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PubMed1985

Role of the parasympathetic nervous system in acute lung response to ozone.

We conducted an ozone (O3) exposure study using atropine, a muscarinic receptor blocker, to determine the role of the parasympathetic nervous system in the acute response to O3. Eight normal subjects with predetermined O3 responsiveness were randomly assigned an order for four experimental exposures. For each exposure a subject inhaled either buffered saline or atropine aerosol followed by exposure either to clean air or 0.4 ppm O3. Measurements of lung mechanics, ventilatory response to exercise, and symptoms were obtained before and after exposure. O3 exposure alone resulted in significant changes in specific airway resistance, forced vital capacity (FVC), forced expiratory flow rates, tidal volume (VT), and respiratory rate (f). Atropine pretreatment prevented the significant increase in airway resistance with O3 exposure and partially blocked the decrease in forced expiratory flow rates but did not prevent a significant fall in FVC, changes in f and VT, or the frequency of reported respiratory symptoms after O3. These results suggest that the increase in pulmonary resistance during O3 exposure is mediated by a parasympathetic mechanism and that changes in other measured variables are mediated, at least partially, by mechanisms not dependent on muscarinic cholinergic receptors of the parasympathetic nervous system.

Adolescent↗
PubMed1999

Comparison of normal respiratory function values in young Kenyans with those of other Africans and Caucasians.

OBJECTIVE: To compare the normal respiratory function values in young Kenyans with those reported for regional African neighbours and Caucasians. DESIGN: Forced expiratory volume in one second (FEV1), forced vital capacity (FVC) and peak expiratory flow rate (PEFR) were measured in a non-randomised sample of young indigenous Kenyans and the values were compared with those of age-matched regional African neighbours (Ethiopians and South Africans) and Caucasians (Australians). SETTING: Faculty of Health Sciences, Moi University, Eldoret. SUBJECTS: Eighty eight apparently healthy young Kenyan university students (64 males, 20-25 years and 24 females, 19-23 years) were examined. RESULTS: The mean values (males versus females) were FEV1, 3.95 +/- 0.07 versus 2.97 +/- 0.08, FVC, 4.31 +/- 0.08 versus 3.19 +/- 0.09, and PEFR, 586.30 +/- 8.54 versus 438.30 +/- 8.55. The values for females were 25-26% less than those for males. The expiratory ratios (FEV1/FVC x 100) were 92.22 +/- 0.60% and 93.44 +/- 0.61% for males and females respectively, well within normal range. The FEV1, FVC and PEFR for both males and females correlated positively with heights. CONCLUSION: These results were comparable to values reported for age-matched regional neighbours (Ethiopians and South Africans) but were lower than those reported for Australian caucasians. This highlights the need for the Kenyan population to have its own local reference values.

Adult↗
PubMed1992

The effect of maternal smoking during pregnancy on early infant lung function.

We studied the effect of prenatal maternal cigarette smoking on the pulmonary function (PF) of 80 healthy infants tested shortly after birth (mean, 4.2 +/- 1.9 wk). Mothers' prenatal smoking was measured by: (1) questionnaire reports at each prenatal visit of the number of cigarettes smoked per day, and (2) urine cotinine concentrations (corrected for creatinine) obtained at each visit. Infant PF was assessed by partial expiratory flow-volume curves and helium-dilution measurement of FRC. Forced expiratory flow rates were significantly lower in infants born to smoking mothers, both when unadjusted and after controlling for infant size, age, sex, and passive exposure to environmental tobacco smoke (ETS) between birth and the time of PF testing. Flow at functional residual capacity (VFRC) in infants born to smoking mothers was lower than that found in infants whose mothers did not smoke during pregnancy (74.3 +/- 15.9 versus 150.4 +/- 8.9 ml/s; p = 0.0007). Differences remained significant when flow was corrected for lung size (VFRC/FRC: 0.87 +/- 0.26 versus 1.77 +/- 0.12 s-1; p = 0.013). No differences in pulmonary function were evident among infants exposed and unexposed to ETS in the home after stratifying by prenatal exposure status. We conclude that maternal smoking during pregnancy is associated with significant reductions in forced expiratory flow rates in young infants. The results suggest that maternal smoking during pregnancy may impair in utero airway development and/or alter lung elastic properties. We speculate that these effects of maternal prenatal smoking on early levels of forced expiratory flow may be an important factor predisposing infants to the occurrence of wheezing illness later in childhood.

