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A lung function information system.

A lung function information system (LFIS) was developed for the data analysis of pulmonary function tests at different locations. This system was connected to the hospital information system (HIS) for the retrieval of patient data and the storage of the lung function variables of patients to generate follow-up reports and to support financial and administrative management. The application programs were developed in such a way that high flexibility was obtained with respect to the patient-computer-technician interaction. The sampled data are stored on a disc to correct earlier decisions, perform recalculations and reanalyse the data for research purposes. When the measurements performed on a patient are authorized, the sampled data are deleted, except for when they are needed for future research. A distributed computer system was chosen to combine the benefits of a centralized system with those of several stand-alone systems. The main tasks of the central unit are to store collected data and computer programs, generate a final lung function report on laser printer and provide a connection to the HIS. In the satellite computers, which are located close to the lung function equipment, the signals and raw data are processed. Furthermore, the satellite computers were in use for program development and several research projects, and for the offline data processing of the lung function measurements from two other hospitals by means of a modem connection. The LFIS improved the quantity and quality of data acquisition. It resulted in an increased capacity of about 50% concerning spirometry, and facilitated time-consuming complex analyses. It also avoided miscalculations and mistakes in reports previously experienced with hand calculations.

Computer Systems

[Radioisotopic diagnosis of regional lung functions in occupational lung diseases].

The results are reported from the radioisotope investigations of the regional blood supply, ventilation and difussion of 133 Xenon from four zones of both lungs in 78 patients with all stages of silicosis and 43 patients with chronic bronchitis--emphysema. Unsystemic and scattered focal disturbances of the separate respiration processes are established. They should be given consideration separately and together with the classical non-isotope investigations, with a view to the making of a precise functional diagnosis and occupational expertise, because they reflect the changes due to the basic disease as well as the other accompanying lung diseases as pneumosclerosis, chronic bronchitis, emphysema, tumors, etc. The complete safety, lack of unpleasant procedures for the patient and sufficient accuracy urge their wider application in practice, including as screening tests.

Bronchitis

Lung function in acromegaly.

Lung function has been assessed by spirometry, body plethysmography, flow volume loops and single breath transfer factor in thirty patients with acromegaly. Having excluded eight patients with kyphosis and/or clinical or radiological evidence of pulmonary venous hypertension we have found a significant correlation between duration of acromegaly and lung size as assessed by total lung capacity. Excluding the same eight patients we have found evidence of small airways narrowing in eight patients, seven of these eight had had acromegaly for nine years or longer, and the duration of acromegaly was significantly longer in the patients with small airways narrowing than in those without. In the absence of other recognized causes it is possible that small airways narrowing in acromegaly is caused either by the increased whole blood volume with pulmonary vascular engorgement, or by increase in size of the soft tissues of the small conducting airways. Six of the eight patients with kyphosis and/or pulmonary venous hypertension also had evidence of small airways narrowing. Thus fourteen of the thirty patients with acromegaly had small airways narrowing. Five men had evidence of extra thoracic airway narrowing and in four the duration of acromegaly was ten years or longer. We conclude that the increase in total lung capacity, the incidence of small airways narrowing and the incidence of upper airway narrowing are all related to the duration of acromegaly. It seems that once duration exceeds eight years patients are very likely to develop abnormalities of lung function either primarily from the effects of acromegaly on the airways and lung or secondarily from the associated cardiovascular and thoracic skeletal abnormalities. It seems probable that the small airways and upper airway narrowing contribute to the morbidity and mortality of this disease. This study provides further evidence that acromegaly should be treated early.

Acromegaly

Lung function in sisal ropemakers.

Lung function was measured by spirometry in 66 workers in a sisal ropemaking factory, and in their matched controls. The major atmospheric contaminant was the lubricant (or a component part thereof) used to soften the fibre. The concentration of airborne matter was generally less than 1 mug m--3. There was no difference in lung function between the two groups before the start of the working shift, that is, the mixture of softening lubricant and sisal caused no long-term effects. Although there was no change in lung function over the working shift in the group making sisal rope, the control group did show a significant increase in lung function over the same period. This suggests that an effect attributable to the lubricant and sisal dust did exist. In previous studies little mention has been made of the softeners used in the processing of sisal fibre. These additives may exert a significant effect on ventilatory capacity and may act in conjunction with sisal dust.

Adult

Plasma theophylline concentration and lung function in ponies with recurrent obstructive lung disease.

