Obstructive Airway Disorders Research Articles

Epidemiological aspects and early detection of chronic obstructive airway diseases in the elderly.

The burdens of chronic obstructive airway diseases among the elderly in Europe, and worldwide, are increasing. Although asthma is common in all ages, the main airway disease affecting the elderly is chronic obstructive pulmonary disease (COPD). The aim of this paper is to review the prevalence and incidence of COPD on the basis of population studies. As the prevalence estimates of asthma are probably well known, only the incidence and remission of asthma will be discussed. The underdiagnosis of obstructive airway diseases is huge. A Dutch programme for early detection of obstructive airway disease among the elderly has, thus, been included in the presentation. A prerequisite for fighting COPD is to acquire data on illnesses and death. COPD has only recently been defined by cut-off points of spirometric outcomes, which is why measures of the prevalence of COPD have been distorted by use of a large number of different diagnostic terms and lung function criteria. The prevalence of clinically-relevant COPD has been estimated in several community studies to 4-6% in adult population samples, with a considerable increase by age, particularly among smokers. The incidence of COPD not only increases heavily with age and smoking, but also occupational exposure to dust, gas and damp. Precise estimates of the incidence of COPD or spirometric airflow limitation are not available. Demographic changes will result in a further substantial increase of chronic obstructive airway disorders, mainly chronic obstructive pulmonary disease, among the elderly. The increasing burden of chronic obstructive pulmonary disease has to come to the awareness of the public, governments, health authorities, and industry.

Severe obstructive airway disorders and diseases: vocal fold dysfunction.

Vocal Fold Dysfunction is a syndrome characterized by abnormal adduction of the focal folds during inspiration and is the cause of a wide spectrum of clinical manifestations ranging from mild inspiratory stridor to an inability to move any air. Patients present with varying degrees of intermittent respiratory difficulty, the most severe caused by intense laryngospasm. Distinguishing Vocal Fold Dysfunction from Refractory Asthma is important to avoid unnecessary pharmacotherapy and intubation. The diagnosis of Vocal Fold Dysfunction can only be made with certainty by flexible fiberoptic laryngoscopy while the patient is symptomatic. Pulmonary function studies and a lack of response to bronchodilators may provide clues to the diagnosis. Most patients with the condition can be managed by speech therapy and the use of breathing strategies that eliminate the abnormal vocal fold movement. Chronic laryngeal irritation may be a trigger for Vocal Fold Dysfunction and conditions such as laryngopharyngeal reflux disease should be aggressively managed in this patient population.

Low QOL, high risk of hospitalisation in obstructive airway disorders

Low QOL, high risk of hospitalisation in obstructive airway disorders

Anatomic and functional lesions resulting in partial or complete upper airway obstruction.

The study advances the idea of using computational fluid dynamics in the process of planning surgical treatment modalities for patients with obstructive airway disorders. It is hypothesized that the a priori knowledge of the functional outcome of surgical intervention on the flow and airway resistance can guide the surgeon in choosing an effective surgical strategy. Computed tomography images spanning the respiratory tract of an adult patient with a combined glottic and subglottic stenosis are used to reconstruct three-dimensional geometrical models of the airway. Computational fluid dynamics is used to obtain airway flow patterns during inspiration and expiration in these models. Numerical predictions about flow velocity, pressure distribution on the airway lumen, wall shear stress, and airway resistance are obtained so that the relevance of each individual stenotic level is quantified. Four different virtual surgeries in different combinations are assessed in order to remedy the constricted airway. The virtual surgery based airway models are evaluated by comparisons with the pre-treatment flow modeling results. The predicted numerical data revealed that the removal of the constriction at the level of the vocal folds will have the most significant effect on the airway resistance. The flow simulations offer a quantitative method of evaluating the airway resistance in patients with combined glottic and subglottic stenoses. Predictions of airway resistances and other numerical calculations from different virtual surgeries give additional inputs for the surgeon, in deciding the most appropriate surgery on a case-by-case basis.

Occupational obstructive airway diseases in Germany

In industrialized countries, occupational asthma caused by allergens and irritants due to workplace exposure is increasing. More than 8,000 such claims were made in Germany (10.5% of all decided occupational disease claims) in 1995; 1,900 were confirmed (6.5% of all confirmed claims). The legal basis and the occupational disease-related regulations of trade-assigned statutory accident insurance institutions (‘Berufsgenossenschaften’) in Germany are described. Hitherto, three occupational disease categories for obstructive airway disorders existed: due to sensitizing agents, due to chemical-irritative or toxic agents, and due to isocyanates. Approximately 40% of accepted claims for occupational asthma and rhinitis result from exposure to flour. Ongoing changes in the recognition of work-related airway disease symptoms account for differences in the incidence and prevalence as reported over the years. Recently, chronic obstructive bronchitis and/or emphysema of hard coal miners have been included in the German list of occupational diseases. Am. J. Ind. Med. 33:454–462, 1998. © 1998 Wiley-Liss, Inc.

