Mecanismos patogénicos en la enfermedad pulmonar obstructiva crónica causada por exposición a humo de biomasa / Pathogenic Mechanisms in Chronic Obstructive Pulmonary Disease Due to Biomass Smoke Exposure

Las tasas de mortalidad y morbilidad de la enfermedad pulmonar obstructiva crónica (EPOC) han aumentado mundialmente de forma significativa durante las últimas décadas. A pesar de que el humo de tabaco se sigue considerando el principal factor etiopatogénico para el desarrollo de la enfermedad, se estima que entre una tercera y una cuarta parte de los pacientes con EPOC son no fumadores. De todos los factores de riesgo que pueden incrementar la probabilidad de sufrir EPOC en estos sujetos se ha propuesto al humo de biomasa como uno de los más importantes, afectando sobre todo a mujeres y a niños de países emergentes. Aunque existen numerosas evidencias epidemiológicas que relacionan la exposición al humo de biomasa con efectos nocivos para la salud, todavía no se conocen bien los mecanismos celulares y moleculares específicos mediante los cuales este contaminante puede suponer una noxa para los sistemas respiratorio y cardiovascular. En esta revisión se recogen los mecanismos patogénicos propuestos hasta la fecha que sitúan al humo de biomasa como uno de los principales factores de riesgo para la EPOC

Chronic obstructive pulmonary disease (COPD) mortality and morbidity have increased significantly worldwide in recent decades. Although cigarette smoke is still considered the main risk factor for the development of the disease, estimates suggest that between 25% and 33% of COPD patients are nonsmokers. Among the factors that may increase the risk of developing COPD, biomass smoke has been proposed as one of the most important, affecting especially women and children in developing countries. Despite the epidemiological evidence linking exposure to biomass smoke with adverse health effects, the specific cellular and molecular mechanisms by which this pollutant can be harmful for the respiratory and cardiovascular systems remain unclear. In this article we review the main pathogenic mechanisms proposed to date that make biomass smoke one of the major risk factors for COPD

Preventing influenza: an overview of systematic reviews.

BACKGROUND: Many options are available for preventing people from getting infected by influenza virus, with vaccination being the most widely used. METHODS: We assessed the evidence available in Cochrane systematic reviews. We found nine reviews, five of them addressing influenza vaccination, and four addressing medication. RESULTS: Vaccination is effective in healthy adults and children, but the effect is modest in adults, and for young children few data are available. In patients with asthma, chronic obstructive pulmonary disease (COPD) and cystic fibrosis, more evidence is needed to determine effectiveness. Vaccination does not result in exacerbation of asthma. Neuraminidase inhibitors may also have a place in limiting the spread of infection, at least in adults. Amantadine and rimantadine seem effective but have unfavourable adverse-effect profiles. The popularity of homoeopathic Oscillococcinum, especially in France, is not supported by current evidence. CONCLUSION: In many areas, more clinical trials are needed, as the current evidence is inconclusive. Furthermore, several other measures that may be helpful in preventing influenza that have not been addressed in Cochrane reviews.

[Intervention effect of tongfei mixture on nocturnal hypoxia in patients with chronic obstructive pulmonary disease].

OBJECTIVE: To study the effect of tongfei mixture (TFM, a Chinese recipe mainly consisted of angelica and rehmannia root) on nocturnal hypoxia in patients with chronic obstructive pulmonary disease (COPD). METHODS: Sixty patients with COPD of remission phase were randomly divided into 3 groups, 20 in each group. Group A was the control group; Group B, the group simply treated with oxygen; Group C, treated with oxygen and TFM. Changes of pulmonary function, diaphragm muscle mobility (DMM), 6 min walk distance (6MWD), morning arterial blood gas, nocturnal lowest oxygen saturation (LSaO2), mean blood oxygen saturation (MSaO2), the percentage of saturation lower than 90% time account for total sleeping time (SLT90%) and ultrasonocardiogram before and after treatment were observed. RESULTS: Levels of LSaO2, MSaO2 and SLT90% in Groups B and C were significantly higher than those in Group A (P<0.05, P<0.01). The lowering of PaCO2 in Group C was more significant than that in Group B (P<0.05). The mPAP level in Group C was lower, FEV1, 6MWD and DMM were improved than those in Group A and B, showing significant difference (P<0.05). CONCLUSION: Combined use of oxygen therapy and TFM could not only improve the nocturnal hypoxia, but also lower PaCO2. TFM is an important supplement of oxygen therapy.

Esberitox N as supportive therapy when providing standard antibiotic treatment in subjects with a severe bacterial infection (acute exacerbation of chronic bronchitis). A multicentric, prospective, double-blind, placebo-controlled study.

