Future directions for respiratory muscle training in neuromuscular disorders: a scoping review.

BACKGROUND: Respiratory muscle training (RMT) aims to improve inspiratory and/or expiratory muscle function in neuromuscular disorders (NMDs). A comprehensive overview of the available literature is lacking. This scoping review explores methodological characteristics, (adverse) effects, and adherence of RMT studies in NMDs. Moreover, it identifies limitations and research gaps in the literature, and provides future research directions. SUMMARY: Eligible studies were identified using MEDLINE, Embase, Cochrane Database of Systematic Reviews, and Cochrane Central Register of Controlled Trials databases Three reviewers independently selected articles. Inclusion criteria were English language, original research articles on RMT using a device, patients with an NMD, and pulmonary function tests or respiratory muscle strength as outcome measures. We included NMDs with slow, intermediate and fast progression. Exclusion criteria were critically ill patients, weaning from mechanical ventilation, other neurological disorders, and RMT combined with non-respiratory interventions. One reviewer extracted the data on patients characteristics, methodological characteristics, results of outcome measures, adverse events, and patient adherence. Forty-five studies were identified. We found a large diversity in study designs and training protocols. The effects of RMT on respiratory muscle strength and/or endurance are variable. Patient adherence was high and no serious adverse events were reported. KEY MESSAGES: The diversity in studies across the available literature precludes definitive conclusions regarding effects of RMT on respiratory muscle function and clinically relevant outcomes in NMDs. Therefore, well-powered and -designed studies that focus on clinically relevant outcomes and assess whether RMT can improve or offset deterioration of respiratory muscle weakness in NMDs are needed.

Validity and reliability of the Dutch version of the S3-NIV questionnaire to evaluate long-term noninvasive ventilation.

OBJECTIVES: Noninvasive ventilation (NIV) is an effective treatment for chronic respiratory failure (CRF). Patient-centered outcomes need to be evaluated regularly and the S3-NIV questionnaire seems an applicable tool. We translated this short, self-administered questionnaire into a Dutch version and tested its construct validity and reliability. METHODS: An observational study was conducted, including 127 stable long-term NIV users with CRF or complex sleep related breathing disorders due to different underlying diseases: chronic obstructive pulmonary disease (25%), slowly progressive neuromuscular disorders (35%), rapidly progressive neuromuscular disorders (12%) and 'other disorders' (28%) including complex sleep apnea and obesity hypoventilation syndrome. Construct validity and reliability were tested. RESULTS: The Dutch version of the questionnaire was obtained after a translation and back-translation process. Internal consistency of the total score was good (Cronbach's α coefficient of 0.78) as well as for the 'respiratory symptoms' subdomain and the 'sleep and side effects' subdomain (Cronbach's α coefficient of 0.78 and 0.69, respectively). The reproducibility was excellent with an intraclass correlation of 0.89 (95% CI 0.87-0.93). Construct validity was good for the 'respiratory symptoms' subdomain. CONCLUSION: The Dutch S3-NIV questionnaire is a reliable and valid tool to evaluate symptoms, sleep, and NIV related side effects in long-term NIV users.

Clinical practice of non-invasive ventilation for acute exacerbations of chronic obstructive pulmonary disease.

BACKGROUND: Non-invasive ventilation (NIV) is an evidence-based treatment for acute respiratory failure in chronic obstructive pulmonary disease (COPD). However, suboptimal application of NIV in clinical practice, possibly due to poor guideline adherence, can impact patient outcomes. This study aims to evaluate guideline adherence to NIV for acute COPD exacerbations and explore its impact on mortality. METHODS: This retrospective study was performed in two Dutch medical centers from 2019 to 2021. All patients admitted to the pulmonary ward or intensive care unit with a COPD exacerbation were included. An indication for NIV was considered in the event of a respiratory acidosis. RESULTS: A total of 1162 admissions (668 unique patients) were included. NIV was started in 154 of the 204 admissions (76%) where NIV was indicated upon admission. Among 78 admissions where patients deteriorated later on, NIV was started in 51 admissions (65%). Considering patients not receiving NIV due to contra-indications or patient refusal, the overall guideline adherence rate was 82%. Common reasons for not starting NIV when indicated included no perceived signs of respiratory distress, opting for comfort care only, and choosing a watchful waiting approach. Better survival was observed in patients who received NIV when indicated compared to those who did not. CONCLUSIONS: The adherence to guidelines regarding NIV initiation is good. Nevertheless, further improving NIV treatment in clinical practice could be achieved through training healthcare professionals to increase awareness and reduce reluctance in utilizing NIV. By addressing these factors, patient outcomes may be further enhanced.