Adult↗
PubMed2001

Respiratory ciliary function in bone marrow recipients.

Bone marrow transplantation (BMT) recipients, particularly those with chronic graft-versus-host disease (GVHD), suffer from respiratory tract problems, including bronchiolitis obliterans (BO) and recurrent lower respiratory tract infections. Minute cilia beat continuously on the surface of respiratory mucosa, and this beating maintains the sterility of the lower respiratory tract. Dysfunction of respiratory cilia could lead to development of recurrent respiratory tract infections, which are also features of BMT recipients, although ciliary function has not been systematically studied among these subjects. We have, therefore, investigated the ciliary beat frequency (CBF) of 36 Chinese patients who had undergone allogeneic BMT. The CBF was significantly lower in the BMT group compared to controls (P < 0.001). The reduction in CBF was more severe in patients with cGVHD and BO compared with their counterparts (P = 0.048 and P = 0.077, respectively). There was a correlation between CBF with forced expiratory flow rate FEF (P = 0.024) and forced expiratory volume FEV (P = 0.044). We conclude that abnormal ciliary clearance is a common feature after allogeneic BMT, particularly among patients with BO and cGVHD. Further studies are indicated to evaluate this important phenomenon, which could be an important cause of the susceptibility for BMT recipients to respiratory infections.

Adolescent↗
PubMed1978

[The oral application of berotec in the therapy of obstructive airway diseases].

The intensity and duration of action of Berotec (fenoterol) syrup in doses of 2.5 mg and 5.0 mg were investigated in an acute cross-over study in comparison with placebo, using the double blind technique. By measurement of the forced expiratory volume (FEV1) and the forced expiratory flow rate (FEF200-1200) significant improvement in pulmonary function could be detected from 1 to 4 hours after administration of 2.5 mg and from 1 to 8 hours after administration fo 5.0 mg Berotec syrup. The intensity of action exhibited a statistically significant dose dependence and was greater after the 5.0 mg dose (p=0.05) than after 2 puffs from Berotec metered aerosol taken by the patients in a pre-test. Minor side effects were observed in 2 cases: in one patient on the 5.0 mg dose they were clearly sympathomimetic and accompanied by a stronger bronchodilating effect.

Adult↗
PubMed1981

Use of isovolume flow curves in the detection of exercise-induced bronchospasm.

A simple 9-min progressive cycle ergometer test revealed exercise-induced bronchospasm in 23 of 29 asthmatic subjects (80%) in terms of a 15% decrement in the isovolume forced expiratory flow rate at 50% of the baseline vital capacity (Vmax iso 50%VC). A similar percentage was detected by the Vmax iso 60% TLC (78%), but that found with the FVC (35%) and FEV1.0 (48%) was somewhat lower The maximum change of Vmax iso 50%VC following exercise in normal subjects was -5.2 +/- 2.1%. The Vmax iso 50%VC thus combines sensitivity with specificity, and seems a very suitable procedure for routine clinical use. Asthmatics showing a positive reaction to this test were distinguished by poor pre-exercise lung function.

Adult↗
PubMed2004

The effects of hormone therapy on pulmonary function tests in postmenopausal women.

OBJECTIVE: To investigate the effects of hormone therapy (HT) administered to postmenopausal women on pulmonary function tests (PFT). METHODS: Eighty-two postmenopausal women who were having natural or surgically initiated menopause and had no risk factor that could affect the respiratory system were included into this prospective, randomized study. Twenty-five women who refused to use HT were assessed as the control group (Group I). Nineteen women who accepted using HT and who were having surgically initiated menopause were given continuous estrogen (Group II), 23 were given continuous estrogen and progesterone in combination (Group III) and 15 were given cyclic estrogen and progesterone combination (Group IV). Forced expiratory volume (FEV1), forced vital capacity (FVC), FEV1/FVC, forced expiratory flow rate over 25-75% of the forced vital capacity volume and peak expiratory flow rate were assessed at the beginning of the treatment and in the third month in order to evaluate the effects of HT regimens on the women's PFT. RESULTS: A statistically significant increase was observed only in the FEV1 and FVC parameters of Group III after three months of therapy (P<0.05). The comparison between pre- and posttherapy FEV1 and FVC values showed an increase in the Group IV, but the difference was not statistically significant, while there was no difference between basal and third month FEV1 and FVC values of the group receiving estrogen only. CONCLUSIONS: It was seen that particularly continuous combined HT regimen positively affected the FEV1 and FVC parameters of the postmenopausal women.

