PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Forced Expiratory Flow Rates”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 523 records · Page 29Linked to original sources
PubMed1994

[Error factors in spirometry].

Spirometry is the more frequently used method to estimate pulmonary function in the clinical laboratory. It is important to comply with technical requisites to approximate the real values sought as well as adequate interpretation of results. Recommendations are made to establish: 1--quality control 2--define abnormality 3--classify the change from normal and its degree 4--define reversibility. In relation to quality control several criteria are pointed out such as end of the test, back-extrapolation and extrapolated volume in order to delineate most common errors. Daily calibration is advised. Inspection of graphical records of the test is mandatory. The limitations to the common use of 80% of predicted values to establish abnormality is stressed. The reasons for employing 95% confidence limits are detailed. It is important to select the reference values equation (in view of the differences in predicted values). It is advisable to validate the selection with local population normal values. In relation to the definition of the defect as restrictive or obstructive, the limitations of vital capacity (VC) to establish restriction, when obstruction is also present, are defined. Also the limitations of maximal mid-expiratory flow 25-75 (FMF 25-75) as an isolated marker of obstruction. Finally the qualities of forced expiratory volume in 1 sec (VEF1) and the difficulties with other indicators (CVF, FMF 25-75, VEF1/CVF) to estimate reversibility after bronchodilators are evaluated. The value of different methods used to define reversibility (% of change in initial value, absolute change or % of predicted), is commented. Clinical spirometric studies in order to be valuable should be performed with the same technical rigour as any other more complex studies.

Adolescent↗
PubMedDate not supplied

[Changes of static and dynamic characteristics of external respiration in divers after short-term dives down to 100 m].

In a series of short (up to 45 min without considering time of decompression) dives (SD) at depths down to 100 m under conditions of the Barentsev Sea five professional deep-sea divers were examined. In dives down to 40 m compressed air was used as breathing media, in dives to 60, 80 and 100 m--nitrogen-heliox mixture. Before the SD series the volume and velocity lung variables at rest and during forced expiration in air and heliox media were measured between separate SDs and on the 3rd day after the end of decompression with dive to 100 m, using computer spiro- and pneumotachometry methods. Bronchospastic syndrome, playing the leading role in the development of transient isolated or generalized airway obstruction, was shown to be evoked in divers during conduction of SD series. Obstructive phenomena are presumed to be connected with elastic properties' disturbance of lung tissue and development of expiratory collapse; they might cause continuous lung dilatation.

Adult↗
PubMed1994

[Usefulness of peak expiratory flow measurements in assessing degree of bronchial obstruction in patients with chronic obstructive lung diseases].

An analysis was carried of relations between PEF measurements and FEV1 values and between PEF and FEF25-75 in 130 patients with COLD (48 females and 82 males). PEF was assessed using the Wright peak flow meter, while FEV1 and FEF25-75 from the spirographic curve. A positive linear correlation was found between PEF and FEV1 in absolute values, % predicted and standardised residuals (r = 0.91, r = 0.87, p < 0.001). Diagnostic sensitivity of PEF in detecting bronchial obstruction was 82%, while the specificity was 85%. The weakest correlation was found between PEF and FEV1 in standardised residuals of 41 patients with PEF between 50% and 79% predicted (r = 0.41, p < 0.05). In this subgroup of patients, twenty one (51%) had normal FEV1, and twenty (49%) low FEV1 values. Measurements of PEF despite a strong correlation with FEF25-75 did not allow to single out cases without small airway involvement, because in 28% of the patients with PEF 100% predicted lowered FEF25-75 were noted. In 97% of patients with PEF values 80% predicted abnormal low FEF25-75 were demonstrable.

Adult↗
PubMed1994

[Effect of vaporizing high doses of ipratropium bromide on lung ventilation in patients with chronic obstructive pulmonary disease and bronchial asthma].

