airway syndrome, is often observed in non-brachycephalic dogs. This prospective, case-control study aimed to compare soft palate dimensions, nasopharyngeal cross-sectional area (CSA), and nasopharyngeal collapsibility at various locations in non-brachycephalic dogs with and without stertor. A total of 50 dogs were recruited and stratified into control (n = 34) and stertor (n = 13) groups. Static and dynamic computed tomography was conducted without tracheal intubation, and the following variables were calculated: normalized soft palate length and thickness, normalized maximum and minimum nasopharyngeal CSAs (rCSAmax and rCSAmin), and nasopharyngeal collapsibility at the level of the cranial end of the soft palate, pterygoid hamulus, foramen lacerum, bony labyrinth, and caudal end of the soft palate. The stertor group demonstrated significantly lower rCSAmax and rCSAmin, as well as higher nasopharyngeal collapsibility compared with the control group, while no significant differences were noted in the soft palate dimension. Evaluating nasopharyngeal collapse at the foramen lacerum level was recommended due to the clear presence of identifiable bony landmarks and lower overlap in the nasopharyngeal collapsibility between dogs with and without stertor. Physical dimensions of the soft palate may not be the primary contributing factor to nasopharyngeal collapse and clinical signs in non-brachycephalic dogs.

A Preliminary Study of Voluntary Cough Motor Performance and Learning With Skill Training and Biofeedback

PURPOSE

Sensorimotor cough skill training (CST) has been shown to improve cough strength, as well as facilitate changes during training (i.e., motor performance) and generalization to untrained tasks (i.e., motor learning). However, there is a gap in our understanding of the effects of voluntary CST (without sensory stimuli) on motor performance and learning. Furthermore, the contribution of physiologic factors, such as lung volume, a driver of cough strength in healthy adults, and treatment-specific factors, such as biofeedback, remains unexamined.

METHOD

Twenty individuals with Parkinson's disease (PD) completed pre- and post-CST single voluntary, sequential voluntary, and reflex cough testing. Participants were randomized to biofeedback or no biofeedback groups. They completed one CST session involving 25 trials of voluntary coughs, with the treatment target set 25% above baseline peak flow. Participants were instructed to "cough hard" to exceed the target. In the biofeedback group, participants received direct visualization of the target line in real time.

RESULTS

Cough peak flow showed positive improvements in motor performance (β = .02; 95% credible interval [CI]: 0.01, 0.03) and learning (β = .26; 95% CI: 0.03, 0.47). Changes in lung volume from pre- to post-CST did not predict treatment response. No differences in treatment response were detected between the biofeedback groups.

CONCLUSIONS

A single session of voluntary CST improved voluntary cough motor performance and learning. Although lung volume increased during CST, changes to lung volume did not predict treatment response. These findings demonstrate the potential of voluntary CST to improve motor performance and motor learning among individuals with PD and cough dysfunction.

SUPPLEMENTAL MATERIAL AND OPEN SCIENCE FORM

https://doi.org/10.23641/asha.25447444.

Assessment of MMP-9 and clinical characteristics in dogs with tracheal collapse based on cough severity and fluoroscopic findings: a cross-sectional study

BACKGROUND

Tracheal collapse (TC), a common disease in dogs, is characterized by cough; however, little is known about the serum biomarkers that can objectively evaluate the severity of cough in canine TC. Furthermore, studies elucidating the relationship of fluoroscopic characteristics with the severity of cough are lacking. Therefore, this study aimed to evaluate the relationship between cough severity and clinical characteristics, fluoroscopic images, and new serum biomarkers in canine TC.

RESULTS

Fifty-one client-owned dogs diagnosed with TC based on fluoroscopic and clinical signs were enrolled in this study and divided into three groups according to the severity of cough (grade of cough: 0, 1, and 2). Signalments, comorbidities, and fluoroscopic characteristics were compared among the groups retrospectively. The serum matrix metalloproteinase-9 (MMP-9), interleukin-6 (IL-6), surfactant protein-A (SP-A), and syndecan-1 (SDC-1) levels were measured in all groups. No significant differences in age, breed, sex, or clinical history were observed among the groups. Concomitant pharyngeal collapse increased significantly with the severity of cough (p = .031). Based on the fluoroscopic characteristics, the TC grade of the carinal region increased significantly and consistently with the grade of cough (p = .03). The serum MMP-9 level was significantly higher in the grade 2 group than that in the grade 0 group (p = .014). The serum IL-6 level was significantly lower in the grade 1 group than that in the grade 0 group (p = .020). The serum SP-A and SDC-1 levels did not differ significantly among the groups.

CONCLUSIONS

The severity of cough with the progression of TC can be predicted with the fluoroscopic TC grade at the carinal region. MMP-9 may be used as an objective serum biomarker that represents cough severity to understand the pathogenesis.

The role of lung volume recruitment therapy in neuromuscular disease: a narrative review

Respiratory muscle weakness results in substantial discomfort, disability, and ultimately death in many neuromuscular diseases. Respiratory system impairment manifests as shallow breathing, poor cough and associated difficulty clearing mucus, respiratory tract infections, hypoventilation, sleep-disordered breathing, and chronic ventilatory failure. Ventilatory support (i.e., non-invasive ventilation) is an established and key treatment for the latter. As survival outcomes improve for people living with many neuromuscular diseases, there is a shift towards more proactive and preventative chronic disease multidisciplinary care models that aim to manage symptoms, improve morbidity, and reduce mortality. Clinical care guidelines typically recommend therapies to improve cough effectiveness and mobilise mucus, with the aim of averting acute respiratory compromise or respiratory tract infections. Moreover, preventing recurrent infective episodes may prevent secondary parenchymal pathology and further lung function decline. Regular use of techniques that augment lung volume has similarly been recommended (volume recruitment). It has been speculated that enhancing lung inflation in people with respiratory muscle weakness when well may improve respiratory system "flexibility", mitigate restrictive chest wall disease, and slow lung volume decline. Unfortunately, clinical care guidelines are based largely on clinical rationale and consensus opinion rather than level A evidence. This narrative review outlines the physiological changes that occur in people with neuromuscular disease and how these changes impact on breathing, cough, and respiratory tract infections. The biological rationale for lung volume recruitment is provided, and the clinical trials that examine the immediate, short-term, and longer-term outcomes of lung volume recruitment in paediatric and adult neuromuscular diseases are presented and the results synthesised.

Predictors of Peak Expiratory Cough Flow in Individuals with Amyotrophic Lateral Sclerosis

Dystussia is prevalent in individuals with amyotrophic lateral sclerosis (ALS), leading to a diminished physiologic capacity to effectively defend the airway. We aimed to identify predictors of peak expiratory cough flow rate in individuals with ALS. One hundred and thirty-four individuals with a confirmed diagnosis of ALS (El-Escorial criteria revised) completed the ALS Functional Rating Scale-Revised (ALSFRS-R) and underwent pulmonary function and cough spirometry testing. Pearson's correlation coefficients and hierarchical multiple regression modeling were conducted to determine predictors of voluntary cough peak expiratory flow rate (p < 0.05). The full model including age, bulbar disease, cough spirometry metrics, and respiratory parameters had a marginal R² = 0.635, F (7, 126) = 30.241, p < 0.0005, adjusted R² = 0.61. Maximum expiratory pressure, compression phase, and vital capacity did not contribute and were therefore removed (p < 0.05). The most parsimonious predictive model included age, bulbar disease, peak inspiratory flow rate and duration, peak expiratory rise time, and inspiratory pressure generation with a marginal R² = 0.543. Although expiratory pressure generation has historically served as the therapeutic target to improve dystussia in ALS, the current dataset highlighted that the inability to quickly and forcefully inspire during the inspiratory phase of voluntary cough places patients at a mechanical disadvantage to generate subsequent high-velocity expiratory airflow to clear the airway. Thus, therapeutic training programs that include both inspiratory and expiratory strength targets may optimize airway clearance capacity in this challenging patient population.

