The Effect of Pressure Changes During Mechanical Insufflation-Exsufflation on Respiratory and Airway Physiology.

BACKGROUND: Respiratory muscle weakness can impair cough function, leading to lower respiratory tract infections. These infections are an important contributor to morbidity and mortality in patients with neuromuscular disease. Mechanical insufflation-exsufflation (MIE) is used to augment cough function in these patients. Although MIE is widely used, there are few data to advise on the optimal technique. Since the introduction of MIE, the recommended pressures to be delivered have increased. There are concerns regarding the use of higher pressures and their potential to cause lung derecruitment and upper airway closure. RESEARCH QUESTION: What is the impact of high-pressure MIE (HP-MIE) on lung recruitment, respiratory drive, upper airway flow, and patient comfort, compared with low-pressure MIE (LP-MIE), in patients with respiratory muscle weakness? STUDY DESIGN AND METHODS: Clinically stable patients using domiciliary MIE with respiratory muscle weakness secondary to Duchenne muscle dystrophy, spinal cord injury, or long-term tracheostomy ventilation received LP-MIE (30/-30 cm H2O) and HP-MIE (60/-60 cm H2O) in a random sequence. Lung recruitment, neural respiratory drive, and cough peak expiratory flow were measured throughout, and patients reported comfort and breathlessness following each intervention. RESULTS: A total of 29 patients (10 with Duchenne muscle dystrophy, eight with spinal cord injury, and 11 with long-term tracheostomy ventilation) were included in this study. HP-MIE augmented cough peak expiratory flow compared with LP-MIE (mean cough peak expiratory flow HP-MIE 228 ± 81 L/min vs LP-MIE 179 ± 67 L/min; P = .0001) without any significant change in lung recruitment, neural respiratory drive, or patient-reported breathlessness. However, in patients with more pronounced respiratory muscle weakness, HP-MIE resulted in an increased rate of upper airway closure and patient discomfort that may have an impact on clinical efficacy. INTERPRETATION: HP-MIE did not lead to lung derecruitment or breathlessness compared with LP-MIE. However, it was poorly tolerated in individuals with advanced respiratory muscle weakness. HP-MIE generates more upper airway closure than LP-MIE, which may be missed if cough peak expiratory flow is used as the sole titration target. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov; No.: NCT02753959; URL: www. CLINICALTRIALS: gov.

Effects of non-invasive ventilation on sleep in chronic hypercapnic respiratory failure.

Chronic respiratory disease can exacerbate the normal physiological changes in ventilation observed in healthy individuals during sleep, leading to sleep-disordered breathing, nocturnal hypoventilation, sleep disruption and chronic respiratory failure. Therefore, patients with obesity, slowly and rapidly progressive neuromuscular disease and chronic obstructive airways disease report poor sleep quality. Non-invasive ventilation (NIV) is a complex intervention used to treat sleep-disordered breathing and nocturnal hypoventilation with overnight physiological studies demonstrating improvement in sleep-disordered breathing and nocturnal hypoventilation, and clinical trials demonstrating improved outcomes for patients. However, the impact on subjective and objective sleep quality is dependent on the tools used to measure sleep quality and the patient population. As home NIV becomes more commonly used, there is a need to conduct studies focused on sleep quality, and the relationship between sleep quality and health-related quality of life, in all patient groups, in order to allow the clinician to provide clear patient-centred information.

Sleep disorders and exercise: a mini-review.

Sleep disturbance in a growing problem in the general population. As the prevalence of sleep disturbance rises, interest in treatment modalities including non-pharmaceutical interventions also grows. One of these potential modalities is exercise therapy. In individuals without sleep disorders, exercise appears to be beneficial in improving sleep architecture without any impact of the timing of exercise in relation to onset of sleep. The mechanisms for this are largely unknown but may be due to a combination of the effects of exercise on body temperature, autonomic control, endocrine and metabolic function. In obstructive sleep apnoea (OSA), supervised exercise therapy appears to have positive impact on daytime sleepiness with an unknown impact on sleep quality. The effect of exercise on central sleep apnoea (CSA) will be difficult to ascertain due to the low prevalence of this condition. In primary sleep disorders such as insomnia, narcolepsy and restless syndrome exercise may be useful in improving sleep architecture but the quality of the evidence supporting this remains low. In addition, the timing of exercise in relation to sleep onset remains under investigated. In individuals with circadian rhythm disorders, evening exercise appears to delay sleep onset. In shift-pattern workers, individuals with increased cardiorespiratory fitness report better sleep quality, suggesting exercise may be protective in this important population. To allow high quality evidence-based recommendations to be made about the value of exercise in individuals with sleep disorders, there is a significant need for large prospective studies with objective and subjective sleep quality as a primary outcome.

