Chronic respiratory failure in patients with neuromuscular diseases: diagnosis and treatment

Sonographic Phrenic Nerve Changes in Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease that affects both the upper and lower motor neurons in the nervous system, causing muscle weakness and severe disability. The progressive course of the disease reduces the functional capacity of the affected patients, limits daily activities, and leads to complete dependence on caregivers, ultimately resulting in a fatal outcome. Respiratory dysfunction mostly occurs later in the disease and is associated with a worse prognosis. Forty-six participants were included in our study, with 23 patients in the ALS group and 23 individuals in the control group. The ultrasound examination of the phrenic nerve (PN) was performed by two authors using a high-resolution "Philips EPIQ 7" ultrasound machine with a linear 4-18 MHz transducer. Our study revealed that the phrenic nerve is significantly smaller on both sides in ALS patients compared to the control group (p < 0.001). Only one significant study on PN ultrasound in ALS, conducted in Japan, also showed significant results (p < 0.00001). These small studies are particularly promising, as they suggest that ultrasound findings could serve as an additional diagnostic tool for ALS.

Respiratory muscle training in children and adults with neuromuscular disease

BACKGROUND

Neuromuscular diseases (NMDs) are a heterogeneous group of diseases affecting the anterior horn cell of spinal cord, neuromuscular junction, peripheral nerves and muscles. NMDs cause physical disability usually due to progressive loss of strength in limb muscles, and some NMDs also cause respiratory muscle weakness. Respiratory muscle training (RMT) might be expected to improve respiratory muscle weakness; however, the effects of RMT are still uncertain. This systematic review will synthesize the available trial evidence on the effectiveness and safety of RMT in people with NMD, to inform clinical practice.

OBJECTIVES

To assess the effects of respiratory muscle training (RMT) for neuromuscular disease (NMD) in adults and children, in comparison to sham training, no training, standard treatment, breathing exercises, or other intensities or types of RMT.

SEARCH METHODS

On 19 November 2018, we searched the Cochrane Neuromuscular Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase. On 23 December 2018, we searched the US National Institutes for Health Clinical Trials Registry (ClinicalTrials.gov), the World Health Organization International Clinical Trials Registry Platform, and reference lists of the included studies.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) and quasi-RCTs, including cross-over trials, of RMT in adults and children with a diagnosis of NMD of any degree of severity, who were living in the community, and who did not need mechanical ventilation. We compared trials of RMT (inspiratory muscle training (IMT) or expiratory muscle training (EMT), or both), with sham training, no training, standard treatment, different intensities of RMT, different types of RMT, or breathing exercises.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methodological procedures.