Drug Administration Schedule↗
PubMed1993

Pulmonary risk factors of elective abdominal aortic surgery.

PURPOSE: The purpose of this study was to retrospectively identify risk factors for postoperative pulmonary complications in patients undergoing elective abdominal aortic surgery via a midline incision. METHODS: We reviewed 181 consecutive patients who underwent operation between July 1986 to December 1992. Preoperative factors analyzed included age, sex, diabetes mellitus, history of smoking, chronic obstructive pulmonary disease, obesity, indication for surgery (aneurysm [126] or aortoiliac occlusive disease [AIOD] [55]), history of coronary artery disease, length of preoperative hospital stay, American Society of Anaesthesiologists class, and pulmonary function tests. Intraoperative factors analyzed included endotracheal tube diameter, percent of inspired oxygen, blood loss, blood and crystalloid replacement, total operative time, epidural analgesia, and stress ulcer prophylaxis. RESULTS: Although the operative mortality rate was only 1.7% (3 of 181), major pulmonary complications occurred in 29 (16%) patients, including two lung-related deaths. Pneumonia occurred in 17 (9%) patients, prolonged intubation greater than 24 hours occurred in nine (5%), and reintubation caused by pulmonary insufficiency occurred in three (2%). On univariate analysis, the following were associated with major pulmonary complications (p < 00.05): American Society of Anaesthesiologists class IV, age greater than 70 years, ideal body weight greater than 150%, forced vital capacity of 80% or less predicted, forced expiratory flow rate (25 to 75) of 60% or less predicted, crystalloid replacement greater than 6 L, and total operative time greater than 5 hours. CONCLUSIONS: The presence of these pulmonary risk factors, notably increased age and weight, decreased forced vital capacity and forced expiratory flow rate (25 to 75), and expected prolonged operative time, influences our decision not to proceed with surgery for small aortic aneurysms or for AIOD causing claudication. Patients at high pulmonary risk with AIOD who require revascularization for limb salvage would be more likely to undergo extraanatomic bypass. Pulmonary risk factors may play as important a role as cardiac factors in elective aortic surgery.

Age Factors↗
PubMed1989

Inhaled lignocaine does not alter bronchial hyperresponsiveness to hyperventilation of dry cold air in asthmatic subjects.

It has been hypothesized that bronchoconstriction due to exercise and hyperventilation is caused by the stimulation of irritant receptors in the upper airways. However, controversial results have been reported on the effect of lignocaine, which can inhibit the stimulation of these receptors. The aim of this study was to investigate the effect of inhaled lignocaine on bronchial responsiveness to hyperventilation of cold dry air in asthmatic subjects. Eight adult asthmatic subjects in a clinical steady state came on four different days (two placebo and two active days in random order) with a maximum interval of 3 weeks. After assessment of forced expiratory flow rates, inhalation of either phosphate-buffered saline (placebo) or lignocaine solution (40 mg) was carried out in a single-blind fashion. The technician was not aware which medication was being inhaled, but the asthmatic subject knew which drug it was by the sensation in his or her throat. Forced expiratory flow rates were reassessed 15 min after the nebulization; then, the subjects were asked to inhale cold dry air (-20 degrees C) in progressively increasing levels of ventilation (7.5, 15, 30 and 60 l/min and maximum voluntary ventilation). PD20 was interpolated from the dose-response curve, relating the dose of cold air on a non-cumulative logarithmic scale on the abscissa and the percentage change in FEV1 on the ordinate. There were no significant changes in FEV1 and PD20 after inhalation of lignocaine as compared to the placebo. We conclude that inhaled lignocaine does not significantly alter bronchial hyperresponsiveness to hyperventilation of cold air in asthmatic subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Inhalation↗
PubMed2004

Association between self-reported childhood socioeconomic position and adult lung function: findings from the British Women's Heart and Health Study.