Building a home ventilation programme: population, equipment, delivery and cost.

Home mechanical ventilation (HMV) improves quality of life and survival in patients with neuromuscular disorders (NMD). Developing countries may benefit from published evidence regarding the prevalence, cost of equipment, technical issues and organisation of HMV in NMD, facilitating the development of local turn-key HMV programmes. Unfortunately, such evidence is scattered in the existing literature. We searched Medline for publications in English and French from 2005 to 2020. This narrative review analyses 24 international programmes of HMV. The estimated prevalence (min-max) of HMV is ±7.3/100 000 population (1.2-47), all disorders combined. The prevalence of HMV is associated with the gross domestic product per capita in these 24 countries. The prevalence of NMD is about 30/100 000 population, of which ±10% would use HMV. Nocturnal (8/24 hour), discontinuous (8-16/24 hours) and continuous (>16/24 hours) ventilation is likely to concern about 60%, 20% and 20% of NMD patients using HMV. A minimal budget of about 168€/patient/year (504€/100 000 population), including the cost of equipment solely, should address the cost of HMV equipment in low-income countries. When services and maintenance are included, the budget can drastically increase up to between 3232 and 5760€/patient/year. Emerging programmes of HMV in developing countries reveal the positive impact of international cooperation. Today, at least 12 new middle, and low-income countries are developing HMV programmes. This review with updated data on prevalence, technical issues, cost of equipment and services for HMV should trigger objective dialogues between the stakeholders (patient associations, healthcare professionals and politicians); potentially leading to the production of workable strategies for the development of HMV in patients with NMD living in developing countries.

Diaphragm Pacing in Patients with Spinal Cord Injury: A European Experience.

BACKGROUND: Patients with high spinal cord injury (SCI) are unable to breathe on their own and require mechanical ventilation (MV). The long-term use of MV is associated with increased morbidity and mortality. In patients with intact phrenic nerve function, patients can be partially or completely removed from MV by directly stimulating the diaphragm motor points with a diaphragm pacing system (DPS). OBJECTIVES: We describe our multicenter European experience using DPS in SCI patients who required MV. METHODS: We conducted a retrospective study of patients who were evaluated for the implantation of DPS. Patients evaluated for DPS who met the prospectively defined criteria of being at least 1 year of age, and having cervical injury resulting in a complete or partial dependency on MV were included. Patients who received DPS implants were followed for up to 1 year for device usage and safety. RESULTS: Across 3 centers, 47 patients with high SCI were evaluated for DPS, and 34 were implanted. Twenty-one patients had 12 months of follow-up data with a median DPS use of 15 h/day (interquartile range 4, 24). Eight patients (38.1%) achieved complete MV weaning using DPS 24 h/day. Two DPS-related complications were surgical device revision and a wire eruption. No other major complications were associated with DPS use. CONCLUSIONS: Diaphragm pacing represents an attractive alternative stand-alone treatment or adjunctive therapy compared to MV in patients with high SCI. After a period of acclimation, the patients were able to reduce the daily use of MV, and many could be completely removed from MV.

Nasal versus oronasal masks for home non-invasive ventilation in patients with chronic hypercapnia: a systematic review and individual participant data meta-analysis.

