Twenty-four hour noninvasive ventilation in Duchenne muscular dystrophy: a safe alternative to tracheostomy

Population longitudinal analysis of Gait Profile Score and North Star Ambulatory Assessment in children with Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is a rare X-linked recessive disorder characterized by loss-of-function mutations in the gene encoding dystrophin. These mutations lead to progressive functional deterioration including muscle weakness, respiratory insufficiency, and musculoskeletal deformities. Three-dimensional gait analysis (3DGA) has been used as a tool to analyze gait pathology through the quantification of altered joint kinematics, kinetics, and muscle activity patterns. Among 3DGA indices, the Gait Profile Score (GPS), has been used as a sensitive overall measure to detect clinically relevant changes in gait patterns in children with DMD. To enhance our understanding of the clinical translation of 3DGA, we report here the development of a population nonlinear mixed-effect model that jointly describes the disease progression of the 3DGA index, GPS, and the functional endpoint, North Star Ambulatory Assessment (NSAA). The final model consists of a quadratic structure for GPS progression and a linear structure for GPS-NSAA correlation. Our model was able to capture the improvement in function in GPS and NSAA in younger subjects, as well as the decline of function in older subjects. Furthermore, the model predicted NSAA (CFB) at 1 year reasonably well for DMD subjects ≤7 years old at baseline. The model tended to slightly underpredict the decline in NSAA after 1 year for those >7 years old at baseline, but the prediction summary statistics were well maintained within the standard deviation of observed data. Quantitative models such as this may help answer clinically relevant questions to facilitate the development of novel therapies in DMD.

Respiratory Management of Patients With Neuromuscular Weakness: An American College of Chest Physicians Clinical Practice Guideline and Expert Panel Report

BACKGROUND

Respiratory failure is a significant concern in neuromuscular diseases (NMDs). This CHEST guideline examines the literature on the respiratory management of patients with NMD to provide evidence-based recommendations.

STUDY DESIGN AND METHODS

An expert panel conducted a systematic review addressing the respiratory management of NMD and applied the Grading of Recommendations, Assessment, Development, and Evaluations approach for assessing the certainty of the evidence and formulating and grading recommendations. A modified Delphi technique was used to reach a consensus on the recommendations.

RESULTS

Based on 128 studies, the panel generated 15 graded recommendations, one good practice statement, and one consensus-based statement.

INTERPRETATION

Evidence of best practices for respiratory management in NMD is limited and is based primarily on observational data in amyotrophic lateral sclerosis. The panel found that pulmonary function testing every 6 months may be beneficial and may be used to initiate noninvasive ventilation (NIV) when clinically indicated. An individualized approach to NIV settings may benefit patients with chronic respiratory failure and sleep-disordered breathing related to NMD. When resources allow, polysomnography or overnight oximetry can help to guide the initiation of NIV. The panel provided guidelines for mouthpiece ventilation, transition to home mechanical ventilation, salivary secretion management, and airway clearance therapies. The guideline panel emphasizes that NMD pathologic characteristics represent a diverse group of disorders with differing rates of decline in lung function. The clinician's role is to add evaluation at the bedside to shared decision-making with patients and families, including respect for patient preferences and treatment goals, considerations of quality of life, and appropriate use of available resources in decision-making.

Non-invasive ventilation usage and adherence in children and adults with Duchenne muscular dystrophy: A multicenter analysis

INTRODUCTION/AIMS

Non-invasive ventilation (NIV) is routinely prescribed to support the respiratory system in Duchenne muscular dystrophy (DMD) patients; however, factors improving NIV usage are unclear. We aimed to identify predictors of NIV adherence in DMD patients.

METHODS

This was a multicenter retrospective analysis of DMD patients prescribed NIV and followed at (1) The Hospital for Sick Children, Canada; (2) Rady Children's Hospital San Diego, USA; and (3) University of California San Diego Health, USA, between February 2016 and October 2020. The primary and secondary outcomes were 90-day period NIV adherence and clinical and socioeconomic predictors of NIV adherence.

RESULTS

We identified 59 DMD patients prescribed NIV (mean ± SD age = 20.1 ± 6.7 y). Overall, percentage of nights used, and average nightly usage, were 79.9 ± 31.1% and 7.23 ± 4.12 h, respectively. Compared with children, adults had higher percentage of nights used (92.9 ± 16.9% vs. 70.4 ± 36.9%; P < .05), and average nightly usage (9.5 ± 4.7 h vs. 5.3 ± 3.7 h; P < .05). Non-English language (P = .01), and absence of deflazacort prescription (P = .02) were significantly associated with higher percentage of nights used while Hispanic ethnicity (P = .01), low household income (P = .02), and absence of deflazacort prescription (P = .02) were significantly associated with higher nightly usage. Based on univariable analysis, older age and declining forced vital capacity were associated with increased percentage of nights used and increased average nightly usage.