Authors compared efficacy of high Atrovent doses and Salbutamol on pulmonary ventilation. Examinations were performed in 20 patients with BA and 20 patients with COPD. Each drug was given on separate days in increasing doses (0.04; 0.25 and 0.5 mg) of Atrovent and 0.2 mg of Salbutamol. Bronchodilatation was assessed by measurement of FEV1; FEF25%, FEF50%, FEF75%. Maximal effect in patients with COPD was reached with doses of 0.25 and 0.5 mg of Atrovent (delta FEV1(%) +22). Salbutamol and 0.04 mg of Atrovent were significantly less effective. In patients with BA Salbutamol (delta FEV1(%) +49) are likely to be more effective bronchodilator an Atrovent (delta FEV1(%) +26).

Albuterol↗
PubMed1994

The "88% saturation test": a simple lung function test for young children.

OBJECTIVE: The 88% saturation test (88%-SAT) was developed as an alternative to standard spirometry for those young children unable to perform standard forced expiratory maneuvers. In adults, this test revealed rapid desaturation in those persons with a history of asthma when compared with healthy control subjects. Similar findings in children were tested. SETTING: Tertiary care hospital. PATIENTS: Thirty-three former premature infants (28.3 +/- 2.3 weeks gestation), aged 5 to 7 years, who were participating in a follow-up study, were enrolled in this study. DESIGN: The study compared the 88%-SAT with standard spirometry and respiratory health characteristics ascertained through a parental questionnaire. The 88%-SAT consists of continuous measurement of hemoglobin saturation by pulse oximetry (SaO2) while the subject breathes a nonhumidified 12% oxygen and nitrogen mixture for 10 minutes or until SaO2 decreases to 88%, whichever occurs first. Abnormal 88%-SAT was defined as a decrease of SaO2 to 88% within the 10-minute period, and abnormal spirometry was defined using standardized values. RESULTS: Of the 20 children who successfully completed both spirometry and the 88%-SAT, 10 had normal spirometry results and did not desaturate to 88%, and 5 had abnormal spirometry and 88%-SAT results. Four children did not desaturate during the 88%-SAT, but had abnormal spirometry results, and one child had abnormal 88%-SAT results, but normal spirometry. Ten additional children completed the 88%-SAT, but not standard spirometry. Three children were unable to complete either test. Of those 30 children tested, 7 (23%) had a history of reactive airways disease, and all 7 had abnormal 88%-SAT results. The 88%-SAT had greater sensitivity (100% vs 75%) and specificity (87% vs 63%) than spirometry in identifying children with known reactive airways disease. The mean McCarthy general cognitive index (GCI) of the group performing both spirometry and the 88%-SAT (n = 20) achieved a mean (+/- SD) GCI of 96.2 +/- 16.7, and the group (n = 30) that completed the 88%-SAT had a mean (+/- SD) GCI of 75.2 +/- 26.3 (chi 2 P < .012). The 10 children able to perform only the 88%-SAT had a mean GCI (+/- SD) of 72.8 +/- 26.9, and the 3 children unable to perform either test had a mean GCI (+/- SD) of 63 +/- 11. CONCLUSIONS: Our data suggest that the 88%-SAT may be more effective than spirometry for identifying reactive airways disease in young, uncooperative, or developmentally delayed children. The dry air of the hypoxic inspired gas may function as an airway challenge, leading to decreased oxygenation in patients with reactive airways.

Child↗
PubMed1993

Hispanic children with asthma: morbidity.

Hispanic children represent a large and growing segment of the poor and disadvantaged children in our country. Asthma and other chronic respiratory diseases have a significant impact on poor children. Yet there are few descriptions of the specific morbidities and barriers to health that Hispanic children with asthma encounter, and data on predictors of morbidity among these children are unavailable. The purpose of this study is to describe the morbidity associated with asthma in Hispanic children and to identify factors that predict morbidity. A group of Hispanic children with moderate asthma followed in the clinics of the University of Texas Health Science Center at San Antonio were studied. Children aged 6 to 16 years with at least two acute-care visits or one hospitalization for asthma during the previous year were enrolled. Data sources included standardized questionnaires, spirometry, medical records, and school attendance records. Seventy-eight Hispanic children were enrolled in the study (mean age = 9.4 +/- 2.7 [SD]; 62% male). Fifty-two (67%) of children had been hospitalized previously. The other morbidity variables (mean +/- SD) were number of days/week impaired (1.1 +/- 1.2), number of days absent from school per year (13 +/- 9.6), number of acute-care visits per year (3.3 +/- 2.4), and number of hospital admissions per year (0.6 +/- 0.8). The mean forced expiratory volume in 1 second/forced vital capacity was 79.3% (+/- 9.1) and the mean forced expiratory flow, mid-expiratory phase, percent predicted was 69.9% (+/- 25.1). Thirty-four children (44%) were exposed to cigarette smoke in the home.(ABSTRACT TRUNCATED AT 250 WORDS)

Absenteeism↗
PubMed1996

[Respiratory symptoms, diseases and ventilatory function in shoe industry workers].

