50例健康老年人肺功能10年随访观察

目的为临床和基础研究提供健康老年人肺功能各项指标随增龄改变的参考资料。方法采用日本Ｃｈｅｓｔａｃ６５型肺功能检查仪,按常规方法进行肺功能检查。结果用力肺活量（ＦＶＣ）每年下降００３２Ｌ,第１秒用力呼气量（ＦＥＶ１）每年下降００３Ｌ,ＦＥＶ１占用力肺活量比值（ＦＥＶ１％）每年下降０１５１％,呼气流量峰值（ＰＥＦＲ）每年下降０１１８Ｌ／ｓ,最大呼气中段流量（ＭＭＥＦ）每年下降００４Ｌ／ｓ,最大通气量（ＭＶＶ）每年下降０８７６Ｌ,肺活量（ＶＣ）每年下降００４Ｌ,残气容积（ＲＶ）每年升高００３３Ｌ,功能残气量（ＦＲＣ）每年升高００３３Ｌ,残气容积／肺总量（ＲＶ／ＴＬＣ）每年升高０５９６％。戒烟组的健康老年人ＶＣ、ＦＶＣ、ＦＥＶ１、ＲＶ、ＲＶ／ＴＬＣ与从不吸烟健康老年人比较差异有显著性;不同年龄组的健康老年人肺功能下降不明显。结论肺功能各项指标随增龄而改变,健康老年人各年龄组肺功能改变不明显,吸烟对健康老年人肺功能改变有一定影响。     

Pulmonary function test before and after operation of coronary artery by-pass surgery

Respiratory complications after successful CABG operation continuous to have on influence on the immediate recovery of a patient. It was reported that the mortality risk of the CABG patients increased, proportional to the reduction of pulmonary function tests (PFT). In the present study we aimed to investigate PFT values (vital capacity: VC, total lung capacity: TLC, residual volume: RV, functional residual capacity: FRC, force expiratory volume first second: FEV1, force mid expiratory flow: FEF25-75, duration force expiratory flow in vital capacity 25%: FEF25, duration force expiratory flow in vital capacity 50%: FEF50, duration force expiratory flow in vital capacity 75%: FEF75, peak expiratory flow: PEF, RV/TLC, FEF/FIF, FEV1/FVC) and arterial blood gases (pH, PaCO2, PaO2, SaO2) pre- and postoperatively which undergo CABG. The PFT and arterial blood gases values of 20 patients, age between 39-74 years, were measured that were undergo CABG operation before a week and three months after.The measured PFT values of 20 patients were recorded by system 2400 computerized and sensor medix 6200 and arterial blood gases analysed by radiometer ABL 300. The results were compared by the time and periods of before and after CABG operation, statistically evaluated the pearson's correlation and Student's t-test. In the results the postoperative PFT values were significantly decreased (p< 0.05, p< 0.001). But the RV, RV% and RV/TLC values were not changed significantly. In arterial blood gases values were not significantly changes. To avoid the postoperative complications we suggested that should be done the PFT and arterial blood gases measurement preoperatively.     

Functional assessment of allergic asthmatic children while asymptomatic.

The aim of this study was to detect the best test lung function to identify abnormalities in asthmatic children while asymptomatic. We studied 200 asthmatic children. Patients were evaluated by questionnaire to evaluate the presence of symptoms and drug consumption in the previous 3 months. Allergological evaluation by skin-prick tests and seric-specific IgE determination for relevant local inhalant allergens was made. Lung function was studied evaluating expiratory flows and measuring lung volumes by nitrogen washout technique. One hundred twenty-seven of 200 (63%) children showed functional abnormalities: 21 (10.5%) children had flow reductions, 56 (28%) children had volume modifications, and 50 (25%) children had either flow and lung volume alterations, respectively. We observed increased total lung capacity (TLC), residual volume (RV), and ratio RV/TLC values more often in patients with mild and moderate persistent asthma than in patients with intermittent asthma. No significant difference was detected considering expiratory flows. Measurements of lung volumes are an important tool to evaluate "air trapping" in asthmatic patients and this could be related to disease severity. According to the literature, our data suggest that an increase of RV, functional residual capacity RV/TLC could be the only functional airway dysfunction present in asthmatic children during asymptomatic period.     