53 patients with planned antibiotic therapy for the treatment of acute exacerbation of chronic bronchitis as an example of a severe bacterial infection requiring antibiotics were included in a prospective, multicentre, double-blind, placebo-controlled study. The chronic bronchitis was staged by forced expiratory volume of the 1st second (FEV(1)) measured in the infection-free interval prior to the current episode and had to be between 35 and 75% for the predicted value. Patients were randomly assigned to receive newer macrolide antibiotics plus either Esberitox N or placebo. Antibiotic therapy was administered according to generally accepted guidelines and Esberitox N or placebo was given for 28 days. The baseline-adjusted means for FEV(1) (%) on day 10 were 68.7 points for the Esberitox N group and 59.2 points for the placebo group (p = 0.0303). For FEV(1) the difference between the two treatment groups was 267 ml (p = 0.0499). The time to half maximal improvement was 5.7 days in the Esberitox N group compared to 12.8 days in the placebo group. The treatment was well tolerated; no serious adverse events were documented. In conclusion, comedication of antibiotics with Esberitox N in subjects with acute exacerbation of chronic bronchitis seems to be of benefit for the patient. Apparently, therapy with Esberitox N leads to a faster recovery from this severe bacterial infection, possibly via preventing an impairment of the host's immune system which might otherwise occur as a consequence of aggressive antimicrobial therapeutics.

Inspiratory muscle training in patients with COPD: effect on dyspnea, exercise performance, and quality of life.

OBJECTIVE: The aim of the study was to assess the effect of target-flow inspiratory muscle training (IMT) on respiratory muscle function, exercise performance, dyspnea, and health-related quality of life (HRQL) in patients with COPD. PATIENTS AND METHODS: Twenty patients with severe COPD were randomly assigned to a training group (group T) or to a control group (group C) following a double-blind procedure. Patients in group T (n = 10) trained with 60 to 70% maximal sustained inspiratory pressure (SIPmax) as a training load, and those in group C (n = 10) received no training. Group T trained at home for 30 min daily, 6 days a week for 6 months. MEASUREMENTS: The measurements performed included spirometry, SIPmax, inspiratory muscle strength, and exercise capacity, which included maximal oxygen uptake (VO(2)), and minute ventilation (VE). Exercise performance was evaluated by the distance walked in the shuttle walking test (SWT). Changes in dyspnea and HRQL also were measured. RESULTS: Results showed significant increases in SIPmax, maximal inspiratory pressure, and SWT only in group T (p < 0.003, p < 0.003, and p < 0.001, respectively), with significant differences after 6 months between the two groups (p < 0.003, p < 0.003, and p < 0.05, respectively). The levels of VO(2) and VE did not change in either group. The values for transitional dyspnea index and HRQL improved in group T at 6 months in comparison with group C (p < 0.003 and p < 0.003, respectively). CONCLUSIONS: We conclude that targeted IMT relieves dyspnea, increases the capacity to walk, and improves HRQL in COPD patients.

Respiratory muscle endurance training in chronic obstructive pulmonary disease: impact on exercise capacity, dyspnea, and quality of life.

Inspiratory muscle training may have beneficial effects in certain patients with chronic obstructive pulmonary disease (COPD). Because of the lack of a home training device, normocapnic hyperpnea has rarely been used as a training mode for patients with COPD, and is generally considered unsuitable to large-scale application. To study the effects of hyperpnea training, we randomized 30 patients with COPD and ventilatory limitation to respiratory muscle training (RMT; n = 15) with a new portable device or to breathing exercises with an incentive spirometer (controls; n = 15). Both groups trained twice daily for 15 min for 5 d per week for 8 wk. Training-induced changes were significantly greater in the RMT than in the control group for the following variables: respiratory muscle endurance measured through sustained ventilation (+825 +/- 170 s [mean +/- SEM] versus -27 +/- 61 s, p < 0.001), inspiratory muscle endurance measured through incremental inspiratory threshold loading (+58 +/- 10 g versus +21.7 +/- 9.5 g, p = 0.016), maximal expiratory pressure (+20 +/- 7 cm H(2)O versus -6 +/- 6 cm H(2)O, p = 0.009), 6-min walking distance (+58 +/- 11 m versus +11 +/- 11 m, p = 0.002), V O(2peak) (+2.5 +/- 0.6 ml/kg/min versus -0.3 +/- 0.9 ml/kg/min, p = 0.015), and the SF-12 physical component score (+9.9 +/- 2.7 versus +1.8 +/- 2.4, p = 0.03). Changes in dyspnea, maximal inspiratory pressure, treadmill endurance, and the SF-12 mental component score did not differ significantly between the RMT and control groups. In conclusion, home-based respiratory muscle endurance training with the new device used in this study is feasible and has beneficial effects in subjects with COPD and ventilatory limitation.

