Spirometric lung function tests in normal non-smoking Ethiopian men and women.

Forced vital capacity (FVC), FEV1, FEV1/FVC ratio (FEV1%), forced expiratory flow (FEF 200-1200), and peak expiratory flow rate (PEFR) were measured in 143 male and 117 female healthy Ethiopians. Multiple linear regression analysis was used to correlate these indices with anthropometric variables. The results show that FVC, FEV1, and PEFR give significant regressions with age and height in both sexes. These indices have significant regression coefficients with percentage body fat, weight, and fat free mass (FFM) expressed independently of height in the men; only PEFR is significantly regressed on weight and FFM in the women. FVC and FEV1 in Ethiopians are found to be lower than in caucasians and higher than in other Africans, Chinese, and Indians. Prediction equations are provided for future use for obtaining reference values for lung function indices in similar subjects.     

Pulmonary function and symptoms in workers exposed to wood dust.

BACKGROUND: Exposure to wood dust can cause a variety of lung problems, including chronic airflow obstruction. METHODS: Forced vital capacity (FVC), forced expiratory volume in one second (FEV1), forced expiratory ratio (FEV1/FVC x 100), forced expiratory flow (FEF), forced mid expiratory flow (FMF), peak expiratory flow (PEF), and respiratory symptoms (cough, phlegm, breathlessness, wheezing, and nasal symptoms) were recorded in 145 non-smoking workers (77 male, 68 female) exposed to wood dust in a furniture factory in Umtata, Republic of Transkei, and 152 non-smoking control subjects (77 male, 75 female) from a bottling factory with a clean environment. RESULTS: After adjustment for age and standing height the forced expiratory indices were significantly lower in the exposed male workers than in the control subjects. FEF and PEF in the exposed men were 81.3% and 89.4% of predicted values and were lower than other indices. FVC in exposed men showed a significant inverse correlation with exposure (expressed in number of years of employment). The FVC was reduced by 26 ml per year of employment. The proportion of men with an FEV1/FVC below 70 was higher in exposed workers than in control subjects and higher in the exposed workers with more years of employment. The exposed workers had more respiratory symptoms than the control subjects, the prevalence, especially of cough and nasal symptoms, increasing with the increase in the number of years of employment. CONCLUSION: Workers exposed to pine and fibre dust have more respiratory symptoms and a greater risk of airflow obstruction.     

Forced expiratory indices in normal Libyan children aged 6-19 years.

Forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) were measured in 796 Libyan children (386 boys and 410 girls) with ages ranging from 6 to 19 years. Values in girls were significantly less than those in boys after allowance had been made for age and height. FVC and FEV1 correlated best with standing height but were also correlated with body weight. These results may be used as a source of standard values for Libyan children.     

Forced expiratory indices in normal black southern African children aged 6-19 years.

Forced vital capacity (FVC), forced expiratory volume in one second (FEV1), forced expiratory ratio (FEV1/FVC x 100), forced mid expiratory flow (FMF), and peak expiratory flow (PEF) were measured in 2000 non-smoking black African schoolchildren aged 6-19 years from Umtata in the Republic of Transkei in Southern Africa. FVC, FEV1, FMF, and PEF were highly correlated with each other and all were highly correlated with age and standing height in both sexes. There was a significant negative correlation between FEV1/FVC and both age and standing height. An increase in the slope of the increase in FVC for both age and height occurred at 11 years and 143 cm in girls and at 13 years and 150 cm in boys. This continued for about two years and 10 cm in both groups before it declined. The mean values of FEV1, FEV1/FVC, and PEF in the present study were 14% lower than those obtained in black American schoolchildren. The present study is the largest study of urban black African schoolchildren and provides useful reference values.     

