Mechanically Assisted Coughing Research Articles

User-perceived impact of long-term mechanical assisted cough in paediatric neurodisability.

To (1) compare the perceived benefit of long-term mechanical insufflation-exsufflation (MI-E) of children with neuromuscular disorders (NMDs) and central nervous system (CNS) disorders, including health care needs and treatment routines and (2) describe the children's health-related quality of life (HRQoL). This cross-sectional study used a questionnaire and memory card data to assess the perceived benefit of MI-E via the Visual Analogue Scale (VAS; 10 maximum), willingness to pause treatment, level of health care needs before and after MI-E initiation, and the children's treatment routines. A DISABKIDS questionnaire assessed HRQoL (100 maximum). Seventy-three children using MI-E participated (42 males, median [interquartile range {IQR}] age 10 years 2 months [6 years 3 months-14 years 1 month]), 47 with NMDs (such as spinal muscular atrophy and Duchenne muscular dystrophy) and 26 with CNS disorders (such as cerebral palsy, encephalitis, neurometabolic and other diseases). The median (IQR) VAS score for the perceived benefit of MI-E therapy at stable state and respiratory tract infection were 9 (6-10) and 10 (8.5-10) respectively. Sixty-two per cent were reluctant or unwilling to pause MI-E therapy, with no NMD versus CNS disorder group difference. After MI-E initiation, fewer physician consultations and hospitalizations were reported by the group with NMDs. The MI-E routine was similar in both groups. The mean (SD) HRQoL score for 26 of 51 eligible children was 71 (16.7). MI-E treatment was generally perceived as beneficial and performed equally in both diagnostic groups. HRQoL was in line with children with a moderate-to-severe chronic condition. Mechanical insufflation-exsufflation (MI-E) was generally perceived as beneficial by the children and parents. The reported benefit of MI-E was higher among daily than sporadic MI-E users. The MI-E treatment routine did not differ between diagnostic groups. The health-related quality of life in this neuropaediatric population was in line with that of children with other moderate-to-severe chronic conditions.

Waveforms Analysis in Patients With Amyotrophic Lateral Sclerosis for Enhanced Efficacy of Mechanically Assisted Coughing.

Effectiveness of mechanical assisted coughing with insufflation-exsufflation (MI-E) in amyotrophic lateral sclerosis (ALS) depends largely on severity of bulbar dysfunction, which can generate different upper-airway responses. The aim of the study was to evaluate the use of graphs generated by MI-E in ALS to detect airway obstruction and set parameters to achieve an effective mechanically assisted coughing. This was a prospective study enrolling patients with ALS. Several sessions with MI-E were applied, administering different insufflation-exsufflation (± 20, ± 30, ± 40, ± 50 cm H2O) levels in each session. The graphs produced were recorded and analyzed, and the results were used to select the parameters resulting in more effective MI-E. Sixty-nine subjects with ALS were included, yielding a total of 351 analyzed records. A pattern of obstruction during insufflation was detected in 34 subjects (50.7%) and of upper-airway collapse during exsufflation in 18 subjects (26%). The variable associated with obstruction during insufflation was bulbar upper motor neuron dysfunction (odds ratio 7.19 [95% CI 2.32-22.29], P = .001), whereas bulbar lower motor neuron dysfunction was related to upper-airway collapse during exsufflation (odds ratio 0.32 [95% CI 0.11-0.98], P = .046). After parameters were adjusted, in 68 subjects (98.55%) an effective MI-E was achieved. The only variable that predicted absence of alterations in the graphs was Norris bulbar score (odds ratio 0.87 [95% CI 0.78-0.96], P = .007). Analysis of graphics generated by applying MI-E in ALS was an effective method to detect upper-airway responses and select optimal set parameters. Obstruction during insufflation is related to bulbar upper motor neuron dysfunction and collapse during exsufflation to bulbar lower motor neuron dysfunction.