MAIN RESULTS

We included 11 studies involving 250 randomized participants with NMDs: three trials (N = 88) in people with amyotrophic lateral sclerosis (ALS; motor neuron disease), six trials (N = 112) in Duchenne muscular dystrophy (DMD), one trial (N = 23) in people with Becker muscular dystrophy (BMD) or limb-girdle muscular dystrophy, and one trial (N = 27) in people with myasthenia gravis.Nine of the trials were at high risk of bias in at least one domain and many reported insufficient information for accurate assessment of the risk of bias. Populations, interventions, control interventions, and outcome measures were often different, which largely ruled out meta-analysis. All included studies assessed lung capacity, our primary outcome, but four did not provide data for analysis (1 in people with ALS and three cross-over studies in DMD). None provided long-term data (over a year) and only one trial, in ALS, provided information on adverse events. Unscheduled hospitalisations for chest infection or acute exacerbation of chronic respiratory failure were not reported and physical function and quality of life were reported in one (ALS) trial.Amyotrophic lateral sclerosis (ALS)Three trials compared RMT versus sham training in ALS. Short-term (8 weeks) effects of RMT on lung capacity in ALS showed no clear difference in the change of the per cent predicted forced vital capacity (FVC%) between EMT and sham EMT groups (mean difference (MD) 0.70, 95% confidence interval (CI) -8.48 to 9.88; N = 46; low-certainty evidence). The mean difference (MD) in FVC% after four months' treatment was 10.86% in favour of IMT (95% CI -4.25 to 25.97; 1 trial, N = 24; low-certainty evidence), which is larger than the minimal clinically important difference (MCID, as estimated in people with idiopathic pulmonary fibrosis). There was no clear difference between IMT and sham IMT groups, measured on the Amyotrophic Lateral Sclerosis Functional Rating Scale (ALFRS; range of possible scores 0 = best to 40 = worst) (MD 0.85, 95% CI -2.16 to 3.85; 1 trial, N = 24; low-certainty evidence) or quality of life, measured on the EuroQol-5D (0 = worst to 100 = best) (MD 0.77, 95% CI -17.09 to 18.62; 1 trial, N = 24; low-certainty evidence) over the medium term (4 months). One trial report stated that the IMT protocol had no adverse effect (very low-certainty evidence).Duchenne muscular dystrophy (DMD)Two DMD trials compared RMT versus sham training in young males with DMD. In one study, the mean post-intervention (6-week) total lung capacity (TLC) favoured RMT (MD 0.45 L, 95% CI -0.24 to 1.14; 1 trial, N = 16; low-certainty evidence). In the other trial there was no clear difference in post-intervention (18 days) FVC between RMT and sham RMT (MD 0.16 L, 95% CI -0.31 to 0.63; 1 trial, N = 20; low-certainty evidence). One RCT and three cross-over trials compared a form of RMT with no training in males with DMD; the cross-over trials did not provide suitable data. Post-intervention (6-month) values showed no clear difference between the RMT and no training groups in per cent predicted vital capacity (VC%) (MD 3.50, 95% CI -14.35 to 21.35; 1 trial, N = 30; low-certainty evidence).Becker or limb-girdle muscular dystrophyOne RCT (N = 21) compared 12 weeks of IMT with breathing exercises in people with Becker or limb-girdle muscular dystrophy. The evidence was of very low certainty and conclusions could not be drawn.Myasthenia gravisIn myasthenia gravis, there may be no clear difference between RMT and breathing exercises on measures of lung capacity, in the short term (TLC MD -0.20 L, 95% CI -1.07 to 0.67; 1 trial, N = 27; low-certainty evidence). Effects of RMT on quality of life are uncertain (1 trial; N = 27).Some trials reported effects of RMT on inspiratory and/or expiratory muscle strength; this evidence was also of low or very low certainty.

AUTHORS' CONCLUSIONS

RMT may improve lung capacity and respiratory muscle strength in some NMDs. In ALS there may not be any clinically meaningful effect of RMT on physical functioning or quality of life and it is uncertain whether it causes adverse effects. Due to clinical heterogeneity between the trials and the small number of participants included in the analysis, together with the risk of bias, these results must be interpreted very cautiously.

Respiratory involvement in neuromuscular disorders

PURPOSE OF REVIEW

In numerous neuromuscular disorders (NMDs), respiratory muscle weakness is present, and acute or chronic respiratory failure may evolve. Very often, respiratory involvement substantially adds to the burden of disease, impairs quality of life, or reduces life expectancy. This article summarizes new aspects of both diagnosis and management of respiratory muscle weakness in patients with NMDs.

RECENT FINDINGS

Drugs like deflazacort, ataluren, eteplirsen, and nusinersen are now approved treatments for Duchenne Muscular Dystrophy and Spinal Muscular Atrophy, and others are on their way in NMDs. Although observing how innovative drugs will change the natural history of these diseases, including respiratory function over time, adequate symptomatic treatment remains meaningful and is strongly recommended. Physicians should systematically take respiratory involvement into account to improve patients' quality of life and prognosis.

SUMMARY

First, it is outlined in which subtypes of NMD respiratory muscle dysfunction is particularly relevant. Second, new developments regarding diagnostic procedures, including respiratory muscle strength testing, spirometry, and sleep studies, are covered. Third, this article gives an overview on current concepts of ventilatory support and management of secretions in patients with NMD.

Inspiratory muscle training for children and adolescents with neuromuscular diseases: A systematic review

Patients with neuromuscular diseases are at risk of morbidity and mortality due to respiratory compromise caused by respiratory muscle weakness. A systematic review was performed using pre-specified search strategies to determine the safety of inspiratory muscle training (IMT) and whether it has an impact on inspiratory muscle strength and endurance, exercise capacity, pulmonary function, dyspnoea and health-related quality of life. Randomised, quasi-randomised, cross-over and clinical controlled trials were included if they assessed the use of an external IMT device compared to no, sham/placebo, or alternative IMT treatment in children aged 5-18 years with neuromuscular diseases. Seven full-text articles and two on-going trials (n = 168) were included. Most studies used threshold IMT devices over a medium to long-term period, and none reported any adverse events. Studies differed regarding intensity, repetitions, frequency, rest intervals and duration of IMT. Six studies reported no significant improvement in pulmonary function tests following IMT. Two comparable studies reported significant improvement in inspiratory muscle endurance and four studies reported significantly greater improvement in inspiratory muscle strength in experimental groups. The latter was confirmed in a meta-analysis of two comparable studies (overall effect p < 0.00001). Other outcome measures could not be pooled. There is currently insufficient evidence to guide clinical IMT practice, owing to the limited number of included studies; small sample sizes; data heterogeneity; and risk of bias amongst included studies. Large sample randomised controlled trials are needed to determine safety and efficacy of IMT in paediatric and adolescent patients with neuromuscular diseases.

