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Results for “Maximal Expiratory Flow-Volume Curves”

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At least 19 recordsLinked to original sources
PubMed1976

Asthma: comparative bronchodilator effects of ipratropium bromide and isoproterenol.

The effect of ipratropium bromide administered at two dosage levels, 40 and 80 mug, isoproterenol, 150 mug, and placebo using a metered dose inhaler was evaluated in ten adult patients with asthma in a double-blind, crossover study. The new atropine-like drug proved to be as effective a bronchodilator as isoproterenol in this study, although it had a later peak effect. Ipratropium bromide had a longer course of action than isoproterenol (4 hours compared to 1-2 hours) and was free of significant side effects. The larger dose of the new drug produced a slightly greater and longer-acting effect than the smaller dose. Ipratropium bromide seems to have had bronchodilator effects on both large and small airways.

Adult↗
PubMed1975

Acute effects of smoking tobacco and a tobacco substitute on lung function in man.

The acute effects on airway function of smoking one cigarette of a tobacco substitute 'New Smoking Material' (NSM), one cigarette of conventional tobacco, and one cigarette containing 70% tobacco and 30% NSM, were studied in 6 healthy nonsmokers and 6 healthy smokers. None of the cigarettes produced any change in three tests of small-airway function (flow-volume curves, closing volume, frequency dependence of compliance). However, smoking either one conventional tobacco cigarette or the 30% NSM/70% tobacco cigarette produced an acute fall in specific airways conductance, of similar degree with both cigarettes, whereas the 100% NSM cigarette produced no such change.

Adolescent↗
PubMed1979

Flow-volume curves and total pulmonary resistance in normal bonnet and rhesus monkeys.

We measured expiratory flow-volume curves and total pulmonary resistance in 15 normal, anesthetized, upright bonnet (Macaca radiata) and 8 rhesus (M. mulatta) monkeys. Absolute maximum flows are about half that found in humans, but, if expressed in vital capacities per second, monkey flows are about four times that of humans. However, irrespective of flow rate, the typical shape of maximum expiratory flow-volume (MEFV) curves of rhesus monkeys is similar to that of normal young adults and that of bonnet monkeys is similar to that of normal older adults. Flow-limiting mechanisms that may determine MEFV curve shape and explain the differences and similarities of monkey and human MEFV curves are discussed. We propose that differences in function between bonnet and rhesus monkeys relates to the concept of dysanaptic lung growth that evolved to subserve behavioral differences between the two species of monkey.

Airway Resistance↗
PubMed1975

Effects of therapeutic irradiation delivered in early childhood upon subsequent lung function.

To determine the long-term effects of therapeutic pulmonary irradiation and treatment with actinomycin D during a period of lung growth, 12 patients treated for Wilms' tumor metastatic to the lung and 8 patients treated for Wilms' tumor with no evidence of pulmonary metastases were studied 7 to 14 years after their initial tumor therapy. All patients had received irradiation to the tumor bed and treatment with actinomycin D. Group 1 had received a single course of bilateral pulmonary irradiation; group 2 had received additional pulmonary irradiation and/or thoracic surgery; group 3 had received no therapeutic irradiation directed primarily to the chest. Total lung capacity (TLC) averaged 71% of predicted value in group 1, 58% in group 2, and 94% in group 3. Diffusing capacity in groups 1 and 2 was reduced to the same extent as lung volume. Quasi-static pressure-volume relationships, studied in three of six patients in group 1, were within the normal range when lung volume was expressed as percentage of observed TLC. Airway resistance, evaluated by spirometry, maximum expiratory flow-volume curves, and resistance of the total respiratory system, was normal or reduced. The data support the hypothesis that therapeutic irradiation during a period of lung growth primarily affects the lung parenchyma and produces a decrease in subsequent size of both the lung and chest wall. No effect of actinomycin D alone upon the lung could be demonstrated.

Adolescent↗
PubMed1978

Discriminant analysis of bronchial asthma by linear discriminant function with parameters of flow-volumes: discriminant analysis of bronchial asthma in young male non-smokers.

