Determination of %FVC (FEV/FVC%) at expiratory flow rate of 1 lit/sec and 0.5 lit/sec from forced expiratory spirogram

A method for determination of %FVC (FEV/FVC%) at forced expiratory flow rate (FEF) of 1 lit./sec. and 0.5 lit/sec from the forced expiratory spirogram is described. This parameter is simpler to determine and is a better expression of end expiratory flow rate than FEF 75%-85%.     

The effect of tiotropium on the pulmonary diffusing capacity

To our knowledge, there is no data on the effect of tiotropium on pulmonary gas exchange in healthy subjects. The aim of this study was to assess the effects of tiotropium on pulmonary diffusing capacity. Twenty-one healthy volunteers were enrolled for a prospective, randomized, double-blind, placebo-controlled study. Spirometric measurements, including pulmonary-diffusing capacity, were obtained before and after inhalation of drug or placebo. There was a significant decrease in forced vital capacity (FVC) and, consequently, an increase in the forced expiratory volume in one second (FEV1) to FVC ratio after placebo inhalation (p < 0.05), but no changes were found for percent-predicted FVC, FEV1, percent-predicted FEV1, percent-predicted forced expiratory flow (FEF25%-75%), percent-predicted peak expiratory flow (PEF), diffusing capacity of the lung for carbon monoxide (DLCO), single-breath alveolar volume (VA) and DLCO/VA ratio when compared with the baseline. Tiotropium inhalation caused a significant increase in FVC, percent-predicted FEV1, FEV1/FVC and percent-predicted FEF25%-75%, although the decrease in DLCO was insignificant (12.4 +/- 0.9 to 11.4 +/- 0.9). In conclusion, tiotropium does not change the pulmonary-diffusing capacity in healthy volunteers.     

Lung function development in Indian men and women during late adolescence and early adulthood--a longitudinal study

Lung function development was studied in a cohort of Indian men (n = 31) and women (n = 36), over a period of four years during late adolescence and early adulthood. Forced expiratory spirograms and peak expiratory flow rates were recorded at intervals of approximately two years. All volumes and flow rates were higher in men, but volume adjusted flow rates were higher in women. Forced vital capacity (FVC) forced expiratory volume in one second (FEV1) and peak expiratory flow (PEF) were significantly higher in men even after standardizing for age, height and weight. Height and PEF increased significantly in men and women over the four years. Volumes showed a greater increase whereas flow rates and volume adjusted flow rates showed a greater decrease in men. The decline in the forced expiratory flow in the middle half of the FVC (FEF 25-75%) was significantly less in women. These results suggest that although lung size is greater in men, small airway dynamics may be better in young women.     

Cardiorespiratory responses to submaximal incremental exercise are not affected by one night's sleep deprivation during the follicular and luteal phases of the menstrual cycle

The purpose of the study was to investigate the effects of one night's sleep deprivation on the cardiorespiratory responses to exercise during the follicular and luteal phases of the menstrual cycle. We have studied nine, healthy females aged 24-35 years with regular menstrual cycles. Each subject performed spirometric tests at rest and then an incremental exercise testing during 11-13 days of follicular phase and 22-24 days of luteal phase following one normal night's sleep or one night's sleep loss. Compared with resting values exercise produced significant increases in cardiorespiratory variables including oxygen uptake (VO2), carbon dioxide production (VCO2), tidal volume (VT), respiratory rate (RR), minute ventilation (VE), systolic blood pressure, heart rate (HR) and respiratory quotient (R). However, it did not alter significantly diastolic blood pressure, end-tidal PO2 (PETO2), end-tidal PCO2 (PETCO2) and arterial oxygen saturation (SaO2). Spirometric variables which include forced vital capacity (FVC), forced expiratory volume in one s (FEV1), FEV1/FVC%, forced expiratory volume in three s (FEV3), forced expired flow from 25-75% of FVC (FEF 25-75%), forced expired flow at 25% of FVC (FEF 25%), forced expired flow at 50% of FVC (FEF 50%), forced expired flow at 75% of FVC (FEF 75%), forced expired flow from 75-85% of FVC (FEF 75-85%), peak expiratory flow (PEF), expiratory reserve volume (ERV), inspiratory capacity (IC) and maximal voluntary ventilation (MVV) and cardiorespiratory variables were not different between the cycle phases after one normal night's sleep or one night's sleep deprivation. Neither menstrual cycle phase nor sleep deprivation affected spirometric and cardiorespiratory parameters. We suggest that one night's sleep deprivation does not produce alterations in spirometric parameters and cardiorespiratory responses to submaximal incremental exercise during the follicular and luteal phases.     