An 8-year follow-up study of pulmonary function in patients with rheumatoid arthritis

To evaluate longitudinal alterations in pulmonary function, 63 patients suffering from rheumatoid arthritis (RA) with previously reported reduced pulmonary diffusing capacity were re-examined in an 8-year follow-up study. Cross-sectional examination revealed normal values for vital capacity (VC), forced expiratory volume in 1 s (FEV1) and diffusing capacity per litre alveolar volume (KCO). Total diffusing capacity (D_LCO; P>0.0001), maximal expiratory flow at 75% of expired VC (MEF 75; P>0.0001) and MEF 50 (P>0.01) were decreased. Longitudinal evaluation revealed unchanged MEF50, MEF75 and FEV1, whereas increases in D_LCO (P>0.0001) and KCO (P>0.0001) and a decrease in VC (P>0.05) were found. The longitudinal changes in diffusing capacity were unrelated to patient age, disease duration, disease activity in the study period or pulmonary function at the first examination. Thus, in patients suffering from RA, the most prominent functional pulmonary abnormality, decreased diffusing capacity, appeared to improve in the course of time, despite a slight decrease in VC and continued articular disease activity.     

Respiratory function in children undergoing bone marrow transplantation.

We conducted a prospective study of respiratory function in children undergoing bone marrow transplantation (BMT) for onco-hematological disorders. Each child was evaluated before and 100 days after BMT. The investigations included clinical examination, chest X-ray, and pulmonary function tests (PFT) to determine: slow vital capacity (VC), functional residual capacity (FRC), total lung capacity (TLC), forced expiratory volume in 1 s (FEV1), carbon monoxide diffusing capacity (DLCO), ratio of residual volume (RV) to TLC, and FEV1/VC. The values obtained before and after BMT were compared to predicted values, and the post-BMT values were compared to the pre-BMT values (Student's t-test). From 1986 to 1995, 77 children underwent BMT, of whom 39 were available for testing. The pre-BMT VC (P = 0.0234) and DLCO (P < 0.0001) were lower and FRC higher (P < 0.0001) than predicted values. After BMT, the VC (P = 0.004), TLC (P = 0.044), and FEV1 (P = 0.012) were lower, and the RV/TLC ratio was higher (P = 0.043), compared with pre-BMT data. The observed respiratory abnormalities were not clinically relevant. The only identifiable risk factor for a decrease in lung function was age at BMT. This study shows that some lung dysfunction may be present before BMT and be further altered by BMT. This stresses the need for longitudinal respiratory monitoring and follow up to detect such dysfunctions and to insure an optimal treatment program for these children.     

Lung involvement in essential mixed cryoglobulinemia.

Lung function studies were performed in 23 patients with the syndrome of essential mixed cryoglobulinemia. Signs of exposure to hepatitis B virus were present in nine (HBV+) and absent in 14 (HBV?). Pulmonary symptoms were generally absent or moderate except in three patients who presented with either asthma, hemoptysis or pleurisy together with the other manifestations of the disease. On the contrary, tests indicative of small airways disease, such as forced end-expiratory flow (FEF_0.75-0.85VC) and maximal expiratory flow at low lung volume (Vmax_0.75VC) were markedly altered (61.9 per cent and 40.4 per cent of the expected values, respectively). Other lung function tests, such as residual volume (RV), airway resistance (Raw), FEF_0.25-0.75VC, maximal expiratory flow at 50 per cent vital capacity (VC)(Vmax_0.50VC) showed smaller deviations from normal, whereas vital capacity (VC), total lung capacity (TLC), forced expiratory volume in 1 second (FEV₁), FEV₁:VC, RV:TLC and intrathoracic gas volume (ITGV) were within the normal limits. Nine of 14 of the HBV? patients showed impairment of gas exchange, measured as alveoloarterial oxygen gradient D(A-a)O₂, which, on the contrary, was always within normal limits in the nine HBV+ patients. The difference between the two groups was significant (28.4 mm Hg and 18.6 mm Hg, respectively, p < 0.025). Roentgenographic signs of interstitial lung involvement were present in 18 of 23 patients. Lung scan showed, in all instances in which it was performed, inhomogeneities of regional lung perfusion; they were, however, minimal in nearly half of the cases. The present data indicate that lung involvement is frequent in essential mixed cryoglobulinemia, that it should be recognized in addition to the other features of the disease and that it seems to be more pronounced in the HBV? patients. Indirect evidence suggests that circulating immune complexes may play a role in the genesis of the lung abnormalities observed in these patients.     