DISCUSSION

Certain clinical and socioeconomic determinants had a significant impact on NIV adherence in DMD patients, providing insight into those at risk for high versus low compliance with respiratory therapy.

Health System Factors Affecting the Experience of Non-Invasive Ventilation Provision of People with Neuromuscular Disorders in New Zealand

Non-invasive ventilation (NIV) is a critical therapy for many patients with neuromuscular disorders (NMD), supporting those with respiratory failure to achieve adequate respiration and improve their quality of life. The aim of this study was to explore the experiences of access to, consent, uptake, maintenance and safe use of non-invasive ventilation by people with NMD. Semi-structured individual interviews were conducted with 11 people with NMD, each using NIV for more than 12 months. A critical realism ontological paradigm with contextualism epistemology guided the Reflexive Thematic Analysis. An Equity of Health Care Framework underpinned the analysis. Three themes were interpreted: Uptake and informed consent for NIV therapy; Practicalities of NIV; and Patient-clinician relationships. We identified issues at the system, organization and health professional levels. Conclusions: We recommend the development of national service specifications with clear standards and dedicated funding for patients with NMD and call on the New Zealand Ministry of Health to proactively investigate and monitor the variations in service delivery identified. The specific areas of concern for patients with NMD suggest the need for NMD-related NIV research and service provision responsive to the distinct needs of this population.

The Dystrophinopathies

PURPOSE OF REVIEW

This article reviews the history, epidemiology, genetics, clinical presentation, multidisciplinary management, and established and emerging therapies for the dystrophinopathies.

RECENT FINDINGS

The multidisciplinary care of individuals with dystrophinopathies continues to improve in many ways, including early surveillance and implementation of respiratory, cardiac, and orthopedic health management. The era of genetic therapeutics has altered the treatment landscape in neuromuscular disorders, including the dystrophinopathies.

SUMMARY

The dystrophinopathies are a spectrum of X-linked genetic disorders characterized by childhood-onset progressive weakness and variable cardiac and cognitive involvement. Corticosteroids are the mainstay of therapy to slow disease progression. Additional strategies for disease amelioration and dystrophin restoration, including gene replacement therapy, are under investigation.

Drug development progress in duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is a severe, progressive, and incurable X-linked disorder caused by mutations in the dystrophin gene. Patients with DMD have an absence of functional dystrophin protein, which results in chronic damage of muscle fibers during contraction, thus leading to deterioration of muscle quality and loss of muscle mass over time. Although there is currently no cure for DMD, improvements in treatment care and management could delay disease progression and improve quality of life, thereby prolonging life expectancy for these patients. Furthermore, active research efforts are ongoing to develop therapeutic strategies that target dystrophin deficiency, such as gene replacement therapies, exon skipping, and readthrough therapy, as well as strategies that target secondary pathology of DMD, such as novel anti-inflammatory compounds, myostatin inhibitors, and cardioprotective compounds. Furthermore, longitudinal modeling approaches have been used to characterize the progression of MRI and functional endpoints for predictive purposes to inform Go/No Go decisions in drug development. This review showcases approved drugs or drug candidates along their development paths and also provides information on primary endpoints and enrollment size of Ph2/3 and Ph3 trials in the DMD space.

"Me and 'that' machine": the lived experiences of people with neuromuscular disorders using non-invasive ventilation

PURPOSE

Neuromuscular disorders (NMD) encompasses a wide range of conditions, with respiratory weakness a common feature. Respiratory care can involve non-invasive ventilation (NIV) resulting in fewer hospital admissions, a lower mortality rate and improved quality of life. The aim of this study was to explore the 'lived experience' of NIV by people with NMD.

METHODS

Interpretive Phenomenological Analysis (IPA) with semi-structured, face to face interviews with 11 people with NMD, using bi-level positive airway pressure for NIV for more than 12 months.

RESULTS

Three themes were interpreted: (i) Alive, with a life; (ii) Me and 'that' machine; and (iii) Precariousness of this life. NIV enabled hope, independence and the opportunity to explore previously perceived unattainable life experiences. Yet, participants felt dependent on the machine. Furthermore, practical considerations and fear of NIV failure created a sense of precariousness to life and a reframing of personal identity.