Multiple breath washout lung function reveals ventilation inhomogeneity unresponsive to mechanical assisted cough in patients with neuromuscular disease

BackgroundRespiratory involvement defines the clinical outcome of neuromuscular diseases (NMD). The lung clearance index (LCI) is a marker of lung ventilation inhomogeneity and indicates small airway disease. It is determined by mulitple breath washout lung function (MBW). The merit of LCI is undisputed for primary lung diseases like cystic fibrosis, but its role in NMD is unclear.MethodsWe investigated the role of MBW in patients with NMD and the effect of two different tracer gases and cough assist devices on the LCI. Patients and controls performed MBW with nitrogen (N2) and sulfur hexafluoride (SF6), whereas the latter analysis was repeated after the use of a cough assist device in the NMD group. LCI was compared to forced vital capacity (FVC) and peak cough flow (PCF).Results24 NMD patients (12 Duchenne Muscular Dystrophy, 8 Spinal Muscular Atrophy, 4 other NMDs) and 15 healthy controls were enrolled. In the NMD group, overall LCI N2 was higher than LCI SF6 (9.67 ± 1.56 vs. 8.71 ± 1.47; mean ± SD; p < 0.033). In controls, LCI N2 did not differ significantly from LCI SF6 (7.03 ± 0.37 vs. 7.05 ± 0.67; p = 0.882). Both LCI N2 and LCI SF6 were significantly higher in NMD patients as in controls (9.67 ± 1.56 vs. 7.03 ± 0.37, p < 0.001, and 8.71 ± 1.478.65 vs. 7.05 ± 0.67, p < 0.001). In the NMD group, both LCI N2 and LCI SF6 showed a negative correlation to FVC (r = − 0.525; p = 0.008 and r = − 0.526; p = 0.008, respectively) and PCF (r = − 0.590; p = 0.002 and r = − 0.641; p = 0.001, respectively). LCI N2 and LCI SF6 correlated well in the NMD group. LCI SF6 did not change significantly after the use of the cough assist in NMD patients (n = 22; 8.65 ± 1.52 pre vs. 8.79 ± 2.03 post, p = 0.667).ConclusionLung involvement of patients with neuromuscular diseases goes beyond weakness of respiratory muscles. MBW with both N2 and SF6 is suitable to detect ventilation inhomogeneity in NMD patients with respiratory impairment. Cough assist devices with low to moderate pressure levels do not immediately improve the LCI.

Practical approach to respiratory emergencies in neurological diseases.

Many neurological diseases may cause acute respiratory failure (ARF) due to involvement of bulbar respiratory center, spinal cord, motoneurons, peripheral nerves, neuromuscular junction, or skeletal muscles. In this context, respiratory emergencies are often a challenge at home, in a neurology ward, or even in an intensive care unit, influencing morbidity and mortality. More commonly, patients develop primarily ventilatory impairment causing hypercapnia. Moreover, inadequate bulbar and expiratory muscle function may cause retained secretions, frequently complicated by pneumonia, atelectasis, and, ultimately, hypoxemic ARF. On the basis of the clinical onset, two main categories of ARF can be identified: (i) acute exacerbation of chronic respiratory failure, which is common in slowly progressive neurological diseases, such as movement disorders and most neuromuscular diseases, and (ii) sudden-onset respiratory failure which may develop in rapidly progressive neurological disorders including stroke, convulsive status epilepticus, traumatic brain injury, spinal cord injury, phrenic neuropathy, myasthenia gravis, and Guillain–Barré syndrome. A tailored assistance may include manual and mechanical cough assistance, noninvasive ventilation, endotracheal intubation, invasive mechanical ventilation, or tracheotomy. This review provides practical recommendations for prevention, recognition, management, and treatment of respiratory emergencies in neurological diseases, mostly in teenagers and adults, according to type and severity of baseline disease.

The effects of a practical guideline on medical management of patients with Duchenne muscular dystrophy

We conducted questionnaire surveys of Japanese certified Neurologists and Child Neurologists (CN) before and four years after the publication of the Japanese practical guideline for Duchenne muscular dystrophy (DMD-GL), published in 2014. After the publication, the number of responders who did not require expert support to treat new DMD patients increased from 33% to 37%. In addition, DMD-GL was listed as a preferred information source by 86% of specialists practicing DMD. Although there was no significant difference, CN has become more active in steroid therapy (Fig. 1), rehabilitation, and management of scoliosis. The ratio of introduction of non-invasive ventilation and mechanical assisted cough was significantly increased for respiratory care (Fig. 2). Nevertheless, the implementation rate for disaster countermeasure was rather declined. As for the myocardial treatment, specialists using ACEI preferentially increased while diuretics and digitalis decreased. There was no change in beta-blockers. Regarding nutritional management, the response to wait for the explanation of gastrostomy until the advanced stage decreased, and the response to recommend it early increased (Fig. 3). About medical care of carriers, around 40% of specialists responded that they did not have carriers requiring medical assessments. Excluding them, there was a tendency for the rate of cardiopulmonary assessment to increase. In rare disease such as DMD, it is difficult even for specialists to have sufficient experience. In this survey, we could confirm that DMD-GL became an essential tool in best practicable care. Based on the results, we wish to use it for DMD-GL revision and future activities.