Domiciliary transcutaneous electrical stimulation in patients with obstructive sleep apnoea and limited adherence to continuous positive airway pressure therapy: a single-centre, open-label, randomised, controlled phase III trial.

Background: Hypoglossal nerve stimulation (HNS) for obstructive sleep apnoea (OSA) is a novel way to manage the condition. We hypothesised that in patients with OSA and limited adherence to continuous positive airway pressure (CPAP) therapy, domiciliary transcutaneous electrical stimulation (TESLA) would control sleep apnoea and provide health benefits. Methods: We undertook a single-centre, open-label, randomised, controlled phase III trial in patients with OSA (apnoea-hypopnoea-index [AHI] 5-35 h-1), a BMI of 18.5-32 kg∗m-2, and a documented lack of adherence to CPAP therapy (<4 h∗night-1) at Guy's & St Thomas' NHS Foundation Trust (hospital), UK. Patients were randomly assigned (1:1) using minimisation (gender and OSA severity) to receive TESLA or usual care (CPAP) for at least 3 months; sleep study analysis was provided without knowledge of the assignment arm. The primary outcome was change in AHI at 3-months. The primary outcome and safety were analysed in the intention-to-treat population. Data are reported as median (interquartile range), unless otherwise explained. This trial is registered at ClinicalTrials.gov, NCT03160456. Findings: Between 6 June 2018 and 7 February 2023, 56 participants were enrolled and randomly assigned (29 patients in the intervention group and 27 in the usual care group). Patients were followed up for a median of 3.0 months (IQR 3.0; 10.0). The groups were similar in terms of age (55.8 (48.2; 66.0) vs 59.3 (47.8; 64.4) years), gender (male:female, 19:10 vs 18:9) and BMI (28.7 (26.4; 31.9) vs 28.4 (24.4; 31.9) kg∗m-2). The unadjusted group difference in the ΔAHI was -11.5 (95% CI -20.7; -2.3) h-1 (p = 0.016). Adjusted for the baseline value, the difference was ΔAHI -7.0 (-15.7; 1.8) h-1 (p = 0.12), in favour of the intervention. Minor adverse events were found in one of the participants who developed mild headaches related to the intervention. Interpretation: Domiciliary TESLA can be used safely and effectively in OSA patients with poor adherence to CPAP, with favourable impact on sleepiness and sleep fragmentation. Despite pandemic-related limitations of the amended protocol this trial provides the evidence that TESLA improves clinically meaningful outcomes over the observed follow up period, and the transcutaneous approach is likely to offer an affordable alternative for responders to electrical stimulation in clinical practice. Funding: British Lung Foundation, United Kingdom Clinical Research Collaboration-registered King's Clinical Trials Unit at King's Health Partners.

ERS International Congress 2022: highlights from the Respiratory Clinical Care and Physiology Assembly.

It is a challenge to keep abreast of all the clinical and scientific advances in the field of respiratory medicine. This article contains an overview of the laboratory-based science, clinical trials and qualitative research that were presented during the 2022 European Respiratory Society International Congress within the sessions from the five groups of Assembly 1 (Respiratory Clinical Care and Physiology). Selected presentations are summarised from a wide range of topics: clinical problems, rehabilitation and chronic care, general practice and primary care, mobile/electronic health (m-health/e-health), clinical respiratory physiology, exercise and functional imaging.

Respiratory complications of obesity: from early changes to respiratory failure.

Obesity is a significant and increasingly common cause of respiratory compromise. It causes a decrease in static and dynamic pulmonary volumes. The expiratory reserve volume is one of the first to be affected. Obesity is associated with reduced airflow, increased airway hyperresponsiveness, and an increased risk of developing pulmonary hypertension, pulmonary embolism, respiratory tract infections, obstructive sleep apnoea and obesity hypoventilation syndrome. The physiological changes caused by obesity will eventually lead to hypoxic or hypercapnic respiratory failure. The pathophysiology of these changes includes a physical load of adipose tissue on the respiratory system and a systemic inflammatory state. Weight loss has clear, well-defined benefits in improving respiratory and airway physiology in obese individuals.

Quality of life in patients with chronic respiratory failure on home mechanical ventilation.