Helping patients with COPD manage episodes of acute shortness of breath.

The most disabling and frightening symptom experienced by patients with COPD is dyspnea. Even with the use of bronchodilators, the symptom may not be completely relieved. Patients often develop their own strategies for managing shortness of breath, including the use of a breathing technique called pursed-lip breathing. Although most nurses are familiar with this breathing technique, they often have difficulty assisting patients to use it during acute episodes of shortness of breath. A strategy is described which nurses can use to assist patients in implementing pursed-lip breathing effectively during episodes of acute dyspnea.

[Metabolic and nutritional neuropathies]. / Neuropathies métaboliques et carentielles.

The two main causes of metabolic neuropathies are successively diabetes and chronic renal insufficiency. Diabetic neuropathies include both diffuse polyneuropathies and focal neuropathies. Sensori(motor) polyneuropathy is the most frequent form and different therapeutic trials have been initiated on the ground of the vascular and metabolic factors implicated in its pathogenesis. Autonomic neuropathy is the major cause of morbidity and mortality. In patients with chronic renal failure, the polyneuropathy is improved by renal transplantation. The carpal tunnel syndrome is frequent in hemodialysis patients, and surgery gives the opportunity to look for beta-2-microglobulin amyloid deposits. Among the less frequent causes of peripheral neuropathies in which metabolic factors have been considered, we review hypoglycemia, chronic respiratory insufficiency due to chronic obstructive pulmonary disease, chronic liver diseases, and the polyneuropathy occurring in the critically ill patients with nutritional or metabolic failures. In chronic excessive drinkers peripheral neuropathy is classically associated with thiamine deficiency, but the direct effect of alcohol itself has been discussed. Various vitaminic deficiencies have been responsible for the development of peripheral neuropathies. The clinical forms often associate peripheral neuropathy with myelopathy, and serum vitamin E concentrations should be measured in patients with spinocerebellar disorders. Usually nutritional deficiencies need multivitamins supplementation.

Effect of intravenous fructose 1,6-diphosphate administration in malnourished chronic obstructive pulmonary disease patients with chronic respiratory failure.

BACKGROUND: Weight loss and skeletal muscle wasting are common in patients with chronic obstructive pulmonary disease (COPD) and can influence the course and the prognosis of COPD. Hypophosphatemia is a pathologic status often characterized by muscle weakness and is a frequent laboratory finding in these patients. OBJECTIVE: The aim of the present study was to evaluate the effect of an organic phosphate (fructose 1,6-diphosphate, FDP) administration on respiratory performance in 45 malnourished COPD patients in stable clinical conditions. METHODS: Physiologic evaluation including spirometry, maximal voluntary ventilation (MMV), elevated arm test, maximal mouth pressures (PImax and PEmax), respiratory response to CO(2), oxygen (PaO(2)) and carbon dioxide (PaCO(2)) arterial tension, a visual analogic scale (VAS) to measure dyspnea, and complete blood tests were done at the beginning and again at the end of the study. RESULTS: After FDP administration, there was a significant increase in PImax (43.0 +/- 18.3 cm H(2)O before treatment vs. 49.8 +/- 14.9 cm H(2)O after treatment; p < 0.005). This did not occur in the placebo group (40.3 +/- 17.4 cm H(2)O before treatment vs. 42.6 +/- 20.1 cm H(2)O after treatment, nonsignificant). There was also a trend of VAS to decrease and of MVV to increase. CONCLUSIONS: These results show that FDP administration may be useful in the management of malnourished COPD patients, especially in increasing their respiratory muscle strength.

Long-term effects of outpatient rehabilitation of COPD: A randomized trial.

OBJECTIVE: To examine the short- and long-term effects of an outpatient pulmonary rehabilitation program for COPD patients on dyspnea, exercise, health-related quality of life, and hospitalization rate. SETTING: Secondary-care respiratory clinic in Barcelona. METHODS: We conducted a randomized controlled trial with blinding of outcome assessment and follow-up at 3, 6, 9, 12, 18, and 24 months. Sixty patients with moderate to severe COPD (age 65 +/- 7 years; FEV(1) 35 +/- 14%) were recruited. Thirty patients randomized to rehabilitation received 3 months of outpatient breathing retraining and chest physiotherapy, 3 months of daily supervised exercise, and 6 months of weekly supervised breathing exercises. Thirty patients randomized to the control group received standard care. RESULTS: We found significant differences between groups in perception of dyspnea (p < 0.0001), in 6-min walking test distance (p < 0.0001), and in day-to-day dyspnea, fatigue, and emotional function measured by the Chronic Respiratory Questionnaire (p < 0. 01). The improvements were evident at the third month and continued with somewhat diminished magnitude in the second year of follow-up. The PR group experienced a significant (p < 0.0001) reduction in exacerbations, but not the number of hospitalizations. The number of patients needed to treat to achieve significant benefit in health-related quality of life for a 2-year period was approximately three. CONCLUSION: Outpatient rehabilitation programs can achieve worthwhile benefits that persist for a period of 2 years.