The respiratory health status was studied in 376 female shoe workers. The mean age of workers was 32 years and the mean exposure 12 years. A significantly higher prevalence of all chronic respiratory symptoms and diseases was found in exposed compared to control workers. This was particularly pronounced for chest tightness (exposed: 44.7%; control: 0%), dyspnoea (exposed: 42.6%; control: 2.0%) and rhinitis (exposed: 46.3%; control: 2.4%). In exposed workers there was also a high prevalence of acute symptoms which developed during work shift, particularly irritation of the throat (56.6%), dryness of the throat (61.4%), dryness of the nose (56.4%), and eye irritation (63.6%). The prevalence of acute and chronic respiratory symptoms and diseases increased with duration of exposure. There were also statistically significant acute reductions in all ventilatory capacity tests (FVC, FEV1, FEF50, FEF25) during work shift. The measured ventilatory capacity values in exposed workers were significantly lower in comparison with the predicted values (P < 0.01). Lung function severity increased with duration of employment. The data suggest that occupational exposure to atmospheric pollution in the shoe manufacturing industry may be responsible for the development of acute and chronic respiratory impairment.

Adolescent↗
PubMed1997

[Estimation of initial interobserver variability of forced spirometry in the multicenter epidemiological study IBERPOC. Scientific Committee of the IBERPOC study].

To estimate the interobserver variability and degree of agreement for basic spirometric parameters before beginning field work for the IBERPOC Project. Study of agreement between 7 observers (pneumologists) and a gold standard, using a scheme of incomplete balanced and randomized blocks with an equal number of spirometric measurements (n = 3) per patient and an equal number of measurements (n = 9) per observer performed at the same session. The study population consisted of 14 patients with different degrees of air flow obstruction and 7 normal volunteers. Statistically significant differences attributable to subjects (inter-patient variability) were found for the three variables analyzed. Variability attributable to the observer was found for FVC and FEV1 but not for FEV1/FVC. The greatest interobserver differences were found for FEV1, such that 4 of the 7 observers recorded values that were significantly different from the mean (p < 0.05). The differences were less marked for FVC and for the FEV1/FVC ratio, with only 2 observers recording significantly different values for each variable. The high degree of reproducibility as well as the excellent interobserver agreement found in this standardization session provide an a priori guarantee of validity for spirometric measurements and rule out the existence of differential bias in data recorded at the various geographic areas involved in the study.

Data Interpretation, Statistical↗
PubMed1976

Use of H2 as an inert gas during diving: pulmonary function during H2-O2 breathing at 7.06 ATA.

A review of the characteristics of hydrogen as an inert gas for use in diving is presented, with special emphasis on the extension of the respiratory limitation in diving by use of this least dense of all gases. Forced vital capacity, FEV1, FEV2, PEFR, PIFR, and MVV were measured on groups of subjects using the following gas mixtures, all at 7.06 ATA: four subjects breathing 97% H2-3% O2, two subjects breathing 97% He-3% O2, and two subjects using 97% N2-3% O2. The MVV while breathing H2-O2 at 7.06 ATA was 14% higher than with air at the surface, and was improved 40% compared with He-O2 and 171% when compared with N2-O2 at 7.06 ATA. Similar findings were obtained for FEV1, FEV2, PEFR, and PIFR. The values in this study for the relationship of relative gas density (rho) to flow are rho-0.41 for MVV, rho-0.44 for PEFR, and rho-0.45 for PIFR (method of Wood and Bryan).

Atmospheric Pressure↗
PubMedDate not supplied

Late pulmonary toxicity after treatment for Hodgkin's disease.