Pulmonary function in childhood connective tissue diseases.

The term connective tissue diseases (CTD) defines a group of illnesses characterized by the presence of immune abnormalities and by widespread inflammation involving various organs and tissues including the lung. These diseases are not frequent in the paediatric age group. Very few data on pulmonary function are available in paediatric CTD. We investigated possible early lung function abnormalities and any likely relationship with clinical activity of the disease in a group of 81 paediatric CTD patients, without clinical or radiological evidence of pulmonary involvement. Measurement of lung volumes and diffusion lung capacity were performed. A sample of 65 subjects, defined as normal on the basis of history and clinical examination, and matched by age and height with the group of patients, was chosen as control group. CTD patients did not show significant deviations from the control distribution with respect to functional residual capacity (FRC) and maximal expiratory flow at 75% of the forced vital capacity (MEF75) values. On the contrary, both vital capacity (VC) and diffusing capacity of the lungs for carbon monoxide (DLCO) were quite impaired in most CTD during the active phase of the disease. Our results show a functional lung impairment in most children with clinically active CTD, even in absence of abnormalities on chest X-ray pictures.     

Forced expiratory parameters in healthy preschool children (3-6 years of age)

In a group of 173 healthy preschool children 3-6 years of age (body height, 90-130 cm; 102 boys and 71 girls) out of total 279 children examined, maximum expiratory flow-volume (MEFV) curves were recorded in cross-sectional measurements. The majority (62%) of preschool children were able to generate an MEFV curve as correctly as older children. From the curves, maximum expiratory flows at 25%, 50%, and 75 % of vital capacity (MEF(25), MEF(50), and MEF(75)), peak expiratory flow (PEF), forced expiratory volume in 1 sec (FEV(1)), forced vital capacity (FVC), and area delineated by MEFV curve (A(ex)) were obtained. The purpose of the study was to establish reference values of forced expiratory parameters in preschool children suitable for assessment of lung function abnormalities in respiratory preschool children. The values of the studied parameters increased nonlinearly and correlated significantly with body height (P < 0.0001); the correlation was much lower with age. A simple power regression equation was calculated for the relationship between each parameter and body height. A best-fit regression equation relating functional parameters and body height was a power function. Based on the obtained regression equations with upper and lower limits, we prepared tables listing reference values of forced expiratory parameters in healthy Caucasian preschool children, against which patients can be compared. No statistically significant gender differences were observed for MEF(25), MEF(50), MEF(75), PEF, FEV(1), FVC, and A(ex) by extrapolation. The reference values were close to those obtained in our older children. A decline of the ratios PEF/FVC, FEV(1)/FVC and MEF/FVC with increasing body height suggested more patent airways in younger and smaller preschool children.     

