FVC Measurements Research Articles

Lung Function and Respiratory Symptoms Related to Changes in Smoking Habits in Asbestos-Exposed Subjects

The purpose of this study was to examine respiratory symptoms and lung function (forced vital capacity [FVC] and forced expiratory volume in 1 second [FEV1]) as related to changes in smoking habits in subjects previously exposed to asbestos. The study was linked to a smoke-ending program among asbestos-exposed males. Subjects were recruited from a population-based survey, and 231 smokers met for the baseline consultation. The baseline prevalences of cough, chronic cough, and dyspnea among smokers were 68.0%, 44.6%, and 42.4%, respectively. Both smoke-ending (n = 10) and tobacco reduction (n = 52) during the 2-year follow-up resulted in remission of cough and chronic cough, whereas dyspnea was unaffected. When the 2-year measurements of FVC and FEV1 were adjusted for the respective baseline measurements, FEV1 tended to improve in subjects who had quit during the study, relative to the continuing smokers. It was concluded that both smoke-ending and reduction of tobacco consumption resulted in reduction of cough and chronic cough, but not of dyspnea. The study further suggests a possible positive effect of smoking cessation on FEV1, but not merely by reduction of tobacco consumption.

Pulmonary function tests in HIV-infected patients without AIDS. Pulmonary Complications of HIV Infection Study Group.

To determine the prevalence, incidence, and types of lung diseases that occur in association with HIV infection, 1,353 subjects, including HIV-seropositive homosexual men, injection drug users, female sexual partners of HIV-positive men, and HIV-seronegative control subjects from the first two transmission categories were evaluated prospectively in a multicenter study. Patients with AIDS at the time of initial evaluation were excluded. One thousand two-hundred ninety-four subjects who had no AIDS-defining diagnosis within 3 mo of enrollment had measurements of FVC, FEV1 and DLCO at the time of enrollment. As a group, all subjects had mean values of FVC and FEV1 close to 100% predicted. Those with CD4 counts below 200/mm3 had slightly reduced DLCO compared with the others. Subjects with a history of HIV-associated symptoms (thrush, weight loss, herpes zoster) also had a reduced DLCO compared with those without symptoms. Injection drug users had reduced FVC, FEV1 and DLCO compared with homosexual men and female sexual partners of HIV-infected men, with DLCO more substantially reduced. Part of the reduction in DLCO in drug users was attributable to factors other than HIV infection, especially cigarette smoking and race. Using predicted values that take cigarette smoking into account, the prevalence of abnormality in DLCO was higher among injection drug users (33.3%) than among homosexual men (11.2%) and female sexual partners (12.7%). These results show that advanced HIV infection, characterized by CD4 count < 200/mm3 or HIV-associated symptoms, and factors unrelated to HIV infection, including race, cigarette smoking, and injection drug use, are all associated with reductions in DLCO measurements.

Ventilation and perfusion lung imaging - which nebulizer?

Three commercially available 99Tcm-diethylenetriamine pentaacetate (99Tcm-DTPA) aerosol delivery nebulizers for lung ventilation imaging were investigated. Two were air-jet systems, 'Optimist' (Medicaid) and 'Microcirrus' (Amersham), and one was an ultrasonic device (Europlus). Altogether, 112 consecutive patients were scanned, 37 using the Optimist, 40 using the Microcirrus and 35 the Europlus. The age mix, FEV1, FVC and PEFR measurements of the patients in each group were similar. Each contained a proportion of patients with poor respiratory function, with PEFR rates ranging from 30 to 582 l min-1 for patients studied with all systems. Ease of use, image quality and cost were evaluated as well as radioactive and microbiological contamination. The Optimist system gave the best combination of image quality and cost, and was associated with the lowest level of radioactive contamination. It also proved the most popular. Airborne contamination for all nebulizers was lower than previously reported and was largely dependent on patient compliance. With poorly compliant patients, the contamination levels are sufficient to warrant an extraction device. There was no evidence of bacterial contamination of the nebulizers or tubing on repeated use over 5 days.

The influence of increased bronchial responsiveness, atopy, and serum IgE on decline in FEV1. A longitudinal study in the elderly.