Home mechanical ventilation (HMV) is a treatment for chronic respiratory failure that has shown clinical and cost effectiveness in patients with underlying COPD, obesity-related respiratory failure and neuromuscular disease (NMD). By treating chronic respiratory failure with adequate adherence to HMV, improvement in patient-reported outcomes including health-related quality of life (HRQoL) have been evaluated using general and disease-specific quantitative, semi-qualitative and qualitative methods. However, the treatment response in terms of trajectory of change in HRQoL is not uniform across the restrictive and obstructive disease groups. In this review, the effect of HMV on HRQoL across the domains of symptom perception, physical wellbeing, mental wellbeing, anxiety, depression, self-efficacy and sleep quality in stable and post-acute COPD, rapidly progressive NMD (such as amyotrophic lateral sclerosis), inherited NMD (including Duchenne muscular dystrophy) and obesity-related respiratory failure will be discussed.

Delivery of noninvasive ventilation to people living with motor neuron disease in the UK.

Objective: Noninvasive ventilation (NIV) improves survival and quality of life in motor neuron disease (MND), but many patients fail to receive effective ventilation. This study aimed to map the respiratory clinical care for MND patients at a service and individual healthcare professional (HCP) level to understand where attention may be needed to ensure all patients receive optimal care. Methods: Two online surveys of HCPs working with MND patients in the UK were conducted. Survey 1 targeted HCPs providing specialist MND care. Survey 2 targeted HCPs working in respiratory/ventilation services and community teams. Data were analysed using descriptive and inferential statistics. Results: Responses from 55 HCPs providing specialist MND care who worked at 21 MND care centres and networks and 13 Scotland Health Boards were analysed from Survey 1. Responses from 85 HCPs from respiratory/ventilation services and 73 HCPs from community teams, representing 97 services, were analysed from Survey 2. Significant differences in practice were identified at each stage of the respiratory care pathway as well as evidence of the need for improvement. This included when patients were referred to respiratory services, the time taken waiting to commence NIV, the availability of sufficient NIV equipment and provision of services, particularly out of hours. Conclusion: We have highlighted significant disparity in MND respiratory care practices. Increased awareness of the factors that influence NIV success and the performance of individuals and services is important for optimal practice.

The effect of transcutaneous electrical stimulation of the submental area on the cardiorespiratory response in normal and awake subjects.

Background: Electrical stimulation has recently been introduced to treat patients with Obstructive sleep apnoea There are, however, few data on the effects of transcutaneous submental electrical stimulation (TES) on the cardiovascular system. We studied the effect of TES on cardiorespiratory variables in healthy volunteers during head-down-tilt (HDT) induced baroreceptor loading. Method: Cardiorespiratory parameters (blood pressure, heart rate, respiratory rate, tidal volume, airflow/minute ventilation, oxygen saturation, and end-tidal CO2/O2 concentration) were recorded seated, supine, and during head-down-tilt (50) under normoxic, hypercapnic (FiCO2 5%) and poikilocapnic hypoxic (FiO2 12%) conditions. Blood pressure (BP) was measured non-invasively and continuously (Finapres). Gas conditions were applied in random order. All participants were studied twice on different days, once without and once with TES. Results: We studied 13 healthy subjects (age 29 (12) years, six female, body mass index (BMI) 23.23 (1.6) kg·m-2). A three-way ANOVA indicated that BP decreased significantly with TES (systolic: p = 4.93E-06, diastolic: p = 3.48E-09, mean: p = 3.88E-08). Change in gas condition (systolic: p = 0.0402, diastolic: p = 0.0033, mean: p = 0.0034) and different postures (systolic: 8.49E-08, diastolic: p = 6.91E-04, mean: p = 5.47E-05) similarly impacted on BP control. When tested for interaction, there were no significant associations between the three different factors electrical stimulation, gas condition, or posture, except for an effect on minute ventilation (gas condition/posture p = 0.0369). Conclusion: Transcutaneous electrical stimulation has a substantial impact on the blood pressure. Similarly, postural changes and variations in inspired gas impact on blood pressure control. Finally, there was an interaction between posture and inspired gases that affects minute ventilation. These observations have implications on our understanding of integrated cardiorespiratory control, and may prove beneficial for patients with SDB who are assessed for treatment with electrical stimulation.

Nocturnal continuous positive airway pressure offers symptomatic benefit in excessive dynamic airway collapse despite normal sleep study.