With the parameters of a flow-volume and a volume-time curve, the discriminant analysis of bronchial asthma is described. The subjects were classified into three groups (healthy adults, mild asthmatic patients and moderates ones). The difference of the mean vectors of the parameters of the three groups was made clear by the selection methods of the discriminant analysis between any two of the groups both with 6 parameters (%FVC, FEV1.0%, peak flow rate (PF), flow rate at 50% of FVC (V50), flow rate at 25% of FVC (V25), and V50/V25) and with 8 (6 parameters mentioned above and V75, V10). Forced expiratory volume in 1 second percent (FEV1.0%) or V50 was selected at the first step with 6 parameters, and V75 was selected at the first step with 8 parameters. Probabilities of misclassification with 8 parameters were lower than those with 6 ones and the probability of misclassification at the discriminant analysis between healthy adults and mild asthmatic patients with 8 parameters was 15.75% at the final step.

Adult↗
PubMedDate not supplied

Evaluation of early airway disease in smokers: cost effectiveness of pulmonary function testing.

We studied 73 young adults who were presently cigarette smokers to evaluate whether the identification of abnormalities in pulmonary function tests had a detectable influence on modification of smoking habits. Utilizing rate schedules for these tests presently applicable in Rochester, New York, we determined the potential cost to these subjects and community relative to the number of subjects who stopped smoking as a result of test findings. Subjects were evaluated by questionnaire and function testing including spirometry, flow-volume curves, body plethysmography and single breath nitrogen washout test (SBN2). Functional abnormalities were present in 75% of subjects screened. The SBN2 test was most sensitive, identifying 97% of subjects with any abnormality. The presence of common respiratory symptoms was found to be highly predictive of test abnormalities. Subjects were informed of results and counseled. At six-month follow-up, 7% of subjects with abnormal test results had stopped smoking. Utilizing even our most cost-effective test, the SBN2, it would cost +1,392 for each "benefit" defined as one subject not smoking for six months. Application of these screening techniques is unlikely to be effective in altering smoking habits in the absence of continued physician support.

Adult↗
PubMed1979

Tracheobronchopathia osteochondroplastica.

The clinical, pathological and physiological features of two patients suffering from tracheobronchopathia osteochondroplastica (TO) are described. Unequivocal evidence of extrapulmonary airways obstruction was not able to be obtained by lung function testing, despite extensive central airway involvement in both patients. TO is a rare condition of which there is only one other clinical report from this country. As the bronchoscopic appearance may closely resemble that of endobronchial neoplasms, TO should be remembered in the differential diagnosis of patients with haemoptysis.

Aged↗
PubMed1978

Closing volume and flow volume abnormalities in alpha(1)-antitrypsin phenotype groups in a community population.

Alpha1-antitrypsin phenotype groups, found in a community population studied in Tucson, were compared by using the maximum expiratory flow volume curve and the single-breath nitrogen test, alone and in combination. Subjects 25 to 54 years of age were used for the comparison, among whom there were 728 Pi M, 29 Pi MZ, and 62 Pi MS phenotypes. None of the flow volume parameters or closing volume parameters was able to differentiate among the phenotype groups; subjects in groups heterozygous for alpha1-antitrypsin did not differ from individuals homozygous for Pi M with regard to any or all flow volume or closing volume parameters.

Adult↗
PubMed1979

A double blind cross-over study of maximal expiratory flows and arterial blood gas tensions in normals, asthmatics and bronchitics after salbutamol and ipratropin.

8 normals, 8 asthmatics and 8 bronchitics inhaled comparable doses of ipratropin and salbutamol. Five different flow-volume parameters were measured before and at intervals from 3 to 360 minutes after inhalation, on a total number of 2880 maximal effort expiratory flow-volume curves. Arterial blood gas tensions were measured before and 60 minutes after inhalation. In all parameters a significant larger effect (p less than 0.05) of ipratropin was found in normals, but in different time intervals. The parameter FEV1 and MEF at 50% of FVC showed the largest effect of salbutamol during the interval from 3 to 60 minutes in the asthma patients. None of the parameters showed significant difference in drug effects in the bronchitis patients. The findings suggested a more peripheral action of ipratropin than of salbutamol in the normals. No significant change in gas tensions were found after inhalation in any of the three groups.

Albuterol↗