We have performed a 4-yr prospective survey of the association of allergen skin test positivity, total serum immunoglobulin E (IgE), and bronchial responsiveness to methacholine, with longitudinal decline in FEV1, in subjects over 65 yr of age. In 1987, 324 subjects completed a respiratory questionnaire, and underwent measurement of FEV1 and FVC, methacholine challenge, skin prick testing (to Dermatophagoides pteronyssinus, cat fur, mixed grasses, and Aspergillus fumigatus) and estimation of total serum IgE. After an interval of 4 yr, 212 subjects were reexamined. The mean annual decline in FEV1 was significantly higher in males than in females, but was not significantly influenced by smoking habits defined at the start of the study. The relation of atopy (skin test reaction to allergen > or = 3 mm greater than saline control), increased bronchial responsiveness (PD20FEV1 < or = 6.4 mumoles methacholine) and serum IgE > 80 IU/ml, to annual decline in FEV1 was examined for each risk factor individually with adjustment for age, sex, height, and initial FEV1, by multiple linear regression. Both atopy and bronchial responsiveness were significantly associated with accelerated decline in FEV1. Elevated IgE was correlated with faster FEV1 decline in subjects who were current smokers at the start of the study. In a multiple regression model examining the mutually adjusted associations of all relevant variables with annual decline in FEV1, male sex was the most important predictor (B = 38.6 ml/yr, 95% Cl = 4.3, 72.9). Increased bronchial responsiveness also tended to be associated with accelerated decline in FEV1. In further analyses incorporating the same variables, but restricted to specific smoking categories, age was the only significant factor in the never-smokers, whereas both atopy (B = 44.5 ml/yr, 95% Cl = 3.8, 85.3) and increased bronchial responsiveness (B = 43.5 ml/yr, 95% Cl = 4.6, 82.3) were significant predictors of accelerated FEV1 decline in former and current smokers combined.(ABSTRACT TRUNCATED AT 250 WORDS)

Volume spirometers need automated internal temperature sensors.

Spirometer temperature was measured automatically during all years of the Lung Health Study. Short- and long-term changes in temperature were analyzed for the 23 dry-rolling-seal volume spirometers used at the 10 clinical centers involved in the study. Within-test-session spirometer temperature increased a mean of 0.3 degrees C, and as much as 3.0 degrees C during methacholine challenge testing. The maximal change in spirometer temperature during a test day exceeded 4 degrees C more than 5% of the time. Month-to-month changes of more than 15 degrees C were not uncommon. If ambient temperature had been assumed to apply to all maneuvers and used for BTPS corrections, FEV1, and FVC measurement errors of up to 6% would have occurred. When using volume spirometers, the temperature of air inside the spirometer should be measured accurately during each breathing maneuver.

Bronchodilator reversibility to low and high doses of terbutaline and ipratropium bromide in patients with chronic obstructive pulmonary disease.

There is uncertainty regarding the use of monotherapy or combination therapy with beta 2 agonists and anticholinergic drugs in patients with chronic obstructive pulmonary disease (COPD). The measurement of forced expiratory volume in one second (FEV1) or relaxed vital capacity (RVC) in the assessment of reversibility in these patients has also caused considerable debate. Twenty seven patients with COPD were evaluated on two occasions. Patients received the following treatments in sequence: (sequence 1) low dose terbutaline 500 micrograms, high dose terbutaline 5000 micrograms, low dose ipratropium 40 micrograms, high dose ipratropium 200 micrograms; (sequence 2) low dose ipratropium 40 micrograms, high dose ipratropium 200 micrograms, low dose terbutaline 500 micrograms, high dose terbutaline 5000 micrograms. RVC, FEV1 and FVC were measured at baseline and 30 minutes after successive treatments. Values for FEV1 at baseline on the first and second study days were not significantly different: 0.90 (0.87-0.93) 1 v 0.90 (0.87-0.93) 1. Likewise, baseline values for RVC and FVC were not different. The number of patients showing a greater than 330 ml overall improvement in RVC was 20 of 27 for sequence 1 and 22 of 27 for sequence 2; similar trends were observed for FEV1 and FVC. For all three parameters there was a significant difference between mean responses to low and high doses of terbutaline when the latter was given as the first drug in sequence 1. When ipratropium was given first in sequence 2 there was, however, no significant improvement with high dose terbutaline over and above the response to low dose terbutaline. The latter effect was more noticeable with RVC than with either FEV1 or FVC. The total bronchodilator response at the end of each sequence was similar whether ipratropium was given first or second. The measurement of RVC, FEV1, and FVC were equally effective at picking up those patients who had a significant overall bronchodilator response to combined therapy with inhaled beta 2 agonist and anticholinergic medication. There was no significant benefit of adding a higher dose of terbutaline when ipratropium bromide had been given previously, particularly when using RVC as the parameter of response.