进胸取膈神经移位术后肺功能的变化

目的　研究进胸取膈神经移位术后患者肺功能的变化。方法　对 5例进胸取膈神经移位患者术前及术后 (8～ 14个月 )肺功能的变化进行比较。结果　 5例在术后均未出现供氧不足症状。 3例出现膈肌抬高 ;术后肺活量 (VC)、肺活量预计值百分数 (VC % )分别比术前减少 17.3 %和 3 2 .3 % ,两者差异有显著性意义 (tvc=3 .49、tvc% =4.17,P <0 .0 5 )。其它项目如残气量 (RV)、肺总量 (TLC)、残气量 /肺总量比值 (RV/TLC)、用力肺活量 (FVC)、1s用力呼气量 (FEV1)、1s用力呼气量 /用力肺活量比值(FEV1/FVC)、5 0 %肺活量的最大呼气流量预计值百分数 (FEF 5 0 % )的变化 ,和术前相比均无明显差异。结论　进胸取膈神经移位术后成人的肺容量有部分丧失 ,但其丧失程度在机体可耐受范围内 ,不会导致呼吸功能障碍     

Repeatability of ventilatory function measurements in a population survey of 7 year old children.

The within subject variability of forced vital capacity (FVC), forced expiratory volumes in one second (FEV1) and half a second (FEV0.5), peak expiratory flow (PEF), and flow rates at 25-75%, 75-85%, 25%, 50%, and 75% of expired FVC were assessed among 7 year old children from the general population. Within occasion variability in 232 children was lowest for FVC (coefficient of variation (CV) 5%) and FEV1 (CV 4%), and greatest for end expiratory flow rates. The precision of measurement for FEV1 supports its use for bronchial provocation tests, particularly those using a graded challenge. In this context the value of PEF (CV 7%) and mid expiratory flow rates (CV 11%) is limited by their poorer repeatability. Between occasion variability was assessed in 171 children tested at an interval of one to four weeks. The difference between the variances between occasions and within occasions was attributed to biological variation; this accounted for a substantial component of the between occasion variance in all indices, particularly FEV1 (73%) and PEF (66%). Together, within subject variability, sex, and height accounted for about half of the measured variance between subjects for all indices except FVC (68%). These results have implications for epidemiological studies.     

Spirometry in healthy elderly Chinese.

Forced expiratory volume (FEV1), forced vital capacity (FVC), and peak expiratory flow (PEF) were measured in healthy subjects (129 men, 210 women) aged 60 years and above who were leading an independent and active life in the community. Women but not men showed an age related decline in FEV1 and FVC. Correlations of FEV1 and FVC with height were weaker than those reported for all age groups. Male ex-smokers had lower FEV1 values than current smokers and non-smokers. Regression equations are derived for men and women for predicting values appropriate to Chinese elderly people. These values are slightly lower than those for white people, but the difference is not as great as in values derived from surveys of all age groups.     

Pulmonary function studies in healthy Pakistani adults.

Predicted normal spirometric values have been shown to have significant geographical and ethnic variation. These variations are of epidemiological significance in determining the prevalence of disease and of clinical importance in measuring the effects on pulmonary function of various diseases. A total of 599 men were chosen from employees of a package manufacturer, a general hospital in Lahore, and a village in northern Pakistan; 94 students and staff of a women's college in Lahore were also studied. The forced vital capacity (FVC) was recorded from three satisfactory efforts, and the FVC, one second forced expiratory volume (FEV1), and maximal midexpiratory flow (MMF, or FEF25-75%) were calculated from the best FVC effort. The FVC and FEV1 in men were found to be similar to those of a group of emigrant Pakistanis and a north-western Indian population (Delhi) but higher than populations in south and eastern India. Pakistani women had values similar to those of women in northern India. None of the women smoked and, among Pakistani men, the smokers (285) averaged 6.7 pack years. While the FVC and FEV1 values did not differ between smokers and non-smokers, there was a significant difference in MMF (FEF25-75%) in the two groups. This latter finding corroborates studies on North American populations in which smokers generally have had a higher lifelong cigarette consumption. This confirms the MMF (FEF25-75%) to be a more sensitive test of subtle, asymptomatic changes in pulmonary function than the more widely used FVC and FEV1.     

