Profile of patients treated with omalizumab in routine clinical practice in Spain.

BACKGROUND: Omalizumab is indicated in patients with severe allergic asthma not controlled by high-dose inhaled glucocorticoids and long-acting beta-agonists. Few data are available on the profile of patients treated with this drug in routine clinical practice in Spain. OBJECTIVE: To describe the profile of patients with severe allergic asthma treated with omalizumab and the course of the disease after a period of treatment. METHODS: Retrospective, multicentre study, recording the data on patients of either sex and ≥12 years with uncontrolled severe allergic asthma, previously treated with omalizumab. Data were evaluated in relation to pulmonary function, symptoms, quality of life, and concomitant anti-asthma treatment before the prescription of omalizumab and at the time of the study visit. RESULTS: 214 patients were evaluable (mean age=48.2±17.7 years; mean age at the time of diagnosis=26.6±16.5 years). 90.7% had experienced exacerbations the year before receiving omalizumab, and the mean total IgE level was 273±205.4IU/ml. The mean monthly dose was 380.5±185.4mg. Compared with the baseline situation, differences were observed after treatment with omalizumab in mean FEV1 (62.7±15.9% vs. 70.8±18.7%), in the proportion of patients requiring oral corticosteroids (47.7% vs. 14.0%), and in the ACQ and AQLQ scores. 32.7% of the patients received doses not recommended by the Summary of Product Characteristics (SPC). CONCLUSIONS: Profile of asthmatic patients treated with omalizumab predominantly corresponds to uncontrolled severe asthma cases, in accordance with SPC's indications. The results of the study suggest a favourable clinical course similar to that observed in other studies.

Factors affecting quality of life of asthma patients in Spain: the importance of patient education.

OBJECTIVES: Assessment of demographic and clinical factors that have an impact on the quality of life (QoL) of patients with asthma in Spain. PATIENTS AND METHODS: Multicenter, prospective, observational, cohort study, conducted in 40 Spanish Pneumology Units during a 12-month period. Data on sociodemographic, clinical variables, asthma treatment and QoL were collected in a case report form. RESULTS: 536 patients (64.6% women, mean age: 54) were recruited. Reported QoL was better for patients from Northern and Central Spain as compared with those from the South and the East (p<0.001), students and employed patients as compared with housewives and unemployed (p<0.01), for those who had received asthma information (p<0.01), for those with milder daytime symptoms (p<0.01) and for patients with higher level of education (p<0.05). CONCLUSIONS: Among the factors that have a significant effect on patients' QoL only symptom control and patient education on asthma control are modifiable. Therefore, all the strategies should be tailored to improve such factors when managing asthma patients.

[Electrical impedance tomography in acute lung injury]. / Tomografía de impedancia eléctrica en la lesión pulmonar aguda.

Electrical impedance tomography has been described as a new method of monitoring critically ill patients on mechanical ventilation. It has recently gained special interest because of its applicability for monitoring ventilation and pulmonary perfusion. Its bedside and continuous implementation, and the fact that it is a non-ionizing and non-invasive technique, makes it an extremely attractive measurement tool. Likewise, given its ability to assess the regional characteristics of lung structure, it could be considered an ideal monitoring tool in the heterogeneous lung with acute lung injury. This review explains the physical concept of bioimpedance and its clinical application, and summarizes the scientific evidence published to date with regard to the implementation of electrical impedance tomography as a method for monitoring ventilation and perfusion, mainly in the patient with acute lung injury, and other possible applications of the technique in the critically ill patient. The review also summarizes the limitations of the technique and its potential areas of future development.

Airway inflammation in the elite athlete and type of sport.