BACKGROUND: The optimal interface for the delivery of home non-invasive ventilation (NIV) to treat chronic respiratory failure has not yet been determined. The aim of this individual participant data (IPD) meta-analysis was to compare the effect of nasal and oronasal masks on treatment efficacy and adherence in patients with COPD and obesity hypoventilation syndrome (OHS). METHODS: We searched Medline and Cochrane Central Register of Controlled Trials for prospective randomised controlled trials (RCTs) of at least 1 month's duration, published between January 1994 and April 2019, that assessed NIV efficacy in patients with OHS and COPD. The main outcomes were diurnal PaCO2, PaO2 and NIV adherence (PROSPERO CRD42019132398). FINDINGS: Of 1576 articles identified, 34 RCTs met the inclusion criteria and IPD were obtained for 18. Ten RCTs were excluded because only one type of mask was used, or mask data were missing. Data from 8 RCTs, including 290 IPD, underwent meta-analysis. Oronasal masks were used in 86% of cases. There were no differences between oronasal and nasal masks for PaCO2 (0.61 mm Hg (95% CI -2.15 to 3.38); p=0.68), PaO2 (-0.00 mm Hg (95% CI -4.59 to 4.58); p=1) or NIV adherence (0·29 hour/day (95% CI -0.74 to 1.32); p=0.58). There was no interaction between the underlying pathology and the effect of mask type on any outcome. INTERPRETATION: Oronasal masks are the most used interface for the delivery of home NIV in patients with OHS and COPD; however, there is no difference in the efficacy or tolerance of oronasal or nasal masks.

Chronic non-invasive ventilation for chronic obstructive pulmonary disease.