Occupational obstructive airway diseases in Germany.

In industrialized countries, occupational asthma caused by allergens and irritants due to workplace exposure is increasing. More than 8,000 such claims were made in Germany (10.5% of all decided occupational disease claims) in 1995; 1,900 were confirmed (6.5% of all confirmed claims). The legal basis and the occupational disease-related regulations of trade-assigned statutory accident insurance institutions ('Berufsgenossenschaften') in Germany are described. Hitherto, three occupational disease categories for obstructive airway disorders existed: due to sensitizing agents, due to chemical-irritative or toxic agents, and due to isocyanates. Approximately 40% of accepted claims for occupational asthma and rhinitis result from exposure to flour. Ongoing changes in the recognition of work-related airway disease symptoms account for differences in the incidence and prevalence as reported over the years. Recently, chronic obstructive bronchitis and/or emphysema of hard coal miners have been included in the German list of occupational diseases.

Measurement of upper airway resistance in awake untrained dolichocephalic and mesaticephalic dogs

Summary A technique for measuring upper airway resistance was developed in awake untrained dolichocephalic and mesaticephalic dogs. Twenty healthy dogs, 10 Collies (group A—dolichocephalic) and 10 mixed-breed dogs (group B—mesaticephalic), were studied. All dogs tolerated the procedure well, and adverse effects were not observed. Mean (± sem) value for upper airway resistance was 7.1 ± 0.50 cm of H2O/L/s. There was a trend toward lower upper airway resistance (Ruaw) values in group-A dogs, compared with those in group-B dogs. Values of Ruaw were reproducible for an individual dog. The mean individual dog coefficient of variation for Ruaw was 7.5%. The overall Ruaw coefficient of variation for all 20 dogs was 31.4%. This technique for measuring upper airway resistance in dogs is clinically applicable for objectively assessing response to treatment of obstructive upper airway disorders.

Risk/benefit ratio of long-term treatment withβ 2-adrenoceptor agonists

Optimal control of chronic obstructive airway disorders is usually achieved with therapy based on beta 2-adrenoceptor agonist administration. Aerosols are highly effective, have few side effects, allow for fine adjustment of dosage to titrate symptoms, and result in reduction in hyperreactivity. Equivalent bronchodilating doses of oral agents cause side effects that limit acceptability. With oral agents, cardiohemodynamic disturbances are usually minor, while tremor and restlessness diminish with continued drug use. In chronic regimens, an aerosol beta 2-adrenergic agent should be chosen whose overall incidence of side effects is less than 5%, and an oral agent that produces no more than a 10% incidence of tremor. Suboptimal oral dosages in combination with maximal dosages of beta 2-agonist aerosol, with or without other bronchodilator drugs, are advisable for chronic therapy. An optimal risk/benefit ratio with broxaterol therapy will probably be achieved by using an aerosol-oral combination. Thus, broxaterol, a new beta 2-agent, should be studied further to determine its value in chronic bronchospastic disorders.

Ventilation-Perfusion Scintigraphy in an Adult with Congenital Unilateral Hyperlucent Lung

A variety of congenital and acquired etiologies can give rise to the radiographic finding of a unilateral hyperlucent lung. An unusual case of congenital lobar emphysema diagnosed in a young adult following the initial discovery of a hyperexpanded, hyperlucent lung is reported. Although subsequent bronchoscopy and radiologic studies detailed extensive anatomic abnormalities, functional imaging also played an important role in arriving at this rare diagnosis. In particular, ventilation-perfusion scintigraphy identified the small contralateral lung as the functional lung and helped narrow the differential diagnosis to etiologies involving obstructive airway disorders.

2-(beta-Arylethylamino)- and 4-(beta-arylethylamino)quinazolines as phosphodiesterase inhibitors.

The existence of several forms of cAMP phosphodiesterase having differing kinetic characteristics suggests the feasibility of developing tissue-selective inhibitors of this enzyme. This observation is of particular importance in the development of therapeutic agents for the management of reversible obstructive airways disorders. The present report describes the design, synthesis and pharmacological characterization of a series of 6,7-dimethoxyquinazoline derivatives having beta-arylethylamine substituents at the 2- or 4-positions. The quinazoline nucleus is intended to confer a high degree of inhibitory activity for phosphodiesterase while the beta-aryethylamine moieties are designed to provide selectivity for adrenergically innervated tissue. The target compounds of this study, 6 and 7, were prepared via beta-arylethylamine displacement of chloride from an appropriate chloroquinazoline intermediate. The resulting products were evaluated for their ability to relax guinea pig tracheal smooth muscle and as inhibitors of phosphodiesterase.

