Biomedical subjects

H Hedenström

Publications and source records attributed to H Hedenström.

13 recordsLinked to original sources

PubMed1992

Effect of inhaled formoterol versus terbutaline on respiratory function in moderate bronchial asthma.

In a double-blind cross-over study comparing the duration of action of 12 micrograms and 24 micrograms formoterol, 500 micrograms terbutaline and placebo, lung function tests were performed in 12 never-smokers with non-allergic bronchial asthma. All the patients were hyperreactive to methacholine, had normal serum IgE level, and negative skin or RAST results. The lung function tests were carried out over an 11-h period and included measurements of lung volumes, airway resistance, dynamic spirometry, nitrogen single breath wash-out test and single breath diffusion capacity for CO. The airway resistance and maximal forced expiratory flow tests indicated a pronounced bronchodilator effect without adverse effects of 12 micrograms and 24 micrograms formoterol on both large and peripheral airways. Improved intrapulmonary gas distribution measured by the nitrogen wash-out test and more even distribution of the lung volumes indicating more homogeneous ventilation was seen for approx. 3 h after terbutaline and approx. 11 h after 24 micrograms formoterol. Measurement of the CO diffusion capacity indicates more effective gas diffusion and a better ventilation-perfusion ratio for at least 11 h, especially after inhalation of 24 micrograms formoterol.

Administration, Inhalation↗

PubMed1992

Rapid onset of action of inhaled formoterol in asthmatic patients.

Twelve patients with stable asthma (mean age, 39 years; asthma duration, 11 years; mean forced expiratory volume in 1 s, 65 percent of predicted; and reversibility, 31 percent) were studied in a double-blind crossover trial. The patients were studied during three test days. Airway resistance and specific airway conductance (Raw and SGaw) were measured using a body plethysmograph and pulse rate, blood pressure, tremor, and subjective effects were recorded before and 1, 3, 5, 10, 15, 30, 60, and 120 min after the test doses. A baseline Raw variability of +/- 20 percent was allowed between the test days. Formoterol 12 micrograms, 24 micrograms, and terbutaline 500 micrograms were given in a spacer (Nebulator) in a randomized double-blind crossover manner as two puffs with a 30-s interval in between. The effect of formoterol 12 micrograms on Raw was significantly better than terbutaline after 3, 5, 10, 60, and 120 min. Formoterol 24 micrograms was significantly better than terbutaline as soon as 3 min after inhalation and at every point in time after that. Formoterol 24 micrograms tended to be better than formoterol 12 micrograms but the differences were not significant at any point in time. All three treatments were well-tolerated. No differences were observed for pulse rate, blood pressure, tremor, or palpitations. The overall onset of bronchodilatation after formoterol 12 and 24 micrograms was faster than after terbutaline 500 micrograms. The tolerability of formoterol was good.

Administration, Inhalation↗

PubMed1991

Bronchial hyperresponsiveness to methacholine in patients with primary Sjögren's syndrome.

The prevalence of bronchial hyperresponsiveness (BHR) to methacholine inhalation in a consecutive series of 21 patients with primary Sjögren's syndrome was studied prospectively. Slight to severe BHR was seen in 12/20 (60%) of the patients. Ten of 12 patients with BHR (83%) had a non-productive cough, wheezing, or intermittent breathlessness. Bronchial hyperresponsiveness was more common in patients with extraglandular symptoms (10/14, 71%) than in those with only glandular symptoms (29%). Spirometrically 29% (6/21) of the patients had 'small airways' disease', and all those had BHR. Of 6/21 (29%) who had diffuse interstitial lung disease, two had BHR. Three of the four patients with obstructive lung function were challenged with methacholine and two of them had BHR. Only two patients with BHR had normal spirometry findings. The data showed that respiratory disease--mostly mild or moderate but even severe bronchial hyperresponsiveness--is commonly seen in patients with primary Sjögren's syndrome.

Adult↗

PubMed1990

Intravenous adenosine but not its first metabolite inosine provokes chest pain in healthy volunteers.

Intravenous (i.v.) bolus administration of adenosine causes increased ventilation and an angina pectoris-like chest pain. Whether adenosine per se or one of its metabolites such as inosine mediates these effects is not clear. Bolus doses of adenosine, inosine, or saline were administered i.v. blindly to six volunteers. Spirometry, ECG recordings, and pain ratings were taken. Adenosine induced both an increase in tidal volume and respiration rate, a dose-dependent chest pain and, at higher doses, various degrees of atrioventricular (AV) block. None of these effects were noted after equimolar injections of inosine or saline. The findings indicate that the angina pectoris-like pain and increased ventilation is induced by adenosine per se and is not produced by adenosine metabolites.

Adenosine↗

PubMed1988

Lack of correlation between the grade of methacholine-induced bronchial hyperreactivity and ipratropium bronchodilation in asthmatics.