BACKGROUND: Chronic non-invasive ventilation (NIV) is increasingly being used to treat people with COPD who have respiratory failure, but the evidence supporting this treatment has been conflicting. OBJECTIVES: To assess the effects of chronic non-invasive ventilation at home via a facial mask in people with COPD, using a pooled analysis of IPD and meta-analysis. SEARCH METHODS: We searched the Cochrane Airways Register of Trials, MEDLINE, Embase, PsycINFO, CINAHL, AMED, proceedings of respiratory conferences, clinical trial registries and bibliographies of relevant studies. We conducted the latest search on 21 December 2020. SELECTION CRITERIA: We included randomised controlled trials (RCTs) comparing chronic NIV for at least five hours per night for three consecutive weeks or more (in addition to standard care) versus standard care alone, in people with COPD. Studies investigating people initiated on NIV in a stable phase and studies investigating NIV commenced after a severe COPD exacerbation were eligible, but we reported and analysed them separately. The primary outcomes were arterial blood gases, health-related quality of life (HRQL), exercise capacity (stable COPD) and admission-free survival (post-exacerbation COPD). Secondary outcomes for both populations were: lung function, COPD exacerbations and admissions, and all-cause mortality. For stable COPD, we also reported respiratory muscle strength, dyspnoea and sleep efficiency. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. After inclusion of a study, we requested the IPD. We analysed continuous and time-to-event data using linear- and cox-regression mixed-effect models with a random effect on study level. We analysed dichotomous IPD using generalised estimating equations. We adjusted all models for age and sex. We assessed changes in outcomes after three and 12 months.  We also conducted a meta-analysis on aggregated trial data. MAIN RESULTS: We included 14 new RCTs in this review update, in addition to the seven previously included. Seventeen studies investigated chronic NIV in stable COPD and four studies investigated chronic NIV commenced after a severe COPD exacerbation. Three studies compared NIV to sham continuous positive airway pressure (2 to 4 cmH2O). Seven studies used a nasal mask, one study used an oronasal mask and eight studies used both interfaces. Five studies did not report the interface. The majority of trials (20/21) were at high risk of performance bias due to an unblinded design. We considered 11 studies to have a low risk of selection bias and 13 to have a low risk of attrition bias. We collected and analysed the IPD from 13 stable COPD studies (n = 778, 68% of the participants included) and from three post-exacerbation studies (n = 364, 96% of the participants included). In the stable COPD group, NIV probably results in a minor benefit on the arterial partial pressure of oxygen (PaO2) after three months (adjusted mean difference (AMD) 0.27 kPa, 95% CI 0.04 to 0.49; 9 studies, 271 participants; moderate-certainty evidence), but there was little to no benefit at 12 months (AMD 0.09 kPa, 95% CI -0.23 to 0.42; 3 studies, 171 participants; low-certainty evidence). The arterial partial pressure of carbon dioxide (PaCO2) was reduced in participants allocated to NIV after three months (AMD -0.61 kPa, 95% CI -0.77 to -0.45; 11 studies, 475 participants; high-certainty evidence) and persisted up to 12 months (AMD -0.42 kPa, 95% CI -0.68 to -0.16; 4 studies, 232 participants; high-certainty evidence).  Exercise capacity was measured with the 6-minute walking distance (minimal clinical important difference: 26 m). There was no clinically relevant effect of NIV on exercise capacity (3 months: AMD 15.5 m, 95% CI -0.8 to 31.7; 8 studies, 330 participants; low-certainty evidence; 12 months: AMD 26.4 m, 95% CI -7.6 to 60.5; 3 studies, 134 participants; very low-certainty evidence). HRQL was measured with the Severe Respiratory Insufficiency and the St. Georges's Respiratory Questionnaire and may be improved by NIV, but only after three months (3 months: standardised mean difference (SMD) 0.39, 95% CI 0.15 to 0.62; 5 studies, 259 participants; very low-certainty evidence; 12 months: SMD 0.15, 95% CI -0.13 to 0.43; 4 studies, 200 participants; very low-certainty evidence). Lastly, the risk for all-cause mortality is likely reduced by NIV (adjusted hazard ratio (AHR) 0.75, 95% CI 0.58 to 0.97; 3 studies, 405 participants; moderate-certainty evidence). In the post-exacerbation COPD group, there was little to no benefit on the PaO2 after three months, but there may be a slight decrease after 12 months (3 months: AMD -0.10 kPa, 95% CI -0.65 to 0.45; 3 studies, 234 participants; low-certainty evidence; 12 months: -0.27 kPa, 95% CI -0.86 to 0.32, 3 studies; 170 participants; low-certainty evidence). The PaCO2 was reduced by NIV at both three months (AMD -0.40 kPa, 95% CI -0.70 to -0.09; 3 studies, 241 participants; moderate-certainty evidence) and 12 months (AMD -0.52 kPa, 95% CI -0.87 to -0.18; 3 studies, 175 participants; high-certainty evidence). NIV may have little to no benefit on HRQL (3 months: SMD 0.25, 95% CI -0.01 to 0.51; 2 studies, 219 participants; very low-certainty evidence; 12 months: SMD 0.25, 95% -0.06 to 0.55; 2 studies, 164 participants; very low-certainty evidence). Admission-free survival seems improved with NIV (AHR 0.71, 95% CI 0.54 to 0.94; 2 studies, 317 participants; low-certainty evidence), but the risk for all-cause mortality does not seem to improve (AHR 0.97, 95% CI 0.74 to 1.28; 2 studies, 317 participants; low-certainty evidence). AUTHORS' CONCLUSIONS: Regardless of the timing of initiation, chronic NIV improves daytime hypercapnia. In addition, in stable COPD, survival seems to be improved and there might be a short term HRQL benefit. In people with persistent hypercapnia after a COPD exacerbation, chronic NIV might prolong admission-free survival without a beneficial effect on HRQL. In stable COPD, future RCTs comparing NIV to a control group receiving standard care might no longer be warranted, but research should focus on identifying participant characteristics that would define treatment success. Furthermore, the optimal timing for initiation of NIV after a severe COPD exacerbation is still unknown.

Long-Term Noninvasive Ventilation in Chronic Stable Hypercapnic Chronic Obstructive Pulmonary Disease. An Official American Thoracic Society Clinical Practice Guideline.

