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Results for “Forced Expiratory Flow Rates”

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At least 19 recordsLinked to original sources
PubMed1980

Chronic bronchitis and decreased forced expiratory flow rates in lifetime nonsmoking grain workers.

To determine whether clinical symptoms and pulmonary function abnormalities were more common in lifetime nonsmoking grain elevator workers exposed to grain dust than in lifetime nonsmoking community control subjects who were not occupationally exposed to dust, we obtained an occupational health questionnaire, spirometric variables, and flow-volume curves on 90 lifetime nonsmoking grain workers and 90 lifetime nonsmoking community control subjects. For these groups we calculated the prevalence of chronic bronchitis, defined as daily production of phlegm for 3 months/yr for at least 2 yr. The prevalence of chronic bronchitis was higher in nonsmoking workers (23.1%) than in nonsmoking control subjects (3.3%) (p less than 0.01). Nonsmoking grain workers had lower mean values than did nonsmoking control subjects for maximal mid-expiratory flow rate (p less than 0.01) and for maximal expiratory flow at 50% of vital capacity (p less than 0.01). We conclude that exposure to grain dust inlifetime nonsmoking grain workers is associated with an increased prevalence of chronic bronchitis and evidence of airflow obstruction.

Adult↗
PubMed1982

Comparison of peak expiratory flow rate and forced expiratory volume in one second in histamine challenge studies in children.

The difficulty in performing FEV1 in young children prompted us to assess whether PEFR could be used to measure the response to inhaled histamine. In 123 children with recurrent respiratory symptoms we found a highly significant correlation (r = 0.83, P less than 0.001) between the percentage fall from base-line of FEV1 and PEFR. We also performed histamine challenge tests using PEFR alone on 56 children too young to manage spirometry and found our procedure reliable. PEFR is an adequate measurement in histamine provocation studies and can be used interchangeably with FEV1. The criterion for a positive test is a 20% fall in either PEFR or FEV1.

Adolescent↗
PubMed1994

Objective indicators of severity of asthma.

Subjects with asthma who are intensively treated in residential care facilities frequently demonstrate marked clinical improvement in their disease, with fewer attacks and improved well being. Despite their improved status, it is known that pulmonary function test results often remain abnormal in patients with asthma. This prospective study on children with asthma receiving residential care was carried out to determine which pulmonary function parameter best reflected clinical improvement through correlation with the duration of complete freedom from wheezing. Evaluated in 42 children were spirometry values including forced vital capacity, forced expiratory volume in 1 second, peak expiratory flow rate, forced expiratory flow (between 25% and 75% of forced vital capacity), and lung volumes as reflected by residual volume/total lung capacity. Bronchial hyperreactivity as reflected by bimonthly provocative concentration causing a 20% fall in FEV1 in response to methacholine inhalation was evaluated in 18 patients. All pulmonary function test results were correlated with days since last wheezing episode. Results indicate that only peak expiratory flow rate (r = 0.91; p < 0.001), forced expiratory volume in 1 second (r = 0.69; p < 0.01), and forced expiratory flow (r = 0.62; p < 0.05) demonstrated significant correlation with the number of days since last wheezing episode. Of particular interest was the failure of bronchial hyperreactivity to improve despite intensive therapy with bronchodilators and corticosteroids. Persistence of bronchial hyperreactivity despite intensive therapy with corticosteroids suggests that in at least some children with severe asthma, bronchial hyperreactivity may be especially long-lived, may be perpetuated by inhaled beta 2 agonists, or may exist independently of airway inflammation.

Adolescent↗
PubMed1980

Response of the lung airway to exercise testing in asthma and rhinitis.