[Evaluation and symptomatic treatment of surinfectious exacerbations of COPD: preliminary study of antibiotic treatment combined with fenspiride (Pneumorel 80mg) versus placebo]. / Evaluation du traitement symptomatique des poussées de surinfection de BPCO: étude préliminaire Pneumorel 80 mg versus placebo en association avec une antibiothérapie.

UNLABELLED: Exacerbations of chronic obstructive pulmonary disease (COPD) have an inflammatory component in addition to the possible infectious component. The antiinflammatory properties of fenspiride (Pneumorel(R) 80 mg) should be evaluated in this frequent clinical situation. OBJECTIVES: Assess the supplementary therapeutic benefit provided by fenspiride administered in combination with antibiotics in COPD patients presenting an episode of bronchial infection. PATIENTS AND METHODS: A preliminary randomized placebo-controlled double-blind study was conduced in 7 centers. Patients under 80 years of age of both sexes were included. All patients had COPD and presented a bronchial infection defined as the presence of at least 2 of the 3 criteria defined by Anthonisen. Patients were randomly assigned to group F or group P. Group F received an antibiotic therapy from day 1 to day 11 plus fenspiride (3 x 80mg/d from day 0 to day 30). Group P received the same antibiotic therapy plus placebo. Amoxicillin 500mg plus clavulanic acid 125, 3 tablets/day, was administered in both groups. RESULTS: Thirty-nine patients were included (group F 19 patients, group P 20 patients; 6 women and 33 men; mean age 61.1 +/- 9.8 years). The 3 Anthonisen criteria were present in 79% and 75% of the patients in group F and P respectively (NS). On day 11, expectoration resolved in 39% and 32% (NS) and cough in 44% and 16% (NS) of the patients in groups F and P respectively. Lung auscultation returned to normal in 83% of the patients in group F compared with 47% in group P (p=0.05). A composite clinical score including expectoration cough and auscultation findings showed that 28% of the patients in group F were symptom-free on day 11 compared with 0% in group P (p=0.04). On day 30, the two groups were comparable. CONCLUSION: In this preliminary study of patients with COPD presenting a bronchial superinfection, there was a significant improvement in lung auscultation and in the composite clinical score in patients given fenspiride. Fenspiride was thus found to provide an early clinical benefit.

Dyspnea self-management in African Americans with chronic lung disease.

PURPOSE: To explore dyspnea self-management in African Americans with chronic obstructive pulmonary disease (COPD) or chronic restrictive pulmonary disease resulting from sarcoidosis. DESIGN: Descriptive. SAMPLE: Convenience sample of 29 African Americans, 15 with COPD (forced expiratory volume in 1 second/forced vital capacity = 53%), and 14 with sarcoidosis (forced expiratory volume in 1 second/forced vital capacity = 88%; total lung capacity 62.4% of predicted). METHODS: Semistructured interviews. FINDINGS: Content analysis revealed 4 dyspnea self-management themes: (1) traditional medical care, (2) self-care wisdom, (3) self-care action, and (4) self-care resources. Breathing strategies (a subtheme for self-care action) for patients with COPD focused on both inhalation and exhalation, whereas patients with sarcoidosis described inhalation breathing strategies only. CONCLUSION: African Americans with chronic lung disease described use of different breathing strategies for COPD and sarcoidosis disorders. Both groups actively engaged in health-promoting activities for dyspnea management.

The chronic obstructive pulmonary disease exacerbation.

Chronic obstructive pulmonary disease is the only leading cause of death with a rising prevalence. The medical and economic costs arising from acute exacerbations of COPD are therefore expected to increase over the coming years. Although exacerbations may be initiated by multiple factors, the most common identifiable associations are with bacterial and viral infections. These are associated with approximately 50% to 70% and 20% to 30% of COPD exacerbations, respectively. In addition to smoking cessation, annual influenza vaccination is the most important method for preventing exacerbations. Controlled O2 is the most important intervention for patients with acute hypoxic respiratory failure. Evidence from randomized, controlled trials justifies the use of corticosteroids, bronchodilators (but not theophylline), noninvasive positive-pressure ventilation (in selected patients), and antibiotics, particularly for severe exacerbations. Antibiotics should be chosen according to the patient's risk for treatment failure and the potential for antibiotic resistance. In the acute setting, combined treatment with beta-agonist and anticholinergic bronchodilators is reasonable but not supported by randomized controlled studies. Physicians should identify and, when possible, correct malnutrition. Chest physiotherapy has no proven role in the management of acute exacerbations.