In 46 never-smoking randomly chosen patients with non-allergic asthma, 40 to 60 years old, a methacholine hyperreactivity test and lung function tests were performed after inhalation of different doses of ipratropium bromide (IB). The grade of hyperreactivity was measured as the cumulative dose of methacholine necessary to produce a decrease in the forced expiratory volume in one second of 20% of the lowest post-NaCl value (PD20). The following lung function tests were carried out: Lung volumes, ventilatory capacity including flow-volume curves, airway resistance and nitrogen single-breath wash-out test. The bronchodilator effect, measured as a change in the different lung function tests for different doses of IB given (0.08 mg, 0.15 mg and 0.25 mg), was correlated to the grade of hyperreactivity (PD20 dose). No or only a slight correlation was found between the grade of methacholine-induced hyperreactivity and the bronchodilator effects of the different doses of IB. These results indicate a lack of correlation between an anticholinergic bronchodilator effect and the grade of methacholine-induced bronchial hyperreactivity, or possibly an insensitivity of the above-mentioned methacholine test.

Adult↗

PubMed1987

Learning effects, variation during office hours and reproducibility of static and dynamic spirometry.

Static and dynamic spirometric tests were performed in 21 healthy subjects (21-61 years old, 8 smokers and 9 ex-smokers) on 3 different days within 2 weeks. The design of the study allowed separation of the influence of learning and diurnal changes between 09.00 and 17.00 h. In addition, the reproducibility of the tests and the effect of inhalation of 2.5 mg of terbutaline sulphate were studied. No learning effect was observed. There were slight, but statistically significant differences between morning, noon and afternoon measurements. Thus, the residual volume and flow in the early phase of forced expiration were highest in the afternoon, while maximal voluntary ventilation was lower at noon than in the afternoon or morning. The intraindividual variabilities (defined as standard deviation of difference between first and second measurement) of total lung capacity, vital capacity and forced expiratory volume in 1 s (FEV1) were about 3% of the predicted values. The ratio of intra- to interindividual variability was 0.2-0.3. The remaining tests showed higher variability and a higher intra- to interindividual variability ratio. Terbutaline inhalation caused a significant increase in most forced expiratory flow variables. A 10% increase in FEV1 corresponded to a 50-60% increase in endexpiratory flow. In spite of this, the endexpiratory flow and mean transit time were better discriminators of the effects of bronchodilation in normal subjects.

Adult↗

PubMed1987

Effect of nebulized ipratropium bromide on lung function in nonallergic bronchial asthma.

The present investigation was performed on 64 randomly chosen never-smoking patients, 40-60 years old, with nonallergic bronchial asthma with an average FEV1 of 69-73% of predicted, a positive methacholine test, a normal serum IgE level, and a negative RAST or skin test to common allergens and not receiving oral steroid treatment. Sensitive spirometric tests were used to evaluate the dose-response effect of inhalation of 0.08, 0.15 or 0.25 mg of ipratropium bromide. The drug caused bronchodilatation with a nearly linear dose-response relationship for static lung volumes, while the total lung capacity was unchanged after this inhalation. Airway resistance decreased and specific airway conductance increased after all doses. Ventilation and flows were better after doses of 0.15 and 0.25 mg than after 0.08 mg. The intrapulmonary gas distribution improved only after inhalation of 0.25 and 0.15 mg. The currently recommended dose of 0.08 mg seems to be suboptimal for dilatation of both small and large airways.

Administration, Inhalation↗

PubMed1987

Optimal combinations of lung function tests in the detection of various types of early lung disease.

The ability to detect early lung disease with different combinations of lung function tests was assessed by discriminant analysis. A number of lung function tests were performed in 224 never-smokers, 232 smokers, 111 pneumoconiotic subjects and 137 asthmatic patients. The discriminatory capacities of different combinations of test variables are presented. For detecting lung damage induced by tobacco smoke, a combination of the transfer factor and the slope of the alveolar plateau (phase III) increased the sensitivity from 18% to 32% at a specificity of 95%, compared with phase III alone. Dynamic spirometry did not add to the discriminatory capacity. Patients with asthma could be separated from reference subjects by airway resistance, Phase III or a combination of variables in dynamic spirometry. Pneumoconiotic subjects were best identified by a combination of the transfer factor, volumic compliance and phase III. Closing capacity divided by total lung capacity (TLC) and FEV1/TLC further improved the discrimination between different subgroups.

Airway Resistance↗

PubMed1986

Pulmonary involvement in ankylosing spondylitis.

Thirty two patients with ankylosing spondylitis were investigated with a set of pulmonary function tests and the results compared with those for a control population. The patients had no complaints about lung symptoms and their chest radiographs were normal. The main pathological findings were reduced lung volumes, a raised closing volume/vital capacity ratio, and a decreased volumic airway conductance. The lung volume reduction correlated with disease duration, thoracic mobility, and degree of acute phase reaction. The stiff spondylitic thorax probably makes the main contribution to the impairment of lung function in these patients, but the findings in this study also suggest an involvement of the small airways. This type of pulmonary function testing seems valuable even in patients with ankylosing spondylitis without lung symptoms and it might be used as a tool in the staging of the disease, to evaluate treatment and to differentiate from fibrosis.

