Conventional Lung Function Tests Research Articles

The functional benefit of anti-inflammatory aerosols in the lung periphery

The target of anti-inflammatory therapy in asthma is thought to be situated, at least partly, in the lung periphery, and inhaled steroid aerosols are being engineered to reach it. However, the potential effect of such aerosols cannot be fully evaluated by conventional lung function tests because these are insensitive to peripheral lung structure. A prospective cohort study was conducted to investigate whether ultrafine steroid aerosols can elicit a response in the lung periphery, using a validated multibreath washout technique that can distinguish acinar from conductive lung zone function. In 30 stable patients with asthma with a wide range of disease severity (FEV(1) 27% to 108% predicted), we assessed conductive and acinar airway function abnormality at baseline, with patients on a standard dry powder steroid aerosol and after switching them to an ultrafine steroid aerosol. Only in those patients with abnormal acinar airway function at baseline (n = 16) did acinar heterogeneity show a consistent improvement after switching to an ultrafine steroid aerosol; the improvement was also correlated with baseline acinar heterogeneity (r = -0.67; P = .007). Although all patients with asthma also presented conductive airway abnormality at baseline, no changes were observed in this lung zone with the switch to the ultrafine aerosol (P > .1). Among stable patients with asthma, those with acinar lung zone abnormality at baseline have the potential to receive functional benefit from an ultrafine steroid aerosol. Clinical studies comparing the efficacy of steroid aerosols targeted to the deep lung should at least include a measurement of peripheral lung zone function. A new noninvasive measure of small airways function reveals why, and for which particular patients with asthma, small steroid aerosol particles can be of therapeutic use.

Prophylactic antibiotics for cystic fibrosis.

Patients with cystic fibrosis are sometimes prescribed antibiotics to take continuously on a prophylactic (preventative) basis. This approach is most commonly used in infants where the objective is to reduce pulmonary infection with Staphylococcus aureus and prevent lung damage. This approach may also be used in older patients. This review evaluates the evidence for the effectiveness of this approach and considers potential adverse effects. To compare continuous oral antibiotic prophylaxis with no prophylaxis (short courses of oral antibiotics given as clinically indicated) in patients with cystic fibrosis. This review considers both the effectiveness of prophylaxis (bacteria isolated from the respiratory tract, requirement for additional antibiotic treatment, lung function, survival) and the adverse effects. The Cochrane Cystic Fibrosis and Genetic Disorders Group clinical trials register was used. This comprises references identified from a comprehensive search of electronic databases, as well as hand searching relevant journals and conference abstracts. Companies manufacturing anti-staphylococcal antibiotics were also approached for unpublished data. Date of the most recent search of the Group's specialised register: November 1999. All randomised or pseudo-randomised trials where continuous oral prophylactic antibiotics, given for a period of at least one year, were compared to intermittent antibiotic therapy given "as required." Cystic fibrosis patients of any disease severity were considered. Trials were assessed for eligibility, methodological quality and data extraction by two reviewers (AS & SW). The following outcomes were assessed: lung function; nutrition (weight standard deviation score); survival; requirement for additional antibiotic treatment; isolates of pathogens from the respiratory tract; occurrence of adverse reactions to prophylactic antibiotics. Only two studies, totalling 66 patients (over half of whom were infants), were suitable for inclusion in the review. A reduced prevalence of Staphylococcus aureus in the respiratory secretions was seen in children receiving anti-staphylococcal antibiotic prophylaxis, although no effect was seen on other common pathogens. This is associated with a reduced requirement for additional courses of oral antibiotics and fewer hospital admissions in the first two years of life in patients receiving prophylaxis. No effect on infant lung function has been shown after one year of prophylactic treatment. Data are not available on adverse effects of the interventions. As the duration of the studies reviewed has been of two years or less, conclusions cannot be drawn about the long term effects of prophylaxis on acquisition of Pseudomonas aeruginosa and survival. Anti-staphylococcal antibiotic prophylaxis may be of benefit when commenced early in infancy and continued up to two years of age. There is insufficient evidence from this review to say whether use in older children, or adults, or for periods of over two year is beneficial.

Exhaled nitric oxide at school age in prematurely born infants with neonatal chronic lung disease.