The effect of stimulation and unloading of baroreceptors on cough in experimental conditions

Cough, the main airway defensive process, is modulated by multiple sensory inputs from the respiratory system and outside of it. This modulation is one of the mechanisms that contributes to the sensitization of cough pathways at the peripheral and/or central level via neuroplasticity and it manifests most often as augmented coughing. Cardiorespiratory coupling is an important mechanism responsible for a match between oxygenation and cardiac output and bidirectional relationships exist between respiration and cardiovascular function. While the impact of cough with the robust swings of the intrathoracic pressure on haemodynamic parameters and heart electrophysiology are well characterized, little is known about the modulation of cough by haemodynamic parameters - mainly the blood pressure. Some circumstantial findings from older animal studies and more recent sophisticated analysis confirm that baroreceptor stimulation and unloading alters coughing evoked in experiments. Clinical relevance of such findings is not presently known.

A putative link between pertussis and new onset of gastroesophageal reflux. An observational study

Background

Pertussis is an infectious disease of the respiratory tract with a changing epidemiology. An increasing incidence has been found in the adult population with recurrent infections possibly related to changes in the current vaccine. Is there an association between pertussis infection, refractory cough and atypical gastro-oesophageal reflux (GORD)? Does this magnify and compound respiratory complications?

Methods

Observational study which compares post-pertussis (n=103) with non-pertussis patients (n=105) with established GORD. Patients were assessed for laryngopharyngeal reflux and aspiration of refluxate by a novel scintigraphic study.

Results

Both groups showed severe GORD in association with high rates of laryngopharyngeal reflux (LPR) and pulmonary aspiration and lung disease. High rates of hiatus hernia and clinical diagnosis of “atypical” asthma showed correlations with pulmonary aspiration.

Conclusions

A high level of new onset LPR and lung aspiration has been shown in patients with chronic cough after recent pertussis infection by a novel scintigraphic technique with fused hybrid x-ray computed tomography (SPECT/CT).

Pulsatile parallel flow of air and a viscoelastic fluid with multiple characteristic times. An application to mucus in the trachea and the frequency of cough

We study the dynamics of a binary fluid, where the two fluids are flowing parallel to each other in a cylindrical geometry, and driven by a pulsatile pressure gradient. One of the fluids is a low viscosity Newtonian fluid, the other one is viscoelastic. In order to be able to apply the model to different biofluids, we consider that the viscoelastic fluid has several characteristic times. We characterize the dynamics of the fluids as generalized Darcy's laws, with linear response functions to pulsatile pressure gradients, whose parameters are coupled for both fluids through the fluid-fluid boundary conditions. We apply our results to the dynamics of mucus and air in the trachea and find that the frequency that allows for a larger movement of the mucus, coincides with the experimental frequency of cough. This allows us to propose a plausible explanation for the frequency of cough in healthy individuals, a mechanical process to expel noxious substances from the respiratory system.

Effects of respiratory physiotherapy in patients with amyotrophic lateral sclerosis: protocol for a systematic review of randomised controlled trials

INTRODUCTION

Respiratory muscle weakness and ventilatory failure are common complications in patients with amyotrophic lateral sclerosis (ALS) and may lead to death. Respiratory physiotherapy may improve lung function in this population. This study aims to investigate the effects of respiratory physiotherapy on lung function, cough efficacy and functional status of patients with ALS.

METHODS AND ANALYSIS

A protocol was published on the International prospective register of systematic reviews (PROSPERO). The research will cover randomised controlled trials, with no language or publication date restriction, available in the following databases: MEDLINE/PubMed, EMBASE, Cochrane Library, Web of Science and Physiotherapy Evidence Database. The research question will be answered using a search strategy adapted for each database. Searches in databases will be conducted from January 2021 to December 2022. Two authors using the Cochrane risk of bias tool for randomised trials V.2 and Grading of Recommendations, Assessment, Development and Evaluations, respectively, will assess risk of bias and quality of evidence independently. According to the results obtained, data will be reported as a meta-analysis or a narrative report.

ETHICS AND DISSEMINATION

No previous ethical approval is required for this publication since data used are already published. Results of this review will be disclosed via peer-reviewed publications and conference presentations.

PROSPERO REGISTRATION NUMBER

CRD42021251842.

Herbal medicine used for the treatment of diarrhea and cough in Kampala city, Uganda

BACKGROUND

Globally, diarrheal and respiratory diseases are among the main causes of mortality and morbidity. In Uganda, cities are facing proliferation of trade in herbal medicines (HM), including those for diarrhea and/or cough. Information on the economic, and the ethnopharmacological aspects of these HM is scarce, deterring the sector from achieving optimal capacity to support national development. We profiled the anti-diarrhea and/or anti-cough HM, and the basic economic aspects of HM trade in Kampala city, to support ethnopharmacological knowledge conservation and strategic planning.

METHODS

A cross-sectional survey was conducted on 65 herbalists using semi-structured questionnaires. This was supplemented by an observational survey using a high-resolution digital camera. Data were collected following the guidelines for research on HM, established by Uganda National Drug Authority, and World Health organization.

RESULTS

Eighty-four plant species from 41 families were documented. Fabaceae and Myricaceae had the highest number of species (9, 10.7% each). Citrus limon (L.) Osbeck was the most commonly cited for cough, with a relative frequency of citation (RFC) of 1.00, and its relative medical importance was not significantly different from the other top 5 species except for Azadirachta indica A.Juss (RFC = 0.87). Entada abyssinica A. Rich (RFC = 0.97) was the most cited for diarrhea. Trees (34, 40.5%) were mostly used, and mainly harvested from wild habitats (55.2%) in 20 districts across Uganda. These HM were mainly sold as powders and concoctions, in markets, shops, pharmacies, and roadside or mobile stalls. The highest prices were Uganda Shillings (UGX) 48,000 ($13.15)/kg for Allium sativum L, and UGX 16,000 ($4.38)/kg for C. limon. All participants used HM trade as a sole source of basic needs; majority (60.0%) earned net monthly profit of UGX. 730,000 ($200) ≤ 1,460,000 ($400). The main hindrances to HM trade were the; disruptions caused by the COVID-19 pandemic (n = 65, 100%), and the scarcity of medicinal plants (58, 89.2%).

CONCLUSION

There is a rich diversity of medicinal plant species traded in Kampala to treat diarrhea and cough. The HM trade significantly contributes to the livelihoods of the traders in Kampala, as well as the different actors along the HM value chain throughout the country.