Predictors of Spirometric Changes and Mortality in the Obstructive Airway Disorders

Predictors of Spirometric Changes and Mortality in the Obstructive Airway Disorders

The history of lung imaging with radionuclides

T WO TYPES of lung imaging test agents and procedures for their administration were developed at the UCLA Laboratory of Nuclear Medicine and Radiation Biology between 1963 and 1965./-4 The first of these was devised to image the blood flow pattern in the lungs by rectilinear scanning, after the i.v. injection of macroaggregates of human serum albumin (HSA) labeled with 131I, size range, 10-50pm? The macroaggregates were first produced in January 1963, but this agent stemmed from the development of a simplified method of preparing colloidal-size (10-20nm) 131l albumin suspensions by pH adjustment and heating in a water bath at 90-95~ for 8-10 min under gentle agitation? Albumin colloid labeled with 131I is useful in visualizing the liver, spleen, and bone marrow by scanning./In such studies, however, if the size of the particles exceeds 5-10#m, lung entrapment is easily demonstrable. Therefore, an extensive study was made to determine the optimal size for lung visualization by temporary capillary and arteriolar blockade. The size was adjusted so that pulmonary entrapment lasted no longer than a half-life of 4-8 hr. In the first animal trials, extremely low specific activity (approximately 50~tCi/mg of HSA) was used. Even so, the scan dose (300pCi in 6 mg HSA) was 50100 times below the minimum toxic dose level (20-30mg of HSA/kg). This work was first reported in a scientific exhibit at the Tenth Annual Meeting of the Society of Nuclear Medicine in Montreal, Canada, in June 1963. 6 Lung scanning in man was initiated in November 1963 at UCLA ~'2 after Wagner's Human Studies, using much higher specific activity HSA suspensions (1000pCi/mg of HSA). The second development was made in 1964 and first reported in 1965. 3 Radioaerosols were administered to anesthetized dogs via tracheal intubation. They were produced by a positive pressure nebulizer. Subsequently, similar procedures, radioaerosols, and nebulizer equipment were studied in man. 4 In 1966 colloidal radioactive gold, 198Au, was replaced by 99mTc-HSA and sulfur colloid 99mTC as test agents, to decrease radiation exposure to the lungs. 7 This communication describes in detail lung perfusion and airway patency inhalation procedures, along with an evaluation of their current value in the differential diagnosis of pulmonary embolism, and in the detection of obstructive airways disease. TM The relationship of both procedures to the findings from plain chest radiography and pulmonary angiography is compared in a variety of pulmonary and obstructive airways disorders.

Toluene diisocyanate pulmonary disease: Immunopharmacologic and mecholyl challenge studies

Selected workers exhibiting clinical “sensitivity” to toluene diiosocyanate (TDI) (wheezing, cough, and dyspnea upon entering a TDI-containing area) were studied for: (I) in vitro TDI-induced leukocyte histamine release; (2) determination of cyclic 3′,5′ adenosine monophosphate (cAMP) levels of lymphocytes exposed to TDI; (3) effect of TDI on the isoproterenol-induced increase of lymphocyte cAMP levels; and (4) acetyl-β-methylcholine (mecholyl) inhalation challenge. TDI did not induce histamine release from leukocytes of “sensitive” or “nonsensitive” individuals, nor were lymphocyte cAMP levels affected by in vitro TDI exposure. TDI did, however, diminish in vitro stimulation of cAMP by isoproterenol. This effect, seen with cells of “sensitive” and “nonsensitive” individuals, appeared to be dose-dependent; there were no significant differences between the two groups. When challenged with mecholyl, 7 of 10 “sensitive” but only 1 of 10 “nonsensitive” individuals showed a greater than 20% decrease in FEV 1 . These results suggest that TDI-induced obstructive airways disorders may be associated with altered β-adrenergic function.

Serum IgE level determination in chronic obstructive airway disorders

Serum IgE level determination in chronic obstructive airway disorders

Pulmonary perfusion changes after experimental unilateral bronchial occlusion and their clinical implications.

The authors scanned 15 mongrels—9 normal and 6 with unilateral lung reimplants—to see the effect of unilateral bronchial occlusion on pulmonary arterial perfusion. Pulmonary arterial perfusion decreased promptly following airway occlusion in the intact as well as in the reimplanted denervated lungs and reached a minimum level in ten to fifteen minutes. Perfusion changes seem to occur as a local reflex. For accuracy in interpretation of perfusion lung scans, it is important to recognize that obstructive airway disorders associated with localized ventilatory impairment can cause regional pulmonary ischemia and simulate the scans of acute pulmonary embolism.