Prematurely born infants with neonatal chronic lung disease (CLD) have increased respiratory morbidity and bronchial obstruction at school age. To evaluate the possible inflammatory basis of lung function abnormalities, we studied 40 children, 7.5-9.6 years of age, born very prematurely (birth weights, 600-1,575 g) and 14 nonatopic term-born controls, using flow-volume spirometry and exhaled nitric oxide (eNO) measurements. In children born prematurely, eNO was significantly higher in atopics than in nonatopics (respective means, 14.8 vs. 6.3 ppb, P = 0.02). Nonatopic prematurely born infants did not differ significantly from controls (means, 6.3 vs. 6.4 ppb, P = ns). Of the 27 nonatopic children not on regular glucocorticoid inhalations, 9 had a history of CLD. Spirometry indicated bronchial obstruction and values that were significantly lower in prematurely born infants with or without CLD than in controls, and they were lower in the CLD than the non-CLD group. However, no significant differences were observed in eNO levels between CLD, non-CLD, and control groups (means, 6.8, 5.9, and 6.4 ppb, P = ns). In nonatopic schoolchildren born very prematurely and with a history of CLD, we found no evidence of airway inflammation associated with increased eNO concentrations. Neither were eNO levels associated with severity of chronic lung disease, as determined by conventional lung function tests. eNO levels were higher in atopic children born prematurely than in controls.

Densidad capilar y función respiratoria en el músculo intercostal externo

Changes in lung function have been related to adaptive structural modifications in respiratory muscles. To evaluate the capillary density (Dcap) of the external intercostal muscle in patients with chronic obstructive pulmonary disease (COPD), and its possible relation to respiratory function. Forty-two individuals (61 +/- 9 years old) underwent conventional lung function testing and evaluation of respiratory muscles (maximum pressures at rest and a tolerance test using Martyn's technique). The sample included 10 subjects with normal lung function and 32 COPD patients (FEV1 between 13 and 78% of reference), in stable phase and with no respiratory insufficiency (PaO2 > 60 mmHg). A local biopsy of the external intercostal muscle was taken from all subjects at the fifth intercostal space (anterior axillary [correction of axile]) on the non-dominant side. The sample was processed for morphometry and fiber typing with ATPase staining and for quantifying capillarity with Gomori's trichrome staining. The mean diameter was 61 +/- 10 micrograms, with type I fibers predominating (56 +/- 11%). Dcap was 2.8 +/- 0.6 capillaries/fiber (equivalent to 1.02 +/- 0.37 capillaries/mm2 of fibrillary surface). The number of capillaries/fiber was significantly higher in patients with severe COPD (FEV1 < 50% ref) than in controls (3.0 +/- 0.6 versus 2.3 +/- 0.5, p < 0.01) and was inversely related to FEV1 (r = -0.395, p < 0.01). Muscle capillarity was unrelated to other function variables, including markers of respiratory muscle function and gas exchange. The structural remodelling of external intercostal muscles in COPD patients also includes an increase in density of interfibrillary capillaries. This increase is proportional to the severity of obstruction and probably reflects an adaptive phenomenon.

Aerosol-Derived Airway Morphometry and Aerosol Bolus Dispersion in Patients With Lung Fibrosis and Lung Emphysema

Patients with lung emphysema show increased aerosol-derived dimensions of peripheral airspaces and increased aerosol bolus dispersion (AD). To apply these tests in epidemiologic studies, the objective of this pilot study was to investigate whether morphometric changes caused by lung fibrosis can be distinguished from those caused by emphysema. This study was designed as a cross-sectional study in which airspace dimensions and AD in patients with emphysema and in patients with fibrosis were compared. Forty patients participated in the study: 20 patients had high-resolution CT (HRCT)-proved lung emphysema and 20 patients had HRCT-proved lung fibrosis. All patients underwent conventional lung function tests, aerosol-derived airway morphometry (ADAM), and AD measurements. Patients with lung emphysema showed normal dimensions of small airways but enlarged airspace dimensions in the lung periphery. Patients with fibrosis showed in all lung depths increased airspace dimensions. AD was increased in patients with emphysema but was normal in patients with fibrosis. These results show that when using ADAM and AD, morphometric changes caused by emphysema can be distinguished from those caused by fibrosis with high sensitivity and specificity.

101. Monitoring of pulmonary exacerbations in CF patients with conventional and alternative lung function tests

101. Monitoring of pulmonary exacerbations in CF patients with conventional and alternative lung function tests

Aerosol bolus dispersion in patients with bronchiolitis obliterans after heart-lung and double-lung transplantation. The Munich Lung Transplantation Group.