CONCLUSION

The findings highlight the broad ranging positive and negative effects that may occur for people with NMD when using this important therapy. Ongoing non-judgemental support and empathy are required from health professionals as the use of NIV challenged concepts such as 'living life well' for people with NMD. IMPLICATIONS FOR REHABILITATIONNeuromuscular disorders may result in respiratory weakness requiring non-invasive ventilation (NIV).When prescribed early, NIV can results in fewer hospital admissions, a lower mortality rate and improved quality of life.The relationship of people with NMD with their NIV machine is complex and impacts on and requires adjustment to their identity.NIV users acknowledged that NIV provided hope but simultaneously recognised the precariousness of NIV on their life.In order to better support people with NMD healthcare professionals need to better understand how the physical, psychological and social implications of NIV affect an individual's life.

Non-Invasive Respiratory Assessment in Duchenne Muscular Dystrophy: From Clinical Research to Outcome Measures

Ventilatory failure, due to the progressive wasting of respiratory muscles, is the main cause of death in patients with Duchenne muscular dystrophy (DMD). Reliable measures of lung function and respiratory muscle action are important to monitor disease progression, to identify early signs of ventilatory insufficiency and to plan individual respiratory management. Moreover, the current development of novel gene-modifying and pharmacological therapies highlighted the urgent need of respiratory outcomes to quantify the effects of these therapies. Pulmonary function tests represent the standard of care for lung function evaluation in DMD, but provide a global evaluation of respiratory involvement, which results from the interaction between different respiratory muscles. Currently, research studies have focused on finding novel outcome measures able to describe the behavior of individual respiratory muscles. This review overviews the measures currently identified in clinical research to follow the progressive respiratory decline in patients with DMD, from a global assessment to an individual structure–function muscle characterization. We aim to discuss their strengths and limitations, in relation to their current development and suitability as outcome measures for use in a clinical setting and as in upcoming drug trials in DMD.

Daytime alternatives for non-invasive mechanical ventilation in neuromuscular disorders

Mechanical ventilation in recent years has benefited from the development of new techniques and interfaces. These developments allowed clinicians to offer increasingly personalised therapies with the combination of different complementary techniques for treating respiratory insufficiency in patients with neuromuscular diseases. The mouthpiece ventilation, intermittent abdominal pressure ventilator and the negative pressure ventilation can offer many patients alternative therapy options when ventilation is required for many hours a day. In this non-systematic review, we will highlight the use of alternative methods to non-invasive mechanical ventilation at positive pressure in neuromuscular patients, to ensure the optimal interface for each patient.

The effect of emerging molecular and genetic therapies on cardiopulmonary disease in Duchenne muscular dystrophy

Gene therapy is an attractive approach being intensively studied to prevent muscle deterioration in patients with Duchenne muscular dystrophy. While clinical trials are only in early stages, initial reports are promising for its effects on ambulation. Cardiopulmonary failure, however, is the most common cause of mortality in Duchenne muscular dystrophy (DMD) patients, and little is known regarding the prospects for gene therapy on alleviating DMD-associated cardiomyopathy and respiratory failure. Here we review current knowledge regarding effects of gene therapy on DMD cardiomyopathy and discuss respiratory endpoints that should be considered as outcome measures in future clinical trials.

Respiratory Complications of Pediatric Neuromuscular Diseases

Respiration is an event of oxygen consumption and carbon dioxide production. Respiratory failure is common in pediatric neuromuscular diseases and the main cause of morbidity and mortality. It is a consequence of lung failure, ventilatory pump failure, or their combination. Lung failure often is due to chronic aspiration either from above or from below. It may lead to end-stage lung disease. Ventilatory pump failure is caused by increased respiratory load and progressive respiratory muscles weakness. This article reviews the normal function of the respiratory pump, general pathophysiology issues, abnormalities in the more common neuromuscular conditions and noninvasive interventions.

[Mouthpiece ventilation in neuromuscular diseases]

Le document qui suit est la traduction intégrale du compte rendu établi à l’occasion du 252e atelier international ENMC consacré, du 6 ou 8 mars 2020, au « Développement de recommandations pour l’utilisation de la ventilation par embout buccal dans les maladies neuromusculaires », et publié très récemment dans la revue Neuromuscular Disorders (M. Chatwin, M. Gonçalves, J. Gonzalez-Bermejo, M. Toussaint, et al. 252nd ENMC international workshop: Developing best practice guidelines for management of mouthpiece ventilation in neuromuscular disorders. March 6th to 8th 2020, Amsterdam, the Netherlands. Neuromuscular Disorders 2020 ; 30 : 772–81. https://doi.org/10.1016/j.nmd.2020.07.008).