Pulmonary function for pectus excavatum at long-term follow-up

PURPOSE: The aim of this article was to assess whether and to what extent pulmonary function recovered to normal degree postoperatively and to investigate the changes in pulmonary function after surgical correction and the value of surgical correction. METHODS: A total of 27 patients who could be questioned and examined in person at the outpatient department of our hospital were included in this study. Of these patents, 24 were boys and 3 were girls. Their ages ranged from 3 to 16 years (mean, 8.67) at follow-up. The mean age at surgery was 4 years, and mean years of follow-up was 6.8. Pulmonary functional measurements included in vital capacity (VC), total lung capacity (TLC), residual volume (RV), functional residual capacity (FRC), RV-TLC ratio, maximal voluntary ventilation (MVV), force ventilatory capacity (FVC), forced expiratory volume in one second (FEV1), maximal midexpiratory flow curve (MMEF), maximal expiratory flow in 75% vital capacity (V75), maximal expiratory flow in 50% vital capacity (V50), maximal expiratory flow in 25% vital capacity (V25), and breathing reserve ratio (BR). RESULTS: TLC, FRC, MVV, MMEF, V75, and V50 values were not different from the normal values. IVC, FVC, FEV1, and V25 values were decreased significantly compared with the normal values. The RV and RV-TLC were high in 87.5% cases. CONCLUSIONS: Preoperative symptoms obviously improved after operation. There was little airway obstruction in the patients postoperatively. The patients with pectus excavatum should be operated on as soon as possible.     

A respiratory survey in a black Johannesburg workforce.

BACKGROUND--The burden and determinants of airway disease in the population of southern Africa, which is currently undergoing rapid, often uncontrolled, urbanisation and industrialisation, are unknown. Previous surveys have focused on specific occupational groups and few have included women. This paper describes the respiratory status in a 30% probability sample of 206 men and 203 women drawn from an urban black Johannesburg workforce of almost 1500, all working for an educational institution. METHODS--Subjects answered a respiratory questionnaire and performed spirometric tests. Symptom rates and age and height standardised forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC%, and forced expiratory flow (FEF25-75) were analysed by gender in relation to smoking, past work exposures, past and recent respiratory conditions, and socioeconomic indicators. RESULTS--Symptom prevalence was high, bronchitic symptoms in men being related to smoking and previous occupational exposure, and in women to smoking despite the low intensity of their habit. Phlegm and wheezing were related to childhood respiratory illness in both men and women. FVC and FEV1, based on all subjects including smokers, were higher than previously reported for black residents of southern Africa. FVC was also positively related to education and job category. Higher values for ever smokers than for never smokers suggested health selection into the habit, while significant negative smoking effects were seen only on FEV1/FVC% and only in women. CONCLUSIONS--Despite the high prevalence of symptoms--some smoking related--in this urban workforce, lung function levels were higher than previously reported in African blacks, and may reflect improving socioeconomic conditions.     

Comparison of postoperative pulmonary function tests after cholecystectomy performed through Kocher's incision and mini-incision

Comparative pulmonary function after cholecystectomy performed through Kocher's incision and mini-incision were evaluated. One hundred patients were included and systematically divided into two groups of 50 each. The first group underwent conventional cholecystectomy and the second group underwent mini-cholecystectomy. Vital capacity (VC), forced vital capacity (FVC), forced expiratory volume at 1 second (FEV1), and peak expiratory flow rate (PEFR) were determined on the preoperative day and on postoperative days 1, 2, and 3. The percentage of reduction of VC on postoperative day 1 (P < 0.01), 2 (P < 0.01), and 3 (P < 0.01) after Kocher's incision was more than the percentage of reduction after mini-incisions on the corresponding day, respectively (P < 0.01, P < 0.01, and P < 0.01). The percentage of reduction of FVC (P = 0.0001, 0.0001, and 0.0001) was lesser after mini-incision cholecystectomy than after Kocher's incision cholecystectomy on the three corresponding postoperative days. The percentage of reduction of FEV1 after mini-incision was lesser than after Kocher's incision cholecystectomy on the three corresponding postoperative days (P = 0.001, 0.000, and 0.000). There was no significant difference in PEFR between the two groups on the three corresponding postoperative days (P = 0.731, 0.652, and 0.393). It is observed that min-incision cholecystectomy is followed by superior postoperative pulmonary function to that seen after Kocher's incision.     