Excessive dynamic airway collapse (EDAC) and tracheobronchomalacia (TBM) cause debilitating symptoms yet are often misdiagnosed as asthma or chronic obstructive pulmonary disease (COPD). EDAC/TBM should be considered in all cases of obstructive ventilatory defect refractory to medical management. Diagnosis is made with flexible bronchoscopy and/or inspiratory and expiratory phase computed tomography (CT) scans. Treatment should be individualised and "pneumatic stenting" with the use of continuous positive airway pressure (CPAP) may lead to symptomatic relief, and in some cases regardless of the degree of collapse or absence of sleep disordered breathing in overnight oximetry. The case of a 63-year-old female referred to a tertiary respiratory department for a trial of CPAP due to EDAC is presented. Over the course of a few months, she had presented frequently to hospital with cough and shortness of breath which had been attributed to asthma. As she had not responded to treatment, an inpatient flexible bronchoscopy was performed which identified EDAC of the right main bronchus and she was referred to a tertiary ventilation department. Despite a normal sleep study whilst self-ventilating, nocturnal CPAP therapy significantly improved quality and duration of sleep, daytime symptoms and therefore quality of life. She was discharged with nocturnal CPAP and remains adherent to treatment.

Digital peer-to-peer support programme for informal caregivers of people living with motor neuron disease: study protocol for a multi-centre parallel group, single-blinded (outcome assessor) randomised controlled superiority trial.

BACKGROUND: Peer support is effective in improving psychological well-being of family caregivers of people with conditions such as dementia, cancer, and brain injury. However, there are limited data on effective psychological interventions for family caregivers of people living with motor neurone disease. Our objective is to evaluate the efficacy of a virtual peer support programme for improving caregiver psychological wellbeing and caregiving related outcomes. METHODS: We will conduct a multi-centre parallel group randomised controlled superiority trial. Using a multi-modal recruitment strategy, we will recruit informal caregivers from UK MND clinics, in-patient units, and hospices. We will randomise (1:1, stratified by gender) participants to either a 12-week virtual peer support programme or usual care comprising provision of online information resources publicly available via the MND Association website. Peer support programme elements will be delivered via a secure digital e-platform aTouchAway™ (Aetonix, Canada). Our target sample size is 160 (80 each arm). Our primary outcome is the Hospital Anxiety and Depression Scale (HADS) assessed at 12 weeks (primary endpoint). Secondary outcomes that will also be assessed at 12 weeks include the Zarit Burden Interview, Pearlin Mastery Scale, Personal Gain Scale, Positive Affect Scale, and the Brief COPE. Outcome assessors will be blinded to allocation. Tertiary outcomes include perceived usability (1 item 9-point Likert scale) and acceptability (semi-structured qualitative interviews) of the peer support programme. Intervention fidelity measures will comprise frequency, type (text, audio, video), and duration (audio and video) of peer support contact downloaded from the aTouchAway AWS server. We will use a mixed-effects linear model to test the effect of the intervention on the primary outcome. Secondary outcomes will be analysed using linear regression. We have ethical approval (21/NW/0269) from the North-West Research Ethics Committee, UK. DISCUSSION: This single-blinded randomised controlled trial will determine the effect of a virtual peer support programme on caregiver psychological wellbeing and caregiver burden. This study will examine the impact of a virtual peer support intervention on quality-of-life measures in informal caregivers of individuals with MND living in the community. TRIAL REGISTRATION: ClinicalTrials.gov: NCT04695210.

Cost-effectiveness of outpatient versus inpatient non-invasive ventilation setup in obesity hypoventilation syndrome: the OPIP trial.

BACKGROUND: Current guidelines recommend that patients with obesity hypoventilation syndrome (OHS) are electively admitted for inpatient initiation of home non-invasive ventilation (NIV). We hypothesised that outpatient NIV setup would be more cost-effective. METHODS: Patients with stable OHS referred to six participating European centres for home NIV setup were recruited to an open-labelled clinical trial. Patients were randomised via web-based system using stratification to inpatient setup, with standard fixed level NIV and titrated during an attended overnight respiratory study or outpatient setup using an autotitrating NIV device and a set protocol, including home oximetry. The primary outcome was cost-effectiveness at 3 months with daytime carbon dioxide (PaCO2) as a non-inferiority safety outcome; non-inferiority margin 0.5 kPa. Data were analysed on an intention-to-treat basis. Health-related quality of life (HRQL) was measured using EQ-5D-5L (5 level EQ-5D tool) and costs were converted using purchasing power parities to £(GBP). RESULTS: Between May 2015 and March 2018, 82 patients were randomised. Age 59±14 years, body mass index 47±10 kg/m2 and PaCO2 6.8±0.6 kPa. Safety analysis demonstrated no difference in ∆PaCO2 (difference -0.27 kPa, 95% CI -0.70 to 0.17 kPa). Efficacy analysis showed similar total per-patient costs (inpatient £2962±£580, outpatient £3169±£525; difference £188.20, 95% CI -£61.61 to £438.01) and similar improvement in HRQL (EQ-5D-5L difference -0.006, 95% CI -0.05 to 0.04). There were no differences in secondary outcomes. DISCUSSION: There was no difference in medium-term cost-effectiveness, with similar clinical effectiveness, between outpatient and inpatient NIV setup. The home NIV setup strategy can be led by local resource demand and patient and clinician preference. TRIAL REGISTRATION NUMBERS: NCT02342899 and ISRCTN51420481.