Long-Term Mechanical Ventilation: Recommendations of the Swiss Society of Pulmonology

Long-term mechanical ventilation is a well-established treatment for chronic hypercapnic respiratory failure (CHRF). It is aimed at improving CHRF-related symptoms, health-related quality of life, survival, and decreasing hospital admissions. In Switzerland, long-term mechanical ventilation has been increasingly used since the 1980s in hospital and home care settings. Over the years, its application has considerably expanded with accumulating evidence of beneficial effects in a broad range of conditions associated with CHRF. Most frequent indications for long-term mechanical ventilation are chronic obstructive pulmonary disease, obesity hypoventilation syndrome, neuromuscular and chest wall diseases. In the current consensus document, the Special Interest Group of the Swiss Society of Pulmonology reviews the most recent scientific literature on long-term mechanical ventilation and provides recommendations adapted to the particular setting of the Swiss healthcare system with a focus on the practice of non-invasive and invasive home ventilation in adults.

Liberation and mortality outcomes in pediatric long-term ventilation: A qualitative systematic review

OBJECTIVE

To provide a systematic review of liberation from positive pressure ventilation and mortality of children with chronic respiratory failure who used long-term invasive and noninvasive ventilation (LTV).

METHODS

Papers published from 1980 to 2018 were identified using Pubmed MEDLINE, Ovid MEDLINE, Embase, and Cochrane databases. Search results were limited to English-language papers with (a) patients less than 22 years at initiation, (b) patients who used invasive ventilation (IV) via tracheostomy or noninvasive ventilation (NIV), and (c) data on mortality or liberation from LTV. Data were presented using descriptive statistics; changes in outcomes over time were explored using linear regression. Follow-up variability, cohort heterogeneity, and insufficient data precluded combining data to estimate incidences or rates.

RESULTS

One hundred and thirty papers with 12 704 patients were included. The median number of patients was 37 (interquartile range [IQR] 17-74, range 6-3802). Twenty-five percent of patients were initiated on IV; 75% on NIV. The maximum follow-up ranged from 0.5 to 31.8 years (median 8.8 years). The median proportion of patients liberated in these papers was 3% (IQR 0%-21%). The median proportion of mortality was 18% (IQR 8%-27%). Proportions of liberation and mortality did not significantly change over time. Progression of underlying disease (44%), respiratory illness (19%), and LTV accident (11%) were the most common causes of death.

CONCLUSIONS

These papers collectively show most patients survive for many years using LTV; in many subgroups, death is a more common outcome than liberation. However, the limitations of these papers preclude robust prognostication.

Current and emerging therapies for Duchenne muscular dystrophy and spinal muscular atrophy

Many neuromuscular diseases are genetically inherited or caused by mutations in motor function proteins. Two of the most prevalent neuromuscular diseases are Duchenne Muscular Dystrophy (DMD) and Spinal Muscular Atrophy (SMA), which are often diagnosed during the early years of life, contributing to life-long debilitation and shorter longevity. DMD is caused by mutations in the dystrophin gene resulting in critical muscle wasting, with cardiac or respiratory failure by age 30. Lack of dystrophin protein is the leading cause of degeneration of skeletal and cardiac muscle. Corticosteroids and artificial respirators remain as the gold-standard management of complications and have significantly extended the life span of these patients. Additionally, drug therapies including eteplirsen (EXONDYS 51®), golodirsen (VYONDYS 53™), and viltolarsen (VILTEPSO®) have been approved by the FDA to treat specific types of DMD. SMA is defined by the degeneration of the anterior horn cells in the spinal cord and destruction of motor neuron nuclei in the lower brain-stem caused by SMN1 gene deletion. Loss of SMN1 protein is partly compensated by SMN2 protein synthesis with disease severity being affected by the success of SMN2 gene synthesis. Evidence-based recommendations for SMA are directed towards supportive therapy and providing adequate nutrition and respiratory assistance as needed. Treatment and prevention of complications of muscle weakness are crucial for reducing the phenotype expression of SMA. Furthermore, drug therapies including injectables such as onasemnogene abeparvovec-xioi (ZOLGENSMA®), nusinersen (SPINRAZA®), and an oral-solution, risdiplam (EVRYSDI™), are medications that have been FDA-approved for the treatment of SMA. This review discusses the current and emerging therapeutic options for patients with DMD and SMA.