BACKGROUND: A study was undertaken to assess the associations between indicators of early life socioeconomic position and lung function in older adulthood. METHODS: The associations of self-reported indicators of childhood socioeconomic position with adult lung function (forced expiratory volume in 1 second (FEV(1)), forced vital capacity (FVC), and forced expiratory flow rate during mid expiration (FEF(25-75)), all measured using standard procedures) were assessed in a cross sectional study of 3641 British women aged 60-79 years. RESULTS: In confounder adjusted analyses, each individual indicator of childhood circumstances was inversely associated with each measure of lung function. In the fully adjusted models (including mutual adjustment for each of the other indicators of childhood socioeconomic circumstances), only childhood occupational social class and access to a car were associated with lung function in adulthood. However, there were strong linear trends of worsening lung function with greater numbers of indicators of childhood poverty (all p values <0.001). CONCLUSIONS: Childhood poverty is associated with poorer lung function in women aged 60-79 years. Adverse childhood circumstances that affect both lung growth and development and cardiovascular disease in later life may explain some of the well known associations between poor lung function and cardiovascular disease, or lung function may be an important mediating factor in this association.

Aged↗
PubMed1999

Respiratory abnormalities among male foundry workers in central Taiwan.

The objectives of this study were to determine the relationship between exposure levels and respiratory abnormalities, to measure FVC and FEV1(1) changes per year based on work duties and to investigate the prevalence of and factors related to pneumoconiosis. A total of 583 male workers from 50 iron foundries in central Taiwan were investigated. First, workers' respiratory symptoms were categorized using a modified American Thoracic Society (ATS) questionnaire and then were verified by physician's examination. Next, pulmonary function tests were performed including: forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and forced expiratory flow rate. A chest radiograph was used to diagnose pneumoconiosis according to ILO criteria. Furnace workers were found to have the highest prevalence of chronic phlegm, thoracic disorders and chronic bronchitis. In general, smokers had a higher prevalence of respiratory symptoms as compared with non-smokers. Pulmonary function abnormalities and pneumoconiosis were closely linked to smoking and work duration. After adjusting for age, height and smoking there was a significant decrease based on work duration in FVC and FEV1 for furnace and moulding workers compared with after-processing and administrative workers. The overall prevalence of pneumoconiosis was 8.8%, highest among furnace (16.3%) and after-processing workers (11.4%) and lowest among administrative workers (2.5%). Using multiple logistic regression, the risk of developing pneumoconiosis (as compared with the administrative workers) for furnace workers was highest (8.98 times greater risk), followed by after-processing workers (6.77 times greater risk) and moulding workers (5.41 times greater risk). Prolonged exposure to free silica, and smoking habits, can result in respiratory abnormalities among foundry workers.

Adult↗
PubMed1983

How many blows really make an FEV1, FVC, or PEFR?

We have collected peak expiratory flow rates, one-second forced expiratory volumes, and forced vital capacities in sets of 10 or 20 values at one-minute intervals from 30 normal, 49 asthmatic, and 26 bronchitic subjects. Analysis shows that the derivatives are compatible with a normal distribution of the values in the sets, so that the true value is best represented by the arithmetic mean of all valid attempts. One-third of all subjects showed skewness in one or more indices but these were equally divided between positive and negative directions. There is no sign of the dominant negative skewness that would result if the true value was indeed a maximum, which could be approached or equalled but never exceeded. There is no sign that repetition worsens performance. Seventy-two subjects showed no regression in any index and those of the remainder who deteriorated were balanced by equal numbers in all categories who improved. There is a significant tendency for both the highest and the lowest values to occur in the earlier part of any series. Probability theory suggests that this is a statistical phenomenon. The best estimate of the true value of these indices is probably the mean of as many observations as can be conveniently obtained and the data can be treated statistically as if they were a sample from a normally distributed population.

Adolescent↗
PubMedDate not supplied

Effects of upper respiratory infections on the forced expiratory volumes and flow rates.

The effects of an upper respiratory infection on some commonly measured spirometric indices have been determined in this study. The forcod vital capacity, forced expiratory volume in one second, forced expiratory flow in the middle half of the vital capacity and the peak expiratory flow were significantly lower during the infection. This stresses the need in cross sectional and longitudinal pulmonary function evaluation, to avoid testing a subject while he has an upper respiratory infection.

Adult↗
PubMed1998

[Quebec spirometry reference values].