小气道功能指标在儿童哮喘病情严重程度评估及临床诊断中的应用

目的 探讨小气道功能指标在儿童哮喘病情严重程度评估及临床诊断中的应用价值。方法 选取2013年5月至2016年4月于郑州市第二人民医院56例哮喘急性发作期病儿作为哮喘组,并根据哮喘急性发作严重程度分为轻度(21例)、中度(20例)和重度(15例)三个亚组,同时选取同期、年龄相仿及性别相匹配的30例因其他原因引起喘息咳嗽的慢性炎症病儿和32例入院检查健康儿童分别作为非哮喘组和对照组,收集各组儿童一般资料,采用肺功能测定系统检测各组儿童用力肺活量(FVC)、最大呼气流量(PEF)、第1秒用力呼气容积(FEV1)和FEV1/FVC比值、呼出25%肺活量时呼气流速(FEF25%)、呼出50%肺活量时呼气流速(FEF50%)、呼出75%肺活量时呼气流速(FEF75%)、最大中期呼气流速(MMEF)等指标。结果 与对照组比较,非哮喘组和哮喘组病儿FVC、FEV1、PEF、FEF25%、FEF50%、FEF75%和MMEF等指标均显著降低(P<0.05),且哮喘组病儿上述指标显著低于非哮喘组[(1.42±0.36)L比(1.85±0.47)L、(1.25±0.32)L比(1.42±0.41)L、(2.68±0.64)L比(3.25±0.77)L/s、(2.54±0.65)L/s比(3.74±0.68)L/s、(1.58±0.36)L/s比(2.24±0.71)L/s、(0.61±0.37)L/s比(1.02±0.41)L/s、(1.42±0.49)L/s比(1.89±0.68)L/s)](均P<0.05),而三组病儿FEV1/FVC指标差异无统计学意义(P>0.05)。哮喘急性发作期不同程度病儿用力呼出25%肺活量的呼气流量占预计值百分比(FEF25pred%)、用力呼出50%肺活量的呼气流量占预计值百分比(FEF50pred%)、用力呼出75%肺活量的呼气流量占预计值百分比(FEF75pred%)、最大呼气中期流量占预计值的百分比(MMEFpred%)等指标比较差异有统计学意义(P<0.05),且随着病情程度增加,病儿FEF25pred%、FEF50pred%、FEF75pred%、MMEFpred%等指标呈现明显降低趋势(P<0.05),FEF25%和FEF75%指标在不同严重程度哮喘病儿中异常率比较,差异有统计学意义(P<0.05),FEF50%和MMEF指标比较差异无统计学意义(P>0.05),其中FEF25%主要表现为轻度异常,而FEF75%主要表现为重度异常。结论 小气道功能指标在儿童哮喘病情严重程度评估及临床诊断具有重要意义,随着病情加剧,小气道功能指标明显降低,且异常率显著增加。     

肺高分辨率CT马赛克样灌注与小气道功能指数的相关分析

目的探讨肺小气道病变时高分辨率CT（HRCT）所示马赛克样灌注与小气道功能指标的相关性。方法选择HRCT上显示马赛克样灌注病例80例,由3位放射诊断医师对马赛克样灌注与小气道功能指标的相关性进行分析。结果马赛克样灌注与FEF 25%呈负相关（r=-0.48,P〈0.05）,与FEV1、FEF50%无相关性（r值分别为-0.27和-0.19,P〉0.05）。而空气潴留的程度与FEF25%、FEV1呈负相关（r值分别为-0.62和-0.41,P〈0.05）,与FEF 50%无相关性（r=-0.29,P〉0.05）。结论马赛克样灌注作为小气道病变的主要征象,其与FEF 25%具有良好的相关性,而空气潴留作为小气道阻塞的直接后果,其程度与FEV1、FEF 25%具显著相关性,即使肺功能检查结果正常时,也可以辅助诊断临床可疑的小气道阻塞。     