Six ponies with recurrent obstructive lung disease were studied during two separate 60 min periods while receiving constant equal volume infusions of either aminophylline or sterile water. Dynamic lung compliance, pulmonary resistance, respiratory rate, tidal volume, blood gas tensions and heart rate were measured. Plasma samples were obtained for determination of theophylline concentrations before, and at 10 min intervals during, the infusion period. Excitability was assessed subjectively at these same time periods. The plasma theophylline concentrations in ponies were well predicted by a previously published model of theophylline pharmacokinetics in the horse. Sterile water had no effect on lung function. Aminophylline produced significant changes in lung function compared to baseline values, including a decrease in resistance at 30 min when the mean plasma theophylline concentration was 59 +/- 14 mumol/litre and an increase in compliance at 60 mins at a mean plasma theophylline concentration of 102 +/- 23 mumol/litre. Excitement was noted between 40 and 50 mins in all ponies (mean plasma theophylline concentration 74 +/- 20 and 84 +/- 24 mumol/litre, respectively). Heart rate increased at 50 mins. The therapeutic range for intravenous (iv) theophylline concentration in 'heavey' ponies therefore appears to be between 59 and 84 mumol/litre when aminophylline is administered iv. Below 59 mumol/litre there was no consistent bronchodilator activity and above 84 mumol/litre excitement and tachycardia limited the usefulness of the drug.

Airway Resistance

Asbestos-related lesions of the pleura: parietal plaques compared to diffuse thickening studied with chest roentgenography, computed tomography, lung function, and gas exchange.

Lung function tests, tests of working capacity with gas exchange, and computed tomography (CT) with density measurements with the patient supine and prone were performed in 23 males with asbestos-related bilateral pleural lesions. Two had pulmonary asbestosis grade 1/0 or more; all the others had normal lung parenchyma. On x-ray, the pleural lesions were divided into plaques involving only the parietal pleura There was a and diffuse pleural fibrosis of various degrees involving the visceral pleura. There was a good correlation between the findings at plain chest roentgenography and CT, but more lesions were seen on the CT scan. However, a few pleural plaques seen on conventional films were not observed at CT. Individuals with plaques had slightly lowered lung function compared to reference subjects. Bilateral diffuse pleural fibrosis was associated with a marked decrease in pulmonary function. The two patients with radiologically evident pulmonary asbestosis were found in this group. Decreased lung function was also observed in subjects with pleural fibrosis of only grade 1 (involving less than one fourth of the hemithorax) and a normal exercise capacity. The study shows the importance of differentiation between various asbestos-related pleural lesions.

Adult

[Lung functions after single-lung homotransplantation in dogs (author's transl)].

Unilateral homotransplantation of the lung was performed in ten healthy mongrel dogs. Assessment of pulmonary function was obtained immediately after transplantation ten days and four weeks postoperatively. A conventional endotracheal tube was used for measurement of total lung function. A special tube was deviced for bronchospirometric measurements in dogs. A moderate increase of tidal volume and marked increase of respiratory rate and minute ventilation could be noted immediately after transplantation. Oxygen consumption was not changed significantly. There was a marked decrease in arterial pO2-level following transplantation, which was improved during the follow-up studies and found within normal limits at the tenth postoperative day. Bronchospirometry immediately following transplantation revealed equal ventilation values of both lungs, but oxygen consumption of the transplant was reduced 50% compared to the recipient's own lung. On the tenth postoperative day ventilatory function of the transplant was found close to that of the recipients own lung. Oxygen consumption in respiratory equivalent at this time averaged two thirds of the animal's own lung. Four weeks following transplantation no further significant change of respiratory function could be noted.

Animals

[Simplified prediction of postoperative lung function by plain chest roentgenogram in patients with primary lung cancer--in correlation to postoperative respiratory complications].

For the purpose of simplification of prediction of postoperative lung function, we studied to predict lung function by analizing the frontal and lateral view of chest plain roentgenogram and investigate the correlation to respiratory complication on 111 patients with lung cancer. According to TNM classification of lung cancer, prediction was performed as follows. Predicted postoperative lung function = [(42-number of resected subsegments)/(42-number of occupied subsegments)] x preoperative VC or FEV1.0. In this formula, 42 was the number of functioning subsegments of whole lung (right: 22, left: 20), and then preoperative occupied subsegments was ordered by T factor, where T1 lesion in lung field was prescribed as 1 subsegment and T2 was more than 2 subsegments respectively in plain chest roentgenogram. And also, on the patients having hilar lesions, it was required to calculate the number of subsegments in atelectasis, peripheral obstructive pneumonia and/or partial emphysematous change due to intrabronchial lesions. There was uniformly positive correlations in VC (R = 0.7949) and FEV1.0 (R = 0.8235) of the patients studied respectively. The patients having pneumonectomy showed tendency of over estimation, on the other hand, the patients having resection of a few segments showed under estimation. To predict the postoperative respiratory condition, we calculated the predicted post-operative %VC and %FEV1.0 for predicted preoperative normal VC and FEV1.0. Above the al, we tried to investigate the correlation with predicted postoperative %VC, %FEV1.0 and postoperative respiratory complications.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Effect of chest strapping on regional lung function.