Noninvasive Ventilator Devices and Modes

Noninvasive ventilation has become an increasingly common treatment strategy for patients with diverse conditions involving chronic respiratory failure. An intimate understanding of various advanced respiratory devices and modes is essential in the management of these patients. Pressure-limited modes of ventilation are more commonly used than volume modes for noninvasive ventilation owing to enhanced patient comfort and synchrony with the ventilator, as well as improved leak compensation. Common pressure modes include spontaneous/timed and pressure control, with volume-assured pressure support being an additive feature available on certain devices. Evidence guiding the optimal mode of ventilation for specific diseases is limited.

Mask interfaces for home non-invasive ventilation in infants and children

The selection of the mask interface for non-invasive ventilation (NIV) is recognized to be an essential part for therapy success. While nasal masks are the first recommended option in children and adults, there are indications for other mask types such as intolerance or complications from nasal masks. Evidence comparing performance, adherence and complication risk among mask interfaces in pediatrics is, however, scarce and information is often extrapolated from adult studies. Given this gap in knowledge and the lack of guidelines on NIV initiation in children, mask selection often relies on the clinicians' knowledge and expertise. Careful mask selection, a well-fitting headgear and time investment for mask desensitization are some important recommendations for adequate mask adaptation in children. Frequent mask-related complications include nasal symptoms, unintentional leak, mask displacement, skin injury, and midface hypoplasia. Close monitoring and a pro-active approach may help to minimize complications and promote the optimal use of home NIV.

When Adolescent and Parents Disagree on Medical Plan, Who Gets to Decide?

An adolescent with Duchenne Muscular Dystrophy wants a life-extending tracheostomy whereas parents do not want this for him.

Muscular Dystrophies

Muscular dystrophies represent a complex, varied, and important subset of neuromuscular disorders likely to require the care of a pulmonologist. The spectrum of conditions encapsulated by this subset ranges from severe and fatal congenital muscular dystrophies with onset in infancy to mild forms of limb and girdle weakness with onset in adulthood and minimal respiratory compromise. The list and classification of muscular dystrophies are undergoing near-constant revision, based largely on new insights from genetics and molecular medicine. The authors present an overview of the muscular dystrophies, including their basic features, common clinical phenotypes, and important facets of management.

Long-Term Ventilation in Neuromuscular Patients: Review of Concerns, Beliefs, and Ethical Dilemmas

BACKGROUND

Noninvasive mechanical ventilation (NIV) is an effective treatment in patients with neuromuscular diseases (NMD) to improve symptoms, quality of life, and survival.

SUMMARY

NIV should be used early in the course of respiratory muscle involvement in NMD patients and its requirements may increase over time. Therefore, training on technical equipment at home and advice on problem solving are warranted. Remote monitoring of ventilator parameters using built-in ventilator software is recommended. Telemedicine may be helpful in reducing hospital admissions. Anticipatory planning and palliative care should be carried out to lessen the burden of care, to maintain or withdraw from NIV, and to guarantee the most respectful management in the last days of NMD patients' life. Key Message: Long-term NIV is effective but challenging in NMD patients. Efforts should be made by health care providers in arranging a planned transition to home and end-of-life discussions for ventilator-assisted individuals and their families.

Respiratory Management of the Patient With Duchenne Muscular Dystrophy

In 2010, Care Considerations for Duchenne Muscular Dystrophy, sponsored by the Centers for Disease Control and Prevention, was published in Lancet Neurology, and in 2018, these guidelines were updated. Since the publication of the first set of guidelines, survival of individuals with Duchenne muscular dystrophy has increased. With contemporary medical management, survival often extends into the fourth decade of life and beyond. Effective transition of respiratory care from pediatric to adult medicine is vital to optimize patient safety, prognosis, and quality of life. With genetic and other emerging drug therapies in development, standardization of care is necessary to accurately assess treatment effects in clinical trials. This revision of respiratory recommendations preserves a fundamental strength of the original guidelines: namely, reliance on a limited number of respiratory tests to guide patient assessment and management. A progressive therapeutic strategy is presented that includes lung volume recruitment, assisted coughing, and assisted ventilation (initially nocturnally, with the subsequent addition of daytime ventilation for progressive respiratory failure). This revision also stresses the need for serial monitoring of respiratory muscle strength to characterize an individual's respiratory phenotype of severity as well as provide baseline assessments for clinical trials. Clinical controversies and emerging areas are included.