Background: Noninvasive ventilation (NIV) is used for patients with chronic obstructive pulmonary disease (COPD) and chronic hypercapnia. However, evidence for clinical efficacy and optimal management of therapy is limited.Target Audience: Patients with COPD, clinicians who care for them, and policy makers.Methods: We summarized evidence addressing five PICO (patients, intervention, comparator, and outcome) questions. The GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach was used to evaluate the certainty in evidence and generate actionable recommendations. Recommendations were formulated by a panel of pulmonary and sleep physicians, respiratory therapists, and methodologists using the Evidence-to-Decision framework.Recommendations:1) We suggest the use of nocturnal NIV in addition to usual care for patients with chronic stable hypercapnic COPD (conditional recommendation, moderate certainty); 2) we suggest that patients with chronic stable hypercapnic COPD undergo screening for obstructive sleep apnea before initiation of long-term NIV (conditional recommendation, very low certainty); 3) we suggest not initiating long-term NIV during an admission for acute-on-chronic hypercapnic respiratory failure, favoring instead reassessment for NIV at 2-4 weeks after resolution (conditional recommendation, low certainty); 4) we suggest not using an in-laboratory overnight polysomnogram to titrate NIV in patients with chronic stable hypercapnic COPD who are initiating NIV (conditional recommendation, very low certainty); and 5) we suggest NIV with targeted normalization of PaCO2 in patients with hypercapnic COPD on long-term NIV (conditional recommendation, low certainty).Conclusions: This expert panel provides evidence-based recommendations addressing the use of NIV in patients with COPD and chronic stable hypercapnic respiratory failure.

Home initiation of chronic non-invasive ventilation in COPD patients with chronic hypercapnic respiratory failure: a randomised controlled trial.

INTRODUCTION: Chronic non-invasive ventilation (NIV) has become evidence-based care for stable hypercapnic COPD patients. While the number of patients increases, home initiation of NIV would greatly alleviate the healthcare burden. We hypothesise that home initiation of NIV with the use of telemedicine in stable hypercapnic COPD is non-inferior to in-hospital NIV initiation. METHODS: Sixty-seven stable hypercapnic COPD patients were randomised to initiation of NIV in the hospital or at home using telemedicine. Primary outcome was daytime arterial carbon dioxide pressure (PaCO2) reduction after 6 months NIV, with a non-inferiority margin of 0.4 kPa. Secondary outcomes were health-related quality of life (HRQoL) and costs. RESULTS: Home NIV initiation was non-inferior to in-hospital initiation (adjusted mean difference in PaCO2 change home vs in-hospital: 0.04 kPa (95% CI -0.31 to 0.38 kPa), with both groups showing a PaCO2 reduction at 6 months compared with baseline (home: from 7.3±0.9 to 6.4±0.8 kPa (p<0.001) and in-hospital: from 7.4±1.0 to 6.4±0.6 kPa (p<0.001)). In both groups, HRQoL improved without a difference in change between groups (Clinical COPD Questionnaire total score-adjusted mean difference 0.0 (95% CI -0.4 to 0.5)). Furthermore, home NIV initiation was significantly cheaper (home: median €3768 (IQR €3546-€4163) vs in-hospital: median €8537 (IQR €7540-€9175); p<0.001). DISCUSSION: This is the first study showing that home initiation of chronic NIV in stable hypercapnic COPD patients, with the use of telemedicine, is non-inferior to in-hospital initiation, safe and reduces costs by over 50%. TRIAL REGISTRATION NUMBER: NCT02652559.

Dental side effects of long-term obstructive sleep apnea therapy: a 10-year follow-up study.