BACKGROUND: The prevalence of asthma and bronchial hyper-responsiveness is greater in elite athletes than in the general population, and its association with mild airway inflammation has recently been reported. OBJECTIVE: To study the relationship between the type of sport practised at the highest levels of competition (on land or in water) and sputum induction cell counts in a group of healthy people and people with asthma. MATERIAL AND METHODS: In total, 50 athletes were enrolled. Medical history, results of methacholine challenge tests and sputum induced by hypertonic saline were analysed RESULTS: Full results were available for 43 athletes, who were classified by asthma diagnosis and type of sport (land or water sports). Nineteen were healthy (10 land and 9 water athletes) and 24 had asthma (13 land and 11 water athletes). Although the eosinophil counts of healthy people and people with asthma were significantly different (mean difference 3.1%, 95% CI 0.4 to 6.2, p = 0.008), analysis of variance showed no effect on eosinophil count for either diagnosis of asthma or type of sport. However, an effect was found for neutrophil counts (analysis of variance: F = 2.87, p = 0.04). There was also a significant correlation between neutrophil counts and both duration of training and bronchial hyper-responsiveness among athletes exposed to water (Spearman's rank correlations, 0.36 and 0.47, p = 0.04 and 0.04, respectively). CONCLUSIONS: Elite athletes who practice water sports have mild neutrophilic inflammation, whether or not asthma is present, related to the degree of bronchial hyper-reactivity and the duration of training in pool water.

Carbon dioxide rebreathing in non-invasive ventilation. Analysis of masks, expiratory ports and ventilatory modes.

BACKGROUND AND AIM: Carbon dioxide (CO2) rebreathing is a complication of non-invasive ventilation (NIV). Our objectives were to evaluate the ability of masks with exhaust vents (EV) to avoid rebreathing while using positive pressure (PP) NIV with different levels of expiratory pressure (EPAP). Concerning volume-cycled NIV, we aimed to determine whether cylindrical spacers located in the circuit generate rebreathing. MATERIALS AND METHODS: 5 healthy volunteers were evaluated. Bi-level PP was used with 3 nasal and 2 facial masks with and without EV. Spacers of increasing volume attached to nasal hermetic masks were evaluated with volume NIV. Inspired CO2 fraction was analyzed. RESULTS: Rebreathing was zero with all nasal masks and EPAP levels. Using facial masks 1 volunteer showed rebreathing. There was no rebreathing while using all the spacers. CONCLUSIONS: In healthy volunteers, nasal and facial masks with EV prevent rebreathing. In addition, the use of spacers did not generate this undesirable phenomenon.

Inspired oxygen fraction achieved with a portable ventilator: determinant factors.

INTRODUCTION: Non-invasive positive pressure ventilation (NIPPV) is an effective treatment in respiratory failure. Continuous positive pressure (CPAP) may also be useful in acute hypoxaemic patients. Supplementary oxygen is usually necessary in both systems. However, the inspired oxygen fraction (FiO2) delivered by a NIV portable ventilator is unknown. The main objectives of this study were to establish the maximal FiO2 that could be achieved by these devices and to analyse the FiO2 determinant factors. METHOD: Ten healthy volunteers were evaluated using a BiPAP ST30 ventilator (Respironics, USA) with a single-limb circuit, expiratory port and nasal mask (Respironics, USA). Oxygen (15 L/min) was administered at two connection points (proximal and distal). Each volunteer carried out a NIPPV (inspiratory pressure 20 cmH2O [1.95 kPa]-expiratory pressure 8 cmH2O [0.78 kPa]) and a CPAP (10 cmH2O [0.981 kPa]) session. FiO2 was analysed by a probe located in the mask. Minute volume (MV) was measured using a pneumotachograph. RESULTS: Maximal FiO2 was obtained with CPAP and distal oxygen connection point (67.39 +/- 15.39%). NIPPV achieved higher MV than CPAP. FiO2 was inversely correlated with MV. CONCLUSIONS: FiO2 obtained while using a NIPPV portable ventilator depends on the ventilatory assistant mode, the oxygen connection point and the MV reached.

[The relationship between lung function and health-related quality of life in patients with generalized myasthenia gravis]. / Relación entre función pulmonar y calidad de vida relacionada con la salud en la miastenia gravis generalizada.