A normal FEV1/VC ratio does not exclude airway obstruction

BACKGROUND: A decreased forced expiratory volume in 1 s/vital capacity (FEV(1)/VC) ratio is the hallmark of the definition of airway obstruction. We recently suggested that a lung function pattern, we called small airways syndrome (SAOS), has a normal FEV(1)/VC and total lung capacity (TLC) and reflects obstruction of small airways. OBJECTIVES: To substantiate our hypothesis we measured and compared lung function tests including maximal expiratory flow rates (MEFR), sensitive indicators of airway obstruction, in SAOS subjects and in matched controls. METHODS: We selected 12 subjects with the pattern of SAOS, but without chronic lung or heart disease (average age: 40.7 +/- 7.8 years) and 36 age-matched subjects with normal lung function (42.8 +/- 6.3 years). We measured static and dynamic lung volumes, MEFR and lung diffusing capacity (DL(CO)). RESULTS: SAOS subjects were heavier smokers (p < 0.05) and body mass index was less than in control subjects (p < 0.01). Both FEV(1)/VC ratio and TLC were comparable in the two groups. However, FEV(1), VC, DL(CO), and MEFR were lower and residual volume (RV) and RV/TLC ratio were higher (p < 0.05) in the SAOS group than in the control one. Furthermore, the MEFR curve of the SAOS group was displaced to the left without any change in slope, suggesting premature airway closure. CONCLUSION: Our results suggest that a normal FEV(1)/VC ratio does not exclude airway obstruction. A decrease of FEV(1), provided TLC is normal, reflects small airway obstruction.     

Pulmonary function in bronchopulmonary dysplasia

The purpose of this study was to examine lung function and bronchodilator responsiveness in infants with a history of prematurity and bronchopulmonary dysplasia (BPD), using the raised volume rapid thoracoabdominal compression technique as well as with whole-body plethysmography. Spirometric measurements were obtained in 28 infants with a history of BPD, defined as preterm birth with O2 requirement at 36 weeks postmenstrual age (gestational age at birth, 26.4 +/- 2.1 weeks, mean +/- SD; birthweight, 898 +/- 353 g; age at study, 68.0 +/- 35.6 weeks). Fractional lung volumes were measured in 27 subjects. Values were expressed as percentage of predicted normal values. Compared to normal infants, those with a history of BPD exhibited decreases in forced expiratory flows including forced expiratory volume in 0.5 sec (76.3 +/- 19.6%), forced expiratory flow at 75% of expired forced vital capacity (FEF75; 59.5 +/- 30.7%), and FEF(25-75) (74.0 +/- 26.8%; P<0.01 for all). Functional residual capacity (107.9 +/- 25.3%), residual volume (RV, 124.5 +/- 42.7%), and RV/total lung capacity (RV/TLC, 128.2 +/- 35.3%) were increased in infants with a history of BPD (P<0.05 for each). There was no difference in TLC between groups. Seventeen infants were studied both pre- and postalbuterol, and 6 (35%) demonstrated significant bronchodilator responsiveness. Infants with recurrent wheezing showed greater expiratory flow limitation, hyperinflation, and airways responsiveness, whereas those without wheezing showed only modest airway dysfunction. We conclude that infants with a history of BPD have pulmonary function abnormalities characterized by mild to moderate airflow obstruction and air trapping.     

Lung growth and function in children and adolescents with idiopathic pectus excavatum

Patterns of lung growth and function were studied retrospectively in 103 patients (73 male and 30 female) with idiopathic pectus excavatum in order to determine: 1) the prevalence of restrictive lung defect and/or other lung function abnormalities; 2) the possible association between type of lung function abnormalities and age of the patient; and 3) whether the type of lung function is associated with other clinical conditions. Forty-three patients (42%) were between 5-9 years of age; 36 (35%) were between 10-14 years; and 24 (23%) were between 15-19 years. Restrictive lung disease was detected only in 5 patients (5%), whereas 42 patients (41%) had evidence of obstructive pattern, and the remaining 56 patients (54%) had a normal pattern. The mean values for lung volume (total lung capacity (TLC) and/or forced vital capacity (FVC)) were lowest in the 10-14-year group, whereas the mean values of the indices of lower airway function (forced expiratory volume at 1 sec (FEV(1)), FEV(1)/FVC, forced expiratory flow at 25-75% of forced vital capacity (FEF(25-75)), and FEF(25-75)/FVC) were higher in the younger group. Residual volume (RV) and RV/TLC were elevated in all age groups, but they declined toward normalization with increasing age. There were no significant differences between groups (stratified either by pattern of lung function or by age) with regard to their demographics or clinical characteristics (scoliosis, direction of sternal rotation, history of asthma/reactive airways disease, or exercise intolerance). We conclude that idiopathic pectus excavatum may be associated with a variety of lung function abnormalities (in particular, lower airway obstruction) even in the absence of overt clinical symptoms. There was no evidence of significant worsening of lung function with increasing age.     