Cough peak flow with different mechanically assisted coughing approaches under different conditions in patients with neuromuscular disorders.

Mechanically assisted coughing (MAC) is an airway clearance method in which the thorax/abdomen is compressed in synchronization with mechanical insufflation-exsufflation (MI-E). MAC can be performed with manual assistance at the upper thorax (MAC-UT), lower thorax (MAC-LT), and upper thorax + abdomen (MAC-UT/A). This study aimed to determine the most effective approach under different conditions (air stacking or tracheostomy) in patients with neuromuscular disorders (NMDs). The study included 34 patients with NMDs. The patients were categorized into air stacking group (n=15), no air stacking group (n=9), and tracheostomy/tracheostomy positive-pressure ventilation (TPPV) group (n=10). In each group, the cough peak flow (CPF) at 75% of the forced vital capacity (V̇75), V̇50, V̇25, and V̇10 were investigated during the approaches. In the air stacking group, the CPF was higher with MAC-UT, MAC-LT, and MAC-UT/A than with MI-E (p < 0.05). Additionally, V̇75 was higher with MAC-LT and MAC-UT/A than with MI-E (p < 0.05 and p < 0.01, respectively). In the no air stacking group, V̇75 was higher with MAC-UT/A than with MI-E (p < 0.05). In the tracheotomy/TPPV group, there were no significant differences. MAC approaches, especially MAC-LT and MAC-UT/A, are preferred in air stacking patients. However, in tracheostomy/TPPV patients, the CPF might not increase with MAC.

Physiological predictors of respiratory and cough assistance needs after extubation

BackgroundIdentifying patients at high risk of post-extubation acute respiratory failure requiring respiratory or mechanical cough assistance remains challenging. Here, our primary aim was to evaluate the accuracy of easily collected parameters obtained before or just after extubation in predicting the risk of post-extubation acute respiratory failure requiring, at best, noninvasive mechanical ventilation (NIV) and/or mechanical cough assistance and, at worst, reintubation after extubation.MethodsWe conducted a multicenter prospective, open-label, observational study from April 2012 through April 2015. Patients who passed a weaning test after at least 72 h of endotracheal mechanical ventilation (MV) were included. Just before extubation, spirometry and maximal pressures were measured by a technician. The results were not disclosed to the bedside physicians. Patients were followed until discharge or death.ResultsAmong 3458 patients admitted to the ICU, 730 received endotracheal MV for longer than 72 h and were then extubated; among these, 130 were included. At inclusion, the 130 patients had mean ICU stay and endotracheal MV durations both equal to 11 ± 4.2 days. After extubation, 36 patients required curative NIV, 7 both curative NIV and mechanical cough assistance, and 8 only mechanical cough assistance; 6 patients, all of whom first received NIV, required reintubation within 48 h. The group that required NIV after extubation had a significantly higher proportion of patients with chronic respiratory disease (P = 0.015), longer endotracheal MV duration at inclusion, and lower Medical Research Council (MRC) score (P = 0.02, P = 0.01, and P = 0.004, respectively). By multivariate analysis, forced vital capacity (FVC) and peak cough expiratory flow (PCEF) were independently associated with (NIV) and/or mechanical cough assistance and/or reintubation after extubation. Areas under the ROC curves for pre-extubation PCEF and FVC were 0.71 and 0.76, respectively.ConclusionIn conclusion, FVC measured before extubation correlates closely with FVC after extubation and may serve as an objective predictor of post-extubation respiratory failure requiring NIV and/or mechanical cough assistance and/or reintubation in heterogeneous populations of medical ICU patients.ClinicalTrials.gov as #NCT01564745

Laryngeal response patterns influence the efficacy of mechanical assisted cough in amyotrophic lateral sclerosis

BackgroundMost patients with amyotrophic lateral sclerosis (ALS) are treated with mechanical insufflation–exsufflation (MI-E) in order to improve cough. This method often fails in ALS with bulbar involvement, allegedly due to...