The reactivity of the large and small airways of the lung in a group of ten atopic subjects with rhinitis was compared with that in ten non-atopic control subjects and in 17 with atopic asthma. Atopic state was assessed by skin prick testing with 22 common allergens and by measurement of total serum immunoglobulin E (IgE) antibody. The atopic state of the rhinitis and asthma patients was similar. Exercise provocation tests were performed on each subject and changes in airway function were measured by peak expiratory flow rate, forced expiratory volume in one second, vital capacity, maximal expiratory flow volume curves and closing volume. There were no statistically significant differences between the changes in lung function after exercise in the rhinitis patients compared with the controls. There were, however, statistically significant changes in all the measurements of respiratory function in those with asthma compared with the other two groups. The falls in forced expiratory flow rates in the asthmatic subjects were greater at lower lung volumes than near the total lung capacity, perhaps indicating that narrowing of small, as well as large, airways was occurring. No correlation was found between the magnitude of the airway response to exercise and either the total serum IgE antibody or the mean weal diameter of positive skin tests in each subject. Atopic subjects with rhinitis but not asthma showed no evidence of bronchial hyper-reactivity on exercise testing. It is therefore suggested that single exercise provocation test can discriminate subjects with atopic asthma from those with other atopic disorders.

Adult↗
PubMed1995

Comparison of the bronchodilatory effects of cetirizine, albuterol, and both together versus placebo in patients with mild-to-moderate asthma.

BACKGROUND: Many potential users of the H1 antihistamine cetirizine are asthmatic and may be using inhaled albuterol. This study was conducted to assess the possible bronchodilatory effect of cetirizine in patients with mild-to-moderate asthma and to determine whether cetirizine interacts with albuterol. METHODS: In a randomized, double-blind, placebo-controlled, crossover study, the effects on pulmonary function of 5, 10, and 20 mg oral doses of cetirizine with and without inhaled albuterol (180 micrograms) were determined in 12 patients at 11 time points over 8 hours. The primary measure of efficacy was forced expiratory volume in 1 second (FEV1). RESULTS: Cetirizine with or without albuterol significantly increased FEV1, peak expiratory flow rate, and forced expiratory flow rate between 25% and 75% of vital capacity relative to baseline and placebo but did not have a significant effect on forced vital capacity. The effect of 20 mg of cetirizine on FEV1 was generally greater than that of 10 or 5 mg, but the difference was statistically significant only at the 30-minute time point (p < 0.05). All three cetirizine doses produced significantly greater increases than placebo in FEV1 and forced expiratory flow rate between 25% and 75% of vital capacity for 8 hours and in peak expiratory flow rate for 7 hours (p < 0.02). Albuterol alone had a significant effect on the four pulmonary function variables from 1 to 5 hours after baseline (p < 0.05), which is consistent with albuterol's recommended dosing frequency of every 4 to 6 hours. Albuterol alone increased FEV1 significantly more than 5 mg of cetirizine alone but not 10 mg or 20 mg of cetirizine alone at 60, 90, and 120 minutes after baseline, but all three doses of cetirizine increased FEV1 significantly more than albuterol 7 and 8 hours after baseline (p < 0.05), indicating that the bronchodilatory action of cetirizine lasts longer than that of albuterol. Cetirizine neither potentiated nor inhibited the bronchodilatory action of albuterol, but the two drugs appeared to have an additive bronchodilatory effect. None of the cetirizine treatments caused a worsening of pulmonary function, and all were well tolerated. CONCLUSIONS: Cetirizine has a significant bronchodilatory effect in patients with mild-to-moderate asthma and can be used to treat concomitant conditions (e.g., allergic rhinitis) without concern that it will interfere with the bronchodilatory effect of albuterol or cause worsening of asthma by itself.

Albuterol↗
PubMedDate not supplied

[Usefulness of forced expiratory flow rate measurements in diagnosis of selected lung diseases in children].

The study group was composed of 2512 healthy children (age range 7-15 years) randomly selected from schools of the Upper Silesian Industrial District. In each child 5 PEF measurements were carried out using the Vitalograph meter. A statistical analysis of the results was carried out. The results seen in tables and centile charts can be used as normal values for children in given age groups and sex. PEF is useful in clinical diagnosis of different respiratory diseases.

Adolescent↗
PubMed1984

[Study of forced expiratory flow rates in respiratory paralysis].

