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PubMed1978

Indications for pulmonary function testing.

Pulmonary function testing is needed to determine the pathophysiology present in the patient with cardiopulmonary disease. Blood gases and pH should be obtained during emergency situations and during cranial, thoracic, and extensive cervical or abdominal surgery. Lung function tests can be divided in global such as spirometry and diffusing capacity which study the ventilation and transfer of gases and regional determinations of ventilation and perfusion. Both types of tests complement each other and should be used together. The spirometry should consist at least of determination of the vital capacity and is determined in the first second to ascertain if there is obstructive lung disease. Some tests such as flow-volume curves, alveolar-arterial gradients and closing volume are very useful to detect early pulmonary disease before any symptoms or findings are present. This is probably one of the most important medical indications for pulmonary function testing. Before certain types of surgery pulmonary function testing is indicated; if the spirometry and diffusing capacity tests are normal, there is no pulmonary contraindication for the planned surgery. In chest surgery if there is significant compromise of the spirometry and diffusing capacity regional lung function tests are indicated to study the pathophysiology at regional level, thus trying to circumscribe the lung resection to the diseased areas.

Blood Gas Analysis↗
PubMedDate not supplied

Reactive airway disease in patients with prolonged exposure to industrial solvents.

This study examines the effects of volatile organic compounds (VOCs) at the workplace on pulmonary function tests. Forty-two patients with a history of industrial exposure to organic solvents and pulmonary symptomatology were studied. Lung function tests were determined utilizing screening spirometry lung volumes, diffusion capacity and methacholine stimulation test. While only 10-15% of the symptomatic patients had abnormal screening spirometry, 42% of the patients had significantly abnormal methacholine stimulation tests. These data show that exposure to volatile organic solvents is associated with bronchial hyperreactivity not commonly detected by screening spirometry and requires methacholine stimulation testing in individuals with unexplained symptomatology and history of exposure to industrial solvents. These findings indicate that the incidence of bronchial hyperreactivity is underestimated in patients with (1) verifiable exposure history to volatile organic compounds known to be pulmonary irritants, (2) pulmonary symptomatology with normal screening spirometry.

Adult↗
PubMed1996

Total respiratory impedance measured by means of the forced oscillation technique in subjects with and without respiratory complaints.

The purpose of this study was to determine whether the forced oscillation technique is more sensitive than spirometry to detect lung function alterations in subjects with respiratory complaints. The input impedance of the respiratory system (between 2 and 24 Hz) and maximal expiratory flows and volumes were measured in 1,255 subjects referred for routine spirometry. A questionnaire concerning respiratory complaints was administered. A discriminant analysis was performed between subgroups of subjects without (137 males and 140 females), with moderate (115 males and 109 females) and with marked respiratory complaints (149 males and 132 females). A clear-cut separation was achieved by this analysis only between those subjects without and with marked complaints. Both lung volumes and flows as well as impedance parameters (mean value and frequency dependence of resistance in females, mean resistance in males) contributed to the discrimination of subjects without and with marked respiratory complaints, although there was only a moderate decrease of discriminative power when the impedance parameters were excluded. The contribution of the forced oscillation parameters to discriminative power was larger in females than in males (40 vs 19%), which may be related to the higher prevalence of asthma in our population of females. Excluding the subjects with marked functional impairment improved the share of forced oscillation parameters only slightly with respect to lung volumes and flows (females 54 vs males 23%). Considered separately, however, the sensitivity of spirometry and forced oscillation technique to detect symptomatic people appeared to be similar. We conclude that impedance measurements by forced oscillation technique and routine spirometry are both associated with respiratory complaints. Our results indicate that the information provided by impedance measurements can be complimentary to that obtained by spirometric indices.

Adult↗
PubMed1992

Histamine challenge in young children using computerized lung sounds analysis.