Physiotherapy Intervention During Level I of Pulmonary Rehabilitation on Chronic Obstructive Pulmonary Disease: A Systematic Review

Background:

The progressive and chronic course of COPD, characterized by difficulty in breathing, can be aggravated by periods of increased symptoms (exacerbation). The treatment often involves in-hospital care and among the interventions applied in COPD patients, physical therapy prompts good results. However the most used techniques are not properly pinpointed and there is no consensus in the literature regarding its effectiveness.

Methods:

A systematic review was performed to identify which physical therapy treatment was applied in these cases. The following bibliographic databases were consulted: PubMed, and Bireme Portal, Periódicos Capes. Controlled randomized clinical trials that is under went physical therapy intervention in patients hospitalized for exacerbated COPD without the use of NIV (non-invasive ventilation) were included in the study. The PEDro scale, which has a score of 0-10, was used to evaluate the quality of studies included in this review.

Results:

The electronic search yielded a total of 302 references published in English, of which only 6 met the criteria for inclusion and exclusion.

Conclusion:

It is possible to infer that physiotherapy’s techniques used in patients hospitalized for COPD exacerbation, based on this review, were the high frequency chest wall oscillation (HFCWO) on the chest; relaxing massage and active exercises, electrical stimulation via electro-acupuncture; strengthening of the quadriceps; the ELTGOL bronchial drainage technique (expiration with the glottis open in the lateral posture) and an incentive spirometer.

Brazilian recommendations of mechanical ventilation 2013. Part 2

Perspectives on invasive and noninvasive ventilatory support for critically ill patients are evolving, as much evidence indicates that ventilation may have positive effects on patient survival and the quality of the care provided in intensive care units in Brazil. For those reasons, the Brazilian Association of Intensive Care Medicine (Associação de Medicina Intensiva Brasileira - AMIB) and the Brazilian Thoracic Society (Sociedade Brasileira de Pneumologia e Tisiologia - SBPT), represented by the Mechanical Ventilation Committee and the Commission of Intensive Therapy, respectively, decided to review the literature and draft recommendations for mechanical ventilation with the goal of creating a document for bedside guidance as to the best practices on mechanical ventilation available to their members. The document was based on the available evidence regarding 29 subtopics selected as the most relevant for the subject of interest. The project was developed in several stages, during which the selected topics were distributed among experts recommended by both societies with recent publications on the subject of interest and/or significant teaching and research activity in the field of mechanical ventilation in Brazil. The experts were divided into pairs that were charged with performing a thorough review of the international literature on each topic. All the experts met at the Forum on Mechanical Ventilation, which was held at the headquarters of AMIB in São Paulo on August 3 and 4, 2013, to collaboratively draft the final text corresponding to each sub-topic, which was presented to, appraised, discussed and approved in a plenary session that included all 58 participants and aimed to create the final document.

Amyotrophic Lateral Sclerosis: New Perpectives and Update

Amyotrophic lateral sclerosis (ALS), Charcot's disease or Lou Gehrig's disease, is a term used to cover the spetrum of syndromes caracterized by progressive degeneration of motor neurons, a paralytic disorder caused by motor neuron degeneration. Currently, there are approximately 25,000 patients with ALS in the USA, with an average age of onset of 55 years. The incidence and prevalence of ALS are 1-2 and 4-6 per 100,000 each year, respectively, with a lifetime ALS risk of 1/600 to 1/1000. It causes progressive and cumulative physical disabilities, and leads to eventual death due to respiratory muscle failure. ALS is diverse in its presentation, course, and progression. We do not yet fully understand the causes of the disease, nor the mechanisms for its progression; thus, we lack effective means for treating this disease. In this chapter, we will discuss the diagnosis, treatment, and how to cope with impaired function and end of life based on of our experience, guidelines, and clinical trials. Nowadays ALS seems to be a more complex disease than it did two decades - or even one decade - ago, but new insights have been plentiful. Clinical trials should be seen more as experiments on pathogenic mechanisms. A medication or combination of medications that targets more than one pathogenic pathway may slow disease progression in an additive or synergistic fashion.