ERS International Congress 2021: highlights from the Respiratory Clinical Care and Physiology Assembly.

It is a challenge to keep abreast of all the clinical and scientific advances in the field of respiratory medicine. This article contains an overview of laboratory-based science, randomised controlled trials and qualitative research that were presented during the 2021 European Respiratory Society International Congress within the sessions from the five groups of the Assembly 1 - Respiratory clinical care and physiology. Selected presentations are summarised from a wide range of topics: clinical problems, rehabilitation and chronic care, general practice and primary care, electronic/mobile health (e-health/m-health), clinical respiratory physiology, exercise and functional imaging.

The Value of Dyspnea and Spirometry in Detecting Relapse of Benign Tracheal Stenosis.

BACKGROUND: Benign tracheal stenosis may relapse after management. OBJECTIVES: This study aimed to assess the value of dyspnea and spirometry in detecting relapse of benign tracheal stenosis. METHODS: Patients with benign tracheal stenosis were evaluated post-management, at regular follow-up and emergency visits, with the Medical Research Council (MRC) dyspnea scale, spirometry, and flexible bronchoscopy. Patient visits were categorized and compared, in terms of change in clinical and functional parameters, in 2 groups: visits with relapse (case group) and visits with no relapse (control group). The ability of the MRC dyspnea scale and spirometry to predict relapse was evaluated. RESULTS: Thirty-five patients with benign tracheal stenosis were included. Mean follow-up duration was 3.2 years (standard deviation = 3.3). Spirometry data were analyzed from 43 relapse visits (23 patients) versus 90 nonrelapse visits. The MRC dyspnea score and most spirometric indices were associated with relapse. In the receiver operating characteristic analysis, forced expiratory volume in 1 s, forced expiratory flow when 25% of forced vital capacity has been expired, peak expiratory flow (PEF), and total peak flow were superior to the MRC dyspnea score in predicting relapse. Among spirometric indices, >10.8% of PEF reduction has been very sensitive and specific. CONCLUSIONS: This study supports the role of dyspnea and spirometry in monitoring benign tracheal stenosis, with spirometry predicting relapse even in clinically stable patients. PEF being a very sensitive index has the additional advantage of being assessed by peak flow meter and could potentially be used for remote monitoring.

Telemedicine in the management of patients with chronic respiratory failure.

Patients with chronic respiratory failure are often required to attend multiple hospital appointments, which may be difficult due to their physical disabilities and the amount of equipment they are required to bring. Their caregivers often struggle with the lack of immediate care available when the patient suffers difficulties at home. Telemedicine is an opportunity to bridge the gap between home and healthcare professionals by allowing the healthcare team to reach into patients' homes to provide more frequent support. The evidence for the use of telemedicine in patients with chronic respiratory failure remains equivocal. Although the uptake of telemedicine has been slow, the SARS-CoV-2 pandemic has resulted in the rapid dissemination of telemedicine to allow the delivery of care to vulnerable patients while reducing the need for their attendance in hospital. Logistical and legal challenges to the delivery of telemedicine remain, but the pandemic may serve as a driver to ameliorate these challenges and facilitate wider use of this technology to improve the experience of patients with chronic respiratory failure. EDUCATIONAL AIMS: To provide an overview of the rationale for delivering care via telemedicine for patients with chronic respiratory failure.To provide the evidence base for establishing a telemedicine service.To highlight the potential opportunities and challenges in delivering a telemedicine service for patients with chronic respiratory failure.

Home parasternal electromyography tracks patient-reported and physiological measures of recovery from severe COPD exacerbation.

Physiological phenotyping using daily home-based assessments reveals early improvement in load-capacity-drive imbalance following #AECOPD and feasibility of home parasternal electromyography measurement, which tracks symptoms, health status and spirometry https://bit.ly/3o6I0Ty.