The use of the histamine challenge test (HCT) for the diagnosis of asthma has so far been limited to older children who can perform spirometry consistently. Recently, wheeze detection by tracheal auscultation with analog recording into a tape recorder has been utilized in young children in place of spirometry. Wheezing can also be identified using computerized lung sounds analysis (LSA) by a typical pattern on spectral analysis. Our aim was to develop a practical computerized system in which the response to histamine could be identified in an objective manner and documented on hard copy. Lung sounds were recorded with a Hewlett-Packard HP 21050A contact sensor placed over the right upper anterior chest. Sounds were amplified, band-filtered (50 to 2,000 Hz), and digitized at a sampling rate of 5.5 kHz into a Macintosh SE computer, and spectral LSA was performed. To validate our method, six older children (ages 9 to 16 years) with mild or moderate asthma underwent HCT. The identification of typical wheezing pattern (discrete, high-amplitude power peaks) on LSA was compared to 20 percent fall in FEV1 (PC20) and symptoms (cough, wheeze, chest tightness). In five children, the histamine concentration required to produce the characteristic wheezing pattern on LSA was half that required to produce a 20 percent fall in FEV1. In the sixth patient, wheezing on LSA and PC20 occurred at the same histamine concentration. To determine the technique's applicability to young children, we then studied six young asthmatic children (age 2 to 5 years). All children showed the wheezing pattern at a histamine concentration of 25 percent or 50 percent (one or two steps prior) to that producing symptoms (cough, wheeze, chest tightness) or wheezing on tracheal auscultation. Six age- and sex-matched nonasthmatic children (control subjects) did not show this pattern on LSA and had no symptoms or tracheal wheeze with HCT. We describe a sensitive method enabling application of HCT to young children who are unable to perform spirometry. This method is as sensitive as, and often more sensitive than, conventional PC20 with spirometry or tracheal auscultation.

Adolescent↗
PubMed2004

Obstructive lung disease among the urban homeless.

STUDY OBJECTIVES: Homelessness is a growing problem in the United States that may significantly impair physical health. The homeless have a high prevalence of cigarette smoking, poor nutrition, and adverse environmental exposures, which could contribute to obstructive lung disease (OLD). Despite this risk, the prevalence of OLD among the homeless remains unknown. We aimed to systematically assess the prevalence of OLD among the urban homeless. DESIGN, SETTING, AND PARTICIPANTS: We conducted a cross-sectional study of the prevalence of OLD among homeless individuals in San Francisco. By random sampling, we recruited 68 adults living in one homeless shelter to participate in a structured interview survey and spirometry assessment. We used a multifaceted approach to assess OLD, including respiratory symptoms, self-reported physician diagnosis of asthma, chronic bronchitis, emphysema, or COPD, and spirometry (defined as FEV1 < 80% predicted and FEV1/FVC ratio < 0.70). RESULTS: Sixty-eight adults completed the survey, and 67 adults completed the spirometry. Homeless adults were likely to be homeless < 1 year and homeless for the first time. There was a high prevalence of cigarette smoking (75% ever smokers, 68% current smokers). The prevalence of symptoms suggestive of OLD was high, including cough (29%), wheezing (40%), chronic bronchitis symptoms (21%), and dyspnea on exertion (29%). A substantial proportion of homeless subjects indicated a prior diagnosis of asthma (24%), chronic bronchitis (19%), and COPD (4%). Based on spirometry, the prevalence of OLD was 15% (95% confidence interval, 8 to 26%), which was more than double the expected prevalence in the general US population. CONCLUSIONS: As OLD is a leading cause of death in the United States, it is important to identify it early for treatment. Homeless individuals have a higher-than-expected prevalence of OLD. Public health interventions should target the homeless population for prevention and treatment of OLD.

Adult↗
PubMed1982

The UCLA population studies of chronic obstructive respiratory disease. 5. Agreement and disagreement of tests in identifying abnormal lung function.