Transit-time analysis of the forced expiratory spirogram during clinical remission in juvenile asthma.

The mean transit time (MTT), coefficient of variation (CoV), and index of skewness (IoS) of transit times of the forced expiratory flow/time curve have been compared with maximal mid-expiratory flow (MMEF), flow at 75, 50, and 25% of vital capacity (V75, V50, and V25), and the ratio of forced expiratory volume in 1 second (FEV1) to vital capacity (VC) in 51 asthmatic children judged on clinical grounds to be in remission. In 19 children all eight indices were normal. Of the remaining 32, MTT was normal in 5, V50 in 11, V75 in 12, and FEV1/VC and MMEF in 13 each. MTT was significantly more sensitive in detecting abnormality when other indices were normal, and abnormalities in MTT were of significantly greater magnitude when present. In 12 patients with at least one abnormal index given salbutamol aerosol, MTT was not more sensitive than MMEF, V25, FEV1/VC, or V50 in detecting change.     

Spirometry in healthy men: a correlation with smoking and with mild symptoms.

Symptoms, smoking history, and variates taken from the forced expiratory manoeuvre were studied in a group of 271 healthy men attending a mass radiography unit. It was found that correlation of the forced expiratory ratio (FEV1/FVC) with the presence of mild or moderate respiratory symptoms was at least as satisfactory as that of technically more complicated measurements such as MEF50 and MEF75. In asymptomatic individuals those differences associated with smoking were the same for FEV1/FVC as for MEF75. Asymptomatic abnormalities of lung function were not observed. Simple measurements such as FEV1/FVC can therefore provide as much information from a forced expiratory manoeuvre to screen for early airways obstruction as MEF50 and MEF75.     

Which spirometric indices best predict subsequent death from chronic obstructive pulmonary disease?

BACKGROUND: Previous epidemiological studies have related mortality from chronic obstructive pulmonary disease (COPD) to forced expiratory volumes (FEV(1) or FEV(0.75)) and it is unknown whether other spirometric indices might have greater predictive power. METHODS: A case-control study of fatal COPD was conducted within a cohort of London civil servants who performed forced expiratory spirograms in 1967-9 and were followed up for mortality over 20 years. The spirograms of 143 men who died of COPD (ICD8 491, 492 or 519.8) were compared with those of 143 controls individually matched for age, height, and smoking habit who survived longer than their matched case. Flow rates in different parts of the spirogram were compared within case-control pairs and analysed as predictors of fatal COPD by conditional logistic regression. RESULTS: Within pair case:control ratios of FEV(1), mid expiratory flow rates (e.g. FEF(50-75)) and FEF(75-85) were highly intercorrelated (r>0.7) but correlations with FEF(85-95) were weaker (r<0.5). All indices except the FEV(1)/FVC ratio were stronger predictors of death from COPD within the first 10 years than of later deaths (15-19 years). After adjustment for FEV(1), mid expiratory flow rates independently predicted fatal COPD but end expiratory flow rates did not. The FEV(1) adjusted mortality ratios associated with a 10% decrement in each index were 2.24 (95% CI 1.54 to 3.76) for FEF(50-75), 1.20 (95% CI 1.00 to 1.42) for FEF(75-85), and 1.10 (95% CI 0.96 to 1.26) for FEF(85-95). CONCLUSION: This study confirms FEV(1) and mid expiratory flow rates as powerful predictors of mortality from COPD, and suggests that measurement of end expiratory flow rates would add little extra predictive information.     