We studied lung mechanics and regional lung function in five young men during restrictive chest strapping. The effects on lung mechanics were similar to those noted by others in that lung elastic recoil increased as did maximum expiratory flow at low lung volumes. Chest strapping reduced the maximum expiratory flow observed at a given elastic recoil pressure. Breathing helium increased maximum expiratory flow less when subjects were strapped than when they were not. These findings indicated that strapping decreased the caliber of airways upstream from the equal pressure point. Regional lung volumes from apex to base were measured with xenon 133 while subjects were seated. The distribution of regional volumes was measured at RV, and at volumes equal to strapped FRC and strapped TLC; no change due to chest strapping was observed. Similarly, the regional distribution of 133Xe boluses inhaled at RV and strapped TLC was unaffected by chest strapping. Closing capacity decreased with chest strapping. We concluded that airway closure decreased during chest strapping and that airway closure was not the cause of the observed increase in elastic recoil of the lung. The combination of decreased slope of the static pressure-volume curve and unchanged regional volumes suggested that strapping increased the apex-to-base pleural pressure gradient.

Adult

Lung function testing and AIDS.

Lung function testing on patients with acquired immune deficiency syndrome (AIDS) has been restricted because of the risks of cross infection. We have adapted equipment which is currently used for routine lung function testing with inexpensive disposable components to remove the risk of contamination. Results from the modified equipment were compared with those obtained using conventional equipment on 56 subjects. We found an excellent correlation between compared values for all parameters.

Acquired Immunodeficiency Syndrome

Lung function in fire fighters.

Lung function tests were performed on 49 fire fighters of the city of New Haven. Their mean age was 36.4 years, with a mean of 11.7 years as fire fighters. The lung function tests were compared to a control group with a mean age of 33.4 years. There was no significant difference between the mean normal pulmonary function tests of the fire fighters and the control group. The results showed that in this group of fire fighters long-term occupational exposure was not associated with pulmonary function abnormalities.

Adolescent

Relations between occupation, smoking, lung function, and incidence and mortality of chronic non-specific lung disease: the Zutphen Study.

Information gathered in the "Zutphen study", the Dutch contribution to the Seven Countries Study was used for the present study. Follow up data from 1965 to 1 July 1985 were used. During this follow up, the morbidity state of the participants was verified at regular intervals. In 1965 lung function was measured by spirometry and the vital capacity (VC) and forced expiratory volume in one second (FEV1) were available. A complete set of data was available for 668 men. The occurrence of chronic non-specific lung disease (CNSLD) at a specific time was coded by one physician, using strict criteria. Information about the cause of death was obtained and coded by one physician in 1985. Occupation was coded and a distinction between blue and white collar workers was made. For the analysis of the relation between age, lung function, smoking habits, and occupational state with CNSLD incidence and mortality, proportional hazard models were used. Blue collar workers had a significantly raised risk for incidence of CNSLD only. The hazard ratio for blue v white collar workers with CNSLD mortality was 1.4 but not statistically significant. It was concluded that occupation is clearly related to incidence of CNSLD. There were indications that occupation is related to mortality from CNSLD. A reduced FEV1 was a strong predictor of both CNSLD incidence and mortality. It is noteworthy that small differences in age and height standardised lung function were significantly related to incidence of CNSLD, mortality from CNSLD, and total mortality. Although these differences in lung function have no direct clinical importance for the individual subject, they indicate a raised morbidity and mortality risk for the population.

Age Factors

Exposure to grain dust and changes in lung function.

