F Gimeno

RESPIRATORY RESISTANCE MEASURED BY FLOW-INTERRUPTION IN A NORMAL POPULATION

Data on reference values of total respiratory resistance (Rint) in healthy people are limited. The aim of this study was to examine the relationship between Rint and gender, height, weight, age and smoking habits. The instrument used was the Jaeger Pneumoscope with a flow interruption device. The method is based on transient interruption of airflow at the mouth for a brief period during which alveolar pressure equilibrates with mouth pressure. Measurement of mouth pressure is used to estimate alveolar pressure prior to interruption. The ratio of this to the flow prior to interruption gives airway resistance. The Rint data were correlated with height, weight, age, gender and smoking habits in 172 healthy subjects. They had a normal lung function (VC, FEV1) and no signs of pulmonary disease. The important determining factor for the value of the Rint were height and age. The mean Rint of 172 subjects was 0.38 +/- 0.17 kPa.1-1.s. The average within-subject variability of repeated measurements of Rint expressed as coefficient of variation was 14.4 +/- 6.9%. Reference equation and normal values for Rint in a healthy population are related to height and age. The measurements were obtained with a commercially available interruption technique.

Comparison of Histamine and Acetylcholine for Use in Bronchial Challenge Testing in Atopic and Nonatopic Subjects with Chronic Airways Obstruction: A Review of 180 Cases

A retrospective study was performed to evaluate the diagnostic yield for bronchial hyperresponsiveness from histamine and acetylcholine challenge tests. The records of 180 cases from the last 10 years were analysed. They were selected because their hyperresponsiveness to inhaled histamine or acetylcholine was equal or less than 32 mg.ml-1. Increasing doses of histamine and acetylcholine were given up to a maximum of 32 mg.ml-1 according to the method of de Vries et al. [3]. The challenges were accomplished on two separate days. The provocative dose of agonist causing a 20% fall in FEV1 (PC20) was noted. The interrelationships between smoking history, objective markers of allergy, patients complaints, histamine and acetylcholine responsiveness were examined. Separate statistical analyses are presented for atopic and nonatopic subjects with chronic airways obstruction. More subjects had a measurable PC20 with acetylcholine than with histamine (43 vs. 16 subjects, p < 0.0001). Using the chi 2 test, the relationship between PC20 histamine and PC20 acetylcholine was similar in smokers and nonsmokers, and in atopics and nonatopics. It is concluded that for an equal molar basis, acetylcholine evokes a higher frequency of bronchus obstruction than histamine in patients.

Effect of Intramuscular Administration of Thiazinamium and Inhaled Histamine on Forced Inspiratory Volume in 1 s

Twenty-one patients with symptoms suggestive of asthma were evaluated clinically by allergy skin tests, pulmonary function, and histamine inhalation challenge. In addition to the forced expiratory manoeuvres (FEV1), forced inspiratory manoeuvres (FIV1), were performed before and after intramuscular administration of thiazinamium (Multergan), a bronchodilator with markedly anticholinergic properties. The same lung function parameters (FEV1 and FIV1) were obtained before and after histamine inhalation challenge. The response after bronchodilatation in litres of FEV1 2.42 +/- 1.12 to 3.27 +/- 0.98 (mean +/- SD) was much larger than in FIV1 3.44 +/- 1.35 to 4.05 +/- 1.14 (p < 0.05). After histamine inhalation the observed decrease in FEV1 (2.65 +/- 0.99 to 2.06 +/- 0.89) was not so great as in FIV1 (3.76 +/- 1.09 to 2.90 +/- 1.15) (p < 0.02). These results suggest that patients often have more difficulty with inspiration rather than expiration.

Analisis de un test de esfuerzo para enfermos pulmonares cronicos no especificos

Resumen Se ha estudiado un metodo para valorar durante el ejercicio fisico, los parametros cardiopulmonares en pacientes con CNSLD. La reproductibilidad, expresada en el mismo sujeto como diferencia entre dos determinaciones, se ha investigado en personas normales y en pacientes con CNSLD en periodo estable de su enfermedad. Estos pacientes hicieron el ejercicio fisico seis semanas en la clinica y luego lo continuaron en casa. Se encontraron cambios significativos despues del ejercicio, del punto maximo de esfuerzo y de la concentracion de acido lactico en sangre. El grupo mantenia gran parte de su recuperacion ocho meses mas tarde. Esto sugiere que los parametros cardiopulmonares estudiados son indices utiles de cambio en la mejoria del ejercicio fisico.

Exercise-induced airway obstruction in relation to chronic obstructive lung disease

Gimeno, F., Berg, W. Chr., Steenhuis, E. J., de Vries, K., Peset, R., and Sluiter, H. J. (1974).Thorax,29, 16-20. Exercise-induced airway obstruction in relation to chronic obstructive lung disease. Forty-two patients with chronic obstructive lung disease and clinically suspected exercise-induced airway obstruction were studied to ascertain whether those with proven exercise-induced airway obstruction had specific distinguishing features. Exercise-induced airway obstruction (defined as a fall of FEV1 of at least 10% of the pre-exercise values) was detected in 20 of the 42 patients. These 20 were found to have a lower elastic recoil but were otherwise identical with the remainder as regards clinical and physiological abnormality. It is postulated that exercise-induced airway obstruction can be a manifestation of chronic obstructive lung disease.