The relative sensitivity and specificity of symptoms, spirometry, the flow-volume (FV) curve, the single-breath nitrogen test (SBNT), and specific airway conductance (SGaw) were estimated by cross comparison of these tests with the FEV1/FVC ratio and other tests in 1,201 residents of Los Angeles. Spirometry and the flow-volume curve were estimated to be the most sensitive, yet reasonably specific composite measures, and FEV1/FVC and V75 to be the most sensitive individual indices. Among current smokers, FEV1/FVC was more frequently abnormal (23 percent) than FEF25-75% (16 percent), showed higher concordance with an abnormal FEF25-75% (88 percent), and identified a greater percentage of individuals as abnormal when the FEF25-75% was normal (9 percent) than vice versa. SGaw and SBNT showed a poor concordance with FEV1/FVC and identified more individuals as abnormal who had a normal FEV1/FVC. Although the proportion of current smokers with productive cough was relatively high (26 percent), none of the function tests showed a reasonable concordance with this symptom. These findings suggest that: 1) spirometry, the flow-volume curve, V75 and FEV1/FVC are relatively sensitive and specific indicators of respiratory impairment; 2) spirometry and the FV curve provide similar but not completely overlapping information; 3) SGaw and SBNT yield different (or less specific) information than the other tests; and 4) effects of cigarette smoking identified by productive cough are different from those identified by other tests.

Adult↗
PubMed1975

[Comparison in patients with chronic bronchitis of the data offered by the output-volume loop and the transfer capacity of CO].

The present study concerns 78 cases of chronic bronchitis (mean age : 55,3 years) submitted to a complete enough functional respiratory study (spirometry, RV, blood gases) and distributed into three groups:--Group I: 78 cases, mean age : 55 years. All these patients were submitted to spirometry, blood gases determination and determination of the transfer capacity of CO (by making use of the method under single breath : 54 cases,--or the method with steady state : 24 cases).--Group II : 15 cases, mean age 54 years. All these patients were submitted to spirometry, blood gases determination, determination of the transfer capacity of CO with the method under single breath and to a determination of the V (60-70%) CT output on the output-volume loop.--Group III : 13 cases, mean age 53,9 years. All these patients were submitted to spirometry, blood gases determination, determination of the transfer capacity of CO with the method under steady state and a determination of the V (60-70%) CT output on the output-volume loop. The comparison of the data and the study of the eventual correlations between the various parameters determined suggests that the determination of the V (60-70 %) CT on the V/V loop is a more reliable parameter of the obstructive ventilatory syndrome than the determination of the disorders in the transfer capacity of CO. This latter method of study under steady state appears often modified when there exists an alveolar (as yet mentioned by other authors); however, this is not the case when the test is performed under single breath. In the detection of chronic bronchitis, the informations obtained with the determination of the V (60-70 %) CT output appear thus to assume a great value, but these results necessitate to be verified in a greater number of patients.

Bronchitis↗
PubMed1995

The use of objective measures of asthma severity in primary care: a report from ASPN.

BACKGROUND: The rising incidence of and mortality from asthma have prompted the development of practice guidelines for diagnosis and management. A cornerstone of these guidelines is the use of objective measures of asthma severity: spirometry or peak expiratory flow rates. We studied the extent to which primary care clinicians used objective measures of asthma severity. METHODS: Practices affiliated with the Ambulatory Sentinel Practice Network in the United States and Canada collected data on 490 asthma-related encounters involving 439 patients. For each encounter, the practice recorded the availability of the results of spirometry, peak expiratory flow rates, oxygenation (arterial blood gas or pulse oximetry), and chest radiograph to the clinician. RESULTS: Objective data about asthma severity were infrequently available to ASPN clinicians at the time of the encounter. In 67.8% of encounters, there was no current or past spirometry result, in 55.1% there was no current or past peak flow measurement, and in 74.3% there was no current or past determination of oxygenation. Chest radiographs, on the other hand, were available for most (64.7%) patients. The lack of objective measures was not related to lack of access to the relevant technologies. Most practices noted easy access to spirometry (72.2% of practices), peak flow meters (72.2%), oxygenation determination (61.1%), and radiography (83.3%). CONCLUSIONS: In this study, most primary care clinicians did not have objective data about the severity of their patients' asthma at the time of the encounter. This relative lack of objective data was not explained by lack of access to the relevant technology for determining severity. It may instead reflect the opinion of primary care physicians that such information is not necessary in the care of these patients.

Adolescent↗
PubMed1997

The acting site of bronchodilator, methacholine and upper respiratory tract infection on airways.