The combination of mediastinal radiotherapy (RT) with chemotherapy (CT) including bleomycin is associated with an increased risk of pulmonary toxicity. The aim of the present investigation was to evaluate late pulmonary effects of RT plus CT consisting of the ABVD regimen in patients suffering from early stage Hodgkin's disease. For this purpose pulmonary function was serially evaluated before, at the end and at least 1 year after therapy in 32 patients (median age 28 years) with Hodgkin's disease stages IA,B-IIA. Treatment consisted of four cycles of ABVD chemotherapy followed by mediastinal irradiation at the median dose of 36 Gy (range 30.6-43.2). At the end of treatment, resting mean pulmonary function tests showed a significant decline of forced expiratory volume in 1 second (FEV1), forced expiratory flow at 25-75%, (FEF25-75%), total lung capacity (TLC), vital capacity (VC) and carbon monoxide diffusing capacity (DLCO). The decline of TLC, VC and DLCO, indicative of a pulmonary defect of restrictive type, persisted 1 year from the end of therapy. Only seven patients developed symptoms of cough and mild shortness of breath with effort. These data confirm that RT combined with short term ABVD result in pulmonary dysfunction that does not seem to have clinical significance.

Adolescent↗
PubMedDate not supplied

Assessment of the bronchodilator effect of inhaled furosemide compared to salbutamol in asthmatic patients.

To compare the bronchodilator effects of high-dose inhaled furosemide, we studied 80 patients who were nonsmokers presenting some degree of bronchial obstruction. Of these patients, 40 were given salbutamol (1%) aerosol and the remaining 40 were given furosemide aerosol (100 mg). Respiratory functional tests were conducted at 10 min and 30 min, as well as measurement of pulse and blood pressure. Patients in the salbutamol group showed an improvement in forced expiratory volume (FEV1) of 7.9% at 10 min and 30 min, and the group given furosemide improved 6.9% (p > 0.05). Systolic blood pressure showed a slight increase of 2 mmHg in the salbutamol group and a decrease of 6 mmHg in the furosemide group (p < 0.05). The same occurred for diastolic blood pressure (p < 0.05). Pulse increased from 73.7 to 75.2 beats per min in the salbutamol group; however, in the furosemide group, pulse declined from 73.7 to 71.8 beats per min (p < 0.05). We conclude that furosemide at a dose of 100 mg has the same bronchodilator effect as salbutamol, as measured by FEV1 and forced expiratory flow of 25% to 75%. Furosemide was also related with a mild hypotensive effect and drop in pulse.

Administration, Inhalation↗
PubMed1998

[Normograms of spirometric values for the city of Buenos Aires].

There is a large variability between the different normograms of spirometric values, so that we designed our normogram for Buenos Aires and Gran Buenos Aires. We performed forced spirometry, under American Thoracic Society standardization, in 237 normal subjects (105 females) between 18 to 86 years old, and 144 to 194 cm. We measured Forced Vital Capacity (FVC), forced Expiratory Volume in one second (FEV1), and forced expiratory flow during the middle half of the Forced vital capacity (FEF25-75), in previously calibrated by the explosive decompressor spirometers. Linear regression using height and age was used for each measured value for each sex. The values obtained were in normal distribution, so that we determined the Low Limit of Normality calculating the 95% confidence interval to one tail, and this should replace the common method of the fixed percent of each value to determine the lower limit of normality for a predicted value.

Adolescent↗
PubMed1998

Effects of smoking cessation on maternal airway function and birth weight.