OBJECTIVES: Patients with obstructive sleep apnea (OSA) are usually treated with either mandibular advancement device (MAD) or continuous positive airway pressure (CPAP) therapy. The objective of this study is to evaluate changes in dental occlusion associated with long-term MAD and CPAP therapy. MATERIALS AND METHODS: Data from 14 OSA patients using MAD and 17 OSA patients using CPAP therapy were evaluated at baseline, 2-year and 10-year follow-up. Changes in dental occlusion were analyzed from dental plaster casts with a digital sliding caliper. RESULTS: At 2-year follow-up, MAD therapy resulted in significant dental changes when compared with baseline values. In MAD therapy, overjet and overbite decreased with 1.1 ± 1.8 mm and 1.1 ± 1.2 mm respectively. With CPAP therapy overjet and overbite decreased significantly with 0.2 ± 0.5 mm and 0.3 ± 0.5 mm, respectively. Both groups also showed significant changes in molar occlusion. After a 10-year follow-up, significant and more pronounced changes were seen in overjet and overbite. In MAD therapy, overjet and overbite decreased with 3.5 ± 1.5 mm and 2.9 ± 1.5 mm respectively when compared with baseline values. In CPAP therapy, overjet and overbite decreased with 0.7 ± 1.5 mm and 0.8 ± 1.4 mm respectively when compared with baseline values. CONCLUSIONS: This study demonstrates that MAD and CPAP therapy result in significant changes in dental occlusion. These changes appear progressive and more pronounced with MAD compared to CPAP therapy. CLINICAL RELEVANCE: Long-term OSA treatment results in significant dental side effects that may progress over time. Informed consent is fundamental before starting MAD treatment and individualized long-term follow-up is of eminent importance.

An Official American Thoracic Society/European Respiratory Society Policy Statement: Enhancing Implementation, Use, and Delivery of Pulmonary Rehabilitation.

RATIONALE: Pulmonary rehabilitation (PR) has demonstrated physiological, symptom-reducing, psychosocial, and health economic benefits for patients with chronic respiratory diseases, yet it is underutilized worldwide. Insufficient funding, resources, and reimbursement; lack of healthcare professional, payer, and patient awareness and knowledge; and additional patient-related barriers all contribute to the gap between the knowledge of the science and benefits of PR and the actual delivery of PR services to suitable patients. OBJECTIVES: The objectives of this document are to enhance implementation, use, and delivery of pulmonary rehabilitation to suitable individuals worldwide. METHODS: Members of the American Thoracic Society (ATS) Pulmonary Rehabilitation Assembly and the European Respiratory Society (ERS) Rehabilitation and Chronic Care Group established a Task Force and writing committee to develop a policy statement on PR. The document was modified based on feedback from expert peer reviewers. After cycles of review and revisions, the statement was reviewed and formally approved by the Board of Directors of the ATS and the Science Council and Executive Committee of the ERS. MAIN RESULTS: This document articulates policy recommendations for advancing healthcare professional, payer, and patient awareness and knowledge of PR, increasing patient access to PR, and ensuring quality of PR programs. It also recommends areas of future research to establish evidence to support the development of an updated funding and reimbursement policy regarding PR. CONCLUSIONS: The ATS and ERS commit to undertake actions that will improve access to and delivery of PR services for suitable patients. They call on their members and other health professional societies, payers, patients, and patient advocacy groups to join in this commitment.

Validity and Predictive Value of a Portable Two-Channel Sleep-Screening Tool in the Identification of Sleep Apnea in Patients With Heart Failure.

BACKGROUND: Sleep apnea is an important comorbidity in heart failure (HF) and is associated with an adverse outcome. Diagnosing sleep apnea is difficult, and polysomnography, considered to be the criterion standard, is not widely available. We assessed the validity of a portable 2-channel sleep-screening tool for the identification of sleep apnea in patients with HF. METHODS AND RESULTS: One hundred patients with stable HF had simultaneous recordings of home-based polysomnography and the screening tool (Apnealink). To compare the apnea-hypopnea index of the screening tool with polysomnography, intraclass correlation (ICC), sensitivity, and specificity were calculated, and a Bland-Altman plot and receiver operating characteristic (ROC) curves were constructed. Ninety valid measurements with the screening tool were obtained (mean age 65.5 ± 11.0 y, 72% male, mean left ventricular ejection fraction 34.6 ± 11.0%). Agreement between the screening tool and polysomnography was high (ICC 0.85). The optimal cutoff value was apnea-hypopnea index ≥15/h (area under the ROC curve 0.94). Sensitivity and specificity were 92.9% and 91.9%, respectively. CONCLUSIONS: The screening tool is useful in excluding the presence of sleep apnea in HF patients to refer only high-risk patients for more extensive polysomnography. This method may potentially reduce the need for the more expensive polysomnography.