沙美特罗/丙酸氟替卡松对哮喘儿童肺功能的改善及临床意义

目的:观察沙美特罗/丙酸氟替卡松对哮喘儿童肺功能改善情况。方法:采用德国Jaeger公司的MasterscreenIOS测定仪,对61例支气管哮喘患儿在沙美特罗/丙酸氟替卡松治疗前后进行通气肺功能(F-V)和脉冲振荡(IOS)检测。观察用力肺活量(FVC)、第一秒用力呼气容积(FEV1)、最大呼气流速(PEF)、呼出25%肺活量时最大呼气流量(FEF25)、呼出50%肺活量时最大呼气流量(FEF50)、呼出75%肺活量时最大呼气流量(FEF75);呼吸阻抗(Zrs)、气道总阻力(R5)、中心气道阻力(R20)、响应频率(Fres)。结果:沙美特罗/丙酸氟替卡松治疗后FVC、FEV1、PEF均明显升高(P<0.001),而Zrs、R5、R20、Fres均明显降低(P<0.05),两者检查结果均有显著统计学意义。结论:吸入沙美特罗/丙酸氟替卡松能改善哮喘儿童的肺通气功能,降低气道阻力,是治疗儿童哮喘的理想药物之一。     

Pulmonary functions in air conditioner users

Air conditioning may affect human health since it has profound effect on our environment, than just lowering temperature. The present study was planned to assess the effect of air conditioners (AC) on pulmonary functions in young healthy non-smoker males. The study group comprised of ten subjects who were using AC's in their cars for at least 1 hr daily since last 6 months. While ten subjects who did not use AC at all served as controls. The pulmonary functions were assessed using PK Morgan 232 spirometer in a closed room. The peak expiratory flow rate (PEFR) and Forced expiratory flow between 25-75% of vital capacity (FEF25-75) were significantly reduced in subjects using car AC's. Inspiratory flow rates also showed a trend towards decline in AC users but could not reach the level of significance. The lung volumes and capacities were not significantly different in the two groups except for forced expiratory volume in 0.5 sec (FEV 0.5 sec), which also decreased in AC users. The airway resistance and lung compliance did not show significant change. In the presence of normal FEV1, reduced FEF25-75% which is the flow rate over the middle half of vital capacity, is an evidence of mild airflow limitation. The result is suggestive of predisposition of AC users towards respiratory disorders in form of mild airflow restriction.     

Large and small airway responses to procaterol hydrochloride administered through different extension devices in asthmatic patients.

The effects of spacer devices on the magnitude and velocity of large and small airway bronchodilator responses in asthmatic patients who can correctly operate a metered dose inhaler (MDI) remain unclear. According to a double-blinded, randomized, crossover protocol, 14 asthmatic patients were studied on seven separate occasions. On each occasion, patients inhaled doubling methacholine concentrations until forced expiratory volume in 1 second (FEV1) had fallen by 20% of baseline. Changes in forced expiratory flow between 25% and 75% of vital capacity (FEF25-75) were also evaluated. Subsequently, patients were administered 20 or 50 micrograms of procaterol from an MDI either alone or in conjunction with a small- or large-volume spacer device. Changes in FEV1 and FEF25-75 corrected for baseline forced vital capacity (isoFEF25-75) were assessed at 3-minute intervals for 15 minutes and at 30 minutes. Spontaneous recovery was similarly evaluated. The time required to attain significant increases in both FEV1 and isoFEF25-75 was calculated in bronchodilator trials. With 20 micrograms of procaterol, both spacers allowed larger and faster FEV1 increases than the MDI alone (P < 0.01); with 50 micrograms, the velocity and magnitude of FEV1 increases were further enhanced in trials with the MDI alone. The lower procaterol dose via the large-volume spacer determined larger and faster isoFEF25-75 increases than the higher dose via both the small-volume spacer and the MDI alone (P < 0.01). Spacers enhance bronchodilation even in patients using MDIs optimally. Compared with both the small-volume device and the MDI alone, the large-volume spacer allows faster and larger small airway dilation with less than half of the procaterol dose.     