Bronchiolitis obliterans (BO) is one of the main late complications in patients after lung transplantation. Because BO is located in small airways, conventional lung function tests are supposed to be rather insensitive to detect early stages of this disease. In this study, the capability of the aerosol bolus dispersion test to detect BO was tested in 12 subjects with heart-lung and double-lung transplantation. Four of these patients had histological evidence of BO. The broadening (dispersion) of inhaled boluses consisting of monodispersed inert test particles during respiration was repeatedly measured in each subject. Additional measurements of spirometric and bodyplethysmographic measurements were performed. Patients with evidence of BO showed significantly increased aerosol bolus dispersion and significantly reduced maximal airflow parameters. Calculation of receiver operating characteristics (ROCs) revealed that from all lung function parameters under consideration, aerosol bolus dispersion divided by the maximum expiratory flow rate at 50% of vital capacity (MEF50) and MEI50 had the highest sensitivity and specificity for the detection of BO. Both parameters showed a sensitivity and specificity of 100%. Therefore, it may be speculated that even in early stages of disease, the combination of MEF50 measurement with aerosol bolus dispersion measurements may be a powerful tool for the detection of BO in patients with lung transplantation.

Aerosol bolus dispersion and aerosol-derived airway morphometry: assessment of lung pathology and response to therapy, Part 1.

review discusses the potential utility of two methods using inhaled aerosols to detect and diagnose lung disease and to evaluate the efficacy of therapy. Aerosol bolus dispersion measures convective gas mixing; aerosol-derived airway morphometry assesses the calibers of airway and airspaces. These two methods are discussed in terms of their ease of use (simplicity and acceptability) and current data regarding their validity, reproducibility, specificity, sensitivity, and detection of lung improvement with therapy. Part 1 of this review focuses upon aerosol bolus dispersion; Part 2(1) focuses upon aerosol-derived airway morphometry. Aerosol bolus dispersion has many features that make it clinically attractive. It is simple to administer and patients can successfully perform the maneuvers. It detects known alterations in the lungs. It is reproducible and has high specificity and sensitivity. However, every lung disease or condition known to be detected by aerosol bolus dispersion is also detected by spirometery, maximal expiratory flow-volume curves, or another conventional lung function test. This, aerosol bolus dispersion appears best reserved as a specialized method to supplement conventional lung function tests and to characterize convective gas transport.

Evaluation of the interrupter technique for measuring change in airway resistance in 5‐year‐old asthmatic children

The interrupter technique is a noninvasive method for measuring airway resistance during quiet breathing which requires minimal subject cooperation. It, therefore, has enormous potential for use in young children unable to cooperate with conventional lung function tests. We evaluated the interrupter technique during bronchial challenge with methacholine administered by the tidal breathing method in 10 5-year-old asthmatic children. The mouth pressure/time [P mo(t)] curve obtained following brief airflow interruption during the expiratory phase of quiet breathing was analyzed to determine the interrupter resistance (Rint) using four different methods: RintC, a smooth curve fit with back-extrapolation; RintEO, calculated from the pressure change after the postinterruption oscillations had decayed (end-oscillation); RintL, two-point linear fit with back-extrapolation; and RintEI, calculated from the pressure change at the end of the period of interruption. The four Rint methods were compared for repeatability and sensitivity with the direct measurement of resistance by the forced oscillation technique (Rrs), and with an independent method of measuring the response to challenge, utilizing the change in transcutaneous oxygen tension (PtcO2). The sensitivity of the methods was defined by a sensitivity index (SI), the change after challenge expressed in multiples of the baseline standard deviation. The PtcO2 method had the lowest variability and was by far the most sensitive method (geometric mean SI 18.9), at least 1 doubling concentration more sensitive than the other techniques in every subject (P < 0.05). RintL was more sensitive than the other interrupter methods (geometric mean SI: RintL 4.2; RintC 1.0; RintEO 2.7; RintEI 3.1; P < 0.05) and similar in sensitivity to Rrs (geometric mean SI 4.6) in 7 out of 10 children in which this could be measured. We conclude that the interrupter method provides a simpler method than the oscillation technique for assessing airway obstruction in this age group.

Forced oscillation technique (FOT): a new tool for epidemiology of occupational lung diseases?