OBJECTIVE: To study lung function abnormalities and health-related quality of life (HRQL) in a group of patients diagnosed with generalized myasthenia gravis, and to analyze the relationship between these 2 sets of variables. PATIENTS AND METHODS: In a prospective study of 20 patients diagnosed with generalized myasthenia gravis, the following parameters were measured: spirometry, static lung volumes, breathing pattern, maximal respiratory pressures, and maximum voluntary ventilation. HRQL was assessed using the 36-item short form general health questionnaire (SF-36). RESULTS: The mean (SD) age of the patients was 64 (11) years. Patients were classified into 2 groups depending on whether they had IIa (12 patients) or IIb (8 patients) type disease. A small decrease in total lung capacity (86%) and slight reductions in maximal inspiratory pressure (88%) and maximum voluntary ventilation (63% in group IIb) were observed. The HRQL domains most affected were those related to physical activity and self-perceived health status in all groups, although women were more affected. The scores relating to vitality and physical activity were found to be significantly associated with forced vital capacity and lung volumes. Tidal volume was associated with maximal inspiratory and expiratory pressures, inspiratory capacity, and maximum voluntary ventilation. The respiratory rate to tidal volume ratio was inversely associated with the first three of these variables. CONCLUSIONS: A very slight restrictive pattern and a reduction in inspiratory muscle strength were observed. The HRQL domains most affected were those related to physical activity and the patients' self-perceived health status. The weakness of the respiratory muscles contributes to the abnormalities observed in lung function and to the deterioration of health-related quality of life.

[Markers of airway remodeling in induced sputum from healthy smokers]. / Marcadores de remodelado bronquial en el esputo inducido de fumadores sanos.

OBJECTIVE: Airway remodeling in chronic obstructive pulmonary disease (COPD) has been linked to the equilibrium between matrix metalloproteinase (MMP) 9 and its inhibitor, tissue inhibitor of metalloproteinase (TIMP) 1. However, that equilibrium has not been analyzed in healthy smokers. The aim of this study was to assess the equilibrium between MMP-9 and TIMP-1 in induced sputum from healthy smokers, healthy nonsmokers (controls), and patients with COPD. PATIENTS AND METHODS: Samples of induced sputum were obtained from 35 individuals: 12 healthy smokers, 12 controls, and 11 patients with COPD. In each sample, a differential cell count was performed and enzyme-linked immunosorbent assays were used to analyze the concentrations of MMP-9 (total and active fraction) and TIMP-1. RESULTS: Compared with controls, healthy smokers were found to have a higher mean (SD) concentration of total MMP-9 (273 [277] ng/mL vs 128 [146] ng/mL) and a higher ratio of total MMP-9 to TIMP-1 (0.16 [0.14] vs 0.08 [0.06]). However, the ratio of active MMP-9 to TIMP-1 was similar in the 2 groups. Samples from patients with COPD had the highest concentrations of total MMP-9 (477 [262] ng/mL) and active MMP-9 (178 [126] ng/mL) and the lowest concentrations of TIMP-1 (1.044 [1.036] microg/mL). When all groups were considered together, there was an inverse relationship between the MMP-9/TIMP-1 ratio and the forced expiratory volume in the first second (FEV1). The relationship between the active MMP-9/TIMP-1 ratio and FEV1 was even stronger, and the relation of both ratios with FEV1 became stronger still when smoking was considered. CONCLUSIONS: Healthy smokers had a higher concentration of total MMP-9 and that concentration was correlated with their exposure to tobacco smoke. Maintenance of the active MMP-9/TIMP-1 ratio in healthy smokers may explain the absence of progressive airway obstruction. Measurement of active MMP-9 concentration could be useful for assessment of airway remodeling.

[Expansion of primary bronchial epithelial cell cultures]. / Método para amplificar cultivos primarios de células epiteliales bronquiales.

OBJECTIVE: Cell cultures provide a good model for studying lung diseases but they are difficult to reproduce and the number of cells obtained is limited. The aim of this study was to develop a way to increase the production of human bronchial epithelial cells (BEC) in primary cultures. MATERIAL AND METHODS: A total of 12 samples (9 from surgical specimens and 3 from endoscopic biopsies) were processed on plates coated with type I collagen with growth medium supplemented for BEC. When cell proliferation started, the explants were removed for successive subculturing. The remaining cells were left to proliferate and were trypsinized after 50% confluence. We recorded the number of cells obtained, cell viability, and the percentage positive for cytokeratin 7. RESULTS: The total number of cells obtained by this method was 3-fold the number of human BEC obtained with simple primary cultures. The maximum number of subcultures was 5, mean (SD) cell viability was 91.9% (11.7%), and the percentage of cells positive for cytokeratin 7 was 30.71% (10.68%). CONCLUSIONS: The described method for expanding primary BEC cultures increases cell production.

[Exhaled breath condensate: standardized collection of samples from healthy volunteers]. / Condensado de aire espirado: estandarización de la recogida de muestras en voluntarios sanos.