Pulmonary function in patients with diabetes mellitus.

The present study was carried out to assess the lung functions in oral medicated and insulin administered patients with normal controls. 20 subjects were selected as the study group for oral medication (Group I), 20 subjects were selected as the study group for insulin treatment (Group II) and 40 subjects were selected as normal controls. Age group of Group I and Group II were 51.25 +/- 6.28 and 50.8 +/- 6.56 respectively and controls were age and height matched. Seventeen patients of Group I were undergoing treatment for the last 10-20 years and 20 patients in Group II were undergoing treatment for the last 30 years. Only male subjects were selected for the study. Lung function test were carried out with Spirometer (Vitallograph Compact II). A significant reduction in forced expiratory volume/forced vital capacity (FEV1/FVC%) was observed in oral pills used subjects and insulin administered subjects as compared to controls. Significant decrease in forced expiratory flow rate (FEF25-75%) in group I subjects was also observed as compared to controls. Forced mid flow time (FMFT) showed a significant increase in group II in comparison to controls. These changes clearly show the expiratory flow rates are reduced both in orally medicated and insulin administered patients. Increase in FMFT in group I may be due to the reduced respiratory ability to carry out the FVC test along with the side effects of oral medication for diabetes mellitus.     

Longitudinal study of lung function development in a cohort of Indian medical students: interaction of respiratory allergy and smoking

This study was done to identify some factors that affect the growth and development of lung function during adolescence and early adulthood. Forced expiratory spirograms and peak expiratory flow rates were obtained in a cohort of normal young men (n = 63) over a period of 4 years, at intervals of approximately 2 years. Two factors that disturbed the normal pattern of lung function development in this group were smoking and respiratory allergy. Among the smokers and the allergics the decline in the forced expiratory volume expressed as a percentage of the forced vital capacity (FEV1%), the forced expiratory flow in the middle half of the forced vital capacity (FEF25-75%) and the FEF25-75% expressed as a ratio of the forced vital capacity (FEF/FVC) was more than double that among the normal subjects. The number of smokers and of allergics increased during the course of the study from 15 to 19 and from 16 to 23 respectively. There was a significant (P less than .01) interaction between smoking and the manifestation of respiratory allergy. Among nonsmokers, the number of allergic subjects increased from 12 to 13, while among smokers it increased from 4 to 10, during the four years.     

Comparison of fenoterol, isoproterenol, and isoetharine with phenylephrine aerosol in asthma

The bronchodilator effect of fenoterol hydrobromide (0.5, 1.25, and 2.5 mg) was compared with either isoproterenol (2.8 mg) or isoetharine (5 mg) with phenylephrine (1.25 mg) in a double-blind placebo-controlled study. When delivered by an intermittent positive-pressure breathing device to 24 nonsmoking young adult asthmatic subjects, fenoterol produced significant improvement in forced expiratory volume at 1 second (FEV1), in maximum midexpiratory flow (FEF25-75%), and in forced expiratory flow at 25 per cent of vital capacity (FEF25%) for 6 to 8 hours, whereas isoproterenol and isoetharine with phenylephrine produced improvement for 1 and 2 hours, respectively. The lowest dosage of fenoterol was as effective as the highest but had fewer adverse effects.     

Prediction equation for lung functions in South Indian children

Lung functions including VC, IVC, FVC, FEV0.5, FEV1, PEF, FEF0.2-1.2, FEF25-75%, FEF75-85%, PIF, FMFT, MVV(IND), peak expiratory flow at 25%, 50% and 75% of FVC, peak inspiratory flow at 75%, 50%, 25% and the ratio between different lung volumes were measured with Vitallograph Compact-II spirometer on 109 South Indian school boys in the age group of five to sixteen years. The results show an increase in "lung volumes" and "flow rates" with increase in age, height and weight. FMFT and MVV(IND) also increase with increase in anthropometric measurements. All the lung functions except FEF75-85% and the ratio between different lung volumes show significant positive correlation with age, height and weight. Regression equations were derived for predicting normal lung functions for healthy South Indian boys. Lung volumes and flow rates were lower than North Indian and foreign boys. The decrease in lung functions in South Indian boys were due to their sea level dwelling, dietary habits and comparatively lower anthropometric measurements.     