Respiratory symptoms and lung function were assessed in 41 seasonal grain handlers and related to duration of employment and level of exposure to grain dust. Ten public works department employees, not exposed to grain dust, were examined during the same period. Respiratory symptoms, forced expired volume in one second (FEV1), and bronchial responsiveness (dose of methacholine provoking a 20% fall in FEV1-PD20) were assessed before starting work and at weekly intervals during a period of employment lasting up to four weeks. Two atopic grainhandlers with pronounced bronchial hyperresponsiveness (PD20 less than 1 mumol) and a history of asthma withdrew from the study within two weeks because they developed severe asthma. Respiratory symptoms were more frequent and more often attributed to work in the grainhandlers than in the non-exposed subjects. In the grainhandlers the FEV1 decreased by a mean (95% confidence intervals) of 321 ml (198-444) (p less than 0.05) and the mean (95% confidence interval) PD20 decreased from 20.6 mumol (10.3-41.2) to 6.0 mumol (2.8-12.5) (p less than 0.05) after one week of work. Over the next three weeks the mean FEV1 returned towards the prestudy values. The mean PD20, however, remained significantly lower than the initial value. The mean FEV1 and PD20 did not change significantly in the non-exposed subjects. The frequency of symptoms and decreases in FEV1 were greater in grainhandlers when working in jobs where total exposure to dust was greater than 20 mg/m3 than when working in jobs where it was less than 10 mg/m3. The results indicate that occupational exposure to grain dust results in respiratory symptoms and changes in lung function, including increased airway responsiveness, within the first week of exposure to grain dust at work. These changes appear to be determined by the degree of dust exposure and suggest a direct effect of grain dust on the lung in these subjects.

Agricultural Workers' Diseases

Longitudinal analysis of lung function growth in healthy children and adolescents.

Lung function and height in 242 8-yr-old and 299 12-yr-old children without known or suspected predisposition to lung disease were measured annually over 6 and 8 yr, respectively. Growth of forced expiratory volume in 1 s (FEV1), vital capacity, and expiratory flow after expiring 50% of vital capacity were statistically modeled by age and height by use of a multivariate normal model for longitudinal data. This method has the flexibility to fit an appropriate (not necessarily linear) mathematical description of average lung function while concurrently modeling the covariance between measures on the same individual. Differences in lung function growth between girls and boys, pre- and post-puberty, showed that girls had a steadier though less pronounced increase in lung function with height. In boys, before puberty there was deficit in lung volume relative to height (not evident in girls), which was compensated for by rapid growth after puberty. The standard error of FEV1 predictions based on current height and age were more than halved when measurements of FEV1, age, and height taken 1 yr before were incorporated. We found evidence for dysanaptic growth in childhood. Fitted models have application to early detection of departures from healthy lung function.

Adolescent

Lung function associated with histologically diagnosed acute lung rejection and pulmonary infection in heart-lung transplant patients.

A group of 34 heart-lung transplant patients were studied with serial pulmonary function measurements, chest radiographs, and transbronchial biopsies from the time of surgery. These investigations were carried out routinely at 3 and 6 months and then annually after transplantation as well as on clinical suspicion of acute lung rejection or infection. A total of 61 transbronchial biopsies and concurrent lung function and chest radiographs were obtained. Of the biopsies, 30 (49.2%) showed histologic evidence of lung rejection, 12 (19.7%) demonstrated various opportunistic infections, and 19 (31.1%) were normal. Compared to during episodes of normal biopsies, FEV1 decreased significantly with lung rejection (p less than 0.001) and with infection (p less than 0.01). Vital capacity (VC) and DLCO also fell with these acute lung complications. Using histologic diagnosis as a standard, lung function testing had a sensitivity of 86% in detecting lung rejection in the first 3 months postoperation and 75% in the subsequent period. Its sensitivity for detecting lung infection was 75%. Although not distinguishing between these two complications, lung function had a specificity of 84% for detecting occurrence of an acute lung complication. Chest radiographs, although of similar sensitivity in the first 3 months postsurgery, had a sensitivity of only 19% for rejection in subsequent months and 58% for infection. Its specificity was 100%. Lung function testing changes in a predictable fashion with lung rejection and infection, offers an improvement over chest radiographs, and provides a quantitative measurement to aid the decision of when to undertake transbronchial lung biopsy.

Biopsy

A comprehensive on-line computerised lung function screening test.

An on-line computerised lung function screening test is described which prints out 22 lung function parameters and a functional diagnosis. The complete test with print-out data takes less than 8 min per patient which implies that more than 60 out-patients can be 'screened' per day. Furthermore, for patients about to undergo major surgery a lung function operative risk grading is also available. The developed computer system is comparatively inexpensive, simple to operate and can be immediately on-lined to most apparatus without special interfacing. The total screening system can be operated by a single technologist and the required respiratory manoeuvres can be performed by almost all patients irrespective of the degree of lung function impairment. Although comprehensive in itself the screening test has been invaluable in deciding upon which patients require more intensive and time-consuming lung function investigations.

Computers