Expired breath condensate collection is a noninvasive technique for obtaining a sample in which to analyze substances that reflect the functional status of the lung and other tissues. Twenty healthy volunteers provided 3 expired breath samples: the second was collected 20 minutes after the first and the third 48 hours after the first. The air and condensate volumes were assessed. The mean (SD) volume of condensate in exhaled air over a period of 15 minutes was 1.8 (0.5) mL (95% confidence interval [CI], 1.5-2 mL) and the coefficient of variation was 29%. Analysis of variance in the 3 samples demonstrated no significant differences. The mean volume of air inhaled over 15 minutes was 119 (25) L (95% CI, 112-125 L). These results indicate that it takes at least 15 minutes and the inhalation of some 120 L of air to collect a condensate volume that exceeds 1.5 mL, sufficient to allow distribution in aliquots to analyze fundamental physical and chemical properties (conductivity, pH) and certain relevant biomarkers.

[Bronchial exudate of serum proteins during asthma attack]. / Exudado bronquial de proteínas séricas en las crisis de asma.

OBJECTIVE: Although altered vascular permeability and edema of the bronchial mucosa are associated with asthma attack, their influence on its severity remains unknown. We address this issue by comparing relative indices for the concentration of albumin (RIAlb) and alpha2-macroglobulin (RIalpha2M) in induced sputum and peripheral blood from patients with exacerbated asthma, patients with stable asthma, and control subjects. PATIENTS AND METHODS: Forty-six volunteers participated in the study: 14 with exacerbated asthma (forced expiratory volume in the first second [FEV1] 74.3% [SD, 20.8%] of reference), 23 with stable asthma (FEV1 93.6% [7.5%]), and 9 controls (FEV1 101.1% [9.9%]). The concentrations of albumin and alpha2-macroglobulin were quantified by immunoturbidimetry and immunonephelometry, respectively. The relative index was then calculated by dividing the concentration in sputum supernatant by the concentration in peripheral blood. RESULTS: The mean RIAlb was 1.2 (1.1) in the control group, 2.9 (3.1) in the stable asthma group, and 6.0 (6.7) in the exacerbated asthma group. The RIalpha2M values were 11.7 (10.9), 11.9 (14.7), and 3.2 (3.8) for the control group and stable and exacerbated asthma groups, respectively. The increases in the RIAlb values between all groups, and the decrease in the RIalpha2M value between the exacerbated asthma and control groups were statistically significant (P<.05). The percentage of neutrophils, but not of eosinophils, in sputum was correlated with the RIAlb (r=0.39; P=.008) but not the RIalpha2M (r=-0.035; P=.82). FEV1 displayed an inverse relationship with the RIAlb (r=-0.43; P=.009) but not with the RIalpha2M (r=-0.206; P=.24). No correlation was found between oxyhemoglobin saturation and either the RIAlb (r=-0.33; P=.19) or the RIalpha2M (r=-0.12; P=.84). CONCLUSIONS: Vascular permeability is altered during asthma exacerbations and appears to be correlated with the presence of neutrophils and the degree of bronchial obstruction.

Airflow obstruction case finding in community-pharmacies: a novel strategy to reduce COPD underdiagnosis.

BACKGROUND: Community pharmacies (CP) have access to subjects at high-risk of suffering Chronic Obstructive Pulmonary Disease (COPD). We investigated if a COPD case finding program in CP could be a new strategy to reduce COPD underdiagnosis. METHODS: Prospective, cross-sectional, descriptive, uncontrolled, remotely supported study in 100 CP in Barcelona, Spain. Pharmacists were trained in a four-day workshop on spirometry and COPD, and each was provided with a spirometer for 12 weeks. The program included questionnaires and forced spirometry measurements, whose quality was controlled and monitored by web-assistance. FINDINGS: Overall 2295 (73.5%), of 3121 CP customers invited to participate in the program accepted, and 1.456 (63.4%) were identified as "high risk" for COPD using the GOLD questionnaire. Only 33 could not conduct spirometry, and a pre-bronchodilator airflow limitation (FEV1/FVC ratio <0.7) was confirmed in 282 (19.8%); 244 of these were referred to their primary care (PC) physician for further diagnostic and therapeutic work-up, but only 39 of them (16%) fed-back this information to the pharmacist. Clinically acceptable quality spirometries (grade A or B) were obtained in 69.4% of the cases. CONCLUSION: This study shows that adequately trained and supported community pharmacists can effectively identify individuals at high risk of having COPD and can thus contribute to ameliorate underdiagnosis in this disease. Links between PC and CP should be improved to achieve a useful program.