The aim of this study was to evaluate the usefulness of the forced oscillation technique (FOT) in the assessment of occupation-related airway changes. The forced oscillation technique and conventional lung function tests were applied in 80 underground coalface workers, aged 35-48 yrs, with chest roentgenogram films classified 0/1 or 1/0 according to the International Labour Office (ILO) classification (G group), and two control groups matched for age and smoking habits. The first control group, was made up of face-workers having normal chest radiographs, whilst the second comprised underground non-face-workers with normal chest radiographs. Spirometric, plethysmographic and transfer factor of the lungs for carbon monoxide single-breath (TL,CO,sb) indices revealed no significant differences between the three groups. As regards the forced oscillation technique, a higher value of resistance/frequency slope (Pa.L-1.s2) was found in the G group compared with the control groups; 2.11 vs 1.06 in the face-workers, and 1.58 in the underground workers. In all three groups, the forced oscillation technique indices (mean resistance (R), resistance at zero frequency (RO), resistance/frequency slope (S), and resonant frequency (fo)) were found to be higher in subjects having a decreased forced expiratory volume in one second (FEV1) (< or = 90% predicted) or a mildly obstructive pattern of ventilatory function, even though this did not reach statistical significance in each of the groups. These findings together with the feasibility and acceptability of the forced oscillation technique would suggest that it may be a suitable tool for epidemiological studies of occupational respiratory diseases.

Functional advantage of parenchymal-sparing surgery for early hilar lung cancer.

In a group of 27 patients with early hilar lung cancer, standard sleeve lobectomy was performed in 14 cases, standard lobectomy in 9 cases, and another 4 patients underwent parenchymal-sparing operations (2 had sleeve segmentectomy, 1 had sleeve middle lobectomy, and 1 had left second carinal resection). The changes of conventional pulmonary function tests and regional pulmonary function were compared between patients undergoing sleeve lobectomy and those undergoing parenchymal-sparing surgery. The parameters used for the conventional lung function tests were FVC, %FVC, FEV1.0, and %FEV1.0. For the evaluation of regional pulmonary function, perfusion scans using 99mTc-MAA and ventilation scans using 133Xe were performed. The decrease of FVC in the sleeve lobectomy group (n = 5) was 724 +/- 182.7 ml, whereas that in the parenchymal- sparing surgery group (n = 4) was 367.5 +/- 52.1 ml, a significant difference. Both the FEV1.0 and %FEV1.0 showed no marked changes in both groups between the preoperative and postoperative values. Perfusion and ventilation scans in the parenchymal-sparing group showed a superior result in comparison with sleeve lobectomy group. All the patients undergoing parenchymal-sparing operations survived over the long term. It was thus concluded that parenchymal-sparing surgery can be applied to carefully selected patients with tiny localized cancers.

Bronchial reactivity in patients with chronic renal failure undergoing haemodialysis

We hypothesized that patients with chronic renal failure may present nonspecific bronchial hyperreactivity due to subclinical interstitial lung oedema. To assess lung function disturbances and methacholine (MTH) bronchial responsiveness in this condition, we studied 12 patients (9 men and 3 women; 41.8 +/- 13.3 yrs (SD] with chronic renal failure undergoing regular haemodialysis (HD). Before HD, mean results of conventional lung function tests were within the normal range: forced expiratory volume in one second (FEV1), 89 +/- 12.9% predicted; forced mid-expiratory flow (FEF25-75), 81 +/- 36.7% predicted; total lung capacity (TLC), 94 +/- 14.6% predicted, but 3 subjects presented mild reduction in lung volumes and 5 individuals showed mild obstructive ventilatory impairment. After HD, maximal expiratory flow rates increased significantly (FEV1, + 8.2 +/- 5.1% (p less than 0.005); FEF25-75, +26.2 +/- 25.9% (p less than 0.005]. Interestingly, these increases in FEV1 after HD correlated with body weight loss during HD (r = 0.74, p less than 0.01). In contrast, pre-HD bronchial reactivity was within the normal range (mean % change in FEV1 after MTH, -3.7 +/- 4.5%; range, +1- -14%) without significant changes in methacholine bronchial responsiveness after HD. We speculate that interstitial lung oedema may play a significant role in lung function impairment observed in patients with chronic renal failure. This study shows that nonspecific bronchial hyperreactivity is not present in clinically stable patients with this disorder.

Sensitivity and Specificity of Small Airway Tests in Subjects with Normal Conventional Lung Function Tests

Sensitivity and Specificity of Small Airway Tests in Subjects with Normal Conventional Lung Function Tests

Changes of volume of trapped gas after bronchodilation in subjects with suspected subclinical emphysema.