Effect of PEP flute self-care versus usual care in early covid-19: non-drug, open label, randomised controlled trial in a Danish community setting

OBJECTIVE

To determine whether positive expiratory pressure (PEP) by PEP flute self-care is effective in reducing respiratory symptoms among community dwelling adults with SARS-CoV-2 infection and early stage covid-19.

DESIGN

Non-drug, open label, randomised controlled trial.

SETTING

Capital Region and Region Zealand in Denmark from 6 October 2020 to 26 February 2021.

PARTICIPANTS

Community dwelling adults, able to perform self-care, with a new SARS-CoV-2 infection (verified by reverse transcription polymerase chain reaction tests) and symptoms of covid-19.

INTERVENTION

Participants were randomised to use PEP flute self-care in addition to usual care or have usual care only. Randomisation was based on permuted random blocks in a 1:1 ratio, stratified for sex and age (<60 or ≥60 years). The PEP self-care group was instructed to use a PEP flute three times per day during the 30 day intervention.

MAIN OUTCOME MEASURES

Primary outcome was a change in symptom severity from baseline to day 30, as assessed by the self-reported COPD (chronic obstructive pulmonary disease) assessment test (CAT), which was adjusted for baseline values and stratification factors. Participants completed the CAT test questionnaire every day online. Secondary outcomes were self-reported urgent care visits due to covid-19, number of covid-19 related symptoms, and change in self-rated health, all within 30-days' follow-up.

RESULTS

378 participants were assigned to the PEP flute self-care intervention (n=190) or usual care only (n=188). In the PEP self-care group, the median number of days with PEP flute use was 21 days (interquartile range 13-25). For the intention-to-treat population, a group difference was observed in changes from baseline in CAT scores of -1.2 points (95% confidence interval -2.1 to -0.2; P=0.017) in favour of the PEP flute self-care group. At day 30, the PEP flute self-care group also reported less chest tightness, less dyspnoea, more vigour, and higher level of daily activities, but these differences were small, and no consistent effects were seen on the secondary outcomes. No serious adverse events were reported.

CONCLUSIONS

In community dwelling adults with early covid-19, PEP flute self-care had a significant, yet marginal and uncertain clinical effect on respiratory symptom severity, as measured by CAT scores.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04530435.

Assessment of cough in head and neck cancer patients at risk for dysphagia-An overview

BACKGROUND

This literature review explores the terminology, the neurophysiology, and the assessment of cough in general, in the framework of dysphagia and regarding head and neck cancer patients at risk for dysphagia. In the dysphagic population, cough is currently assessed perceptually during a clinical swallowing evaluation or aerodynamically.

RECENT FINDINGS

Recent findings have shown intra and inter-rater disagreements regarding perceptual scoring of cough. Also, aerodynamic measurements are impractical in a routine bedside assessment. Coughing, however, is considered to be a clinically relevant sign of aspiration and dysphagia in head and cancer patients treated with concurrent chemoradiotherapy.

CONCLUSION

This article surveys the literature regarding the established cough assessment and stresses the need to implement innovative methods for assessing cough in head and neck cancer patients treated with concurrent chemoradiotherapy at risk for dysphagia.

Impact of peripheral muscle strength on prognosis after extubation and functional outcomes in critically ill patients: a feasibility study

The influence of peripheral muscle strength on prognosis after extubation and subsequent functional outcomes is not evident. The objectives of this study were to determine (1) whether peripheral muscle strength can be used as a predictor for patients' prognoses after extubation, and (2) whether the peripheral muscle strength before extubation is correlated with patients' subsequent ambulation ability and in-hospital mortality. This study was a prospective observational cohort study. A hand-held dynamometer was used for evaluated the muscle strength of the biceps and quadriceps right before extubation. Besides, after the patients had been transferred from the ICU to the general ward, a 2-minute walk test was performed. A total of 52 patients were enrolled in this study, and the rate of extubation failure was 15%. The muscle strength of the quadriceps was significantly correlated with the prognosis after extubation, 48% of the patients were able to ambulate after being transferred to the general ward. The overall mortality rate was 11%, and there was a significant correlation between the biceps muscle strength and in-hospital mortality. Peripheral muscle strength may serve as an important predictor of a patients' prognoses after extubation. Poor peripheral muscle strength is indicative of not only a higher risk of re-intubation but also higher in-hospital mortality and poorer functional outcomes.Trial registration: ISRCTN16370134. Registered 30 May 2019, prospectively registered. https://www.isrctn.com/ISRCTN16370134 .

PEP-CoV protocol: a PEP flute-self-care randomised controlled trial to prevent respiratory deterioration and hospitalisation in early COVID-19

INTRODUCTION

Infection with SARS-CoV-2 may progress to severe pulmonary disease, COVID-19. Currently, patients admitted to hospital because of COVID-19 have better prognosis than during the first period of the pandemic due to improved treatment. However, the overall societal susceptibility of being infected makes it pivotal to prevent severe courses of disease to avoid high mortality rates and collapse of the healthcare systems. Positive expiratory pressure (PEP) self-care is used in chronic pulmonary disease and has been shown to prevent pneumonia in a high-risk cohort of patients with leukaemia. PEP flute self-care to prevent respiratory deterioration and hospitalisation in early COVID-19: a randomised trial (The PEP-CoV trial) examines the effectiveness on respiratory symptoms and need of hospital admission by regular PEP flute use among non-hospitalised individuals with confirmed SARS-CoV-2 infection and COVID-19 symptoms.

METHODS AND ANALYSIS

In this randomised controlled trial, we hypothesise that daily PEP flute usage as add-on to usual care is superior to usual care as regards symptom severity measured by the COPD Assessment Test (CAT) at 30-day follow-up (primary outcome) and hospital admission through register data (secondary outcome). We expect to recruit 400 individuals for the trial. Participants in the intervention group receive a kit of 2 PEP flutes and adequate resistances and access to instruction videos. A telephone hotline offers possible contact to a nurse. The eight-item CAT score measures cough, phlegm, chest tightness, dyspnoea, activities of daily living at home, feeling safe at home despite symptoms, sleep quality and vigour. The CAT score is measured daily in both intervention and control arms by surveys prompted through text messages.

ETHICS AND DISSEMINATION

The study was registered prospectively at www.clinicaltrials.gov on 27 August 2020 (NCT04530435). Ethical approval was granted by the local health research ethics committee (Journal number: H-20035929) on 23 July 2020. Enrolment of participants began on 6 October 2020. Results will be published in scientific journals.

TRIAL REGISTRATION NUMBER

NCT04530435; Pre-results.

Impact of chronic respiratory diseases on re-intubation rate in critically ill patients: a cohort study

Chronic respiratory diseases’ (CRDs) impact on re-intubation rate remains unclear. We investigated the association between these factors in mechanically ventilated patients. Data were extracted from the freely available online Medical Information Mart for Intensive Care III database. CRDs were defined according to ICD-9 codes. Generalised linear regression and propensity score matching were performed. Of 13,132 patients, 7.9% required re-intubation. Patients with chronic obstructive pulmonary disease (COPD) had higher re-intubation (OR 2.48, 95% CI 1.83–3.33) and mortality rates (OR 1.64, 95% CI 1.15–2.34) than those without. Patients with asthma had a lower mortality rate (OR 0.63, 95% CI 0.43–0.92) but a similar re-intubation rate to those of patients without. These findings remained stable after propensity score matching and bootstrapping analysis. The association of COPD with re-intubation was significantly stronger in patients with high oxygen-partial pressure (PaO₂) or mild disease severity but was independent of carbon dioxide partial pressure. Corticosteroid use was associated with increased re-intubation rates in subgroups without CRDs (OR 1.77–1.99, p < 0.001) but not in subgroups with CRDs. COPD patients with high post-extubation PaO₂ or mild disease severity should be carefully monitored as they have higher re-intubation and mortality rates.