BACKGROUND: The bronchodilator agent is an important drug for patients with chronic obstructive pulmonary disease. Methacholine is a popular bronchial provocative agent. Although the major acting site of bronchodilator, methacholine and upper respiratory tract infection (URI) has been evaluated in some studies, the sites are still in debate. This study investigated the exact major acting sites. METHODS: Thirty subjects participated in this study. Episodes of URI were identified by a questionnaire. Spirometry, bronchial provocative test with methacholine, and five minutes' inhalation of a mixture of helium and oxygen (HeO2) were done on day one. Spirometry, bronchodilator test, with five minutes' inhalation of HeO2 and expiratory flow-volume (F-V) curve were performed on another day. The change of pre- and post-HeO2 VEMax50 was calculated as delta VEMax50. The pre- and post-bronchodilator VEMax50 and delta VEMax50 differences were counted to decide the acting site of bronchodilator. After bronchial provocative test with methacholine, the volume of isoflow (VisoV) was estimated from pre- and post-HeO2 F-V curve to establish the acting site of methacholine. RESULTS: This study indicated that small airways are the major acting sites of bronchodilators, large airways are the major acting sites of methacholine and URI affects mainly large airways. Although airway hyperresponsiveness is more severe in subjects with positive methacholine response, the recovery of spirometry values is not significantly different between the methacholine-positive and -negative groups. CONCLUSIONS: The major acting sites of the bronchodilator, methacholine, and URI are the small, large and large airways, respectively. Bronchial hyperresponsiveness is not a cause of quick restoration of spirometry values in subjects with positive methacholine response.

Adolescent↗
PubMed2004

Airway obstruction is common but unsuspected in patients admitted to a general medicine service.

STUDY OBJECTIVES: Obstructive lung disease (OLD) is a worldwide health problem with major impact on health and economics, and can be easily diagnosed by spirometry. Recent expert panels have emphasized the underreporting and underrecognition of this condition. The goal of this study was to measure the prevalence of airway obstruction in patients admitted to an urban teaching hospital and to determine the frequency of a diagnosis of OLD at admission or discharge. METHODS: Prospective study of 153 patients admitted to a medicine service at the Johns Hopkins Hospital in Baltimore, MD. Patients completed bedside spirometry and a questionnaire. RESULTS: Twenty-six percent of patients had airway obstruction (FEV(1)/FVC < 70%), including 6% with a very severe airway obstruction (FEV(1) < 30% predicted). At hospital discharge, a clinical diagnosis of OLD was present in only 33% of patients with mild airway obstruction (FEV(1) > 70% predicted), 30% of patients with moderate airway obstruction (FEV(1) 50 to 69% predicted), 33% of patients with severe airway obstruction (FEV(1) 30 to 49% predicted), and 89% of patients with very severe airway obstruction (FEV(1) < 30% predicted). Only 40% of patients with airway obstruction were receiving bronchodilator medication at hospital admission or discharge. CONCLUSIONS: Airway obstruction is common in hospitalized patients and is usually undiagnosed and untreated. Spirometry may be a useful component of the examination of hospitalized medical patients to identify OLD.

Comorbidity↗
PubMed1999

Isocyanate medical surveillance: respiratory referrals from a foam manufacturing plant over a five-year period.

This study assesses the causes of medical surveillance changes leading to specialist referral from one isocyanate-using company where 39 workers (about 20% of all employees) were referred to a hospital occupational clinic during a 5-year period for concerns regarding their surveillance respiratory questionnaire or spirometry results. The respiratory assessment determined that the questionnaire had detected 5 workers with non-occupational asthma, 2 with possible occupational asthma (OA), and 1 with subsequently confirmed OA, while no additional asthmatics were detected by spirometry without questionnaire findings. The surveillance questionnaire in this study was sensitive but not specific (no additional compensation claims for OA were made during this time period): workplace spirometry, however, did not add to the detection rate of asthma.

Adult↗
PubMed1998

A placebo-controlled, double-blind trial of the long-term effects of albuterol administration in patients with cystic fibrosis.

