Michel Toussaint

Effect of non-invasive ventilation on respiratory muscle loading and endurance in patients with Duchenne muscular dystrophy

Background: Respiratory muscle weakness in patients with Duchenne muscular dystrophy (DMD) leads to respiratory failure for which non-invasive positive pressure ventilation (NIPPV) is an effective treatment. This is used initially at night (n-NIPPV) but, as the disease progresses, diurnal use (d-NIPPV) is often necessary. The connection between NIPPV and relief of respiratory muscle fatigue remains unclear. A study was undertaken to determine the extent to which n-NIPPV and d-NIPPV unload the respiratory muscles and improve respiratory endurance in patients with DMD. Methods: Fifty patients with DMD were assessed at 20.00 and 08.00 h. More severely affected patients with nocturnal hypoventilation received n-NIPPV; those with daytime dyspnoea also received d-NIPPV via a mouthpiece (14.00–16.00 h). Lung function, modified Borg dyspnoea score, spontaneous breathing pattern, tension-time index (TT0.1 = occlusion pressure (P0.1)/maximum inspiratory pressure (MIP) × duty cycle (Ti/Ttot)) and respiratory muscle endurance time (Tlim) against a threshold load of 35% MIP were measured. Results: More severe respiratory muscle weakness was associated with a higher TT0.1 and lower Tlim. In contrast to non-dyspnoeic patients, patients with dyspnoea (Borg score >2.5/10) showed an increase in Tlim and decrease in TT0.1 after n-NIPPV. At 16.00 h, immediately after d-NIPPV, patients with dyspnoea had lower TT0.1 and Borg scores with unchanged Tlim. Compared with the control day without d-NIPPV, TT0.1, Borg scores and Tlim were all improved at 20.00 h. Conclusions: In patients with dyspnoea with DMD, the load on respiratory muscles increases and endurance capacity decreases with increasing breathlessness during the day, and this is reversed by n-NIPPV. An additional 2 h of d-NIPPV unloads respiratory muscles and reverses breathlessness more effectively than n-NIPPV alone.

Dysphagia in Duchenne muscular dystrophy: practical recommendations to guide management

Abstract Purpose: Duchenne muscular dystrophy (DMD) is a rapidly progressive neuromuscular disorder causing weakness of the skeletal, respiratory, cardiac and oropharyngeal muscles with up to one third of young men reporting difficulty swallowing (dysphagia). Recent studies on dysphagia in DMD clarify the pathophysiology of swallowing disorders and offer new tools for its assessment but little guidance is available for its management. This paper aims to provide a step-by-step algorithm to facilitate clinical decisions regarding dysphagia management in this patient population. Methods: This algorithm is based on 30 years of clinical experience with DMD in a specialised Centre for Neuromuscular Disorders (Inkendaal Rehabilitation Hospital, Belgium) and is supported by literature where available. Results: Dysphagia can worsen the condition of ageing patients with DMD. Apart from the difficulties of chewing and oral fragmentation of the food bolus, dysphagia is rather a consequence of an impairment in the pharyngeal phase of swallowing. By contrast with central neurologic disorders, dysphagia in DMD accompanies solid rather than liquid intake. Symptoms of dysphagia may not be clinically evident; however laryngeal food penetration, accumulation of food residue in the pharynx and/or true laryngeal food aspiration may occur. The prevalence of these issues in DMD is likely underestimated. Conclusions: There is little guidance available for clinicians to manage dysphagia and improve feeding for young men with DMD. This report aims to provide a clinical algorithm to facilitate the diagnosis of dysphagia, to identify the symptoms and to propose practical recommendations to treat dysphagia in the adult DMD population. Implications for Rehabilitation Little guidance is available for the management of dysphagia in Duchenne dystrophy. Food can penetrate the vestibule, accumulate as residue or cause aspiration. We propose recommendations and an algorithm to guide management of dysphagia. Penetration/residue accumulation: prohibit solid food and promote intake of fluids. Aspiration: if cough augmentation techniques are ineffective, consider tracheostomy.

Intrapulmonary Effects of Setting Parameters in Portable Intrapulmonary Percussive Ventilation Devices

BACKGROUND: Despite potential benefits of intrapulmonary percussive ventilation (IPV) in various respiratory diseases, the impact of setting parameters on the mechanical effects produced by IPV in the lungs is unknown. We hypothesized that changing the parameters on IPV would modulate these effects. This in vitro study aimed at comparing the changes in intrapulmonary effects resulting from changes in parameters in 3 portable IPV devices (IMP2, Impulsator, and Pegaso). METHODS: Parameters were set in 72 combinations of frequency (90–250 cycles/min), inspiratory to expiratory (I/E) time ratio (from 1/2 to 3/1), and pressure (10–60 cm H2O). Four resulting effects were recorded on a test lung via a pneumotachometer: the expiratory to inspiratory flow ratio (E/I flow ratio), the PEEP, the ventilation, and the percussion. Percussion was assessed by the end-slope of the pressure curve. Analysis of variance was used for data analysis. RESULTS: E/I flow ratio increased with increasing I/E time ratio (P < .001). The Pegaso produced the lowest E/I flow ratio. PEEP raised 6 cm H2O in both IMP2 and Impulsator, and 17 cm H2O in the Pegaso with increasing frequency (P < .01), pressure, and I/E time ratio (P < .001). In all devices, ventilation increased with increasing pressure and decreasing frequency (P < .001). Percussion increased with increasing frequency and decreasing I/E time ratio (P < .001), and with increasing pressure when I/E time ratio was 1/1 or less. The Pegaso provided the poorest percussion. CONCLUSIONS: This study suggests that changing the parameters considerably modulates the mechanical effects produced by portable IPV devices in the lungs. Increasing frequency increased PEEP and percussion, but decreased ventilation. Increasing I/E time increased PEEP and E/I flow ratio, and decreased percussion. Finally, increasing pressure increased PEEP and ventilation. The Pegaso produced the highest PEEP, least percussion, and smallest change in E/I flow ratio.