Effects of an optimised approach to home-based respiratory care in individuals with amyotrophic lateral sclerosis: a study protocol for a randomised controlled trial

INTRODUCTION

This study aims to investigate the effects of an optimal home-based respiratory care protocol in individuals with amyotrophic lateral sclerosis (ALS).

METHODS AND ANALYSIS

This is a randomised, blinded controlled trial involving patients diagnosed with ALS, both sexes, age between 18 and 80 years. Patients will be randomly allocated into the conventional respiratory care (CRC) group and the optimised respiratory care home-based (ORC) group. Primary outcomes will be peak cough flow, the number of exacerbations and ALS Functional Rating Scale Revised. Secondary outcomes will include chest wall volumes, maximal respiratory pressures, sniff nasal inspiratory pressure, nasal expiratory pressure and forced vital capacity (FVC), forced expiratory volume in the 1st second (FEV1) and FEV1/FVC. The CRC group will receive educational information about respiratory care at the clinic. The ORC group will receive conventional care and home-based care. The clinical status of all individuals will be monitored weekly through telephone calls. A 6-month intervention is planned, the outcomes will be assessed every 3 months and 3 and 6 months follow-up after final evaluation. The primary and secondary results will be described as average or median for continuous variables and absolute and relative frequencies for qualitative variables. Treatment effects or differences between the outcomes (baseline, 3 months and 6 months) of the study groups will be analysed using an analysis of variance. The level of significance will be set as p≤0.05.

ETHICS AND DISSEMINATION

The research ethics committee approved the study. It is expected to evaluate respiratory function in patients with ALS in the short, medium and long terms with home-based care protocol applied. The disease's rapid progression is a limitation for performing a long-term clinical study.

TRIAL REGISTRATION NUMBER

RBR-3z23ts; Pre-results.

Global Physiology and Pathophysiology of Cough: Part 1: Cough Phenomenology - CHEST Guideline and Expert Panel Report

The purpose of this state-of-the-art review is to update the American College of Chest Physicians 2006 guideline on global physiology and pathophysiology of cough. A review of the literature was conducted using PubMed and MEDLINE databases from 1951 to 2019 and using prespecified search terms. We describe the basic phenomenology of cough patterns, behaviors, and morphological features. We update the understanding of mechanical and physiological characteristics of cough, adding a contemporary view of the types of cough and their associated behaviors and sensations. New information about acoustic characteristics is presented, and recent insights into cough triggers and the patient cough hypersensitivity phenotype are explored. Lastly, because the clinical assessment of patients largely focuses on the duration rather than morphological features of cough, we review the morphological features of cough that can be measured in the clinic. This is the first of a two-part update to the American College of Chest Physicians 2006 cough guideline; it provides a more global consideration of cough phenomenology, beyond simply the mechanical aspects of a cough. A greater understanding of the typical features of cough, and their variations, may allow a more informed interpretation of cough measurements and the clinical relevance for patients.

Comparison of physical properties of voluntary coughing, huffing and swallowing in healthy subjects

Coughing, huffing and swallowing protect the airway from aspiration. This study was conducted to compare the physical properties of voluntary coughing, huffing and swallowing in healthy subjects. Ten healthy men were asked to huff, cough and swallow repeatedly. Electromyograms (EMGs) were recorded from the left side of the external oblique (EO), sternocleidomastoid, suprahyoid (SH) and thyrohyoid muscles. Airflow was recorded using a face mask with two-way non-rebreathing valves. The expiratory velocity of huffing and coughing and the SH EMG of all actions presented high intraclass correlation coefficients (> 0.8). The inspiratory and expiratory velocities did not differ significantly between coughing and huffing. The expiratory acceleration of coughing was significantly higher than that of huffing, whereas the expiratory volume of coughing was significantly smaller than that of huffing. The EO EMG of coughing and huffing were significantly larger than that of swallowing. The EO EMG activity during the expiratory phase was significantly higher than that of the other phases of both coughing and huffing. The SH EMG of coughing and huffing were significantly smaller than that of swallowing. Correlation analysis revealed that the expiratory velocity of coughing was strongly positively correlated with that of huffing. The expiratory volume of huffing was significantly positively correlated with hand grip strength. These results suggest that EO and SH muscle activities during huffing or coughing differ those during swallowing, and huffing and coughing may work similarly in expiratory function.

Removal of foreign body airway obstruction: A systematic review of interventions

OBJECTIVE

To summarise in a systematic review the effectiveness of interventions to treat foreign body airway obstructions (FBAO).

METHODS

We searched MEDLINE, EMBASE, and the Cochrane library from inception on 30th September 2019 for studies that described the effectiveness of interventions to treat FBAO in adults and children. We included randomised controlled trials, observational studies and case series (≥5 cases) that described evidence of benefit. For evidence of harm/complications, we included case reports. Two reviewers independently assessed study eligibility, extracted study data, and assessed risk of bias. Data are summarised in a narrative synthesis. The GRADE system is used to assess evidence certainty.

RESULTS

We included 69 publications, comprising three cross-sectional studies (557 patients); eight case series (755 patients), and 59 were case reports (64 patients). One paper was included as a case series and cross-sectional study. For all interventions and associated outcomes, evidence certainty was very low. Early removal of FBAO by bystanders was associated with improved neurological survival (odds ratio 6.0, 95% confidence interval 1.5 to 23.4). Identified evidence showed that key interventions (back blows, abdominal thrusts, chest thrusts/compressions, Magill forceps, manual removal of obstructions from the mouth, suction-based airway clearance devices) are effective in relieving FBAO. We identified reports of harm in relation to back blows, abdominal thrusts, chest thrusts/compressions, and blind finger sweeps.

CONCLUSIONS

Key interventions successfully relieve FBAO, but may be associated with important harms. Guidelines for FBAO management should balance the benefits and harms of interventions.

Differences in voluntary and reflexive cough strength in individuals with amyotrophic lateral sclerosis and healthy adults

INTRODUCTION

Dystussia impacts the ability to protect the airway. Voluntary cough provides a metric of airway defense but differs from the reflexive response to aspiration during swallowing. Therefore, we evaluated relationships between voluntary and reflexive cough among individuals with amyotrophic lateral sclerosis (ALS) and a healthy cohort.

METHODS

Twenty-eight individuals with ALS and 26 healthy individuals completed voluntary and reflexive cough testing. Descriptive statistics, reliability, and paired t tests were conducted to evaluate differences in cough volume acceleration (CVA) and peak expiratory flow rate (PEFR) in voluntary vs reflexive cough.