Lung volumes forced expiratory flow rates and carbon monoxide diffusing capacity (apnea) were measured in 397 non-smoking, nonatopic, asymptomatic subjects (219 women, 178 men). The equipments and methods for measurements met the ATS criteria. The linear regression of the different variables according to age and height allowed the elaboration of a new set of predictive equations (Quebec). When comparing the different reference values used in North America and Europe, it is found that those of Miller and associates as well as those recommended by the CECA provide the best description of the Quebec situation. However, we would eventually prefer the reference values of Miller and associates over those of the CECA, because they better fit the current ATS criteria and also provide references for smokers. Lung volumes and forced expiratory flow rates of 97 non-smoking, nonatopic, asymptomatic manual workers were measured in the same conditions and submitted to the same comparisons. Quebec predictive values as well as those of Miller and associates isolated the same individuals in the so called abnormal zone. We therefore conclude that Quebec's standards should be preferred in the Province of Quebec pulmonary function laboratories.

Adult↗
PubMed1988

Studies in healthy volunteers can demonstrate bronchodilator activity of orally administered drugs.

A panel of healthy volunteers was screened by bronchial histamine provocation. The response used was the flow rate achieved during a partial forced expiratory manoeuvre at a lung volume 30% of the vital capacity above the residual volume. Those subjects who were relatively sensitive to the bronchoconstrictor effects of inhaled histamine took part in a reproducibility study. Those with consistent responses took part in a further study in which the bronchodilator, and bronchoconstriction-protective, effects of orally administered chlorpheniramine, terfenadine and salbutamol were investigated. The technique was able to demonstrate the efficacy of these drugs in non-patient volunteers. Thus it seems to be a suitable method for the early evaluation, in man, of certain drugs with an anti-asthma therapeutic potential. It also provides useful information on the dose and duration of action of compounds prior to the first efficacy trials in patients.

Administration, Oral↗
PubMed1989

Disturbance in respiratory mechanics in infants with bronchiolitis.

The passive flow-volume and partial forced expiratory flow-volume techniques were used to assess pulmonary function in 14 spontaneously breathing infants with acute respiratory syncytial virus bronchiolitis. Two additional infants were studied while paralysed and ventilated. During the acute stage of the illness there was a significant reduction in forced expiratory flow rates and an increase in respiratory resistance. Although the mean thoracic gas volume for the group was increased, five infants did not compensate for their airways obstruction by hyperinflation. Curvilinear passive flow-volume curves were seen in three of the 14 non-ventilated infants and in both ventilated infants. At follow up three to four months later all passive flow-volume curves were linear. There was a significant reduction in hyperinflation and an increase in forced expiratory flow rates, but values still differed significantly from those in normal infants.

Bronchiolitis↗
PubMed1993

Long-term functional results after bilateral lung transplantation. Bordeaux Lung and Heart-Lung Transplant Group.

Between February 1988 and January 1992, 61 patients have undergone bilateral lung transplantations (42 heart-lung and 19 double-lung) in Bordeaux. The underlying diseases were primary or secondary hypertension (20), emphysema (22), or other diseases including cystic fibrosis, pulmonary fibrosis, silicosis, and sarcoidosis (19). Actuarial survival for double-lung and heart-lung transplant recipients was 66% and 72% at 1 year and 57% and 53% at 3 years, respectively. Forty-two patients were still alive 6 months after operation, and we studied their pulmonary function at the short and long term. All parameters except arterial carbon dioxide tension had improved dramatically at 6 months (p < 0.0001). Vital capacity, forced expiratory volume in 1 second, and forced expiratory flow rate between 25% and 75% of vital capacity were at 79% +/- 3%, 92% +/- 5%, and 105% +/- 8% of the predicted values, respectively. Arterial oxygen tension was 88 +/- 3 mm Hg. Nine months after operation, a slight decrease in forced expiratory volume in 1 second and forced expiratory flow rate between 25% and 75% of vital capacity appeared but values remained more than 75% predicted. This was related to the occurrence of obliterative bronchiolitis in 6 patients (14%). At 9 months, flow rates and oxygen tension of these 6 patients were highly different from those of patients free of obliterative bronchiolitis (p < 0.0002 for flow rates and p < 0.01 for oxygen tension). Only 1 patient required retransplantation. The others are living an almost normal life. Our results are discussed in view of the published reports on single-lung transplantation. Short-term results of bilateral lung transplantation are thus excellent and maintained on a long-term basis. Therefore, in our opinion, bilateral lung transplantation is the therapy of choice for pulmonary hypertension and emphysema.

Adult↗