Adolescent↗

PubMed1986

Reference values for lung function tests in men: regression equations with smoking variables.

Prediction formulas for static and dynamic spirometry, gas distribution, static lung mechanics and the transfer test were derived from measurements in healthy men. The measurements included total lung capacity, residual volume, airways resistance, static elastic recoil pressure of the lung, static compliance, closing volume, slope of the alveolar plateau (phase III), flow-volume variables (including mean transit time) during breathing of air or a helium/oxygen mixture, and conventional spirometric indices. The results from 146 smokers and 124 never-smokers were evaluated separately and combined. For all lung function tests a single regression equation was obtained. The prediction formulas included time-related smoking variables and were valid for both smokers and never-smokers. For many lung function tests, a nonlinear age coefficient resulted in a significant reduction in variance compared with simple linear models. Heavy tobacco smoking influenced most lung function tests less than ageing from 20 to 70 years, but for airways resistance, transfer factor and phase III the opposite was found.

Adult↗

PubMedDate not supplied

Utility of relating pulmonary airflow measures to total lung capacity.

Among healthy never-smokers, forced expiratory volume in one second (FEV1) and maximal voluntary ventilation (40 breaths per minute, MVV40) divided by total lung capacity (TLC) showed less interindividual variability than FEV1 and MVV40, whereas the interindividual variability of other flow variables increased after division by TLC. FEV1, MVV40 and peak expiratory flow (PEF) divided by TLC had higher Student's t-values than FEV1, MVV40 or PEF in comparisons between 224 smokers and 232 never-smokers or between 137 asthmatic patients and 456 reference subjects. Thus these airflow variables corrected for lung size appear to be generally useful indicators of airflow limitation. In these comparisons, the variables were adjusted for body size. All t-test comparisons were based on an equal number of tests. Forced expiratory flow at 70% of TLC (MEF70%TLC) and the area of the expiratory part of the flow-volume curve had the highest t-values when comparing airflow before and after bronchodilatation in 70 asthmatic subjects, except in subjects with more advanced bronchoconstriction in whom MVV40 ranked highest. For the computation of MEF70%TLC, measured TLC could be substituted with predicted TLC with little loss of discriminatory capacity. Reference equations for forced expiratory flow at different TLC fractions and for FEV1/TLC are given.

Adult↗

PubMedDate not supplied

Reference values for gas exchange during exercise in healthy nonsmoking and smoking men.

The gas exchange at rest and during exercise was measured in 50 healthy men, 25 lifelong nonsmokers and 25 smokers, between 20 and 65 years of age. Arterial blood samples were taken and expired air was collected at rest, supine and sitting, and during graded exercise. Prediction formulas for various gas exchange variables were obtained by multiple regression. Optimal conditions for gas transfer were present at light exercise. The arterial oxygen tension (PaO2) remained approximately constant during exercise, although in individual smokers and nonsmokers it decreased by up to 1.8 kPa (13.5 mmHg) between a workload of 50 W and the maximal workload. The lower limit for PaO2 at maximal exercise was about 10.7 kPa (80 mmHg). The alveolo-arterial difference in oxygen tension (PA-aO2) increased considerably with increased workload, from 1.09 +/- 1.05 kPa at 50 W to 3.1 +/- 0.9 kPa at maximal exercise. Ageing and tobacco smoking were associated with a decrease in PaO2 and an increase in PA-aO2 at rest in the supine position, but at maximal exercise neither PaO2 nor PA-aO2 was significantly influenced by age or tobacco smoking. In contrast, the dead space and total ventilation were increased during exercise by ageing and tobacco smoking.

Adult↗

PubMedDate not supplied

Reference values for lung function tests in females. Regression equations with smoking variables.

Prediction formulas for static and dynamic spirometry, gas distribution, static lung mechanics and transfer test were derived from measurements in healthy females. The measurements included total lung capacity, residual volume, airway resistance, static elastic recoil pressure of the lung, static compliance, closing volume, slope of the alveolar plateau (phase III), flow-volume variables (including mean transit time) during breathing of air or a helium/oxygen mixture, and conventional spirometric indices. The results from 86 smokers and 100 never-smokers were evaluated separately and combined. For all lung function tests, a single regression equation including time-related smoking variables, valid for both smokers and never-smokers, was obtained. For many lung function tests, a nonlinear age coefficient resulted in a significant reduction in variance compared with simple linear models. Heavy tobacco smoking influenced most lung function tests less than ageing from 20 to 70 years, but for airway resistance, volumic airway conductance, closing volume, phase III, FEV1/VC, volume of isoflow and mean transit time the opposite was found.

Adult↗