Effect of Dexamethasone on Pulmonary Inflammation and Pulmonary Function of Ventilator-dependent Infants with Bronchopulmonary Dysplasia

Seventeen ventilator-dependent premature infants with bronchopulmonary dysplasia (BPD) were enrolled in a double-blind, placebo-controlled study to determine the effects of 3 days of intravenously administered dexamethasone (0.5 mg/kg/day) on pulmonary function, pulmonary inflammation, and the requirement for respiratory support (FIO2, ventilator peak pressure [PP], and respiratory rate [RR]). Assessment of pulmonary function included measurement of FVC, flow at 25% vital capacity (V25), and static compliance of the respiratory system (Crs), whereas pulmonary inflammation was assessed by the neutrophil count, ratio of elastase/2 x alpha-1-antitrypsin, and the concentrations of albumin and fibronectin in the tracheobronchial lavage (TBL) fluid. After 3 days of placebo treatment there were no significant changes in any of the measured parameters. In contrast, the dexamethasone-treated group demonstrated a significant decrease in respiratory support (FIO2: 50 versus 36%; PP: 21 versus 16 cm H2O; RR: 22 versus 14 breaths/min) and improved pulmonary function (Crs: 0.63 versus 0.85 ml/cm H2O/kg; V25: 23 versus 68 ml/s/kg). In addition, pulmonary inflammation was suppressed in the dexamethasone-treated group (neutrophils: 23 versus 11 x 10(4)/mg albumin: elastase/2 x alpha-1-antitrypsin: 0.24 versus 0.10; albumin: 7.1 versus 3.5 mg/dl; fibronectin: 33 versus 17 micrograms/mg albumin). We conclude that short-term treatment with dexamethasone improves pulmonary function and suppresses pulmonary inflammation as well as decreasing the respiratory support required by ventilator-dependent premature infants with BPD.

Acute Postbronchodilator Changes in Pulmonary Function Parameters in Patients with Chronic Airways Obstruction

Pulmonary function studies were performed before and after one-time administration of an inhaled bronchodilator to ascertain the relative diagnostic value of using FVC, FEF25-75%, static lung volumes, Raw, and/or sGaw measurements, in addition to the FEV1, to assess the reversibility of chronic airways obstruction in nonasthmatic patients. A total of 517 patients underwent 686 spirometric tests, 264 (38 percent) of which disclosed a significant response to bronchodilators. In 247 (93 percent) studies, this response included a significant change in FEV1 and/or FEF25-75%, while in 17 studies (7 percent), the postbronchodilator improvement was seen exclusively in the FVC measurement. It is concluded that, in the clinical setting, analyzing static lung volumes, Raw, sGaw, and spirometric parameters other than the FEV1, seldom yields meaningful additional information regarding the reversibility of chronic airways obstruction in nonasthmatic patients. Finally, potentially misleading results can be seen in a relatively small proportion of studies due to errors in the FVC and/or FEF25-75% measurements.

Analyzing cross‐sectional and longitudinal lung‐function measurements: The effects of age

AbstractThe problem of interpreting lung‐function measurements in industrial workers is examined. The data under discussion pertain to FEV1 and FVC measurements in smoking and in nonsmoking groups of grain‐elevator workers in British Columbia and of workers in Vancouver City Hall. Initial observations have now been enriched by longitudinal follow up data on the same groups after three and after six years. It is shown that interesting selection phenomena, favouring “fit” individuals, take place over time, with regard both to lung symptoms and lung functions. Thus cross‐sectional and longitudinal studies refer to somewhat different populations. It also appears that longitudinal studies are considerably more sensitive to identifying cumulative lung damage than are corresponding cross‐sectional studies. The nonlinearity of the effect of age on lung functions is noted in the longitudinal data in a number of cases, lending support to the hypothesis of association between quadratic age effect and cumulative exposure to lung insults.

Present outlook in bronchiectasis: clinical and social study and review of factors influencing prognosis.

One hundred and sixteen patients with proven bronchiectasis diagnosed at least five years previously were studied to determine the clinical outcome, change in pulmonary function, and degree of social disability. Twenty-two patients had died and the mean duration of follow-up in the survivors was 14 years. The patients who died were characterised by a poorer initial ventilatory capacity than the survivors and cor pulmonale was present in 37% at the time of death. The survivors showed a tendency for improvement in symptoms whether treated surgically or medically. Thirty per cent were better than at diagnosis while only 11% were worse. Measurements of FEV1 and FVC were made at diagnosis and at review, mild airways obstruction being the predominant abnormality. The change in pulmonary function was expressed as the decline in FEV1 in ml/yr. The decline in FEV1 was no greater than expected in 80% of patients and in a further 15% was of the order seen in cigarette smokers with mild airways obstruction. Poor ventilatory capacity was therefore not an important limitation in these patients. Of the survivors 77% had a good work record with less than two weeks loss of work annually from chest illness. The spouses of all married patients were interviewed at home by a trained social worker. Fifty per cent reported no social problem but 46% of spouses found the patient's cough distasteful and 29% of couples had experienced difficulties with normal sexual life. Seven per cent of the patients were severely disabled. While the overall prognosis of our patients was good a minority still have severe physical and social problems as a result of bronchiectasis.