Changes in the endurance shuttle walk test in COPD patients with chronic respiratory failure after pulmonary rehabilitation: the minimal important difference obtained with anchor- and distribution-based method.

BACKGROUND: Although the endurance shuttle walk test (ESWT) has proven to be responsive to change in exercise capacity after pulmonary rehabilitation (PR) for COPD, the minimally important difference (MID) has not yet been established. We aimed to establish the MID of the ESWT in patients with severe COPD and chronic hypercapnic respiratory failure following PR. METHODS: Data were derived from a randomized controlled trial, investigating the value of noninvasive positive pressure ventilation added to PR. Fifty-five patients with stable COPD, GOLD stage IV, with chronic respiratory failure were included (mean (SD) FEV1 31.1 (12.0) % pred, age 62 (9) y). MID estimates of the ESWT in seconds, percentage and meters change were calculated with anchor based and distribution based methods. Six minute walking distance (6MWD), peak work rate on bicycle ergometry (Wpeak) and Chronic Respiratory Questionnaire (CRQ) were used as anchors and Cohen's effect size was used as distribution based method. RESULTS: The estimated MID of the ESWT with the different anchors ranged from 186-199 s, 76-82% and 154-164 m. Using the distribution based method the MID was 144 s, 61% and 137 m. CONCLUSIONS: Estimates of the MID for the ESWT after PR showed only small differences using different anchors in patients with COPD and chronic respiratory failure. Therefore we recommend using a range of 186-199 s, 76-82% or 154-164 m as MID of the ESWT in COPD patients with chronic respiratory failure. Further research in larger populations should elucidate whether this cut-off value is also valid in other COPD populations and with other interventions. TRIAL REGISTRATION: ClinicalTrials.Gov (ID NCT00135538).

Oral appliance to assist non-invasive ventilation in a patient with amyotrophic lateral sclerosis.

BACKGROUND: From the moment the respiratory muscle groups are affected in amyotrophic lateral sclerosis (ALS), respiratory complications will be the major cause of morbidity and mortality. Untreated respiratory muscle impairment leads to respiratory insufficiency and additionally to difficulties in airway secretion clearance. Non-invasive ventilation (NIV) is the first choice in treating respiratory insufficiency in ALS as it improves sleep-related symptoms, quality of life and life expectancy. Nevertheless, NIV is not always effective, probably due to bulbar dysfunction or anatomical abnormalities. As a result, tracheostomy ventilation (TV) may become necessary. METHODS: In this case report, we present a 60-year-old female with ALS, for whom it was not possible to provide a sufficient tidal volume with NIV. A chin lift was performed while the patient was awake to see if a more anterior jaw position would lead to an increased tidal volume. As this was the case, a mandibular advancement device (MAD) was fabricated. RESULTS: With a combination of a MAD and NIV, the upper airway obstructions were overcome and a good ventilation and adherence to therapy were seen. CONCLUSIONS: When there is the presumption of airway obstructions in combination with an ineffective NIV, we advise to perform a chin lift to assess whether the obstructions can be overcome by a more anterior jaw position. If that is the case, NIV may be combined with MAD to establish effective ventilation and avoid the use of TV.

Co-morbidities in heart failure.