Effect of breathing circuit resistance on the measurement of ventilatory function

BACKGROUND: The American Thoracic Society (ATS) has set the acceptable resistance for spirometers at less than 1.5 cm H2O/l/s over the flow range 0-14 l/s and for monitoring devices at less than 2.5 cm H2O/l/s (0-14 l/s). The aims of this study were to determine the resistance characteristics of commonly used spirometers and monitoring devices and the effect of resistance on ventilatory function. METHODS: The resistance of five spirometers (Vitalograph wedge bellows, Morgan rolling seal, Stead Wells water sealed, Fleisch pneumotachograph, Lilly pneumotachograph) and three monitoring devices (Spiro 1, Ferraris, mini-Wright) was measured from the back pressure developed over a range of known flows (1.6-13.1 l/s). Peak expiratory flow (PEF), forced expiratory flow in one second (FEV1), forced vital capacity (FVC), and mid forced expiratory flow (FEF25-75%) were measured on six subjects with normal lung function and 13 subjects with respiratory disorders using a pneumotachograph. Ventilatory function was then repeated with four different sized resistors (approximately 1-11 cmH2O/l/s) inserted between the mouthpiece and pneumotachograph. RESULTS: All five diagnostic spirometers and two of the three monitoring devices passed the ATS upper limit for resistance. PEF, FEV1 and FVC showed significant (p < 0.05) inverse correlations with added resistance with no significant difference between the normal and patient groups. At a resistance of 1.5 cm H2O/l/s the mean percentage falls (95% confidence interval) were: PEF 6.9% (5.4 to 8.3); FEV1 1.9% (1.0 to 2.8), and FVC 1.5% (0.8 to 2.3). CONCLUSIONS: The ATS resistance specification for diagnostic spirometers appears to be appropriate. However, the specification for monitoring devices may be too conservative. PEF was found to be the most sensitive index to added resistance.     

Intrasubject variability of maximal expiratory flow volume curve.

Analysis of airflow in the terminal portion of the maximal expiratory flow volume curve has been suggested as a useful test for the early diagnosis of chronic airways obstruction. Whether such an analysis can identify early disease, and whether any subsequent action can prevent the progress of chronic airways obstruction, is unknown and will require prospective studies. As a precursor of such a study we have tried to establish the intrasubject variability of those tests of forced expiration which may be used for screening. We therefore measured expiratory flow volume curves of five healthy males and five healthy females aged 20-30 years as this is an age-group in which early detection of airways obstruction may be of value. Flow volume curves were obtained on the same day of the week for six weeks, and on three separate days during this period we carried out three flow volume curves every hour from 9 am to 6 pm. The data were subjected to analysis of variance to determine the variability of each measurement. Data were collected from forced expired volume in one second (FEV1) forced vital capacity (FVC), maximum expiratory flow rates at 50% and 75% of expired vital capacity, and forced expiratory time (FET). The results showed no consistent pattern of diurnal variation over the working day. The variation in any subject for FEV1 and FVC over the study period was considerably less than variations detected in the maximal expiratory flow rates at 50% and 75% of the expired vital capacity and FET. Our results suggest that the intrasubject variation found in flow rates of the terminal portion of the maximal expiratory flow volume curve and forced expiratory time may limit the usefulness of these tests in detecting early airways obstruction. FEV1 and FVC are more reproducible tests and are therefore particularly suited for cross-sectional screening. The more sensitive maximal expiratory flow volume curve may, however, be more useful for long-term studies in individuals when the onset of disease is sought, or for short-term challenge studies requiring the most sensitive index of change in airway characteristics.     

Airflow in unilateral vocal cord paralysis before and after Teflon injection.

The effect of unilateral vocal cord paralysis and intracordal Teflon injection on maximum expiratory and inspiratory flows was studied in 15 consecutive patients. Ten patients had a ratio of forced expiratory flow to forced inspiratory flow at 50% vital capacity (Ve50/Vi50) more than one. Of the remaining five, four had low Ve50 consistent with underlying bronchial disease. Repeat studies were obtained in 10 patients two or more weeks after Teflon injection into a vocal cord for voice therapy. Maximum expiratory flow rates did not change (means 6.64 +/- 0.881/sec before and 6.47 +/- 1.101/s after injection). Inspiratory flow at 50% vital capacity improved in all six patients with a forced expiratory volume in one second (FEV1) greater than 75% of the forced vital capacity (FVC). In patients with an FEV1 less than 75% FVC, no consistent changes could be seen. We conclude that a high Ve50/Vi50 suggestive of variable extrathoracic airways obstruction is a frequent finding in the presence of unilateral vocal cord paralysis. Teflon injection does not cause a significant reduction in forced expiratory flows and improves inspiratory flows in subjects without evidence of underlying bronchial disease.     