Diagnosis and management of Duchenne muscular dystrophy, part 2: respiratory, cardiac, bone health, and orthopaedic management

A coordinated, multidisciplinary approach to care is essential for optimum management of the primary manifestations and secondary complications of Duchenne muscular dystrophy (DMD). Contemporary care has been shaped by the availability of more sensitive diagnostic techniques and the earlier use of therapeutic interventions, which have the potential to improve patients' duration and quality of life. In part 2 of this update of the DMD care considerations, we present the latest recommendations for respiratory, cardiac, bone health and osteoporosis, and orthopaedic and surgical management for boys and men with DMD. Additionally, we provide guidance on cardiac management for female carriers of a disease-causing mutation. The new care considerations acknowledge the effects of long-term glucocorticoid use on the natural history of DMD, and the need for care guidance across the lifespan as patients live longer. The management of DMD looks set to change substantially as new genetic and molecular therapies become available.

Noninvasive Respiratory Management of Patients With Neuromuscular Disease

This review article describes definitive noninvasive respiratory management of respiratory muscle dysfunction to eliminate need to resort to tracheotomy. In 2010 clinicians from 22 centers in 18 countries reported 1,623 spinal muscular atrophy type 1 (SMA1), Duchenne muscular dystrophy (DMD), and amyotrophic lateral sclerosis users of noninvasive ventilatory support (NVS) of whom 760 required it continuously (CNVS). The CNVS sustained their lives by over 3,000 patient-years without resort to indwelling tracheostomy tubes. These centers have now extubated at least 74 consecutive ventilator unweanable patients with DMD, over 95% of CNVS-dependent patients with SMA1, and hundreds of others with advanced neuromuscular disorders (NMDs) without resort to tracheotomy. Two centers reported a 99% success rate at extubating 258 ventilator unweanable patients without resort to tracheotomy. Patients with myopathic or lower motor neuron disorders can be managed noninvasively by up to CNVS, indefinitely, despite having little or no measurable vital capacity, with the use of physical medicine respiratory muscle aids. Ventilator-dependent patients can be decannulated of their tracheostomy tubes.

Mouthpiece ventilation and complementary techniques in patients with neuromuscular disease: A brief clinical review and update

Noninvasive ventilatory support (NVS) is sometimes reported as suboptimal in patients with neuromuscular disease (NMD). The reasons for this include inadequate ventilator settings and/or lack of interface tolerance. NVS has been used for many years in patients with NMD disorders as a viable alternative to continuous ventilatory support via a tracheostomy tube. The mouthpiece ventilation (MPV) is a ventilatory mode that is used as daytime ventilatory support in combination with other ventilatory modalities and interfaces for nocturnal NVS. However, there is still a poor understanding of this method's benefits compared with other modalities. This review aims to highlight the indications and advantages along with the disadvantages of MPV.

Definition, discrimination, diagnosis and treatment of central breathing disturbances during sleep

The complexity of central breathing disturbances during sleep has become increasingly obvious. They present as central sleep apnoeas (CSAs) and hypopnoeas, periodic breathing with apnoeas, or irregular breathing in patients with cardiovascular, other internal or neurological disorders, and can emerge under positive airway pressure treatment or opioid use, or at high altitude. As yet, there is insufficient knowledge on the clinical features, pathophysiological background and consecutive algorithms for stepped-care treatment. Most recently, it has been discussed intensively if CSA in heart failure is a “marker” of disease severity or a “mediator” of disease progression, and if and which type of positive airway pressure therapy is indicated. In addition, disturbances of respiratory drive or the translation of central impulses may result in hypoventilation, associated with cerebral or neuromuscular diseases, or severe diseases of lung or thorax. These statements report the results of an European Respiratory Society Task Force addressing actual diagnostic and therapeutic standards. The statements are based on a systematic review of the literature and a systematic two-step decision process. Although the Task Force does not make recommendations, it describes its current practice of treatment of CSA in heart failure and hypoventilation.

Impact of invasive ventilation on survival when non-invasive ventilation is ineffective in patients with Duchenne muscular dystrophy: A prospective cohort

BACKGROUND

Many patients with DMD undergo tracheostomy. Tracheostomy is associated with certain complications, however its effect on prognosis is not known.

METHODS

The relationship between type of mechanical ventilation and survival at 12 years was evaluated in a prospective cohort of patients with Duchenne muscular dystrophy followed in a French reference center for Neuromuscular Diseases. Cox proportional-hazards regressions were used to estimate the hazard ratios associated with risk of switching from non-invasive to invasive ventilation, and with risk of death.