Management of patients with neuromuscular disorders and acute respiratory failure

Acute respiratory failure (ARF) is a common cause of morbidity and mortality in most advanced neuromuscular disorders (NMD). Deterioration of lung function during NMD may have different severity and time course. During slowly progressive neuromuscular disease an acute event can precipitate the respiratory failure, while rapidly progressive NMD may present as ARF at the onset of the disease. During ARF a patient with NMD may be affected by inspiratory muscles weakness responsible for decreased ventilation, expiratory muscles weakness responsible for altered coughing effectiveness, and bulbar involvement responsible for altered swallowing and airway protection. Neuromuscular disorders may also affect central control of breathing, sleep disorder, bones and joints deformities with consequent ventilatory dysfunction. Usually ARF in NMD is prompted by precipitating factors such as upper airways infections, pneumonia, atelectasis etc. It is important to distinguish respiratory failure due to an acute event or to a rapidly progression of underlying conditions to properly allocate the patient in the more appropriate setting of care. Generally, excessive invasiveness of care must be avoided, and a pro-active early rehabilitation program may help early recovery and minimize complications. Mechanical non invasive positive pressure ventilation(NIPPV) combined with mechanically assisted coughing (MAC) has been established as the standard treatment of severe ARF in NMD. Superiority of NIPPV vs invasive mechanical ventilation (MV) was showed in term of lower mortality, treatment failure, duration of ICU in several studies. Home mechanical noninvasive ventilation and MAC may result dramatic reduction in the need for hospitalization and a prolongation of life expectancy of these patients. To avoid the progression of respiratory failure an early identification of respiratory deterioration is needed, as such as prevention of acute episodes. So, especially in the progressive diseases, is very important to monitor respiratory status with periodic lung function tests. Any respiratory tract infection in neuromuscular disease could trigger acute respiratory failure so it is mandatory take any aggressive measures to prevent and treat this complication. Some of principal preventive measures include vaccination against Pneumococcus Pn. and influenza virus, early antibiotic treatment when bacterial infection is suspected, chest physiotherapy for removal airway secretions or mechanical assisted maneuvers to increase cough efficiency. In conclusion, a proactive, preventive approach is the key for optimal management acute respiratory problems in neuromuscular disorders.

Tuning of mechanical cough assistance in neuromuscular patients by optoelectroinc plethysmography

Tuning of mechanical cough assistance in neuromuscular patients by optoelectroinc plethysmography

Noninvasive respiratory management and diaphragm and electrophrenic pacing in neuromuscular disease and spinal cord injury

The purpose of this monograph is to describe noninvasive management of respiratory muscle weakness/paralysis for patients with neuromuscular disease (NMD) and spinal cord injury (SCI). Noninvasive ventilation (NIV) assists and supports inspiratory muscles, whereas mechanically assisted coughing (MAC) simulates an effective cough. Long-term outcomes will be reviewed as well as the use of NIV, MAC, and electrophrenic pacing (EPP) and diaphragm pacing (DP) to facilitate extubation and decannulation. Although EPP and DP can facilitate decannulation and maintain alveolar ventilation for high-level SCI patients when they cannot use NIV because of lack of access to oral interfaces, there is no evidence that they have any place in the management of NMD.