Measurement of maximal static respiratory pressures at the mouth with different air leaks.

The effect of two different circuit leaks on the measurement of maximal static inspiratory and expiratory pressures at the mouth (Pimax, Pemax) was assessed in 70 patients with respiratory disease. Patients were divided into three groups with similar anthropometric and spirometric characteristics. The first group (30 patients) had their Pmax measured with a leak of 2.0 mm internal diameter (ID) and 37 mm length (as proposed by T. Ringqvist) and repeated with a second leak of 1.0 mm ID and 15 mm length (as recommended by J. L. Clausen). The two measurements were done in random order. Measurements for the other two groups (20 patients each) were taken with one or another, the two leaks randomly alternated with no leak. Pimax measurements obtained with Ringqvist's leak were 17 percent (p less than 0.005) lower than those with Clausen's leak and 22 percent (p less than 0.005) lower than those with no leak. Pemax measurements performed with Ringqvist's leak in place were 11 percent (p less than 0.005) lower than those with Clausen's leak and 11 percent (p less than 0.005) lower than those obtained with no leak. The comparison between Clausen's leak and no leak showed no statistically significant difference. We conclude that whenever the effect of pressure generated in the mouth is to be avoided in the measurement of respiratory Pmax, a leak of the size proposed by Ringqvist is to be preferred.

Mild exacerbations and eosinophilic inflammation in patients with stable, well-controlled asthma after 1 year of follow-up.

OBJECTIVES: To determine the time to exacerbation and probability of a mild exacerbation of asthma, and the impact of eosinophilic inflammation on these parameters in patients with stable, well-controlled asthma. PATIENTS AND METHODS: A cohort of 31 patients with stable, well-controlled asthma receiving inhaled steroid treatment regularly were followed up for 1 year or until a mild exacerbation occurred. Mild exacerbation was defined as symptoms of asthma lasting > 48 h with a fall in peak expiratory flow > 20%. FEV(1), provocative concentration of methacholine causing a 20% fall in FEV(1), eosinophil count, and eosinophilic cationic protein (ECP) levels in blood and in sputum were measured at the first visit and every 2 months. RESULTS: At baseline, the mean (SD) eosinophil count was 0.39 x 10(9)/L (0.21 x 10(9)/L) in blood and 13% (14%) in sputum; ECP was 30 microg/L (28 microg/L) in blood and 75 microg/L (85 microg/L) in sputum. Thirteen subjects experienced a mild exacerbation during the 1-year follow-up period. The mean time to mild exacerbation was 293 days (95% confidence interval [CI], 248 to 337 days), and the cumulative probability of not experiencing a mild exacerbation in 1 year was 49% (95% CI, 39 to 59%). An increased risk of mild exacerbation was associated with blood eosinophil count > 0.4 x 10(9)/L (relative risk 4.5; 95% CI of relative risk, 1.8 to 38.0), blood ECP > 20 microg/L (relative risk, 2.1; 95% CI of relative risk, 1.0 to 9.2), and sputum ECP > 40 microg/L (relative risk, 2.5; 95% CI of relative risk, 1.2 to 11.2), but was unassociated with other variables. CONCLUSIONS: Patient with stable, well-controlled asthma are at risk of mild exacerbation during 1 year of follow-up despite regular inhaled steroid treatment. Eosinophilic inflammation expressed as eosinophil count and ECP is associated with higher risk of mild exacerbation.

Pain during arterial puncture.