We studied the volume of trapped gas (VTG), using a nitrogen washout method, before and after bronchodilation in four groups with theoretically increasing risk of developing pulmonary emphysema: (1) nonsmoking healthy controls (PiMn), (2) nonsmoking subjects with an intermediate alpha 1-antitrypsin deficiency (PiMZn), (3) smoking subjects with normal concentration of alpha 1-antitrypsin, and (4) smoking PiMZ subjects. VTG was the only lung function variable that showed a significant difference between PiMZn and PiMn subjects but only after bronchodilation. Some conventional lung function tests also distinguished smokers from nonsmokers of both genotypes but VTG was the most sensitive test. VTG decreased after salbutamol inhalation in the control group but showed a consecutively larger increase with more risk factors of developing emphysema. An increase in VTG after bronchodilation may be a sign of alveolar abnormality preceding development of clinical lung emphysema.

Krypton 81m ventilation scanning in chronic obstructive airways disease.

Ventilation and perfusion scans using 81Krm and 99Tcm-labelled macroaggregates have been studied in 60 patients with established chronic obstructive airways disease. Matched defects were found in all patients distributed throughout the lungs. Patients scanned during acute exacerbation frequently showed basal mismatched defects of ventilation (21 out of 30) and in a few follow-up scans showed resolution on treatment. Other patients also scanned in acute exacerbation showed unmatched defects of perfusion thought to represent pulmonary emboli. Poor correlation was found between scan defects assessed on a semiquantitative basis and conventional lung function tests.

The volume of trapped gas in healthy children aged 7–16

A new and sensitive lung function test, the volume of trapped gas (VTG), as well as conventional lung function tests were measured in 22 boys and 28 girls, aged 7 to 16, all healthy. The VTG was best correlated to total lung capacity (TLC) and also showed a good correlation to height (H), vital capacity (VC), was-out volume (WOV), and forced expiratory volume in one second (FEV1). VTG/TLC% or VTG/VC% are probably the best variables for clinical use. The error of a single determination in VTG was only 6 ml, and in VTG/TLC% it was 0.16, giving a variance of about 10%. The reproducibility of VTG and VTG/TLC% must be regarded as good. The VTG test can be performed in children aged 5 and older.

Measurement of “closing volume” as a simple and sensitive test for early detection of small airway disease

A single-breath Argon bolus method for measuring the lung volume at which the dependent lung zones cease to ventilate presumably as a result of airway closure (i.e., the “closing volume”) was used on a group of sixty-six nonsmokers and on a group of forty-six smokers, whose ages ranged between eighteen and eighty-two years. “Closing volumes” were measured with the subjects in the sitting and supine positions together with the subdivisions of lung volume, one second forced expired volume (FEV 1), maximum expiratory flow rate (MEFR), airway resistance (Raw) and specific airway conductance (SGa). In both seated and supine nonsmokers the percentage ratio of “closing volume” to vital capacity increased linearly with age. In thirty-three seated smokers (72 per cent of all smokers studied) either the percentage ratio of “closing volume” to vital capacity was above the normal limits (+2 SD) for nonsmokers or there was a profound abnormality of the expired alveolar plateau, indicating disease of the small airways. Similar results were found with the subjects in the supine position. In only fourteen smokers (30 per cent of all smokers studied) results of one or more of the conventional lung function tests were outside the normal limits. It is concluded that measurement of the “closing volume” provides a test which detects small airway abnormalities much earlier than the conventional lung function tests. Furthermore, the test is so simple and rapid that it is suitable for routine or wide-scale studies.

MOBILE LABORATORY FOR RESPIRATORY SURVEYS IN INDUSTRY Geoffrey Field, M.D., F.R.A.C.P., B.SC.(MED.),* Peter Owen, B.SC.,† and Bryan Gandevia, M.D., F.R.A.C.P.‡

Medical Journal of AustraliaVolume 1, Issue 23 p. 867-869 Original Articles MOBILE LABORATORY FOR RESPIRATORY SURVEYS IN INDUSTRY Geoffrey Field, M.D., F.R.A.C.P., B.SC.(MED.),* Peter Owen, B.SC.,† and Bryan Gandevia, M.D., F.R.A.C.P.‡ First published: 01 July 1962 https://doi.org/10.5694/j.1326-5377.1976.tb141127.x Specialist Thoracic Physician. Chief Technical Officer. Associate Professor of Thoracic Medicine. Address for reprints: Dr G. B. Field, Department of Medicine, Prince Henry Hospital, Little Bay. N.S.W. 2036. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Abstract This paper describes the design and perfonnance of a self-contained mobile respiratory laboratory usedfor the carrying out of complex lung function tests in epidemiological studies of respiratory disease in industry. The laboratory is equipped to perfonn all conventional lung function tests other than those involvingarterial puncture or radioactive isotopes. It has been shown to have a high level of employee acceptability and technical accuracy. Volume1, Issue23June 1976Pages 867-869 RelatedInformation