Eduardo L. De Vito

Peak Flow and Peak Cough Flow in the Evaluation of Expiratory Muscle Weakness and Bulbar Impairment in Patients with Neuromuscular Disease

Suárez AA, Pessolano FA, Monteiro SG, Ferreyra G, Capria ME, Mesa L, Dubrovsky A, De Vito EL: Peak flow and peak cough flow in the evaluation of expiratory muscle weakness and bulbar impairment in patients with neuromuscular diseases. Am J Phys Med Rehabil 2002;81:506–511. Objective To study the expiratory muscle force and the ability to cough estimated by the peak expiratory flow and peak cough flow in patients with Duchenne muscular dystrophy and amyotrophic lateral sclerosis. Design A total of 27 patients with amyotrophic lateral sclerosis and 52 patients with Duchenne muscular dystrophy were studied. From the group of 144 normal subjects of this laboratory, we selected 38 for comparison. Results The maximal inspiratory pressure in patients with Duchenne muscular dystrophy and amyotrophic lateral sclerosis was 64.5 ± 24.7% and 37.8 ± 21.8%, respectively, and maximal expiratory pressure was 64.2 ± 32.5% and 37.7 ± 21.6%, respectively. Patient groups showed a significant lower peak expiratory flow than normal subjects. Higher peak cough flow than peak expiratory flow was found in all groups. The peak cough flow–peak expiratory flow difference was 46 ± 18% in normal subjects, 43 ± 23% in patients with Duchenne muscular dystrophy, and 11 ± 17% in patients with amyotrophic lateral sclerosis. The peak expiratory flow and peak cough flow were not different in bulbar onset amyotrophic lateral sclerosis. In patient groups, the dynamic and static behavior correlated positively. Conclusions These results suggest that peak cough flow–peak expiratory flow is useful to monitor expiratory muscle weakness and bulbar involvement and to assess its evolution in these patients.

Changing trends in the management of end-stage neuromuscular respiratory muscle failure: recommendations of an international consensus.

ObjectiveRespiratory management of patients with end-stage respiratory muscle failure of neuromuscular disease has evolved from no treatment and inevitable respiratory failure to the use of up to continuous noninvasive intermittent positive pressure ventilatory support (CNVS) to avert respiratory failure and to permit the extubation of “unweanable” patients without tracheostomy. An international panel experienced in CNVS was charged by the 69th Congress of the Mexican Society of Pulmonologists and Thoracic Surgeons to analyze changing respiratory management trends and to make recommendations. DesignNeuromuscular disease respiratory consensuses and reviews were identified from PubMed. Individual respiratory interventions were identified; their importance was established by assessing the quality of evidence-based literature for each one and their patterns of use over time. The panel then determined the evidence-based strength for the efficacy of each intervention and made recommendations for achieving prolonged survival by CNVS. ResultsFifty publications since 1993 were identified. Continuous positive airway pressure, oxygen therapy, bilevel positive airway pressure used at both low and high spans, “air stacking,” manually assisted coughing, low pressure (<35 cm H2O) and high pressure (≥40 cm H2O) mechanically assisted coughing, noninvasive positive pressure ventilation part time (<23 hrs per day) and full time (>23 hrs per day; CNVS), extubation and decannulation of ventilator-dependent patients to CNVS, and oximetry feedback for noninvasive positive pressure ventilation and mechanically assisted coughing were identified. All noted interventions are being used with increasing frequency and were unanimously recommended to achieve prolonged survival by CNVS, with the exception of supplemental oxygen and continuous positive airway pressure, which are being used less and were not recommended for this population. ConclusionsCNVS and extubation of unweanable patients to CNVS are increasingly being used to prolong life while avoiding invasive interfaces.