This placebo-controlled study was designed to confirm a previously performed open label study that showed significant improvement in spirometry on maintenance therapy with albuterol for 1 year. In a double-blind, cross-over trial, albuterol (by metered dose inhaler) 180 microg b.i.d. or placebo were given for 6 months each. Spirometry was monitored at the start, and 3 and 6 months following initiation of each arm of the study. Peak expiratory flow rate (PEFR) was measured twice daily at home before and after study drug administration. Only patients with clinically detectable lung disease were enrolled. Twenty-one patients finished the study. All spirometric tests showed a significant improvement from start to end of the 6 month treatment with albuterol; there was no significant change on placebo. Forced vital capacity improved by 8.2% and forced expiratory volume in 1 s by 12.1% on albuterol therapy. Nevertheless, there was no significant difference between change on albuterol and change on placebo. Home measurements of PEFR showed a significant improvement of 4.7% on albuterol and a non-significant change of 2.0% on placebo from the first to the last week of treatment. None of the long-term improvements (spirometry or home PEFR) correlated with mean daily bronchodilation. For albuterol, the number of days of hospitalization was less than half that for patients on placebo (1.0/patient on albuterol versus 2.6 on placebo), but this did not reach statistical significance. These results suggest a beneficial effect from maintenance therapy with albuterol. Bronchodilation alone probably cannot explain the long-term benefits of albuterol, and other mechanisms may play a role. The lack of significant difference between change on albuterol and change on placebo is probably due to too small a number of patients in this study and lack of statistical power.

Administration, Inhalation↗
PubMed2000

Correlation between reversibility of airway obstruction and exhaled nitric oxide levels in children with stable bronchial asthma.

Recent trials measuring exhaled nitric oxide (eNO) concentrations have suggested that it may be a useful measure of ongoing airway inflammation in patients with asthma. The purpose of this study was to examine the relationship between eNO levels and baseline as well as postbronchodilator spirometry, a measurement commonly used in the clinical setting to determine the severity of asthma and as a guide to therapeutic decisions. Forty-nine patients between the ages of 5-16 years with physician-diagnosed asthma who attended the pediatric pulmonary clinic for a routine asthma visit with spirometric evaluation were recruited for the study. eNO levels prior to spirometry were obtained before and after receiving inhaled beta(2) agonist. eNO samples were collected in impermeable bags (Tedlar) and assayed within 24 hr by chemiluminescence. Regression analysis was used to assess the relationships between pre- and postbronchodilator eNO and spirometric variables. eNO was also compared in patients receiving and not receiving inhaled corticosteroids (ICS), as well as those whose therapy had been increased after evaluation by a pediatric pulmonologist or allergist. We found no significant difference between the levels of eNO before and after inhalation of beta(2) agonist (P = 0.60 paired t-test). Positive correlation was found between eNO vs. percentage change in FEV(1) (r = 0.35, P = 0.01) and percentage change in FEF(25-75% )(r = 0.29, P = 0.04). A negative correlation was found between prebronchodilator FEV(1) and eNO (r = -0.29, P = 0.03). Patients on ICS had lower mean eNO levels (29.9 vs. 47.6 parts per billion (ppb), P = 0.053) than those not receiving ICS. Patients whose ICS therapy was increased had higher mean eNO levels (47.2 vs. 26.9 ppb, P = 0.018) than those not having ICS therapy increased. We suggest that eNO levels could be a clinically useful measurement of asthma severity and could be used as an adjunct to spirometry to determine appropriate treatment plans. Longitudinal clinical trials are needed to determine if eNO can enhance therapeutic decisions for asthmatic children.

Adolescent↗
PubMed2003

Non-CF bronchiectasis: clinical and HRCT evaluation.