Brazilian recommendations of mechanical ventilation 2013. Part 2

Perspectives on invasive and noninvasive ventilatory support for critically ill patients are evolving, as much evidence indicates that ventilation may have positive effects on patient survival and the quality of the care provided in intensive care units in Brazil. For those reasons, the Brazilian Association of Intensive Care Medicine (Associação de Medicina Intensiva Brasileira - AMIB) and the Brazilian Thoracic Society (Sociedade Brasileira de Pneumologia e Tisiologia - SBPT), represented by the Mechanical Ventilation Committee and the Commission of Intensive Therapy, respectively, decided to review the literature and draft recommendations for mechanical ventilation with the goal of creating a document for bedside guidance as to the best practices on mechanical ventilation available to their members. The document was based on the available evidence regarding 29 subtopics selected as the most relevant for the subject of interest. The project was developed in several stages, during which the selected topics were distributed among experts recommended by both societies with recent publications on the subject of interest and/or significant teaching and research activity in the field of mechanical ventilation in Brazil. The experts were divided into pairs that were charged with performing a thorough review of the international literature on each topic. All the experts met at the Forum on Mechanical Ventilation, which was held at the headquarters of AMIB in São Paulo on August 3 and 4, 2013, to collaboratively draft the final text corresponding to each sub-topic, which was presented to, appraised, discussed and approved in a plenary session that included all 58 participants and aimed to create the final document.

Exercise capacity and pulmonary function in individuals with leprosy

Introduction In Brazil 23% of leprosy patients have some type of physical disability after discharge. The impact on the respiratory system and correlation with functional exercise capacity is still unknown. Objective To correlate the functional exercise capacity and pulmonary function in individuals with leprosy sequelae. Materials and methods We evaluated 20 subjects and 25 controls by sensory evaluation, muscle strength, graduate the grade of physical disability followed by pulmonary function tests with spirometry and manovacuometry, besides the functional exercise capacity through the six minute walking distance (6MWD). Results The majority (75%) of the subjects showed physical disability grade 1. The mean of the maximal inspiratory pressure were below than normal -71 ± 31 cmH20 and maximal expiratory pressure +89 ± 22 cmH20. Spirometric values presented measures within normal value. The functional exercise capacity found a reduced value with a distance of 404 ± 92m. Positive and statistically significant correlation between the inspiratory pressures with 6MWD (r = 0.49, p = 0.025) and, similarly, expiratory pressure (r = 0.53, p = 0.004). The same evidence is found in maximal respiratory pressures of individuals in grade 1 with significant correlations (r = 0.52, p = 0.036) and (r = 0.51, p = 0.042). Conclusion Individuals with leprosy sequelae had impaired respiratory muscle strength and functional exercise capacity. Maximal respiratory pressures are presented as an independent factor in the change in performance in the functional exercise capacity.

Identification of risk groups for oropharyngeal dysphagia in hospitalized patients in a university hospital

Purpose: To identify risk groups for oropharyngeal dysphagia in hospitalized patients in a university hospital. Methods: The study was design as an exploratory cross-sectional with quantitative data analysis. The researched population consisted of 32 patients admitted to the medical clinic at the university hospital. Patient history data were collected, followed by a universal swallowing screening which included functional feeding assessment, to observe clinical signs and symptoms of dysphagia, and assessment of nutritional status through anthropometric data and laboratory tests. Results: Of the total sample, the majority of patients was male over 60 years. The most common comorbidities related to patients with signs and symptoms of dysphagia were chronic obstructive pulmonary disease, systemic arterial hypertension, congestive heart failure, diabetes mellitus and acute myocardial infarction. The food consistency that showed higher presence of clinical signs of aspiration was pudding and the predominant sign was wet voice. Conclusion: There is a high incidence of risk for oropharyngeal dysphagia in hospitalized patients and an even higher rate of hospitalized patients with nutritional deficits or already malnourished. Hospitalized patients with respiratory diseases, chronic obstructive pulmonary disease, congestive heart failure and patients with xerostomia were indicated as risk group for oropharyngeal dysphagia.