Nutritional Assessment of Patients with Neuromuscular Diseases

Pessolano FA, Súarez AA, Monteiro SG, Mesa L, Dubrovsky A, Roncoroni AJ, De Vito EL: Nutritional assessment of patients with neuromuscular diseases. Am J Phys Med Rehabil 2003;82:182–185. Objective To study the nutritional status of patients with Duchenne muscular dystrophy and amyotrophic lateral sclerosis. Design A total of 34 Duchenne muscular dystrophy and seven amyotrophic lateral sclerosis patients were studied. Body mass index, patient’s body weight for zero muscle mass as a percentage of the theoretical weight for zero muscle mass, and creatinine-height index were calculated. Results Substantial differences were found between body mass index and percentage of expected weight for zero muscle mass. No amyotrophic lateral sclerosis patients were classified as overweight by body mass index, whereas five were overweight by the percentage of expected weight for zero muscle mass method. Five Duchenne muscular dystrophy patients were classified as overweight by body mass index, and 30 were overweight by the percentage of expected weight for zero muscle mass. According to the creatinine-height index, no patient with amyotrophic lateral sclerosis or Duchenne muscular dystrophy showed normal body muscle mass. No correlation was found between creatinine-height index, percentage of expected weight for zero muscle mass, and body mass index. Conclusions The body mass index should be used with caution for the evaluation of the nutritional status of patients with amyotrophic lateral sclerosis and Duchenne muscular dystrophy. Indices that incorporate the assessment of the compartmental distribution of muscle and fat are more sensitive.

The use of full-setting non-invasive ventilation in the home care of people with amyotrophic lateral sclerosis-motor neuron disease with end-stage respiratory muscle failure: a case series

IntroductionLittle has been written about the use of non-invasive ventilation in the home care of amyotrophic lateral sclerosis-motor neuron disease patients with end-stage respiratory muscle failure. Nocturnal use of non-invasive ventilation has been reported to improve daytime blood gases but continuous non-invasive ventilation dependence has not been studied in this regard. There continues to be great variation by country, economics, physician interest and experience, local concepts of palliation, hospice requirements, and resources available for home care. We report a case series of home-based amyotrophic lateral sclerosis-motor neuron disease patients who refused tracheostomy and advanced non-invasive ventilation to full-setting, while maintaining normal alveolar ventilation and oxygenation in the course of the disease. Since this topic has been presented in only one center in the United States and nowhere else, it is appropriate to demonstrate that this can be done in other countries as well.Case presentationWe present here the cases of three Caucasian patients (a 51-year-old Caucasian man, a 45-year-old Caucasian woman and a 57-year-old Caucasian woman) with amyotrophic lateral sclerosis who developed continuous non-invasive ventilation dependence for 15 to 27 months without major complications and were able to maintain normal CO2 and pulse oxyhemoglobin saturation despite a non-measurable vital capacity. All patients were wheelchair-dependent and receiving riluzole 50 mg twice a day. Patient one developed mild-to-moderate bulbar-innervated muscle weakness. He refused tracheostomy but accepted percutaneous gastrostomy. Patient two had two lung infections, acute bronchitis and pneumonia, which were treated with antibiotics and cough assistance at home. Patient three had three chest infections (bronchitis and pneumonias) and asthmatic episodes treated with antibiotics, bronchodilators and cough assistance at home. All patients had normal speech while receiving positive pressure; they died suddenly and with normal oxygen saturation.ConclusionsAlthough warned that prognosis was poor as vital capacity diminished, our patients survived without invasive airway tubes and despite non-measurable vital capacity. No patient opted for tracheos tomy. Our patients demonstrate the feasibility of resorting to full-setting non-invasive management to prolong survival, optimizing wellness and management at home, and the chance to die peacefully.

Blunted Hypercapnic Respiratory Drive Response in Subjects With Late-Onset Pompe Disease