Nutritional abnormalities and supplementation in chronic obstructive pulmonary disease.

Weight loss and muscle wasting commonly occur in patients with chronic obstructive pulmonary disease (COPD). A decreased dietary intake and elevated energy requirements underlie weight loss in these patients. Disturbances in intermediary metabolism caused by altered anabolic and catabolic mediators such as hormones, cytokines, and growth factors, and resulting in disproportionate muscle wasting have been described. Nutritional supplementation in combination with an anabolic stimulus (e.g. exercise) has been shown effective in improving functional capacity, health status, and mortality in most depleted patients. Nutritional or pharmacologic modulation of the catabolic response may further enhance the response in the near future.

[Nutrition and chronic respiratory failure]. / Nutrition et insuffisance respiratoire chronique.

Protein calorie malnutrition is frequently observed in patients with chronic obstructive pulmonary disease (COPD). The main mechanism is hypermetabolism essentially resulting from increased oxygen consumption of the respiratory muscles. Malnutrition is associated with poor prognosis, irrespective of age and respiratory function impairment. Malnutrition has several harmful consequences on the respiratory system: atrophy and decreased strength of the respiratory muscles, decreased exercise performance, decreased quality of life, and likely increased risk of community-acquired and nosocomial pneumonia. A long-duration oral supplementation may improve the nutritional status and exercise tolerance in ambulatory COPD patients. The interest of anabolic drugs, especially recombinant growth hormone, has not been demonstrated in malnourished COPD patients.

Chronic glucocorticoid therapy-induced osteoporosis in patients with obstructive lung disease.

Long-term glucocorticoid (GC) therapy has been instrumental in decreasing morbidity and mortality in a variety of chronic inflammatory diseases, including persistent asthma. Long-term GC therapy is also widely prescribed for COPD. One of the important and often unrecognized side effects of chronic GC therapy is secondary osteoporosis. The risk of GC-induced bone loss is roughly correlated with daily dose, duration, and total cumulative lifetime dose of GC treatment. Oral prednisone increases the risk of bone loss and fracture. High doses of inhaled GCs may also increase the risk of osteopenia/osteoporosis, but the risk appears to be less than that associated with oral GCs. Hormone replacement therapy, oral and parenteral bisphosphonates, supplemental calcium and vitamin D, calcitonin, and fluoride compounds have been used, experimentally, in the management of GC-induced bone loss. Asthma and COPD specialists are key prescribers of oral and inhaled steroids and are likely to encounter patients with significant bone loss. Despite known risk factors and the availability of reliable diagnostic tools to recognize bone loss, the opportunity to slow, reverse, and treat bone loss is often missed. We present a review of the current literature regarding the incidence, treatment, and prevention of osteopenia/osteoporosis secondary to chronic GC therapy in adult asthma and COPD patients. Guidelines are presented regarding the identification of patients at risk for developing GC-induced secondary bone loss, and therapeutic alternatives are discussed.

Asthma and chronic obstructive airway diseases are associated with osteoporosis and fractures: a literature review.

The objective was to assess the association between asthma and/or chronic obstructive airway diseases (COAD), and osteoporosis, and appraise treatments of osteoporosis in these patients. MEDLINE and Excerpta Medica were searched for original research with control groups which tested the above association. One cohort and nine cross-section studies of bone density in patients with asthma and/or COAD were retrieved. These demonstrated clinically important bone density reductions of up to 29% in subjects, dependent upon daily oral corticosteroids, by a variety of measurement techniques, at various bone sites. Bone density reduction has also been less consistently reported in the absence of oral corticosteroids, suggesting that other factors including high-dose inhaled corticosteroids may have a role. Fracture studies. Three studies in oral corticosteroid-dependent asthmatics demonstrated a vertebral fracture prevalence up to 56%, and annual vertebral fracture incidence of up to 42%. The strength of the available evidence is limited, but suggests that patients with asthma and/or COAD are at increased risk of osteoporosis. The evidence of the association between osteoporosis and inhaled corticosteroids is much more limited than for oral corticosteroids. Bisphosphonates are promising agents to maintain and/or promote bone mass in this patient group.