PULMONARY COMPLICATIONS, VENTILATION AND BLOOD GASES AFTER UPPER ABDOMINAL SURGERY

Forty patients who underwent elective cholecystectomy were examined preoperatively and during the first postoperative week by physical examination, measurement of FVC and FEV1, arterial pH and blood gas analyses, and chest x-ray. Postoperative pulmonary complications (p.p.c.) were detected in 30 (75%) of the patients. Simple auscultation was the most sensitive tool in discovering p.p.c., but 18 of the 30 patients with complications also had a pathological chest x-ray. Obesity, smoking, postoperative naso-gastric tube and postoperative wound infection were predisposing factors for p.p.c. Six patients with preoperative pulmonary disease all had a progress in their lung pathology. There was no definite relationship of duration of anaesthesia or drainage of the abdominal wound to development of p.p.c. The patients with p.p.c. showed a deeper and more prolonged fall in Pao2 postoperatively than the normal group. None of the normals showed an arterial Po2 below 70 mmHg in the postoperative course, while 63% of the p.p.c. group did. FVC and FEV1 showed marked reductions from preoperative values on the first postoperative day, and then gradually increased to near preoperative values after 1 week. Arterial pH and Pco2, showed no definite changes during the postoperative course.

Pulmonary complications, ventilation and blood gases after upper abdominal surgery.

Forty patients who underwent elective cholecystectomy were examined preoperatively and during the first postoperative week by physical examination, measurement of FVC and FEV1, arterial pH and blood gas analyses, and chest x-ray. Postoperative pulmonary complications (p.p.c.) were detected in 30 (75%) of the patients. Simple auscultation was the most sensitive tool in discovering p.p.c., but 18 of the 30 patients with complications also had a pathological chest x-ray. Obesity, smoking postoperative naso-gastric tube and postoperative wound infection were predisposing factors for p.p.c. Six patients with preoperative pulmonary disease all had a progress in their lung pathology. There was no definite relationship of duration of anaesthesia or drainage of the abdominal wound to development of p.p.c. The patients with p.p.c. showed a deeper and more prolonged fall in Pao2 postoperatively than the normal group. None of the normals showed an arterial Po2 below 70 mmHg in the postoperative course, while 63% of the p.p.c. group did. FVC and FEV1 showed marked reductions from preoperative values on the first postoperative day, and then gradually increased to near preoperative values after 1 week. Arterial pH and Pco2 showed no definite changes during the postoperative course.

Aspirin Intolerance in Chronic Childhood Asthma: Detected by Oral Challenge

Most previously reported individuals with acetylsalicylic acid (aspirin, ASA)-induced asthma have been adults. This study was undertaken to define the prevalence of ASA intolerance among children with intractable asthma. Fifty children (34 boys and 16 girls) ranging in age from 6 to 18 years with extrinsic (atopic) asthma were studied. None had a history of ASA sensitivity or nasal polyps; all required continuous medication including cromolyn sodium and daily or intermittent steroids. Anti-asthmatic medications were stopped 12 hours prior to testing. At the same time of day, each subject, in a doubleblind manner, on two separate days, ingested either 300 mg of ASA or 100 mg of lactose (placebo). Measurements of FVC, FEV1, and FEF25-75 were obtained prior to challenge and one half, one, two, three, and four hours after. ASA intolerance required a decrease of 30% in lung function with ASA as compared to placebo. Fourteen of 50 (28%) were ASA-intolerant; a greater number were girls, and they had more sinusitis and an onset of disease prior to 2 years of age. Steroid dependency, frequency of eczema, nasal eosinophilia, serum IgE levels, and peripheral eosinophil counts did not differ between the two groups. The use of aspirin in childhood asthma should be limited.