Spinal Muscular Atrophy Type 1

The aim of this study was to report the outcomes of an oximetry protocol using up to continuous full ventilator-setting noninvasive ventilation (NIV) and mechanically assisted coughing (MAC) to avoid episodes of acute respiratory failure and hospitalizations for children with spinal muscular atrophy type 1 under 3 yrs of age. This study was a retrospective chart review of 16 patients with spinal muscular atrophy type 1 under 3 yrs of age consecutively referred for respiratory decompensations resulting in continuous NIV dependence and oxyhemoglobin desaturation. An avoided hospitalization was defined by the need for continuous NIV using high span bilevel positive airway pressure and reversal of desaturations by MAC in the home setting. The protocol included training and equipping parents to use NIV, MAC, and basic life support. There were 49 acute episodes (1.20/patient per year), of which 43 met the criteria for an avoided hospitalization. Therefore, only six episodes (0.15/patient per year) required hospitalization, and four required endotracheal intubation (0.1/patient per year). Three of the four were extubated after 4, 9, and 15 days, respectively, to full NIV support and aggressive MAC. The fourth patient, for whom NIV could not be provided, underwent an emergency intubation at home and died at the age of 40 mos. A protocol including high span bilevel positive airway pressure along with MAC to expel airway secretions and normalize oxyhemoglobin saturation can be used by trained caregivers to avoid episodes of acute respiratory failure and hospitalization for children with spinal muscular atrophy type 1 under 3 yrs of age.

Home tracheotomy mechanical ventilation in patients with amyotrophic lateral sclerosis: causes, complications and 1-year survival

BackgroundHome tracheotomy mechanical ventilation (HTMV) can prolong survival in patients with amyotrophic lateral sclerosis (ALS) when non-invasive ventilation (NIV) fails, but knowledge about HTMV is scarce. The aim of this...

Duchenne muscular dystrophy: Survival by cardio-respiratory interventions

We describe survival in Duchenne dystrophy by invasive and noninvasive ventilation vs. untreated. Patients were untreated prior to 1984 (Group 1), underwent tracheotomy from 1984 until 1991 (Group 2), and were managed by noninvasive mechanical ventilation and cardioprotective medications subsequently (Group 3). Symptoms, vital capacity, and blood gases were monitored for all and spirometry, cough peak flows, carbon dioxide tension, and oximetry for Group 3. Sleep nasal ventilation was initiated for symptomatic hypoventilation. An oximeter and mechanical cough assistance were prescribed for maximum assisted cough peak flow <300 L/m. Patients used continuous noninvasive ventilation and mechanically assisted coughing as needed to maintain pulse oxyhemoglobin saturation ⩾95%. Survival was compared by Kaplan–Meier analysis. The 56 of Group 1 died at 18.6 ± 2.9, the 21 Group 2 at 28.1 ± 8.3 years of age with three still alive, and the 88 using noninvasive ventilation had 50% survival to 39.6 years, p < 0.001, respectively. We conclude that noninvasive mechanical ventilation and assisted coughing provided by specifically trained physicians and therapists, and cardioprotective medication can result in more favorable outcomes and better survival by comparison with invasive treatment.

Extubation of Patients With Neuromuscular Weakness: A New Management Paradigm

Successful extubation conventionally necessitates the passing of spontaneous breathing trials (SBTs) and ventilator weaning parameters. We report successful extubation of patients with neuromuscular disease (NMD) and weakness who could not pass them.NMD-specific extubation criteria and a new extubation protocol were developed. Data were collected on 157 consecutive "unweanable" patients, including 83 transferred from other hospitals who refused tracheostomies. They could not pass the SBTs before or after extubation. Once the pulse oxyhemoglobin saturation (Spo(2)) was maintained at > or = 95% in ambient air, patients were extubated to full noninvasive mechanical ventilation (NIV) support and aggressive mechanically assisted coughing (MAC). Rather than oxygen, NIV and MAC were used to maintain or return the Spo(2) to > or = 95%. Extubation success was defined as not requiring reintubation during the hospitalization and was considered as a function of diagnosis, preintubation NIV experience, and vital capacity and assisted cough peak flows (CPF) at extubation.Before hospitalization 96 (61%) patients had no experience with NIV, 41 (26%) used it < 24 h per day, and 20 (13%) were continuously NIV dependent. The first-attempt protocol extubation success rate was 95% (149 patients). All 98 extubation attempts on patients with assisted CPF > or = 160 L/m were successful. The dependence on continuous NIV and the duration of dependence prior to intubation correlated with extubation success (P < .005). Six of eight patients who initially failed extubation succeeded on subsequent attempts, so only two with no measurable assisted CPF underwent tracheotomy.Continuous volume-cycled NIV via oral interfaces and masks and MAC with oximetry feedback in ambient air can permit safe extubation of unweanable patients with NMD.

