Peripheral pulmonary wedge angiography in chronic obstructive pulmonary disease. Relationship to pulmonary function, chest x-ray film, and hemodynamic data.

Peripheral pulmonary wedge angiographic studies can investigate only limited areas of the pulmonary vascular bed; nevertheless, this technique is very useful in emphasizing the morphologic changes of small vessels (less than 1 mm in diameter) in pulmonary emphysema. The aim of this work is to determine the relationship between peripheral wedge angiographic appearances and pulmonary function, the chest x-ray film, and hemodynamic data in patients with chronic obstructive pulmonary disease. Three healthy subjects, four patients with type-A chronic obstructive pulmonary disease, and eight patients with type-B chronic obstructive pulmonary disease were studied. Among the tests of pulmonary function, only a marked reduction (less than 60 percent of predicted) of the diffusing capacity for carbon monoxide is always indicative of severe widespread emphysema. No relationship was found between hemodynamic data and peripheral wedge angiographic findings. Some agreement resulted between the chest x-ray film and peripheral wedge angiographic abnormalities only in patients with type-A chronic obstructive pulmonary disease; on the contrary, in patients with type-B chronic obstructive pulmonary disease, both false-positives and false-negatives were noted.

Lung function and diffusing capacity for carbon monoxide in patients with juvenile chronic arthritis: effect of disease activity and low dose methotrexate therapy.

OBJECTIVE: We measured lung function, in terms of lung volumes, forced expiratory flow-volume curves and diffusing capacity of carbon monoxide (DLCO), in a group of 61 patients with juvenile chronic arthritis (42 female; age range 5 to 33 years) to ascertain whether disease activity and treatment with low dose methotrexate (MTX) influenced these parameters. The whole population was divided into subgroups based on onset type (systemic, n = 27; pauciarticular, n = 12; polyarticular, n = 22), disease activity (active, n = 42; inactive, n = 19), and MTX treatment (treated, n = 27; not treated, n = 34). RESULTS: We found that maximal-mid expiratory flow (MMEF) was significantly reduced in patients with active disease (p < 0.025). The mean DLCO value, expressed as a percentage of the predicted value, and DLCO corrected for the hemoglobin value were lower than expected (67% and 80%, respectively). Multiple regression analysis showed that the forced vital capacity (FVC), forced expiratory flow in one second (FEV1) and DLCO were all correlated to the clinical subtype of the disease (p < 0.05, p < 0.02, p < 0.02, respectively), and MMEF was related to disease activity (p < 0.025). There was no evidence of any effect of MTX treatment on the pulmonary parameters. CONCLUSION: This study confirms that JCA is characterized by an impairment of lung function, mainly involving the small airways, and by interstitial damage. These changes are related to the clinical subtypes of the disease and to disease activity.

Prevalence and repeatability of the cough response induced by inhalation of low chloride ion solutions in normal subjects.

Although the inhalation of low Cl- ion solutions has often been used to induce cough, the prevalence and repeatability of the challenge has never been studied in detail. We, therefore, examined cough response in a group of 59 volunteers (aged 15-57 yrs; 34 females and 25 males; 20 smokers) to ascertain prevalence and repeatability. Each subject performed, 2 weeks apart, two identical cough challenges by inhaling four isosmolar solutions with decreasing Cl- ion concentrations (150, 75, 37.5 and 0 mM). Each solution was delivered by a DeVilbiss 65 ultrasonic nebulizer (mean output: 1.9 mL.min-1) for 1 min, and the number of coughs was counted during the inhalation. Cough response was expressed as number of coughs.min-1. Significance of response to the cough challenge was assessed on the basis of mean number of coughs.min-1 and 95% upper confidence limit (CL) of response to the Cl- free solution in the whole population. Cough threshold for a significant response was greater than 8 coughs.min-1. Out of 59 subjects, only 20 exceeded the cough threshold (34%) after inhaling the Cl- free solution. A concentration-response effect was evident only when inhaling 37.5 and 0 mM Cl- ion solutions. A significant cough response was more likely among females (p = 0.03). Smoking did not significantly affect the prevalence of response. Coefficients of repeatability of cough response to 37.5 and 0 mM Cl- solutions in 20 responders were equal to 10.1 and 12.6, respectively. We conclude that a significant cough response to low Cl- ion solutions develops in approximately 1 out of 3 of challenged volunteers and that repeatability is not satisfactory. We suggest that cough threshold and repeatability should be preliminarily assessed, especially when the challenge is used to study the antitussive activity of drugs.

[Forced expiration. Various current concepts, 50 years after Robert Tiffeneau]. / Expiration forcée. Quelques concepts actuels, 50 ans après Robert Tiffeneau.