The Use of Corticosteroids in the Treatment of Acute Asthma

A study of 23 patients admitted to hospital with severe acute asthma is reported in which plasma cortisol level on admission was significantly correlated with the degree of acidaemia and pulse rate. Patients who had not previously received treatment with corticosteroids responded satisfactorily to repeated daily injections of tetracosactrin depot, the rate of improvement being comparable to that observed in other patients treated with intravenous hydrocortisone hemisuccinate. A prompt and sustained rise in plasma cortisol was also seen following tetracosactrin. The total daily dose of hydrocortisone required to achieve plasma cortisol levels above 100 mug/100 ml was less when given by continuous intravenous infusion compared with intermittent injections, and a regime of 3 mg/kg body weight every six hours by infusion appeared satisfactory. Most patients reported subjective improvement by about four hours after starting treatment but objective evidence did not appear until about six hours from the start. Measurements of FEV1 and FVC proved to be the most reliable indices of the beginning of improvement although pulse rate was the first index to show maximum improvement. Previous maintenance treatment with corticosteroids in patients with asthma did not appear materially to affect the plasma half-life of intravenous hydrocortisone (4 mgm/kg body weight) when compared with healthy subjects or other patients with asthma who had not previously been treated with corticosteroids.

Glass fibres: absence of pulmonary hazard in production workers.

Hill, J. W., Whitehead, W. S., Cameron, J. D., and Hedgecock, G. A. (1973). British Journal of Industrial Medicine, 30, 174-179. Glass fibres: absence of pulmonary hazard in production workers. Seventy fibreglass workers with a mean of 19·85 years in the industry are compared with a control group having no exposure to glass fibre but otherwise matched for age, sex, height, and weight, and residing in the same geographical area. Comparison was made by radiography, the administration of the modified Medical Research Council Short Questionnaire on Respiratory Symptoms (1960), amplified to include a detailed occupational history, and measurement of peak expiratory flow, FEV 1 , and FVC. Statistical analysis showed the control group to be at a slight disadvantage compared to the subject group in respect of complaints of phlegm and FVC. No evidence of any respiratory hazard due to glass fibre is shown.

Double Blind Crossover Study of Cromolyn Sodium Inhibition of Aerosol Antigen Challenge

Six men patients, with type I hypersensitivity to pollen antigens, were studied during four separate periods approximately one week apart. During the first and fourth periods, aqueous extracts of ragweed or grass pollen were administered via a nebulizer. During the second and third periods the patients were treated with a single capsule of cromolyn sodium or placebo in a double blind fashion, delivered as a powder 30 minutes prior to antigen bronchial challenge. The test doses of antigen resulted in a decrease of FEV₁ ranging from 20.3 to 61.3 percent with a mean of 35.5 percent. Pretreatment with cromolyn sodium resulted in 21.9 to 100 percent protection with a mean of 65.3 percent which contrasts with the –12.4 ±24 percent protection following placebo (P<0.005). The FVC measurements paralleled these changes. This double blind study demonstrates the ability of cromolyn sodium to provide protection against pollen-induced obstruction in sensitive asthmatic subjects.

Malaria in neighboring Londoners.

<b>Introduction: </b>We have previously reported increased respiratory symptoms in adult survivors of bronchopulmonary dysplasia (BPD) compared with very low birth weight (VLBW) (&lt;1500g) and term controls. Here we report preliminary findings from spirometric and Lung Clearance Index (LCI) measurements. <b>Objective: </b>To investigate whether adult survivors of BPD have greater impairment of lung function and LCI than age and gender matched VLBW and term controls. <b>Methods: </b>Spirometry measurements (MicroLab ML3500 Mk8™) were obtained in 16 BPD [8male; mean (SD) age 24.9 (3.9) y]<b>,</b> 9 VLBW [Mean (SD) age 25.8 (3.73) y] and 55 term controls [30 male; mean (SD) age 26.0 (4.0) y]. LCI measurements (Innocor™ device) obtained in BPD and VLBW participants were compared to 17 healthy controls [6M, mean (SD) age 30.5 (7.5) y]. <b>Results: </b>For all spirometry end points (FEV₁, FVC, FEV₁/FVC and FEF_25-75), BPD adults had significantly lower values than term controls (p&lt;0.001). Mean FEV₁and FEV₁/FVC measurements were lower in BPD adults than VLBW (p&lt;0.05)). Mean LCI measurements were higher (more impaired) in BPD [mean (SD) 6.99 (0.78)] versus healthy controls [mean (SD) 6.36 (0.362)] (p=0.006). LCI measurements were also higher in BPD than VLBW but this was not statistically significant. Three BPD subjects had entirely normal spirometry but abnormal LCI values (value &gt; healthy control mean +2SD). <b>Conclusions:</b> Our preliminary findings suggest persisting lung function impairment in adult survivors of BPD. LCI may be a useful tool in detecting early small airways disease in adult survivors of preterm birth.