OBJECTIVE: To evaluate the effects of smoking cessation before or early in pregnancy on maternal airway function and birth weight. METHODS: Measurements of forced expiratory spirometry including forced vital capacity, forced expiratory volume in 1 second, forced expiratory flow rates between 0.2 and 1.2 L, 25% and 75%, and 75% and 85%, and instantaneous flows at lung volumes of 25%, 50%, and 75% were carried out by a wedge bellow spirometer in 40 pregnant exsmokers and were compared with those of 175 nonsmoking and 97 currently smoking pregnant women. Spirometric testing was conducted at a mean (+/- SD) gestational age of 21.5 +/- 7.0 weeks. In exsmokers, the average lifetime cigarette consumption was 17.1 +/- 8.1/day for a mean duration of 9.7 +/- 3.9 years, similar to that observed in current smokers. The median duration of smoking abstinence was 20 weeks before study spirometry. RESULTS: All spirometric measurements in exsmokers were similar to those of nonsmokers and were significantly higher than those of current smokers. Spirometric measurements for nonsmokers, current smokers, and exsmokers were respectively: forced expiratory volume in 1 second (3.36 +/- 0.39, 3.09 +/- 0.45, and 3.35 +/- 0.32 L); forced expiratory flow rate between 25% and 75% (ie, mid-expiratory phase) (3.85 +/- 0.69, 3.21 +/- 0.76, and 3.86 +/- 0.66 L/sec); forced expiratory flow rate between 75% and 85% (ie end-expiratory phase) (1.39 +/- 0.35, 1.03 +/- 0.35, and 1.41 +/- 0.39 L/sec); instantaneous flow at lung volume of 50% (4.35 +/- 0.82, 3.76 +/- 0.89 and 4.36 +/- 0.68 L/sec); and instantaneous flow at lung volume of 25% (1.91 +/- 0.47, 1.47 +/- 0.49, and 1.92 +/- 0.46 L/sec). Mean gestational age at delivery was similar among the three groups (277 +/- 11,274 +/- 12, and 274 +/- 11 days for nonsmokers, current smokers, and exsmokers, respectively). The mean birth weight of babies born to exsmokers (3408 +/- 511 g) was similar to that of babies born to nonsmokers (3469 +/- 461 g), but was significantly greater than that of babies born to smoking pregnant women (3189 +/- 485 g; P < .001). CONCLUSION: Smoking cessation either before or at an early stage of pregnancy is associated with early, reversible increments of maternal airway function and mean birth weights that are higher than among women who continue smoking.

Adult↗
PubMed1989

Evaluation of heart-lung transplant recipients with prospective, serial transbronchial biopsies and pulmonary function studies.

The insidious development of obliterative bronchiolitis after heart-lung transplantation is thought to be due to rejection and possibly infection (cytomegalovirus). To evaluate further, we prospectively managed the last 16 consecutive heart-lung transplant recipients with serial transbronchial biopsies with lavage and pulmonary function studies as part of a surveillance protocol or as dictated by clinical presentation. A total of 123 transbronchial biopsies with lavage were performed, 77 for clinical indications (group I) and 46 for routine surveillance (group II). Results of 64 (83.1%) group I biopsies were positive for rejection or infection. Thirty-one of these biopsy specimens showed signs of rejection (29 in group I and two in group II), characterized by a perivascular mononuclear infiltrate, lymphocytic bronchiolitis, and occasionally alveolar septal mononuclear infiltrate. Forty-six serial pulmonary function tests were performed. The forced expiratory volume in 1 second (percent predicted), forced expiratory flow rate between 25% and 75% of the forced vital capacity (percent predicted), and arterial oxygen tension (millimeters of mercury) were significantly reduced from baseline values during rejection episodes: forced expiratory volume in 1 second, 75.7% +/- 20.1% versus 52.7% +/- 18.3% (p less than or equal to 0.05); forced expiratory flow rate between 25% and 75% of the forced vital capacity, 97.6% +/- 30.5% versus 49.8% +/- 22.3% (p less than or equal to 0.05); and arterial oxygen tension, 92.1 +/- 8.8 mm Hg versus 71.4 +/- 18.8 mm Hg (p less than or equal to 0.05). The fall in pulmonary function was reversible with pulse methylprednisolone. Asynchronous heart and lung rejection was documented. Of the 29 episodes of pulmonary rejection, 18 (62%) occurred asynchronously. Ten of the 16 (62%) heart-lung recipients had at least one episode of cardiac rejection. Thirteen of 16 (81%) had at least one episode of lung rejection. Serial transbronchial biopsies with lavage, as dictated by pulmonary function tests and clinical status, have guided early and more specific therapy directed against rejection and infection. With early detection, small airway dysfunction has been reversible.

Adult↗
PubMed2000

Maximal and partial expiratory flow rates in a population sample of 10- to 11-yr-old schoolchildren. Effect of volume history and relation to asthma and maternal smoking.