One hundred and fifty years after the original description of spirometry by Hutchinson and 50 years after the definition of his famous ratio by Tiffeneau, a certain number of physiological advances have enabled a better understanding of the determinants of the forced expired manoeuvre and to mitigate some of its inconveniences. This review focuses on three of these advances. The first is the influence of an inspiratory manoeuvre which precedes a forced expiration, on the expiratory flow. This influence is probably a consequence of viscoelastic phenomena and impose some strains on standardisation in current practice. The second is the possibility of detecting in a reproducible and simple fashion, without the need for co-operation on the part of the subject, a limitation in expiratory flow by the application of a negative expiratory pressure at the opening of the airways (NEP for negative expiratory pressure). The third is the possibility to verify in a simple fashion the quality of the expiratory performance achieved by the patient and thus to detect an insufficient effort in the force of a falling expiratory flow.

[Hemorheologic characteristics in beta-thalassemic homozygotes before and after splenectomy]. / Caratteristiche emoreologiche nella beta-talassemia omozigote prima e dopo splenectomia.

In a group of 36 homozigous beta-thalassaemic children we studied the effect of splenectomy on hemorheologic characteristics. The aim of the work was to evaluate the importance of such operation either on anemia or on erythrocyte deformability. Whole blood viscosity was measured with a Brookfield Microviscometer (LVT) and erythrocyte deformability was evaluated with the erythrocyte filtration technique using policarbonate membranes. The more the erythrocyte deformability decreases, the more the erythrocyte filtration rate decreases. Our data show that splenectomized children, have worse hemorheologic characteristics according to the longer survival time of pathological red blood cells in spite of their reduced deformability. This behaviour can be modified only by blood transfusion that we have seen to be able to reduce whole blood viscosity and to increase erythrocyte filtration rate in splenectomized children. We think that splenectomy must be delayed as long as possible so that hemodinamyc conditions cannot be worsened. An hemorheologic monitorage could be useful for diagnostic and prognostic evaluations both in splenectomized and not splenectomized children.

Respiratory function 8 years after a diagnosis of peripheral airways disease.

A program of screening for airways obstruction was designed to examine: (1) the precision and the reliability of the proposed tests (2) the evolution of respiratory impairment in 69 subjects, 8 years after a diagnosis of peripheral (small) airways obstruction. The tests that exhibit very good reliability are: vital capacity, total lung capacity, 1-second forced expiratory volume, single breath CO diffusion capacity, curvilinearity score; and the ratio of closing capacity to total lung capacity. 39% of smokers and 15% of nonsmokers developed central airways obstruction 8 years after the diagnosis of peripheral airways disease. These results confirm the hypothesis that small airways may be regarded as a noisy rather than a silent zone.

Clinical value of rebreathing test in obstructive lung diseases.

The ventilatory response to CO2 inhalation, using rebreathing method, was studied in normal subjects and in patients with bronchial asthma and chronic obstructive lung disease. The patients with lung disease had flatter CO2 response curves. However, it the ventilation was expressed as a fraction of the maximal voluntary ventilation, the difference between normal subjects and patients disappeared. The reduced ventilatory response of these patients may be of mechanical origin and not depending on reduced CO2 sensitivity. The high lung volume of these patients may be the mean factor of the mechanical disadvantage of thoracomuscular system.

FEV1 decline in asymptomatic young adults: relationships with some tests of small airways function.

The aim of this study is to determine whether some tests proposed as diagnostic of small airways obstruction (SAO) are useful in identifying the subjects at risk of developing chronic airflow limitation. Eighty five healthy male workers (46 nonsmokers and 39 smokers, aged 21-41 yrs), living in the same area and not exposed to occupational pollutants were re-examined after an interval of 6 yrs. At the first survey 39 had functional evidence of SAO as determined by the presence of one of: maximal mid-expiratory flow (MMEF) less than 65% of predicted value (pred); maximal expiratory flow when 25% forced vital capacity remains to be expired (Vmax25) less than 60% pred; closing capacity (CC) greater than 130% pred; 46 had all functional values in the normal range. We considered four subgroups: smokers and nonsmokers with and without SAO. The rate of decline in FEV1, the decline in %delta FEV1 and delta FEV1.height-3, have been evaluated and compared in the subgroups. Initial values of specific tests (MMEF, Vmax25, CC and slope of phase III) have been examined for a possible relationship with decline of FEV1. Statistical analysis of our data showed that only CC was related to FEV1 decline. However, there were no significant differences in FEV1 decline among the subgroups. We conclude that in young adult subjects functional characteristics of SAO have no predictive value for development of chronic airways obstruction.