Subjects with a complete paralysis of the abdominal muscles and severe or lesser involvement of the intercostals were studied. The author analysed, under electromyographic control, the flow-volume curves by measuring flow at 50% (V50) and at 25% (V25) of the observed and theoretical vital capacity (CV) above observed residual volume. The results were compared to a group of normal subjects in three situations: sitting and lying in air and sitting in water. A sloping, head down position was also studied. In the handicapped, instantaneous flow at 50% CV was significantly lower than normals in all situations; at 25% CV the difference was not significant but expiration was incomplete for those sitting in air. For the handicapped, sitting in water, the residual volume was close to that of normal subjects sitting in air and the last part of the flow-volume curve was the same gradient as of normal subjects sitting in air: this enabled some comparisons of instantaneous flow. In order that measures of instantaneous flow were made at the same inflation volume, they were made at 50% and 25% of theoretical vital capacity in the handicapped. The results did not differ from those of normal subjects sitting in air. The situation was less satisfactory lying in air, only useable in practice, the most handicapped subjects having notably reduced outputs compared to those whose motor deficit was less severe. The head down position was as for outputs at very low volume.

Adult↗
PubMedDate not supplied

High prevalence of reversible airway obstruction in asbestos-exposed workers.

In this retrospective study of 97 male workers exposed to asbestos for 2-50 yr, data were collected on chest x-ray findings and lung function, including lung volumes, forced expiratory flow rates (i.e., forced expiratory volume in 1 sec [FEV1.0], forced expiratory flow measured between 25% and 75% of forced vital capacity [FEF(25-75%)]), airway resistance (R(aw)), carbon monoxide (CO)-diffusing capacity, and the existence of airway obstruction reversible by a beta-adrenergic agonist (RAO). The authors performed multiple-regression analyses to correlate the variations in lung function data with age, smoking habits, duration of asbestos exposure, and time since last exposure. Occupational activities of subjects that might induce specific lung abnormalities were also considered. No significant decrease was seen in lung volumes or CO-diffusing capacity; however, a decrease in FEV1.0 and an increase in R(aw) were measured in 65% of the subjects, and an isolated decrease in FEF(25-75%) occurred in only 18%. There was no difference in lung-function data between subjects who had chest x-ray signs of abnormalities (n = 59) and those who did not (n = 38). A significant relationship was found between the decrease in FEV1.0 and age; however, no correlation was noted between altered lung function and cigarette smoking, duration of asbestos exposure, or time since last exposure. RAO prevalence was higher (34%) than previously reported (9%) in subjects with chronic obstructive pulmonary disease (COPD) who were not exposed to asbestos or outdoor pollution. The RAO prevalence in asbestos-exposed workers was nearly the same as that measured in COPD subjects who lived downtown and who were exposed to outdoor pollution (36%). The high RAO prevalence in asbestos-exposed workers was found in 43% of subjects who were exposed only to asbestos, and in 33% of subjects who were also exposed to air pollution due to their occupational activities. It is hoped that the observations in this study will encourage practitioners to check for RAO in asbestos workers who use inhaled bronchodilators.

Aged↗
PubMed2000

Exhaled nitric oxide as an indicator of severity of asthmatic inflammation.

Traditional assessment of severity of asthma relies on an evaluation of signs and symptoms and pulmonary function tests. These pulmonary function tests, such as peak expiratory flow rates, forced vital capacity, and forced expiratory flow rates, are indirect measures of airway caliber only, and not inflammation. Since asthma is an inflammatory disease, a measure of the degree of inflammation would be helpful in quantitating severity and titrating of anti-inflammatory therapy. A noninvasive method for measuring pulmonary inflammation would therefore be helpful to assist the emergency physician in initial treatment and assist in titration of anti-inflammatory therapy during repeat visits. Exhaled nitric oxide (NO) assays are convenient and practical and may fulfill this role. In this review, we discuss the role of NO in asthmatic inflammation and the role that exhaled NO values may play in the emergency management of asthma.

Asthma↗