Childhood bronchiectasis not related to underlying disease is still common in some populations in affluent countries. The aims of the study were to: 1) describe demographics, 2) evaluate the effectiveness of routine investigations, and 3) determine the relationship between spirometry and radiology scoring systems, in children with chronic suppurative lung disease (CSLD) living in Central Australia. Data of children living in Central Australia aged </=15 years with noncystic fibrosis CSLD were identified over 2 years. Chest high-resolution computed tomography (HRCT) scans were interpreted by a pediatric radiologist and scored according to three systems. Sixty-five children were identified, resulting in a prevalence of at least 14.7/1,000 aboriginal children aged </=15 years. Comorbidities (most common: suppurative otitis media in >70%) and early hospitalisation for pneumonia were common (median age, 0.5 years). Previous admissions for pneumonia were almost universally present and significantly more common than bronchiolitis (95% CI for proportional difference, 0.4-0.51). Although the majority did not have a treatable underlying cause, investigations had significant impact on management in 12.3% of children. None of the chest HRCT scores related to any spirometry data. In conclusion, CSLD is unacceptably common in indigenous children of this region, commences early in life, and is associated with significant comorbidities. Spirometry data do not reflect the severity of lung disease in HRCT scans. While improvement in the living standards is of utmost importance, the medical management that includes thorough investigations of these children should not be neglected.

Adolescent↗
PubMed2003

Effects of respiratory timing and cheek support on resistance measurements, before and after bronchodilation in asthmatic children using the interrupter technique.

The interrupter technique (Rint) is a noninvasive method for assessing respiratory resistance. The aims of this study were to assess whether upper airway support affects the measurement of Rint, if inspiratory or expiratory Rint were most reproducible, and which method of assessing Rint correlated best with spirometry results and was the most sensitive for identifying bronchodilator response. Twenty-four asthmatic children with a mean age of 10.3 years (range, 7-16 years) were included in the study. Rint measurements were obtained in inspiration and expiration with cheeks supported and unsupported. Spirometry was then performed. Rint and spirometry measurements were repeated after the inhalation of 600 mcg of salbutamol. The mean Rint supported inspiratory (0.708 KPa/l/sec) and expiratory (0.729 KPa/l/sec) values were significantly higher than the unsupported values (inspiratory, 0.622 KPa/l/sec; expiratory, 0.584 KPa/l/sec), P < 0.05 and P < 0.001, respectively. The reproducibility of Rint was not different whether cheeks were supported or not, or whether the measurements were carried out during inspiration or expiration. Cheek support improved the correlation with all the lung function results, both in inspiratory and expiratory measurements. The best correlations, however, were found for the inspiratory supported Rint results. The most sensitive method to ascertain bronchodilator response (BD) was the inspiratory supported Rint measurement, as 83.3% of children were identified as having a positive response to bronchodilator therapy as defined by a reduction of twice the coefficient of variation of the measurement. In conclusion, cheek support increases Rint but does not impact on reproducibility, though it improves the correlation with spirometric indices. Rint with cheek support on inspiration correlates best with spirometric indices and appears to be the most sensitive measure of response to bronchodilators.

Adolescent↗
PubMedDate not supplied

Does the inclusion of wheeze detection as an outcome measure affect the interpretation of methacholine challenge tests? A study in workers at risk of occupational asthma.

Methacholine challenge testing (MCT) is widely used to assess airway hyperresponsiveness (AHR). Traditionally, a 20% or greater decline in forced expiratory volume in 1 (FEV(1)) is the primary outcome measure. We examined whether the inclusion of wheeze detection as outcome measure influenced the categorical interpretation of MCT in workers at risk of occupational asthma (OA). We examined 28 occupationally exposed smokers with asthma-like symptoms (SympAsth), 22 asymptomatic, occupationally exposed smokers (Symp0), and 30 nonexposed, asymptomatic controls (Ctrl). MCT was done using an abbreviated technique. Spirometry and tracheal wheezes were recorded using a computerized system. MCT was considered either positive or negative using three outcome measures separately: (1) > or = 20% fall in FEV(1) (MCT("FEV1")); (2) wheeze appearance (MCT("Wheeze")); and (3) whichever among the two was present (MCT("FEV1Wheeze")). The proportion of reactors in each group were, by outcome measure, as follows: MCT("FEV1"): Ctrl = 2 (6.7%), Symp0 = 6 (27.3%), SympAsth = l2 (42.8%) (chi(2) = 10.2; p = 0.006); MCT("Wheeze"): Ctrl = 1 (3.3%), Symp0 = 4 (18.2%), SympAsth = 13 (46.4%) (chi(2) = l5.7; p = 0.001); MCT("FEV1Wheeze") Ctrl = 2 (6.7%), Symp0 = 7 (31.8%), SympAsth = 18 (64.3%) (chi(2) = 21.5; p = 0.001). Overall, including wheeze detection increased the proportion of "reactors" detected by spirometry by 30% (27 reactors vs. 20). This increase reached 50% (18 vs. 12) among workers with asthma like symptoms. In summary, the inclusion of wheeze detection as outcome measure for MCT allowed the recognition as reactors of subjects that otherwise would be "missed" by spirometry. The resulting increase in the number of true positives improved the sensitivity of MCT to detect AHR in occupationally exposed workers at risk of occupational asthma.