At Home and on Demand Mechanical Cough Assistance Program for Patients With Amyotrophic Lateral Sclerosis

To establish a cost-effective telephone-accessed consultation and mechanical in-exsufflation (MI-E) and manually assisted coughing, oximetry feedback program for 39 patients with amyotrophic lateral sclerosis. Rapid access to healthcare consultation and to MI-E was provided to treat episodes of distress as a result of secretion encumbrance not reversed by suctioning and associated with a decrease in oxyhemoglobin saturation (SpO(2)) baseline. Avoided hospitalizations, defined by relief of respiratory distress and return of SpO(2) baseline to >or=95% by continuous ventilator use and assisted coughing, were recorded. Patient satisfaction was queried at 6 mos, and a cost analysis was performed of continuous vs. on demand MI-E use. Thirty-nine patients made a total of 1661 calls in 7.46 +/- 5.8 mos of follow-up. Twenty-seven patients had 66 home care visits by a respiratory therapist for a total time commitment of 89.7 +/- 99.3 min/patient/mo. Twelve patients, all ventilator users, were also brought mechanical in-exsufflators for mechanically assisted coughing for 47 respiratory episodes. Thirty hospitalizations were avoided. Seventy-five percent of the patients were extremely satisfied. Mean monthly cost per patient for on-demand telephone consultation, professional home healthcare visits, and MI-E as deemed necessary was euro403 +/- euro420 or 59% less than for continuous MI-E rental. Hospitalization costs were also spared. An on-demand consult and MI-E access program can avoid hospitalizations for patients with amyotrophic lateral sclerosis with significant cost savings.

Sekretmanagement bei neuromuskulären Erkrankungen

Many patients with neuromuscular diseases suffer from a weak cough. Due to infection or aspiration a life-threatening situation may occur. There are different options for the therapists to improve secretion clearance from the airways in the patient with a weak cough. Furthermore, there are indications that consequent practice of techniques to ameliorate bronchial clearance may also improve the prognosis of patients with neuromuscular diseases. The management of secretions in neuromuscular disorders does not consist of single actions but is rather a complex programme. Diagnostics and several therapeutic measures have to be performed intensely and regularly. The diagnosis of a weak cough flow is based on anamnestic data, e. g., increase in secretions or dysphagia, physical examination, e. g., paradoxical breathing, and easily measured lung function parameters like vital capacity and peak cough flow (PCF). The diagnosis of an accumulation of secretions in the airways can be made easily by means of a pulse oximetry: while breathing room air the oxygen saturation in the case of a healthy lung and clean airways will be better than 95 %. A decline can, among others, be induced by amounts of secretions in the airways. The consequence should be measures to improve secretion expectoration (so-called oximetry-feedback protocol). To assist in secretion elimination from the airways several means are available like air stacking, manually assisted cough and mechanical assisted coughing--e. g., mechanical insufflator-exsufflator. Which of these techniques should be used depends on the extent of the disease: with preserved facial and bulbar muscles, air stacking alone or in combination with manually assisted coughing may be adequate and effective in the home care of the patient. In case of failure of these means, e. g., in bulbar paralysis, there is the possibility to apply mechanically assisted coughing by means of the mechanical insufflator-exsufflator. In case of tracheostomy, air stacking or mechanical assisted coughing has to be combined with tracheal suctioning. Acute infections of the lower airways are a special challenge: personnel intensive application of a combination of different secretion eliminating techniques, e. g., bronchoscopy in the hospital, manually assisted coughing and mechanically assisted coughing have to be performed in high intensity to avoid intubation. The early diagnosis of a weak cough in NMD patients is important for the timely start of existing and effective measures for improving the capacity of elimination of secretions--air stacking, manually assisted cough and mechanically assisted cough. Although there is no high degree of evidence, we believe that morbidity and possibly mortality can be affected in a positive manner.