Pulmonary function in adolescents with ataxia telangiectasia

INTRODUCTION: Pulmonary complications are common in adolescents with ataxia telangiectasia (A-T), however objective measurements of lung function may be difficult to obtain because of underlying bulbar weakness, tremors, and difficulty coordinating voluntary respiratory maneuvers. To increase the reliability of pulmonary testing, minor adjustments were made to stabilize the head and to minimize leaks in the system. Fifteen A-T adolescents completed lung volume measurements by helium dilution. To assess for reproducibility of spirometry testing, 10 A-T adolescents performed spirometry on three separate occasions. RESULTS: Total lung capacity (TLC) was normal or just mildly decreased in 12/15 adolescents tested. TLC correlated positively with functional residual capacity (FRC), a measurement independent of patient effort (R2=0.71). The majority of individuals had residual volumes (RV) greater than 120% predicted (10/15) and slow vital capacities (VC) less than 70% predicted (9/15). By spirometry, force vital capacity (FVC) and forced expiratory volume in 1 sec (FEV1) values were reproducible in the 10 individuals who underwent testing on three separate occasions (R=0.97 and 0.96 respectively). Seven of the 10 adolescents had FEV1/FVC ratios>90%. CONCLUSION: Lung volume measurements from A-T adolescents revealed near normal TLC values with increased RV and decreased VC values. These findings indicate a decreased ability to expire to residual volume rather then a restrictive defect. Spirometry was also found to be reproducible in A-T adolescents suggesting that spirometry testing may be useful for tracking changes in pulmonary function over time in this population.     

Small airways dysfunction in systemic sclerosis. A controlled study.

A debate exists regarding the importance of small airways disease in systemic sclerosis, while smoking seems to have a major effect on the exact prevalence. In order to evaluate small airways dysfunction (SAD) in a pure systemic sclerosis population, we performed pulmonary function studies in 31 nonsmoking patients and 31 age- and sex-matched nonsmoking control subjects. Patients' FVC, TLC, and Dco mean values were significantly lower compared with the corresponding values of the controls (p less than 0.05), while there was no difference in MEF25, RV, and RV/TLC. Seven (22.6 percent) of 31 patients and four controls (a nonsignificant difference) had evidence of SAD, namely a maximum expiratory flow at 25 percent of vital capacity (MEF25) less than 60 percent of predicted. Positive correlation (p less than 0.001) was found between MEF25 and FEV1/FVC in the patients. Moreover, no differences were found in abnormal lung function patients with and those without SAD in demographic, clinical, roentgenologic, and serologic features and results of pulmonary function tests. These findings suggest that SAD in our patients is not a characteristic and early manifestation of systemic sclerosis and that, when present, it is not correlated with the severity of the pulmonary involvement in scleroderma.     

Pulmonary function and morbidity in 40 adult patients with cystic fibrosis.

Pulmonary function and cardiopulmonary complications were studied in a group of 40 patients with cystic fibrosis who reached the age of 25 years. Mean values for vital capacity (VC), functional residual capacity, residual volume (RV), the ratio of RV over total lung capacity (RV/TLC), conductance, and the ratio of the forced expiratory volume in one second over VC were abnormal. There was a variable pattern of progression from patient to patient. The men differed from the women only in that they had a significantly larger TLC and inspiratory capacity than the women. The resultant preservation of VC may have an advantage for survival in those patients in whom it is observed. Pseudomonas aeruginosa was encountered with increasing frequency with age. Massive hemoptysis did not result in early death. The occurrence of rightsided heart failure secondary to cor pulmonale, with or without respiratory failure, was a poor prognostic sign.     