Adult↗
PubMed2000

Reference values and prediction equations for FVC and FEV(1) in the Greek elderly.

Spirometry prediction equations obtained from middle-age adults, when extrapolated for the elderly, may lead to inaccurate interpretations. The purpose of this study was to determine prediction equations for forced vital capacity (FVC) and forced expiratory volume (FEV(1)) in the Greek elderly population. Spirometry prediction equations for normal FVC and FEV(1) have been derived from tests on 71 healthy persons (38 men, 33 women) aged older than 60 years (range, 65-85 years), nonsmokers, white race, urban population using techniques and equipment that meet American Thoracic Society recommendations. Regression analysis using age, height, and weight as independent variables was used to provide prediction equations and values for both sexes. The FVC age coefficient in this healthy group was about 47.19 mL/y for elderly men and 34.27 mL/y for elderly women, and the FEV(1) age coefficient was about 52.8 mL/y for elderly men and 46.4 mL/y for elderly women. Values from this study predicted equations were compared with those from some of the most commonly used sources of spirometry predicted equations. The FVC and FEV(1) predicted values were found to be of less mean square error than that of other compared studies. Higher correlation is between FVC and FEV(1) predicted values by the present model and FVC and FEV(1) observed values in both sexes. The higher correlation between FVC and FEV(1) predicted and observed from this study allows the use of our model for predicting in a rather reliable way the FVC and FEV(1) for elderly Greek individuals.

Aged↗
PubMed2000

Exposure and acute exposure-effects before and after modification of a contaminated humidification system in a synthetic-fibre plant.

OBJECTIVE: Follow-up study of exposure and acute exposure-effects after modification to steam humidification of a contaminated cold water system which had caused an outbreak of humidifier fever in a synthetic-fibre plant. METHODS: Before and after modification of the system aerobiological measurements were performed. Concentrations of fungi and bacteria, in colony forming units (cfu) per m3, were measured by stationary air sampling with an Andersen sampler. Endotoxin levels (pg/m3) were determined by Limulus Amoebocyte Lysate (LAL) assay in pooled dust from personal air sampling. An indication of exposure levels of oil-mist was obtained by monitoring with a direct reading optical photometer. Changes as acute exposure-effects in spirometry and white blood cell count, during an afternoon shift were compared in exposed and non-exposed workers before and after modification. RESULTS: Measured levels of fungi, total bacteria, Gram-negative bacteria and endotoxins both before and after modification were below levels which would be expected to be associated with the exposure-effects. However, after modification, we found that the statistically significant differences in levels of bacteria and endotoxins with a department without humidification no longer existed. Mean oil-mist concentrations were below 1 mg/m3, with short-time peak exposure during certain tasks of up to 5 mg/m3. Before modification, in exposed workers there was significantly more decline of spirometry, and more increase of white blood cell count during the first afternoon shift, compared with non-exposed workers. In exposed workers, the white blood cell count increase was positively associated with decline of spirometry. After modification, differences between exposed and non-exposed workers no longer existed. CONCLUSION: Follow-up investigation of acute exposure-effects demonstrated the effectiveness of remedial actions taken against a contaminated humidification system. Follow-up of exposure-effects in particular is recommended when there is doubt about the interpretation of exposure measurements.

Bacteria↗