The effect of volume history on forced expiratory flow rates has been reported to differ between patients with asthma and healthy persons, and it has been hypothesized that the peripheral airway inflammation of patients with asthma may underlie this difference. There are no published data, however, on the distribution of such volume history effects or the relation of these effects to airways disease in children. We obtained combined partial and maximal forced expiratory flow-volume curves on 1,834 children, age 10-11 yr, in eight communities in the United States and Canada. The effect of a deep inhalation on forced expiratory flow rates at low lung volumes was quantitated by the ratio of V (30) during a maximal expiratory maneuver (V (30M)) to V (30) during a partial expiratory maneuver (V (30P)). The V (30M)/V (30P) ratio was slightly higher among girls than boys (1.26 versus 1.18, p = 0.0001) indicating that a deep inhalation increased V (30) slightly more among girls than among boys. The V (30M)/V (30P) ratio was related to neither history of asthma nor to maternal smoking. In contrast, most spirometric indices from either the maximal or the partial expiratory flow-volume curve were lower in association with a history of asthma or a report of maternal smoking. The ratio of FEF(25-75)/FVC was particularly consistent as a measurement that discriminated both of these effects in boys and girls. These results suggest that the measurement of volume history effects offers no benefits for epidemiological studies of childhood respiratory disease whereas spirometric indices such as the FEF(25-75)/FVC ratio are quite sensitive to the effects of asthma and environmental tobacco smoke exposure on the airways.

Asthma↗
PubMed2006

Forced expiratory volume in one second and peak expiratory flow rate values in non-professional male tennis players.

AIM: Forced expiratory volume in 1 second (FEV1) is a reliable and easily measured lung function index, which is nowadays used for early detection of chronic obstructive pulmonary disease. It has also been established recently as an important predictor of all-cause, cardiovascular and cerebrovascular morbidity and mortality in the Western World. Similar implications have been made with regard to peak expiratory flow rate (PEFR). The present study was designed in order to compare the FEV1 and PEFR values of non-professional, smoking and non-smoking male athletes to those predicted for the general, non-athlete population. METHODS: A total of 141 non-professional tennis players aged 30-74 years were studied (99 smokers and 42 non-smokers). FEV1 and PEFR of all men were measured by means of a one flow spirometer, and compared to those predicted for their age and height, based on formulas for the non-athlete, healthy, non-smoking population. RESULTS: Non-professional tennis players had significantly higher FEV1 and PEFR values, compared to FEV1 and PEFR predicted, respectively. No statistically significant difference was observed between smokers and non-smokers. CONCLUSIONS: Our study confirms that even moderate physical activity, such as non-professional tennis, can improve FEV1 and PEFR values, maintaining a normal respiratory function, which is a strong predictor of reduced cardiovascular and overall morbidity and mortality. FEV1 and PEFR are easy to measure parameters that should be used more often for the assessment of general health status.

Adult↗
PubMed1985

Role of the parasympathetic nervous system in acute lung response to ozone.

We conducted an ozone (O3) exposure study using atropine, a muscarinic receptor blocker, to determine the role of the parasympathetic nervous system in the acute response to O3. Eight normal subjects with predetermined O3 responsiveness were randomly assigned an order for four experimental exposures. For each exposure a subject inhaled either buffered saline or atropine aerosol followed by exposure either to clean air or 0.4 ppm O3. Measurements of lung mechanics, ventilatory response to exercise, and symptoms were obtained before and after exposure. O3 exposure alone resulted in significant changes in specific airway resistance, forced vital capacity (FVC), forced expiratory flow rates, tidal volume (VT), and respiratory rate (f). Atropine pretreatment prevented the significant increase in airway resistance with O3 exposure and partially blocked the decrease in forced expiratory flow rates but did not prevent a significant fall in FVC, changes in f and VT, or the frequency of reported respiratory symptoms after O3. These results suggest that the increase in pulmonary resistance during O3 exposure is mediated by a parasympathetic mechanism and that changes in other measured variables are mediated, at least partially, by mechanisms not dependent on muscarinic cholinergic receptors of the parasympathetic nervous system.

Adolescent↗