RESULTS

One hundred and fifty patients were included. Initial use of invasive ventilation was associated with an episode of acute respiratory failure (p < 0.0001) and with a severe clinical status (p < 0.05). Risk of death was associated with swallowing disorders (2.51, IC [1.12-5.66], p < 0.03) and cardiac failure (p < 0.05) but not with type of mechanical ventilation.

CONCLUSION

Switching to invasive ventilation is appropriate when non-invasive ventilation is ineffective.

Assessment and management of respiratory function in patients with Duchenne muscular dystrophy: current and emerging options

Duchenne muscular dystrophy (DMD) is an X-linked myopathy resulting in progressive weakness and wasting of all the striated muscles including the respiratory muscles. The consequences are loss of ambulation before teen ages, cardiac involvement and breathing difficulties, the main cause of death. A cure for DMD is not currently available. In the last decades the survival of patients with DMD has improved because the natural history of the disease can be changed thanks to a more comprehensive therapeutic approach. This comprises interventions targeted to the manifestations and complications of the disease, particularly in the respiratory care. These include: 1) pharmacological intervention, namely corticosteroids and idebenone that significantly reduce the decline of spirometric parameters; 2) rehabilitative intervention, namely lung volume recruitment techniques that help prevent atelectasis and slows the rate of decline of pulmonary function; 3) scoliosis treatment, namely steroid therapy that is used to reduce muscle inflammation/degeneration and prolong ambulation in order to delay the onset of scoliosis, being an additional contribution to the restrictive lung pattern; 4) cough assisted devices that improve airway clearance thus reducing the risk of pulmonary infections; and 5) non-invasive mechanical ventilation that is essential to treat nocturnal hypoventilation, sleep disordered breathing, and ultimately respiratory failure. Without any intervention death occurs within the first 2 decades, however, thanks to this multidisciplinary therapeutic approach life expectancy of a newborn with DMD nowadays can be significantly prolonged up to his fourth decade. This review is aimed at providing state-of-the-art methods and techniques for the assessment and management of respiratory function in DMD patients.

Intermittent daytime mouthpiece ventilation successfully augments nocturnal non-invasive ventilation, controlling ventilatory failure and maintaining patient independence

A 53-year-old woman with spinal muscular atrophy and a 7-year history of nocturnal non-invasive ventilation (NIV) use via nasal mask and chinstrap was admitted electively. Outpatient review suggested symptomatic hypercapnia and hypoxaemia. Use of her usual NIV resulted in early morning respiratory acidosis due to excess mouth leak, and continuous face mask NIV was instigated while in hospital. Once stabilised, she elected to return to nasal ventilation. At outpatient review, respiratory acidosis reoccurred despite diurnal use of NIV. Using the patient's routine ventilator and a novel mouthpiece and trigger algorithm, intermittent daytime mouthpiece ventilation (MPV) was introduced alongside overnight NIV. Control of respiratory failure was achieved and, vitally, independent living maintained. Intermittent MPV was practicable and effective where the limits of ventilator tolerance had otherwise been reached. MPV may reduce the need for tracheostomy ventilation and this case serves as a reminder of the increasing options routinely available to NIV clinicians.

Nocturnal mechanical ventilation for chronic hypoventilation in patients with neuromuscular and chest wall disorders

BACKGROUND

Chronic alveolar hypoventilation is a common complication of many neuromuscular and chest wall disorders. Long-term nocturnal mechanical ventilation is commonly used to treat it. This is a 2014 update of a review first published in 2000 and previously updated in 2007.

OBJECTIVES

To examine the effects on mortality of nocturnal mechanical ventilation in people with neuromuscular or chest wall disorders. Subsidiary endpoints were to examine the effects of respiratory assistance on improvement of chronic hypoventilation, sleep quality, hospital admissions and quality of life.

SEARCH METHODS

We searched the Cochrane Neuromuscular Disease Group Specialized Register, CENTRAL, MEDLINE and EMBASE on 10 June 2014. We contacted authors of identified trials and other experts in the field.

SELECTION CRITERIA

We searched for quasi-randomised or randomised controlled trials of participants of all ages with neuromuscular or chest wall disorder-related stable chronic hypoventilation of all degrees of severity, receiving any type and any mode of long-term nocturnal mechanical ventilation. The primary outcome measure was one-year mortality and secondary outcomes were unplanned hospital admission, short-term and long-term reversal of hypoventilation-related clinical symptoms and daytime hypercapnia, improvement of lung function and sleep breathing disorders.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodology to select studies, extract data and assess the risk of bias in included studies.