Lung function in post-poliomyelitis syndrome: a cross-sectional study

OBJECTIVE:

To compare lung function between patients with post-poliomyelitis syndrome and those with sequelae of paralytic poliomyelitis (without any signs or symptoms of post-poliomyelitis syndrome), as well as between patients with post-poliomyelitis syndrome and healthy controls.

METHODS:

Twenty-nine male participants were assigned to one of three groups: control; poliomyelitis (comprising patients who had had paralytic poliomyelitis but had not developed post-poliomyelitis syndrome); and post-poliomyelitis syndrome. Volunteers underwent lung function measurements (spirometry and respiratory muscle strength assessment).

RESULTS:

The results of the spirometric assessment revealed no significant differences among the groups except for an approximately 27% lower mean maximal voluntary ventilation in the post-poliomyelitis syndrome group when compared with the control group (p = 0.0127). Nevertheless, the maximal voluntary ventilation values for the post-poliomyelitis group were compared with those for the Brazilian population and were found to be normal. No significant differences were observed in respiratory muscle strength among the groups.

CONCLUSIONS:

With the exception of lower maximal voluntary ventilation, there was no significant lung function impairment in outpatients diagnosed with post-poliomyelitis syndrome when compared with healthy subjects and with patients with sequelae of poliomyelitis without post-poliomyelitis syndrome. This is an important clinical finding because it shows that patients with post-poliomyelitis syndrome can have preserved lung function.

Early respiratory evaluation should be carried out systematically in patients with multiple sclerosis

The present study aimed at evaluating respiratory parameters in multiple sclerosis (MS). The sample comprised 30 patients with MS diagnosis and 30 healthy subjects, matched by gender and age. Neurological assessment, expanded disability status scale (EDSS), manovacuometry, and peak flow (PEF) were performed. Patients with MS had lower values of maximum inspiratory (MIP) and expiratory (MEP) pressures and PEF compared to healthy controls. It was shown that respiratory impairment may be present in MS patients with low functional disability by EDSS. The data suggest that manovacuometry and PEF determination should be carried out systematically in patients with MS, and may be a reliable tool for the early detection of respiratory impairment allowing early respiratory rehabilitation.

Assessment of respiratory functions by spirometry and phrenic nerve studies in patients of amyotrophic lateral sclerosis

OBJECTIVE

Spirometry is the most common test recommended to monitor respiratory dysfunction in patients of amyotrophic lateral sclerosis (ALS). However, the test depends on the patient's efforts and may be difficult to conduct in patients with faciobulbar weakness. We aimed to study the role of phrenic nerve-electrophysiological studies to predict respiratory dysfunction and correlate it with the forced vital capacity (FVC) in patients of ALS.

METHODS

Forty-three unselected patients (32 male, 25 with limb-onset ALS, age 50±15 years) with clinically definite or probable ALS were included. They were evaluated at entry and after a period of 6 months with the ALS functional rating scale (ALSFRS), their respiratory subscores (ALS-FRSr), their FVC values as determined by spirometry, and phrenic nerve studies.

RESULTS

Six patients could not perform a satisfactory spirometry at the onset and during the course of illness. All the six patients had severe faciobulbar weakness. Respiratory abnormalities on spirometry were found in 85% of patients, whereas only 30% were symptomatic for respiratory dysfunction. In patients with severe respiratory dysfunction (FVC<60%), the phrenic nerve motor amplitudes (PNAMPs) were significantly reduced compared to those with mild-to-moderate respiratory dysfunction (FVC≥60%). The FVC value showed a significant correlation with the PN-AMP. Nine patients had a poor outcome (death or severe disability) at the end of a period of 6 months. Low levels of both FVC and PN-AMP were predictors of poor outcome for patients at the end of 6 months.

CONCLUSION

We conclude that respiratory dysfunction, as determined by spirometry, is common in patients of ALS. However, only about one-third of patients show symptoms of respiratory distress. Clinical symptoms of respiratory distress are unreliable predictors of respiratory failure in ALS. Measurement of PN-AMP at the time of presentation may be an additional tool to assess respiratory dysfunction in ALS. Reduced PN-AMP values may be indicative of low FVC and may have some role in the assessment of respiratory function in patients in whom a routine spirometry is not possible due to limitations arising from the illness. Both low FVC and reduced PN-AMP at the time of presentation are predictors of poor outcome for patients at the end of 6 months.