A study of the respiratory function in insulin-dependent diabetic patients with and without limited joint mobility (LJM)

Summary The respiratory function of 51 insulin-dependent diabetic patients (31 with and 20 without LJM) was studied. The variables age, diabetes duration, height, and metabolic control were similar for both groups. Vital capacity (VC), forced expiratory volume (FEV), mean maximum expiratory flow (MMEF), and FEV/VC ratio were determined before and after the administration of a bronchodilator. VC, FEV, and MMEF showed significantly lower values (p<0.02) in patients without LJM as compared to those with LJM. It is suggested that these alterations may be due to abnormalities of collagen fibers and elasticity in the lung and are not related to reversible bronchial obstruction. We believe that LJM is an extrinsic manifestation of a systemic process, aggravating the prognosis of diabetes mellitus.     

Assessment of right ventricular function by strain rate imaging in chronic obstructive pulmonary disease.

The purpose of the current study was to compare right ventricular (RV) myocardial wall velocities (tissue Doppler imaging) and strain rate imaging (SRI) parameters with conventional echocardiographic indices evaluating RV function in chronic obstructive pulmonary disease (COPD) patients. In total, 39 patients with COPD and 22 healthy subjects were included in the current study. Seventeen patients had pulmonary artery pressure <35 mmHg (group I) and 22 patients had pulmonary artery pressure >35 mmHg (group II). Tissue Doppler imaging, strain and strain rate (SR) values were obtained from RV free wall (FW) and interventricular septum. Respiratory function tests were performed (forced expiratory volume in one second/vital capacity (FEV(1)/VC) and carbon monoxide diffusion lung capacity per unit of alveolar volume (D(L,CO)/V(A))). Strain/SR values were reduced in all segments of group II patients compared with group I patients and controls with lowest values at basal FW site. A significant relationship was shown between peak systolic SR at basal FW site and radionuclide RV ejection fraction. A significant relationship was shown between peak systolic SR at basal FW site and D(L,CO)/V(A) and FEV(1)/VC. In conclusion, in chronic obstructive pulmonary disease patients, strain rate imaging parameters can determine right ventricular dysfunction that is complementary to conventional echocardiographic indices and is correlated with pulmonary hypertension and respiratory function tests.     

Methacholine inhalation challenge after rapid saline infusion in healthy subjects

Five healthy subjects were challenged with methacholine on 2 different days, 1 week apart, the second day after acute intravenous 30 ml/kg 0.9% saline infusion. After infusion, we observed a significant reduction in vital capacity (VC), maximal expiratory volume in 1 s (FEV1), provocation dose producing a 35% fall in SGaw (PD35SGaw) and in 25% of maximal expiratory flow (MEF25), and an increase in the slopes of log dose-response curves. Our results suggest an increased bronchial reactivity in acute minimal interstitial lung edema.     

LUNG FUNCTION AND RESPIRATORY MUSCLE STRENGTH AFTER PROPRANOLOL IN THYROTOXICOSIS

Thirty-five thyrotoxic patients were assessed before treatment, after treatment with propranolol, and after antithyroid drugs. The first group of patients ( n = 17) performed the following tests at all three assessment points: forced expiratory volume in the first second (FEV,), vital capacity (VC), functional residual capacity (FRC), residual volume (RV), total lung capacity (TLC), maximal mid-expiratory flow rate (MMFR), diffusing capacity for carbon monoxide (DLCO), and maximum static inspiratory and expiratory mouth pressures (Plmax and PEmax). Arterial blood gas analysis was also performed for the first group of patients. No significant changes were seen either after propranolol or after antithyroid drugs in the FRC, RV, TLC, MMFR, DLCO, or blood gases. The remaining 18 patients, group 2, performed only the FEV₁, VC, Plmax, and PEmax tests at each assessment. The only index of respiratory function that improved significantly after propranolol was Plmax (from 46.5 ± 16.5 to 53.2 ± 22 cmH₂O, p < 0.01). This suggests that adrenergic excess may play a role in thyrotoxic inspiratory muscle weakness. After antithyroid drugs, Plmax, PEmax, FEV₁, and VC all increased significantly as expected. (Aust NZ J Med 1986; 16: 496–500.)     