Nichtinvasive Beatmung: Möglichkeiten und Grenzen bei eingeschränkter Hustenfunktion

Neuromuscular diseases cover a wide range of pathologies, which are slowly or rapidly progressive. Besides the reduced capacity of the inspiratory muscles there is a limitation of expiration which compromises coughing. Ventilatory respiratory insufficiency (VRI) develops in stages, beginning during sleep with hypercapnia manifesting later on. Several retrospective studies have shown an improved alveolar ventilation, survival and quality of life for most NMD, even in non-bulbar ALS. The initiation of NIV is seen as apropriate when VRI in sleep develops. But patient acceptance to use NIV for more than 4 hours must be taken into account. NIV is limited by the interface which may cause skin abrasions or leakage due to pressure. NIV may be used day and night in stable conditions and with assistance experienced in mechanically-assisted coughing (MAC). The discussion of whether to perform tracheostomy remains a preeminent topic especially in ALS. NIV is effective in NMD and improves and prolongs life in slowly progressive NMD. Mask problems, leakage and bulbar dysfunction can limit the effectiveness. MAC is a tool that is very useful for elimination of bronchial secretions.

Physiologic Benefits of Mechanical Insufflation-Exsufflation in Children With Neuromuscular Diseases

To analyze the physiologic effects and tolerance of mechanical insufflation-exsufflation (MI-E) by means of mechanical cough assistance (Cough Assist; JH Emerson Company; Cambridge, MA) for children with neuromuscular disease. Prospective clinical trial. Physiology laboratory of a pediatric pulmonary department of a university hospital. Seventeen children with Duchenne muscular dystrophy (n = 4), spinal muscular atrophy (n = 4), or other congenital myopathy (n = 9) who were in a stable state. Pressures of 15, 30, and 40 cm H(2)O were cycled to each patient, with 2 s for insufflation and 3 s for exsufflation. One application consisted of six cycles at each pressure for a total of three applications. Airway pressure and airflow were measured during every application. Breathing pattern, vital capacity (VC), sniff nasal inspiratory pressure (SNIP), peak expiratory flow (PEF), and respiratory comfort were evaluated at baseline and after each application. The tolerance of the patients was excellent, with a significant increase in the respiratory comfort score in all of the patients (p = 0.02). Expired volume during the MI-E application increased significantly to reach twice the VC at 40 cm H(2)O. Mean and maximal inspiratory and expiratory flows increased in a pressure-dependent manner. Breathing pattern did not change after the MI-E applications and pulse oximetric saturation remained stable within normal values, but the mean end-tidal carbon dioxide pressure decreased significantly. VC did not change, but the mean SNIP and PEF improved significantly after MI-E applications. Our results confirm the good tolerance and physiologic short-term benefit of the MI-E in children with neuromuscular disease who were in a stable state.

Oximetry and Indications for Tracheotomy for Amyotrophic Lateral Sclerosis

To explore the use of oximetry as a guide for using respiratory aids and tracheotomy in the treatment of patients with amyotrophic lateral sclerosis (ALS). A retrospective review of all ALS patients presenting to a neuromuscular disease clinic since 1996. Patients who were symptomatic for nocturnal hypoventilation were prescribed noninvasive ventilation (NIV). Patients with assisted cough peak flows of < 300 L/min were prescribed oximeters and access to mechanically assisted coughing (MAC) to prevent or reverse decreases in baseline pulse oximetric saturation (Spo(2)) levels of < 95%. The number of decreases in baseline Spo(2) that could be normalized by any combination of NIV and MAC and the duration of normalization were recorded. When the baseline was not or could not be normalized, the time to acute respiratory failure and tracheotomy or death were recorded. Twenty-five patients became dependent on NIV, including 13 patients who received NIV continuously for a mean (+/- SD) period of 19.7 +/- 16.9 months, without desaturation (group 1). For another 76 patients, the daytime baseline Spo(2) level decreased to < 95% 78 times. For 41 patients, the baseline level was corrected by NIV/MAC (group 2) for a mean duration of 11.1 +/- 8.7 months before desaturation reoccurred for 27 patients. Of the latter patients, 11 underwent tracheotomy, 14 died in < 2 months, and 2 had their condition again corrected by the addition of MAC therapy. For 35 patients, the desaturation was not or could not be normalized (group 3). Thirty-three of these 35 patients required tracheotomy or died within 2 months. The only significant difference between groups 1 and 2 and group 3 was significantly poorer glottic function in the patients in group 3. Tracheotomy or death is highly likely within 2 months of a decrease in baseline Spo(2) that cannot be corrected by NIV or MAC. The long-term use of NIV and MAC, and the avoidance of tracheotomy is dependent on glottic function rather than on inspiratory or expiratory muscle failure.