Inhaled dopamine induces bronchodilatation in patients with bronchial asthma.

OBJECTIVE: To determine the probable bronchodilating effect of dopamine administered by inhalation route in patients with crisis of bronchial asthma and the effect of dopamine on bronchial motor tone. DESIGN AND METHOD: We have studied eighteen (18) patients with crisis of bronchial asthma, ten (10) subjects with bronchial hyperreactivity and ten (10) healthy subjects. Patients with other pulmonary or cardiac disease were excluded. All received by inhalation placebo (0.9% saline solution), dopamine at 0.5 microg/kg/min (controlled by heart rate and arterial pressure with a dynamap), and placebo. Respiratory parameters: forced vital capacity (FVC), forced expiratory volume at the first second (FEV1), forced maximal expiratory flow (FEFmax) and forced expiratory flow at the 50% of vital capacity (FEF50) were measured in each protocol period. Student's paired t test, Wilcoxon and Mann Whitney analysis were performed. RESULTS: After dopamine inhalation, there was an increase of FVC by 23% (p<0.001); an increase of FEV1 by 39% (p<0.0001); an increase of FEF50 by 33% (p<0.001) and an increase of FEFmax by 31% (p<0.001). There were no respiratory parameter changes in both, subjects with bronchial hyperreactivity and normal after dopamine inhalation. CONCLUSIONS: Inhaled dopamine induces bronchodilatation in patients with crisis of bronchial asthma. Inhaled dopamine neither alters basal bronchial tone in healthy subjects nor in subjects with bronchial hyperreactivity.     

Effects of the menstrual cycle on timing and depth of breathing at rest

Volume and timing components of resting ventilation were measured serially in 40 women aged 18 to 36 yr, during menstrual, follicular and luteal phases of menstrual cycle. Resting minute ventilation (VE) was significantly higher (P < 0.001) in luteal phase than in menstrual and follicular phases; in the two latter phases VE was almost equal. This increment in VE during the luteal phase was due to a significant rise (P < 0.001) in tidal volume (VT). Respiratory frequency (f) was unchanged throughout the cycle. Although there was a mean increases in inspiratory time (T1) during the luteal phase compared to the other two phases, the difference did not reach statistical significance. Duty cycle, T1/Ttot, was also unchanged throughout menstrual cycle. However, mean inspiratory flow, VT/T1, was significantly higher (P < 0.05 and P < 0.01) during luteal phase as compared to that during menstrual or follicular phases respectively. Pulmonary mechanics, as measured by forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and forced mid expiratory flow rate (FEF25%, 75%), were within normal limits and remained unaltered during the menstrual cycle. Therefore, in the absence of alteration of pulmonary mechanics, the luteal increase in ventilation and inspiratory flow suggests a possible role for progesterone in stimulating the respiratory drive, either centrally or through the peripheral chemoreceptors or by both.     

Bronchial lability in allergic rhinitis.

The aim of this study was to assess the relationship between exercise bronchial lability and the changes in pulmonary function over a one year period in allergic rhinitis. Eighty four nonsmoking male medical students of whom twenty two were allergic rhinitics were studied. Pulmonary function status was significantly lower and exercise bronchial lability significantly higher in the allergics. Over a one year period the mean decline in the forced expiratory volume in one second (FEV1) was three times greater and in the forced expiratory flow rate in the middle half of the vital capacity (FEF 25-75%) 50% greater among the allergics. The change in FEV1 was positively related to the bronchial lability, indicating that greater bronchial lability was associated with less decline in pulmonary function in these subjects.     

Dose-response relationship and time-course of the effect of inhaled magnesium sulphate on airflow in normal and asthmatic subjects.