Ⅰ型神经纤维瘤病合并脊柱侧凸患者肺功能损害模式的研究

目的 分析I型神经纤维瘤病(NF1)合并脊柱侧凸患者肺功能损害的模式,以及影响其肺功能的影像学因素.方法 选取2003年1月至2009年6月间收治的NF1合并脊柱侧凸患者36例(NF1组),特发性脊柱侧凸(IS)患者64例(IS组),术前检测患者的肺活量(VC)、用力肺活量(FVC)、第1秒用力呼气容积(FEV1)、最大呼气中期流量(MMEF)、最大自主通气量(MVV).比较两组肺功能参数的差异.按照弯型部位及有无萎缩性改变将NF1组患者分类并分类比较肺功能损害的差异,分析影响肺功能的影像学指标.结果 两组肺功能参数VC、FVC、FEV1、MMEF、MVV差异均无统计学意义(P>0.05).NF1组胸弯患者肺功能显著低于非胸弯患者;营养不良型患者与非营养不良型患者肺功能损害差异无统计学意义(P>0.05);顶椎位置以及Cobb角与肺功能参数显著相关(P<0.05).结论 NF1合并脊柱侧凸患者的肺功能损害模式与IS患者类似,胸弯患者比非胸弯患者肺功能损害严重,侧凸位置以及Cobb角大小是影响患者肺功能的主要因素.     

Abnormal lung function associated with asbestos disease of the pleura, the lung, and both: a comparative analysis.

The impairment of lung function associated with different types of asbestos related disease was examined in 1298 men. The 310 men with circumscribed pleural lesions (plaques) or diffuse pleural thickening without asbestosis were compared with 596 men with asbestosis only and with 322 men with pleural abnormalities and asbestosis, as classified from chest radiographs by ILO pneumoconiosis criteria. Spirometric indices and total lung capacity (TLC; determined by planimetry) were measured and expressed as percentages of predicted values. Non-smoking men with pleural disease only had reduced values of mid and terminal expiratory flows (80.6 and 69.9% predicted) and a reduced FEV1 (89% predicted) with a forced vital capacity (FVC) of 94% predicted. TLC was 104% predicted. Thus they had airways obstruction with-out restriction. Non-smoking men with pulmonary asbestosis (ILO profusion of opacities mostly 1/0 and 1/1) had pulmonary function similar to that of men with pleural disease. FEV1 and FVC and flow rates at other lung volumes were lower in smokers with asbestosis (after adjustment for duration of smoking) than in the non-smokers with asbestosis. Airflow limitation was worse in the men with both pleural abnormalities and pulmonary asbestosis with lower values for mid expiratory flow, FEV1 and FVC (but not TLC) than those with either abnormality alone, in both non-smokers and current smokers. Men with diffuse pleural thickening that included the costophrenic angles had more airways obstruction and air trapping and lower FVC values than those with circumscribed pleural disease.     

Effects of passive smoking on the pulmonary function of adults.

The effects of exposure to environmental tobacco smoke (passive smoking) on pulmonary function of non-smoking, healthy Iranian men (n = 167) and women (n = 108) were investigated. There were significant reductions in % predicted FEV1 (5.7%), forced vital capacity (FVC, 4.6%) and forced expiratory flow 25-75% (FEF25-75, 9.9%) among men exposed to cigarette smoke (n = 78). The adverse effect of passive smoking was greatest among men exposed at the workplace (reduction in % predicted FEV1 9.4%, FVC 7.6%, and FEF25-75 15.3%). No significant difference in pulmonary function was found among the 54 women exposed to passive smoke, but only eight women had smoke exposure at work. It is concluded that exposure to environmental tobacco smoke, particularly at the workplace, adversely affects the pulmonary function of adults.