RESULTS

Compared with reflexive cough, voluntary CVA and PEFR were greater in individuals with ALS [t(27) = 4.83, P < .001 and t(27) = 8.69, P < .001] and the healthy cohort [t(21) = 5.91, P < .001 and t(21) = 12.26, P < .001], respectively.

DISCUSSION

These findings hold important implications for the use and interpretation of voluntary peak cough flow during clinical swallowing evaluations.

Respiratory Muscle Performance Screening for Infectious Disease Management Following COVID-19: A Highly Pressurized Situation

The 2019-2020 coronavirus pandemic elucidated how a single highly infectious virus can overburden health care systems of even highly economically developed nations. A leading contributor to these concerning outcomes is a lack of available intensive care unit (ICU) beds and mechanical ventilation support. Poorer health is associated with a higher risk for severe respiratory complications from the coronavirus. We hypothesize that impaired respiratory muscle performance is an underappreciated factor contributing to poor outcomes unfolding during the coronavirus pandemic. Although impaired respiratory muscle performance is considered to be rare, it is more frequently encountered in patients with poorer health, in particular obesity. However, measures of respiratory muscle performance are not routinely performed in clinical practice, including those with symptoms such as dyspnea. The purpose of this article is to discuss the potential role of respiratory muscle performance from the perspective of the coronavirus pandemic. We also provide a theoretical patient management model to screen for impaired respiratory muscle performance and intervention, if identified, with the goal of unburdening health care systems during future pandemic crises.

Comparison of the effects of voluntary and involuntary breath stacking techniques on respiratory mechanics and lung function patterns in tracheostomized patients: a randomized crossover clinical trial

Objective:

To compare the effects of voluntary breath stacking (VBS) and involuntary breath stacking (IBS) techniques on respiratory mechanics, lung function patterns, and inspiratory capacity in tracheostomized patients.

Methods:

This was a randomized crossover clinical trial involving 20 tracheostomized patients admitted to the ICU and submitted to the VBS and IBS techniques, in random order, with an interval of 5 h between each. Ten cycles of each technique were performed with an interval of 30 s between each cycle. In VBS, patients performed successive inspirations for up to 30 s through a one-way valve, whereas in IBS, successive slow insufflations were performed with a resuscitator bag until the pressure reached 40 cmH₂O. Respiratory mechanics, inspiratory capacity, and the lung function pattern were evaluated before and after the interventions.

Results:

After IBS, there was an increase in static compliance (p = 0.007), which was also higher after IBS than after VBS (p = 0.03). There was no significant difference between the pre-VBS and post-VBS evaluations in terms of static compliance (p = 0.42). Inspiratory capacity was also greater after IBS than after VBS (2,420.7 ± 480.9 mL vs. 1,211.3 ± 562.8 mL; p < 0.001), as was airway pressure (38.3 ± 2.6 cmH₂O vs. 25.8 ± 5.5 cmH₂O; p < 0.001). There were no changes in resistance or lung function pattern after the application of either technique.

Conclusions:

In comparison with VBS, IBS promoted greater inspiratory capacity and higher airway pressure, resulting in an increase in static compliance.

Role of ICU-acquired weakness on extubation outcome among patients at high risk of reintubation

Background

Whereas ICU-acquired weakness may delay extubation in mechanically ventilated patients, its influence on extubation failure is poorly known. This study aimed at assessing the role of ICU-acquired weakness on extubation failure and the relation between limb weakness and cough strength.

Methods

A secondary analysis of two previous prospective studies including patients at high risk of reintubation after a planned extubation, i.e., age greater than 65 years, with underlying cardiac or respiratory disease, or intubated for more than 7 days prior to extubation. Patients intubated less than 24 h and those with a do-not-reintubate order were not included. Limb and cough strength were assessed by a physiotherapist just before extubation. ICU-acquired weakness was clinically diagnosed as limb weakness defined as Medical Research Council (MRC) score < 48 points and severe weakness as MRC sum-score < 36. Cough strength was assessed using a semi-quantitative 5-Likert scale. Extubation failure was defined as reintubation or death within the first 7 days following extubation.

Results

Among 344 patients at high risk of reintubation, 16% experienced extubation failure (56/344). They had greater severity and lower MRC sum-score (41 ± 16 vs. 49 ± 13, p < 0.001) and were more likely to have ineffective cough than the others. The prevalence of ICU-acquired weakness at the time of extubation was 38% (130/244). The extubation failure rate was 12% (25/214) in patients with no limb weakness vs. 18% (12/65) and 29% (19/65) in those with moderate and severe limb weakness, respectively (p < 0.01). MRC sum-score and cough strength were weakly but significantly correlated (rho = 0.28, p < .001). After multivariate logistic regression analyses, the lower the MRC sum-score the greater the risk of reintubation; severe limb weakness was independently associated with extubation failure, even after adjustment on cough strength and severity at admission.

Conclusion

ICU-acquired weakness was diagnosed in 38% in this population of patients at high risk at the time of extubation and was independently associated with extubation failure in the ICU.

Effects of Expiratory Muscle Training and Air Stacking on Peak Cough Flow in Individuals with Parkinson's Disease

The purpose of this study was to investigate the effects of air stacking (AS) and an expiratory muscle training (EMT) program to increase voluntary and reflex peak cough flow (PCF) in individuals with Parkinson's disease. Participants were allocated to the control (n = 11), EMT (n = 11), or EMT + AS group (n = 11). All groups performed EMT (5 sets of 5 repetitions), 6 times a week for 2 months. The control group used a fixed resistance, EMT plus AS and EMT groups used a progressively increased resistance. The EMT plus AS group additionally performed 10 series of three to four lung insufflations using a manual resuscitator bag. Voluntary and reflex PCF, maximum expiratory pressure, and slow vital capacity were assessed before and after training. EMT plus AS was more beneficial than EMT alone for improving reflex and voluntary PCF. The effect of the EMT plus AS was greater for reflex PCF than for voluntary PCF.

Respiratory muscle activation and action during voluntary cough in healthy humans

Cough is a defensive airway reflex consisting of a modified respiratory act which involves the sequential activation of several laryngeal and respiratory muscles. The contraction of the latter results in thoraco-abdominal volume variations in order to provide enough amount of air available, the operating volume (OV), to be expelled. Because both posture and OV could influence muscular activation and thoraco-abdominal displacements during voluntary cough, we aimed to verify if and how they play a role during inspiratory (ICP) and expiratory (ECP) cough phases, in terms of flow, volumes and surface electromyography activity (sEMG). In 10 healthy subjects, we measured sEMG of 7 muscles (scalene, sternocleidomastoid, parasternal, intercostal, diaphragm (assessed at the 8^th intercostal space), external abdominal oblique and rectus abdominis) in supine and seated position during cough maneuvers performed at 4 different OV measured by opto-electronic plethismography: total lung capacity (TLC), functional residual capacity and two intermediate volumes. The amplitude of sEMG signals tended to be maximal at TLC (p < 0.005) during ICP in the neck and parasternal muscles and during ECP in abdominal muscles. Postures slightly affected only sEMG of the thoracic muscles. sEMG data were similar (p > 0.05) in the other OV, but cough peak flow increased with OV. Thoraco-abdominal volume variations during cough were unaffected by posture and OV as well, being predominantly thoracic (supine: 60 and 64%; seated: 68 and 69%, respectively during ICP and ECP). Our results suggest that voluntary cough OV or posture do not have an important effect on voluntary cough that seems more likely to be resulting from a motor mechanism that activates a synergetic antagonistic contraction of inspiratory and expiratory muscles leading to a specific thoraco-abdominal pattern, in which the rib cage is the predominant.