1. Magnesium is a dietary cation with a wide range of actions of potential relevance to asthma. 2. To determine the dose-response relationship and time-course of the effect of inhaled magnesium sulphate on the airway, we have studied the effect of 0, 90, 135, 180 and 360 mg of magnesium sulphate given by nebulizer on specific airways conductance (sGaw) in 20 normal subjects, and forced expiratory volume in one second (FEV1), forced vital capacity (FVC), flow at 25% forced vital capacity (Vmax25) and peak expiratory flow (PEF) in 19 asthmatic subjects. 3. On five occasions after baseline measurements of airway calibre, one of the five doses of magnesium sulphate in 3 ml normal saline was administered by nebulizer in a randomized, double-blind design. Measurements of sGaw or FEV1, FVC, Vmax25 and PEF were made at 5 and 10 min after nebulization and at 10 min intervals thereafter up to 90 min. 4. There was no significant difference in the mean area under the curve (AUC) for change from baseline in sGaw or maximum increase from baseline between doses in normal subjects. 5. In asthmatic subjects there was no significant difference in the mean AUC for change from baseline in FEV1, FVC or Vmax25 when compared between doses by analysis of variance. There was a difference in the mean AUC for change from baseline in PEF between doses (ANOVA P for all groups 0.052) but this can be explained by a detrimental effect of the maximum dose of magnesium sulphate. 6. It would appear that inhaled magnesium does not act as a bronchodilator in normal or asthmatic subjects.     

核酪注射液足三里穴位注射治疗支气管哮喘临床研究

目的探讨核酪注射液足三里穴位注射治疗支气管哮喘的临床效果。方法收集2017年12月~2019年6月就诊亳州市中医院门诊及住院支气管哮喘患者60例,依照奇偶顺序分为治疗组(n=30)、对照组(n=30)。对照组给予常规治疗,治疗组于常规治疗基础上予以核酪注射液足三里穴位注射治疗。比较两组治疗前后肺功能指标[1秒用力呼气容积(FEV1)、呼气峰流速(PEF)日变异率、1秒用力呼气容积/用力肺活量(FEV1/FVC)]、哮喘控制测试量表(ACT)评分、圣乔治调查问卷(SGRQ)评分、血清免疫球蛋白E(IgE)水平。结果治疗后治疗组FEV1、FEV1/FVC高于对照组,PEF日变异率低于对照组(P<0.05);治疗后治疗组ACT评分高于对照组,血清IgE水平低于对照组(P<0.05);治疗后治疗组SGRQ症状、活动度、影响度评分低于对照组(P<0.05)。结论核酪注射液足三里穴位注射治疗支气管哮喘效果显著,能有效控制病情,改善肺功能及免疫功能,提高生活质量。     

Chronically inhaled salmeterol improves pulmonary function in heart failure

Inhaled beta-agonists are commonly prescribed for the symptoms of exercise intolerance in heart failure despite a paucity of data regarding their safety and efficacy. This was a prospective, randomized, double-blind, double-dummy, placebo-controlled 14-day cross-over study to determine if chronic inhaled salmeterol therapy 84 microg every 12 hours improved pulmonary function without augmentation of neurohormonal systems or ventricular ectopy in 8 symptomatic heart failure subjects with left ventricular ejection fraction (LVEF) <40% and FEV1 相似文献   

Effect of clenbuterol on peripheral airway obstruction in bronchial asthma

A study was carried out in 6 patients with bronchial asthma to investigate the effects of clenbuterol, a beta 2-sympathomimetic bronchodilator, on peripheral airway obstruction. The basal lung functions of the patients were almost within normal range in both vital capacity (VC) and forced expiratory volume in 1 second (FEV1), but their maximal flow rates were lower in effort-independent phase of both maximal expiratory flow volume (MEFV) curve and partial expiratory flow volume (PEFV) curve. Furthermore, they demonstrated marked basal frequency dependence of dynamic compliance [CL,dyn]. Oral administration of clenbuterol (40 micrograms) produced a significant increase in the maximal flow in effort-independent phase of both MEFV and PEFV curves, and markedly decreased frequency dependence of CL,dyn in comparison with the baseline values, while it improved both VC and FEV1 to a lesser extent. These results suggest that clenbuterol preferentially reduced the peripheral airway obstruction in bronchial asthma.