BACKGROUND: Patients with late-onset Pompe disease develop progressive hypercapnic respiratory failure that can be disproportionate to the respiratory muscle compromise and/or thoracic restriction. Although recent studies have reported the presence of a blunted hypercapnic respiratory response in some subjects with neuromuscular disorders and chronic hypercapnia, no study has evaluated the integrity of the respiratory drive in subjects with late-onset Pompe disease. Thus, we endeavor to determine the CO2 rebreathing response in subjects with late-onset Pompe disease. METHODS: Respiratory muscle strength was assessed by measuring the maximum inspiratory pressure, and the maximum expiratory pressure. The maximum inspiratory pressure reflects the strength of the diaphragm and other inspiratory muscles, whereas the maximum expiratory pressure reflects the strength of the abdominal muscles and other expiratory muscles. We studied the hypercapnic drive response (measured as the ratio of the change in airway-occlusion pressure 0.1 s after the start of inspiration and end-tidal PCO2 in 13 subjects with late-onset Pompe disease and 51 healthy controls. RESULTS: Overall inspiratory muscle strength was within normal limits or slightly diminished in the late-onset Pompe disease group. Five subjects (38.5%) were chronically hypercapnic, and 9 (69.2%) had an increased breath-holding time. Compared with controls, the change in airway-occlusion pressure 0.1 s/change in end-tidal CO2 pressure slope (hypercapnic respiratory drive) was lower in the late-onset Pompe disease group (median 0.050 [interquartile range 0.027–0.118] vs 0.183 [0.153–0.233], P < .001). Nine subjects (69.2%) had a blunted change in airway-occlusion pressure 0.1 s/change in end-tidal carbon dioxide pressure slope. CONCLUSIONS: Subjects with late-onset Pompe disease had an impaired hypercapnic respiratory drive response. The clinical impact of this phenomenon in this subject subset deserves further investigation.

Spirometry Reference Values for an Andean High-Altitude Population

We compared the spirometric values of people living at High Altitude at the Andean Plateau with those predicted for lowland population. RATIONALE Spirometry reference values are not yet available for the millions of people living at high altitude in the Andean High Plateau. OBJECTIVE To obtain spirometric prediction equations from a healthy subset of adults living in Argentina at 3440m above sea level. METHODS We randomly recruited 172 healthy men and 235 healthy women, ages 20-70. Spirometry was done according to ATS/ERS standards. Reference equations were computed using regression analysis. RESULTS The resulting prediction equations: For men: FVC=0.0407*height (cm)-0.0250*age(years)-0.81;SEE 0.518. FEV1=0.0327*height (cm)-0.0282*age(years)-0.25;SEE 0.414. For women: FVC(liters)=0.0464*height(cm)-0.0222*age(years)-2.62;SEE 0.396. FEV1(liters)=0.0343*height(cm)-0.0218*age(years)-1.40;SEE 0.316. CONCLUSIONS These results establish spirometric-prediction equations for the population studied and further demonstrate: (1) a linear decline of FVC and FEV1 with age for both genders, (2) age and height satisfactorily predict both parameters, (3) supra-normal values for this population were found when compared to those predicted by lowland Caucasian equations.

More Breathing, Less Fitness: Lessons from Exercise Physiology in Chronic Obstructive Pulmonary Disease–Heart Failure Overlap

Author contributions: both authors contributed equally in manuscript ́s conception and writing. Conflict of interests: none to declare Financing: none Running head: Lessons from exercise physiology in COPD-heart failure overlap Subject descriptor number: 8.13 Exercise in health and disease Word count: 997 Page 1 of 7 AJRCCM Articles in Press. Published on 01-August-2017 as 10.1164/rccm.201707-1430ED

Divertículos bronquiales gigantes múltiples

We report the case of a 36-year-old man, former smoker (14 pack-years), candidate for lung transplant due to acquired non-cystic fibrosis bronchiectasis. Standard chest X-ray showed pulmonary hyperinflation and radiolucent images consistent with bronchiectasis. Bronchiectasis was confirmed on computed axial tomography of the chest, which revealed images of air in the mediastinum suggestive of tracheobronchial diverticula (Fig. 1A). Virtual reconstruction shows multiple sac-like images in both main bronchi (Fig. 1B). The neck of the diverticula can been seen in the upper right image. Small depressions in the mucosa corresponding to diverticular perforations were also observed. Early reports of this condition suggested a prevalence of 0.09%–0.05%, but a more recent study of 503 smokers and another of 200 adults without lung disease found a prevalence of 45% and 41%, respectively.1,2 The bronchial diverticula were small in size (1–3 mm). The interest in our case lies in the large size of the bilateral bronchial diverticula (10–13 mm in diameter) observed

Influence of FIO2 on PaCO2 in COPD Patients With Chronic CO2 Retention

To the Editor : We have read with interest the original article entitled “Influence of FIO2 on PaCO2 During Noninvasive Ventilation in Patients with COPD.”[1][1] In this article, the authors prospectively evaluated 17 CO2-retaining COPD subjects recovering from acute respiratory crisis on