A systematic review of methods of citric acid cough reflex testing

INTRODUCTION

This systematic review summarises and appraises methods of citric acid cough reflex testing (CRT) documented in published literature.

METHODS

Electronic databases, MEDLINE, EMBASE, CINAHL, PsychINFO, Scopus were searched up to and including 11th February 2018. Studies reporting a method of citric acid CRT, published in peer-reviewed journals in English or Spanish, were assessed for the inclusion criteria. Of the selected studies, information on the instrumentation and CRT protocol was extracted.

RESULTS

A total of 129 studies were included. Instrumentation and protocols differed widely across studies. Reporting of methods of citric acid CRT was sub-standard, with many crucial methodological components omitted from published manuscripts, preventing their full replication.

CONCLUSIONS

Considerable methodological variability exists for citric acid CRT in published literature. The findings suggest that caution is warranted in comparing citric acid cough thresholds across studies. Full replication of previously published methods of citric acid CRT is limited due to crucial elements of the citric acid CRT protocol being omitted from published manuscripts. These findings have implications on the use of citric acid CRT in clinical and pharmaceutical studies to evaluate the effects of antitussive medications and cough therapies.

Cough, a vital reflex. mechanisms, determinants and measurements

Cough is a natural defense mechanism that protects the respiratory tract from inhaling foreign bodies and by clearing excessive bronchial secretions. As a spontaneous reflex arc, it involves receptors, an afferent pathway, a center processing information, an efferent pathway and effectors. The determinant factor of cough efficacy is the operational volume of the lung, which in turn relies on the strength and coordination of respiratory and laryngeal muscles as well as on lung mechanics. Respiratory muscle weakness and dysfunction as well as expiratory flow limitation and lung hyperinflation may occur in some neuromuscular disorders and in obstructive airway diseases, respectively. Accordingly, all these diseases may show an ineffective cough. In this brief overview, we deal with the determinants of the cough efficacy and the clinical conditions affecting cough efficacy as well as the cough’s efficacy measurements in clinical setting. (www.actabiomedica.it)

A Mobile Cough Strength Evaluation Device Using Cough Sounds

Although cough peak flow (CPF) is an important measurement for evaluating the risk of cough dysfunction, some patients cannot use conventional measurement instruments, such as spirometers, because of the configurational burden of the instruments. Therefore, we previously developed a cough strength estimation method using cough sounds based on a simple acoustic and aerodynamic model. However, the previous model did not consider age or have a user interface for practical application. This study clarifies the cough strength prediction accuracy using an improved model in young and elderly participants. Additionally, a user interface for mobile devices was developed to record cough sounds and estimate cough strength using the proposed method. We then performed experiments on 33 young participants (21.3 ± 0.4 years) and 25 elderly participants (80.4 ± 6.1 years) to test the effect of age on the CPF estimation accuracy. The percentage error between the measured and estimated CPFs was approximately 6.19%. In addition, among the elderly participants, the current model improved the estimation accuracy of the previous model by a percentage error of approximately 6.5% (p < 0.001). Furthermore, Bland-Altman analysis demonstrated no systematic error between the measured and estimated CPFs. These results suggest that the developed device can be applied for daily CPF measurements in clinical practice.

Rectal, central venous, gastric and bladder pressures versus esophageal pressure for the measurement of cough strength: a prospective clinical comparison

BACKGROUND

Cough pressure, an expression of expiratory muscle strength, is usually measured with esophageal or gastric balloons, but these invasive catheters can be uncomfortable for the patient or their placement impractical. Because pressure in the thorax and abdomen are expected to be similar during a cough, we hypothesized that measurement at other thoracic or abdominal locations might also be similar as well as useful in clinical scenarios. This study aimed to compare cough pressures measured at thoracic and abdominal sites that could serve as alternatives to esophageal pressures (P_es).

METHODS

Nine patients scheduled for laparotomy were asked to cough as forcefully as possible from total lung capacity in supine position. Three cough maneuvers were performed while P_es (the gold standard) as well as gastric, central venous, bladder and rectal pressures (P_ga, P_cv, P_bl, and P_rec, respectively) were measured simultaneously. The intraclass correlation coefficient (ICC) was used to evaluate the repeatability of the measurements in each patient at each site and evaluate agreement between alternative sites (P_ga, P_cv, P_bl, and P_rec) and P_es. Bland-Altman plots were used to compare P_es and the measurements at the other sites.

RESULTS

Median (first quartile, third quartile) maximum pressures were as follows: P_es 112 (89,148), P_ga 105 (92,156), P_cv 102 (91,149), P_bl 118 (93,157), and P_rec 103 (88,150) cmH₂O. The ICCs showed excellent within-site repeatability of the measurements (p < 0.001) and excellent agreement between alternative sites and P_es (p < 0.004). The Bland-Altman plots showed minimal differences between P_es, P_ga, P_cv, and P_rec. However, P_bl was higher than the other pressures in most patients, and the difference between P_es and P_bl was slightly larger.

CONCLUSIONS

Cough pressure can be measured in the esophagus, stomach, superior vena cava or rectum, since their values are similar. It can also be measured in the bladder, although the value will be slightly higher. These results potentially facilitate the assessment of dynamic expiratory muscle strength with fewer invasive catheter placements in most hospitalized patients, thus providing an option that will be particularly useful in those undergoing thoracic or abdominal surgery.

TRIAL REGISTRATION

NCT02957045 registered at November 7, 2016. Retrospectively registered.

Could reflex cough induced through nebulized capsaicin achieve airway clearance in patients with acute retention of lung secretions?

Nasotracheal suctioning (NTS) is a procedure commonly performed by respiratory physiotherapists and nurses to remove excess respiratory secretions from the tracheobronchial tree in a self-ventilating, non-intubated and non-tracheotomized patient. NTS is an important treatment modality for patients with acute secretion retention who are at high risk of progressive respiratory deterioration and arrest. However, NTS is a blind invasive procedure with risk of serious adverse events, and the patient experience of NTS is often extremely negative. Capsaicin, a substance extracted from cayenne pepper, elicits reflex coughs when inhaled. It is hypothesized that capsaicin-induced reflex cough may offer an alternative treatment option to NTS. It is suggested that repeated reflex cough bouts, elicited through inhalation of nebulized capsaicin via a facemask, could achieve clearance of retained secretions from the tracheobronchial tree to the oropharynx, thereby avoiding the need for NTS. This hypothesis is supported by preliminary cough flow data from a stroke trial. Stroke patients underwent assessments of peak cough flow (PCF, a measure of cough effectiveness) of both maximal volitional cough and capsaicin-induced reflex cough. In a sub-group of 20 stroke patients with weak volitional cough (mean PCF 220 L/min, SD 80), PCF of capsaicin-induced reflex cough was on average 184 L/min (SD 130) higher than PCF of subjects' maximal volitional cough effort. Cough flow traces indicate a pattern of cough augmentation during consecutive reflex cough bouts. It is suggested that the hypothesis may best be tested in a pragmatic applied clinical study, i.e. through the application of nebulized capsaicin in relevant clinical situations, as opposed to observational or experimental physiological studies.