The Use of Mechanical Insufflation-Exsufflation Via Artificial Airways

During the past 20 years, airway clearance techniques have been the subject of increasing scientific interest. Cough augmentation with mechanical insufflation-exsufflation is part of this trend. No fewer than 23 studies, of which 21 were published in the past 10 years, have improved the level of

Cough Augmentation in Subjects With Duchenne Muscular Dystrophy: Comparison of Air Stacking via a Resuscitator Bag Versus Mechanical Ventilation

BACKGROUND: Air stacking improves cough effectiveness in people with Duchenne muscular dystrophy (DMD) and respiratory muscle weakness. However, it is not known whether air stacking is more effective via a resuscitator bag or a home ventilator. METHODS: This prospective randomized study investigated the effect of air stacking via a volume-cycled home ventilator versus via a resuscitator bag in participants with DMD. Maximum insufflation capacity and peak expiratory flow during spontaneous (cough peak flow) and air stacking-assisted cough maneuvers (air stacking-assisted cough peak flow) were measured. RESULTS: Fifty-two adult DMD subjects receiving noninvasive ventilation were included in the study: 27 participants performed air stacking via their home ventilator (home-ventilator group; age = 25.3 ± 5.1 y; forced vital capacity (FVC) = 809 ± 555 mL), and 25 participants used a resuscitator bag (resuscitator-bag group; age = 24.7 ± 5.7 y, FVC = 807 ± 495 mL). Following a single training session, air stacking could be performed successfully by 89% (home ventilator) and 88% (resuscitator bag) of participants. There were comparable maximum insufflation capacities (1,481 mL for the home-ventilator group vs 1,344 mL for the resuscitator-bag group, P = .33) and mean air stacking-assisted cough peak flow values (199 L/min for the home-ventilator group vs 186 L/min for the resuscitator-bag group, P = .33) between techniques. Air stacking-assisted cough peak flow increased significantly compared with baseline in both groups (mean increase: +51% [home ventilator] vs +49% [resuscitator bag], P < .001), with individual air stacking-assisted cough peak flow improvements ranging from −20 to 245%. CONCLUSIONS: Cough augmentation is an important component of the respiratory management of people with a neuromuscular disorder. No difference in cough effectiveness as measured by air stacking-assisted cough peak flow was found in air stacking via a ventilator compared with via a resuscitator bag. Both methods achieved mean air stacking-assisted cough peak flow values of >160 L/min. Provision of an inexpensive resuscitator bag can effectively improve cough capacity, and it is simple to use, which may improve access to respiratory care in people with DMD.

Respiratory morbidity in children with cerebral palsy: an overview

Respiratory problems have a significant impact on morbidity and mortality in patients with cerebral palsy (CP). In particular, recurrent aspiration, impaired airway clearance, spinal and thoracic deformity, impaired lung function, poor nutritional status, and recurrent respiratory infections negatively affect respiratory status. Bronchopulmonary dysplasia may contribute to pulmonary problems, but asthma is not more common in CP than in the general population. We discuss treatment options for each of these factors. Multiple coexisting and interacting factors that influence the respiratory status of patients with CP should be recognized and effectively addressed to reduce respiratory morbidity and mortality.

Noninvasive Respiratory Care Received by Individuals With Duchenne Muscular Dystrophy Since 1979

To the Editor: The authors of a recent review of Duchenne muscular dystrophy (DMD) management[1][1] nicely pointed out that Dr Ishikawas group reported survival for DMD subjects to a mean age of 39.6 y, but neither that 38 of them were dependent on continuous noninvasive ventilatory support nor

Intensive Management of Chronic Bronchorrhea in a Tracheostomized Duchenne Patient with Bronchiectasis

Duchenne muscular dystrophy (DMD) is a severe X-linked hereditary neuromuscular disease characterized by progressive muscle degeneration and functional tetraplegia. Advances related to the use of mechanical ventilation and techniques of airway clearance have improved the lifespan of these patients until 30-35 years. In a 27 years old home-ventilated tracheostomized DMD patient affected by bronchiectasis and atelectasis with excessive bronchorrhea (>300ml mucus production/24h), endotracheal suctioning act became so frequent that it severely affected his mental health and that of his family. An intensive programme of airway clearance including ventilation via Intrapulmonary Percussive Ventilation (IPV) and suctioning via mechanical insufflation-exsufflation (MI-E) associated with strong manual chest compression improved mean nocturnal SpO2 from 91 to 95% and reduced mucus production and suctioning rate by 50%. The perceived physical and emotional health (SF-36) increased in the patient and in his family. In the patient, the general mental health score increased from 16 to 48%, the vitality from 10 to 40% and the general health perception from 10 to 35%. In the patient’s father, the social functioning improved from 38 to 63%, the general mental health from 36 to 60% and the vitality from 35 to 60%. In this report, intensive respiratory therapy with IPV in combination with MI-E and chest compression was safe and spectacularly improved the quality of ventilation, the mucus production and the perceived mental health in an adult Duchenne patient with bronchorrhea.