Lung function in children and adolescents with idiopathic interstitial pulmonary fibrosis

Lung function of 65 patients who had idiopathic interstitial pulmonary fibrosis (IIPF) that had been treated with prednisone was evaluated by tests of ventilatory function, lung mechanics, and gas exchange at rest and during exercise. Ages on initial investigation ranged from 5 to 20 years. In 35 of 65 patients the studies were repeated an average of four times over a period of 1 to 9 years. Results of the first testing were as follows: vital capacity (VC)-significantly reduced in all patients; inspiratory capacity (IC)-significantly reduced in all patients; total lung capacity (TLC)-reduced in 91%; functional residual capacity (FRC)-reduced in 31%; residual volume (RV)-reduced in 6%; elastic recoil of the lungs (Pstl)-significantly increased in 97% at 100% TLC, significantly increased in 52% at 90% TLC, reduced in 68% at 60% TLC; 7) static compliance (Cst)-reduced in 83%; 8) dynamic compliance (Cdyn)-reduced in 88%; 9) specific airway conductance at FRC level (Gaw/TGVex)-significantly increased in 50%; 10) maximum expiratory flow rates at 60% TLC (Vmax 60% TLC, in TLC/s)-significantly reduced in 33%; 11) upstream airway conductance (Gus 60% TLC, in TLC/s/cm H2O)-reduced in 32%; 12) diffusing capacity of the lungs for carbon monoxide (DLco) related to body-surface area-abnormal in 58% (when corrected for lung size, i.e., DLco/TLC, abnormal in only 8%); 13) PaO2 at rest and after 6 minutes submaximal exercise-reduced in 25% and 63%, respectively. Changes in lung function that occurred with growth were assessed in terms of percentages of predicted values. Results showed that the VC and IC remained significantly reduced. An actual reduction of TLC, FRC, RV, breathing frequency, DLCO, and Pstl at 100% and 90% TLC was observed. Increases were seen in Pstl at 60% TLC, Gaw/TGVex, Vmax, and Cst. Indices of lung elasticity suggested that regions of fibrosis and emphysema had become present. Smaller patients were also noted to have stiffer lungs.     

Lung volumes in healthy boys and girls, 6–15 years of age

Functional residual capacity (FRC), vital capacity (VC), and its subdivisions, inspiratory capacity (IC) and expiratory reserve volume (ERV) were measured by spirometry in 140 healthy children (74 boys and 66 girls), aged 6–15 years.Total lung capacity (TLC) and residual volume (RV) were calculated on the measured lung volumes.The coefficient of variation was calculated on three successive determinations of IC, ERV and VC and on the calculated values of TLC and RV. The coefficient of variation is considerably large in the RV determination (up to 8,5%) (reflecting the influence of the individual’s cooperation during the measurement of ERV) but it is small in the TCL determination (up to 1,9%) (reflecting the reproducibility of successive measurements of IC and FRC, which is satisfactorily small).A certain training effect could be observed on the final value of successive measurements of some lung volumes, but nevertheless, this individual adaption is slight (expressed in ml) and without practical clinical importance. The relationship between lung volumes (FRC, VC, TLC, RV) and height, weight, age, and surface area, respectively, have been calculated by regression calculations.Standing height is the best independent variable for predicting lung volume except in the determination of VC in girls. However, this discrepancy between the predictive equations of VC versus standing height in girls and the other equations, published in this study, is so slight, that it is of no practical importance.The calculated residual standard deviations of all lung volumes correspond to the values, published by Engström et al. (1956) but are quite different from the results of Geubelle and Breny (1969), whose results are much higher. This discrepancy has been discussed as being caused by the different populations, examined in these studies.FRC, VC, TLC, and RV are larger in boys than in girls, and these differences are significant. In absolute values (i. e., expressed in ml) these differences are small compared to the corresponding actual values of lung volumes. The growing rate of the lung volumes according to the standing height is similar in boys and girls.The mean values (and 2 SD) of the FRC/TLC as well as the RV/TLC ratios were calculated for both boys and girls, being almost identical to those, published in literature. There is a slight but significant change of these ratios in relation to age in boys but not in girls. This significant correlation to age in boys is so small, that it is negligible from the practical point of view.