Thoracoabdominal asynchrony and paradoxical motion in middle stage amyotrophic lateral sclerosis

AIM

To assess thoracoabdominal asynchrony (TAA) and the presence of paradoxical motion in middle stage amyotrophic lateral sclerosis (ALS) and its relationships with chest wall tidal volume (V_T,CW), breathing pattern and cough peak flow (CPF).

METHODS

Phase angle (θ) between upper (RCp) and lower ribcage (RCa) and abdomen (AB), as well as percentage of inspiratory time for the lower ribcage (IP_RCa) and abdomen (IP_AB) moving in opposite directions were quantified using optoelectronic plethysmography in 12 ALS patients during quiet breathing and coughing. Paradoxical motion of the compartments was based on threshold values of θ and IP, obtained in twelve age and sex matched healthy persons.

RESULTS

During quiet breathing, significantly higher RCa and AB θ (p < .05), IP_RCa (p = 0.001) and IP_AB (p < 0.05) were observed in ALS patients as compared to controls. In ALS patients, correlations between RCa and AB θ with forced vital capacity (FVC) (r=-0.773, p < 0.01), vital capacity (r=-0.663, p < 0.05) and inspiratory capacity (IC) (r=-0.754, p < 0.01), as well as between RCp and RCa θ with FVC (r=-0.608, p < 0.05) and CPF (r=-0.601, p < 0.05) were found. During coughing, correlations between RCp and AB θ with CPF (r=-0.590, p < 0.05), IC (r=-0.748, p < 0.01) and V_T,CW (r=-0.608, p < 0.05), as well as between RCa and AB θ with CPF (r=-0.670, p < 0.05), IC (r=-0.713, p < 0.05) and peak expiratory flow (r=-0.727, p < 0.05) were also observed in ALS patients. ALS patients with paradoxical motion presented lower vital capacity and FVC_%pred (p < 0.05) compared to those without paradoxical motion.

CONCLUSIONS

Middle stage ALS patients exhibit TAA and paradoxical motion during quiet spontaneous breathing and coughing. In addition, diaphragmatic weakness (i.e. decrease in excursion of the RCa and AB compartments) was observed earlier in the lower ribcage rather than the abdominal compartment in this population.

Aspiration Pneumonia and Related Syndromes

Aspiration is a syndrome with variable respiratory manifestations that span acute, life-threatening illnesses, such as acute respiratory distress syndrome, to chronic, sometimes insidious, respiratory disorders such as aspiration bronchiolitis. Diagnostic testing is limited by the insensitivity of histologic testing, and although gastric biomarkers for aspiration are increasingly available, none have been clinically validated. The leading mechanism for microaspiration is thought to be gastroesophageal reflux disease, largely driven by the increased prevalence of gastroesophageal reflux across a variety of respiratory disorders, including chronic obstructive pulmonary disease, asthma, idiopathic pulmonary fibrosis, and chronic cough. Failure of therapies targeting gastric acidity in clinical trials, in addition to increasing concerns about both the overuse of and adverse events associated with proton pump inhibitors, raise questions about the precise mechanism and causal link between gastroesophageal reflux and respiratory disease. Our review summarizes key aspiration syndromes with a focus on reflux-mediated aspiration and highlights the need for additional mechanistic studies to find more effective therapies for aspiration syndromes.

Blood Shift During Cough: Negligible or Significant?

Rationale: It was reported how forceful rhythmic coughing can provide effective blood flow during ventricular fibrillation without direct chest compression. This mechanism of cough-assisted cardiopulmonary resuscitation constitutes a form of "cardiac massage" secondary to the intrathoracic and intra-abdominal pressure changes during cough. We have previously shown that significant blood shifts (BSs) occurs from the thorax to the extremities during expulsive maneuvers and that abdominal pressure controls the outflow of blood from the splanchnic vasculature. This mechanism was called abdominal circulatory pump. BS was quantified by using double body plethysmography (DBP), which combines total body plethysmography and opto-electronic plethysmography. Aim: We hypothesized that coughing activates also the abdominal circulatory pump, being an additional mechanism that displaces a circulatory output sufficient to maintain consciousness in a patient with a non-beating heart. Methods and Results: We studied seven healthy subjects (age: 28.6 ± 2.5 years) during series of voluntary coughs at three different operating volumes: after a spontaneous tidal volume, at total lung capacity (TLC) and at an intermediate volume. BS from the thorax to the extremities were measured by DBP during quiet breathing and during cough at each operating lung volume. BS during cough resulted significantly higher than during quiet breathing (p < 0.05). During the compressive phase, the blood outflow is around 200 ml, whereas during the expulsive phase BS increased (p < 0.05) with increasing operating volume, being almost 700 ml at TLC. At lower operating volume it is almost 400 ml. Conclusion: Deep, vigorous coughing and the consequent fluctuations in intra-thoracic and intra-abdominal pressure activate both the thoracic and the abdominal pump mechanism. The former leads the low-resistance pulmonary veins to empty into the left heart. The latter can generate a circulatory output from the splanchnic region, which acts as a blood reservoir, to other body tissues. These findings might help to better understand the cardiopulmonary interactions during cough, particularly in patients with unstable cardiac function, and the mechanism by which coughing during unstable cardiac rhythms can maintain consciousness in human subjects.

Middle Ear Pressures in Wind Instrument Musicians

OBJECTIVES

This study aimed to assess if playing wind instruments leads to a measurable increase in middle ear pressure during note generation and to provide evidence to clinicians to advise musicians undergoing middle ear surgery.

STUDY DESIGN

An observational cohort study of 40 volunteers in 7 different wind instrument categories underwent tympanometry at rest and during note production.

SETTING

Community.

PATIENTS

Recreational musicians aged over 18 years recruited from the student body attending Birmingham University, UK.

INTERVENTION

None.

MAIN OUTCOME MEASURES

Tympanometry is used as a noninvasive measure of middle ear pressure. The pressure at which peak compliance occurred was taken as an indirect measure of middle ear pressure. The data produced at rest and during note production was statistically analysed with paired t testing and significance set at a p value less than 0.01.

RESULTS

Overall a statistically significant increase in middle ear pressure change of 0.63 mm Hg (p = 0.0001) during note production was identified. Musicians playing the oboe and trumpet demonstrate the largest increase in middle ear pressure of 1.46 mm Hg (p = 0.0053) and 0.78 mm Hg (p = 0.0005) respectively.

CONCLUSION

The data provided by this study gives evidence for the first time that playing wind instruments does increase middle ear pressure. Although the clinical significance of this is yet to be determined the authors would advise that musicians who undergo otological procedures should refrain from playing their instruments until full recovery has been achieved as advised by their clinician following direct microscopic review.

Voluntary cough intensity and its influencing factors differ by sex in community-dwelling adults

Background:

Cough peak flow (CPF) is widely used for measuring voluntary cough intensity. However, the respective factors that affect CPF are not known. The aim of this study was to determine the factors affecting CPF by sex in community-dwelling adults.