Heart failure is a clinical syndrome characterized by poor quality of life and high morbidity and mortality. Co-morbidities frequently accompany heart failure and further decrease in both quality of life and clinical outcome. We describe that the prevalence of co-morbidities in patients with heart failure is much higher compared to age-matched controls. We will specifically address the most studied organ-related co-morbidities, that is, renal dysfunction, cerebral dysfunction, anaemia, liver dysfunction, chronic obstructive pulmonary disease, diabetes mellitus and sleep apnoea. The pathophysiologic processes underlying the interaction between heart failure and co-morbid conditions are complex and remain largely unresolved. Although common risk factors are likely to contribute, it is reasonable to believe that factors associated with heart failure might cause other co-morbid conditions. Inflammation, neurohumoral pathway activation and hemodynamic changes are potential factors. We try to provide explanations for the observed association between co-morbidities and heart failure, as well as its impact on survival.

On the relation between tidal and forced spirometry.

Spirometry is a lung function test involving deep inhalation and forceful deep exhalation. It is widely used to obtain objective information about airflow limitation and to diagnose lung diseases. In contrast, tidal spirometry is based on normal breathing and therefore much more convenient, but it is hardly used in medical care and its relation with conventional (forced) spirometry is largely unknown. Therefore, the objective of this work is to reveal the relation between tidal and forced spirometry. Employing the strong correspondence between the forced flow-volume curves and the Tiffeneau-Pinelli (TP) index, we present a method to obtain (a) the expected tidal flow-volume curve for a given TP-index, and (b) the expected TP-index for a given tidal curve. For patients with similar values of the TP-index, the tidal curves show a larger spread than the forced curves, but their average shape varies in a characteristic way with varying index. Therefore, just as with forced curves, the TP-index provides a useful objective ranking of the average of tidal curves: upon decreasing TP-index the expiratory flow rate changes in that its peak shifts towards smaller expiratory volumes, and its post-peak part becomes dented.

Respiratory function in LAMA2-related muscular dystrophy and SELENON-related congenital myopathy, a 1.5-year natural history study.

INTRODUCTION: LAMA2-related muscular dystrophy (LAMA2-MD) and SELENON(SEPN1)-related congenital myopathy (SELENON-RM) are rare neuromuscular diseases with respiratory impairment from a young age. Prospective natural history studies are needed for prevalence estimations, respiratory characterization, optimizing clinical care and selecting outcome measures for trial readiness. METHODS: Our prospective 1.5-year natural history study included spirometry (forced vital capacity (FVC); difference between upright and supine vital capacity (dVC)), respiratory muscle strength tests (sniff nasal inspiratory pressure (SNIP)) (age≥5 years), and diaphragm ultrasound (thickness; thickening; echogenicity; all ages). RESULTS: Twenty-six LAMA2-MD patients (M = 8, median 21 [9; 31] years) and 11 SELENON-RM patients (M = 8, 20 [10; 33] years) were included. At baseline, 17 (85 %) LAMA2-MD (FVC%: 59 % [33; 68]) and all SELENON-RM patients (FVC%: 34 % [31; 46]) had an impaired respiratory function (FVC%<80 %). Nine (35 %) LAMA2-MD and eight (73 %) SELENON-RM patients received mechanical ventilation at baseline, and two additional SELENON-RM patients started during follow-up. Contrarily to LAMA2-MD, SELENON-RM patients had severe diaphragm atrophy (diaphragm thickness z-score: 2.5 [-3.1; -2.1]) and dysfunction (diaphragm thickness ratio: 1.2 [1.0; 1.7]; dVC: 30 % [7.7; 41]). SNIP was low in both neuromuscular diseases and correlated with motor function. In SELENON-RM, respiratory function decreased during follow-up. CONCLUSION: The majority of LAMA2-MD and all SELENON-RM patients had respiratory impairment. SELENON-RM patients showed lower respiratory function which was progressive, more prevalent mechanical ventilation, and more severe diaphragm atrophy and dysfunction than LAMA2-MD patients. Spirometry (FVC%, dVC) and respiratory muscle strength tests (SNIP) are useful in clinical care and as outcome measure in clinical trials. CLINICAL TRIAL NUMBER: NCT04478981.