MAIN RESULTS

The 10 eligible trials included a total of 173 participants. Roughly half of the trials were at low risk of selection, attrition or reporting bias, and almost all were at high risk of performance and detection bias. Four trials reported mortality data in the long term. The pooled risk ratio (RR) of dying was 0.62 (95% confidence interval (CI) 0.42 to 0.91, P value = 0.01) in favour of nocturnal mechanical ventilation compared to spontaneous breathing. There was considerable and significant heterogeneity between the trials, possibly related to differences between the study populations. Information on unplanned hospitalisation was available from two studies. The corresponding pooled RR was 0.25 (95% CI 0.08 to 0.82, P value = 0.02) in favour of nocturnal mechanical ventilation. For most of the outcome measures there was no significant long-term difference between nocturnal mechanical ventilation and no ventilation. Most of the secondary outcomes were not assessed in the eligible trials. Three out of the 10 trials, accounting for 39 participants, two with a cross-over design and one with two parallel groups, compared volume- and pressure-cycled non-invasive mechanical ventilation in the short term. From the only trial (16 participants) on parallel groups, there was no difference in mortality (one death in each arm) between volume- and pressure-cycled mechanical ventilation. Data from the two cross-over trials suggested that compared with pressure-cycled ventilation, volume-cycled ventilation was associated with less sleep time spent with an arterial oxygen saturation below 90% (mean difference (MD) 6.83 minutes, 95% CI 4.68 to 8.98, P value = 0.00001) and a lower apnoea-hypopnoea (per sleep hour) index (MD -0.65, 95% CI -0.84 to -0.46, P value = 0.00001). We found no study that compared invasive and non-invasive mechanical ventilation or intermittent positive pressure versus negative pressure ventilation.

AUTHORS' CONCLUSIONS

Current evidence about the therapeutic benefit of mechanical ventilation is of very low quality, but is consistent, suggesting alleviation of the symptoms of chronic hypoventilation in the short term. In four small studies, survival was prolonged and unplanned hospitalisation was reduced, mainly in participants with motor neuron diseases. With the exception of motor neuron disease and Duchenne muscular dystrophy, for which the natural history supports the survival benefit of mechanical ventilation against no ventilation, further larger randomised trials should assess the long-term benefit of different types and modes of nocturnal mechanical ventilation on quality of life, morbidity and mortality, and its cost-benefit ratio in neuromuscular and chest wall diseases.

Open circuit mouthpiece ventilation: Concise clinical review

In 2013 new "mouthpiece ventilation" modes are being introduced to commercially available portable ventilators. Despite this, there is little knowledge of how to use noninvasive intermittent positive pressure ventilation (NIV) as opposed to bi-level positive airway pressure (PAP) and both have almost exclusively been reported to have been used via nasal or oro-nasal interfaces rather than via a simple mouthpiece. Non-invasive ventilation is often reported as failing because of airway secretion encumbrance, because of hypercapnia due to inadequate bi-level PAP settings, or poor interface tolerance. The latter can be caused by factors such as excessive pressure on the face from poor fit, excessive oral air leak, anxiety, claustrophobia, and patient-ventilator dys-synchrony. Thus, the interface plays a crucial role in tolerance and effectiveness. Interfaces that cover the nose and/or nose and mouth (oro-nasal) are the most commonly used but are more likely to cause skin breakdown and claustrophobia. Most associated drawbacks can be avoided by using mouthpiece NIV. Open-circuit mouthpiece NIV is being used by large populations in some centers for daytime ventilatory support and complements nocturnal NIV via "mask" interfaces for nocturnal ventilatory support. Mouthpiece NIV is also being used for sleep with the mouthpiece fixed in place by a lip-covering flange. Small 15 and 22mm angled mouthpieces and straw-type mouthpieces are the most commonly used. NIV via mouthpiece is being used as an effective alternative to ventilatory support via tracheostomy tube (TMV) and is associated with a reduced risk of pneumonias and other respiratory complications. Its use facilitates "air-stacking" to improve cough, speech, and pulmonary compliance, all of which better maintain quality of life for patients with neuromuscular diseases (NMDs) than the invasive alternatives. Considering these benefits and the new availability of mouthpiece ventilator modes, wider knowledge of this technique is now warranted. This review highlights the indications, techniques, advantages and disadvantages of mouthpiece NIV.