Method:

We recruited participants using posters exhibited at a public gymnasium. Participation was voluntary, and all participants provided informed consent. Nonsmoking community residents (102 males, 49.6 ± 20.2 years of age; 101 females, 51.4 ± 18.4 years of age) participated in this study. The main outcome measures were sex differences in CPF, respiratory function, respiratory muscle strength, thorax extension, and grip strength. Factors affecting CPF by sex were analyzed using multiple regression analysis.

Results:

All parameters were higher in men than in women. CPF was affected by thorax expansion at the tenth rib, inspiratory muscle strength and forced expiration in 1 s in men, and thorax expansion at the tenth rib, inspiratory reserve volume, and expiratory muscle power in women. A weak negative correlation was observed between CPF and age (p = −0.24, p < 0.05) in women.

Conclusions:

The factors affecting CPF differed by sex in community-dwelling adults.

Clinical Trial Number: UMIN000023912

Quantifying the size-resolved dynamics of indoor bioaerosol transport and control

Understanding the bioaerosol dynamics of droplets and droplet nuclei emitted during respiratory activities is important for understanding how infectious diseases are transmitted and potentially controlled. To this end, we conducted experiments to quantify the size-resolved dynamics of indoor bioaerosol transport and control in an unoccupied apartment unit operating under four different HVAC particle filtration conditions. Two model organisms (Escherichia coli K12 and bacteriophage T4) were aerosolized under alternating low and high flow rates to roughly represent constant breathing and periodic coughing. Size-resolved aerosol sampling and settle plate swabbing were conducted in multiple locations. Samples were analyzed by DNA extraction and quantitative polymerase chain reaction (qPCR). DNA from both organisms was detected during all test conditions in all air samples up to 7 m away from the source, but decreased in magnitude with the distance from the source. A greater fraction of T4 DNA was recovered from the aerosol size fractions smaller than 1 μm than E. coli K12 at all air sampling locations. Higher efficiency HVAC filtration also reduced the amount of DNA recovered in air samples and on settle plates located 3-7 m from the source.

Objective Assessment of Adherence to Inhalers by Patients with Chronic Obstructive Pulmonary Disease

RATIONALE

Objective adherence to inhaled therapy by patients with chronic obstructive pulmonary disease (COPD) has not been reported.

OBJECTIVES

To objectively quantify adherence to preventer Diskus inhaler therapy by patients with COPD with an electronic audio recording device (INCA).

METHODS

This was a prospective observational study. On discharge from hospital patients were given a salmeterol/fluticasone inhaler with an INCA device attached. Analysis of this audio quantified the frequency and proficiency of inhaler use.

MEASUREMENTS AND MAIN RESULTS

Patients with COPD (n = 244) were recruited. The mean age was 71 years, mean FEV₁ was 1.3 L, and 59% had evidence of mild/moderate cognitive impairment. By combining time of use, interval between doses, and critical technique errors, thus incorporating both intentional and unintentional nonadherence, a measure "actual adherence" was calculated. Mean actual adherence was 22.6% of that expected if the doses were taken correctly and on time. Six percent had an actual adherence greater than 80%. Hierarchical clustering found three equally sized well-separated clusters corresponding to distinct patterns. Cluster 1 (34%) had low inhaler use and high error rates. Cluster 2 (25%) had high inhaler use and high error rates. Cluster 3 (36%) had overall good adherence. Poor lung function and comorbidities were predictive of poor technique, whereas age and cognition with poor lung function distinguished those with poor adherence and frequent errors in technique.

CONCLUSIONS

These data may inform clinicians in understanding why a prescribed inhaler is not effective and to devise strategies to promote adherence in COPD.

Sound: a non-invasive measure of cough intensity

Introduction

Cough intensity is an important determinant of cough severity reported by patients. Cough sound analysis has been widely validated for the measurement of cough frequency but few studies have validated its use in the assessment of cough strength. We investigated the relationship between cough sound and physiological measures of cough strength.

Methods

32 patients with chronic cough and controls underwent contemporaneous measurements of voluntary cough sound, flow and oesophageal pressure. Sound power, peak energy, rise-time, duration, peak-frequency, bandwidth and centroid-frequency were assessed and compared with physiological measures. The relationship between sound and subjective cough strength Visual Analogue Score (VAS), the repeatability of cough sounds and the effect of microphone position were also assessed.

Results

Sound power and energy correlated strongly with cough flow (median Spearman’s r=0.87–0.88) and oesophageal pressure (median Spearman’s r=0.89). Sound power and energy correlated strongly with cough strength VAS (median Spearman’s r=0.84–0.86) and were highly repeatable (intraclass correlation coefficient=0.93–0.94) but both were affected by change in microphone position.

Conclusions

Cough sound power and energy correlate strongly with physiological measures and subjective perception of cough strength. Power and energy are highly repeatable measures but the microphone position should be standardised. Our findings support the use of cough sound as an index of cough strength.

Voluntary upregulation of reflex cough is possible in healthy older adults and Parkinson's disease

Cough is an airway-protective mechanism that serves to detect and forcefully eject aspirate material. Existing research has identified the ability of healthy young adults to suppress or modify cough motor output based on external cueing. However, no study has evaluated the ability of people with Parkinson's disease (PD) and healthy older adults (HOAs) to upregulate cough motor output. The goal of this study was to evaluate the ability of people with PD and healthy age-matched controls (HOAs) to upregulate reflex and voluntary cough function volitionally with verbal instruction and visual biofeedback of airflow targets. Sixteen participants with PD and twenty-eight HOAs (56-83 yr old) were recruited for this study. Experimental procedures used spirometry to evaluate 1) baseline reflex cough (evoked with capsaicin) and voluntary sequential cough and 2) reflex and voluntary cough with upregulation biofeedback. Cough airflow was recorded and repeated-measures ANOVA was used to analyze differences in cough airflow parameters. Cough peak expiratory airflow rate and cough expired volume were significantly greater in the cueing condition for both induced reflex (P < 0.001) and voluntary cough (P < 0.001) compared with baseline measures. This is the first study to demonstrate the ability of people with PD and HOAs to upregulate induced reflex and voluntary cough motor output volitionally. These results support the development of studies targeting improved cough effectiveness in patients with airway-protective deficits.NEW & NOTEWORTHY Aspiration pneumonia is a leading cause of death in Parkinson's disease (PD) and results from concurrent dysphagia and dystussia (cough dysfunction). This is the first study to demonstrate that people with PD and healthy age-matched controls can volitionally upregulate induced reflex and voluntary cough effectiveness when presented with novel cueing strategies. Thus targeting upregulation of cough effectiveness via biofeedback may be a viable way to enhance airway protection in people with PD.

The nervous system of airways and its remodeling in inflammatory lung diseases

Inflammatory lung diseases are associated with bronchospasm, cough, dyspnea and airway hyperreactivity. The majority of these symptoms cannot be primarily explained by immune cell infiltration. Evidence has been provided that vagal efferent and afferent neurons play a pivotal role in this regard. Their functions can be altered by inflammatory mediators that induce long-lasting changes in vagal nerve activity and gene expression in both peripheral and central neurons, providing new targets for treatment of pulmonary inflammatory diseases.