STUDY OBJECTIVE: To quantify the level of pain reported by patients during arterial puncture with or without local anesthesia, and to compare the results with levels reported for venous puncture. DESIGN: Double-blind study of puncture with and without local anesthesia. SETTING: Pulmonary function laboratory, department of pneumology. PATIENTS: We studied 270 consecutive patients undergoing arterial puncture divided into two groups. In group A (n = 210), we assessed level of pain with and without local anesthesia and with placebo. In group B (n = 60), we compared pain of arterial and venous puncture. INTERVENTIONS: The arterial puncture was performed in the radial artery; venous puncture was in the median basilic vein. MEASUREMENTS AND RESULTS: The pain was quantified on a visual analog scale (10 cm). Mean level of pain for all arterial punctures without anesthesia or placebo was slight to moderate (3.01 +/- 1.94 cm). Subcutaneous anesthetic infiltration before arterial puncture significantly reduced pain by more than 50%, to 1.50 +/- 1.54 cm, a level that was significantly lower than the pain level reported after conventional venous puncture (1.80 +/- 1.10 cm). The pain reported by patients who received no anesthesia was not significantly different (p = 0.45) from that perceived by those who received subcutaneous infiltration of saline solution (placebo). CONCLUSIONS: Arterial puncture with prior infiltration of local anesthetic is the least painful procedure among those studied. Use of local anesthesia is indicated whenever conventional arterial puncture is required.

Long-term effects of outpatient rehabilitation of COPD: A randomized trial.

OBJECTIVE: To examine the short- and long-term effects of an outpatient pulmonary rehabilitation program for COPD patients on dyspnea, exercise, health-related quality of life, and hospitalization rate. SETTING: Secondary-care respiratory clinic in Barcelona. METHODS: We conducted a randomized controlled trial with blinding of outcome assessment and follow-up at 3, 6, 9, 12, 18, and 24 months. Sixty patients with moderate to severe COPD (age 65 +/- 7 years; FEV(1) 35 +/- 14%) were recruited. Thirty patients randomized to rehabilitation received 3 months of outpatient breathing retraining and chest physiotherapy, 3 months of daily supervised exercise, and 6 months of weekly supervised breathing exercises. Thirty patients randomized to the control group received standard care. RESULTS: We found significant differences between groups in perception of dyspnea (p < 0.0001), in 6-min walking test distance (p < 0.0001), and in day-to-day dyspnea, fatigue, and emotional function measured by the Chronic Respiratory Questionnaire (p < 0. 01). The improvements were evident at the third month and continued with somewhat diminished magnitude in the second year of follow-up. The PR group experienced a significant (p < 0.0001) reduction in exacerbations, but not the number of hospitalizations. The number of patients needed to treat to achieve significant benefit in health-related quality of life for a 2-year period was approximately three. CONCLUSION: Outpatient rehabilitation programs can achieve worthwhile benefits that persist for a period of 2 years.

Expiratory flow limitation during exercise in competition cyclists.

In some trained athletes, maximal exercise ventilation is believed to be constrained by expiratory flow limitation (FL). Using the negative expiratory pressure method, we assessed whether FL was reached during a progressive maximal exercise test in 10 male competition cyclists. The cyclists reached an average maximal O2 consumption of 72 ml. kg-1. min-1 (range: 67-82 ml. kg-1. min-1) and ventilation of 147 l/min (range: 122-180 l/min) (88% of preexercise maximal voluntary ventilation in 15 s). In nine subjects, FL was absent at all levels of exercise (i.e., expiratory flow increased with negative expiratory pressure over the entire tidal volume range). One subject, the oldest in the group, exhibited FL during peak exercise. The group end-expiratory lung volume (EELV) decreased during light-to-moderate exercise by 13% (range: 5-33%) of forced vital capacity but increased as maximal exercise was approached. EELV at peak exercise and at rest were not significantly different. The end-inspiratory lung volume increased progressively throughout the exercise test. The conclusions reached are as follows: 1) most well-trained young cyclists do not reach FL even during maximal exercise, and, hence, mechanical ventilatory constraint does not limit their aerobic exercise capacity, and 2) in absence of FL, EELV decreases initially but increases during heavy exercise.

Prediction equations for plethysmographic lung volumes.

Due to the lack of information of reference values for plethysmographic lung volumes, standardized measurements were carried out on a selected sample of 482 healthy non-smoking volunteers (300 men and 182 women), aged 20-70 years, living in the Barcelona area (Spain). Prediction equations using age, height and body surface area (BSA) as covariates were calculated for the subdivisions of lung volumes [TLC, IC, EVC, FRC, RV and RV/TLC (%)], separately for both sexes. Simple linear equations predicted lung volumes as well as more complex equational models. BSA correction was useful for FRC but not for the other parameters. Our predicted FRC was up to 10% higher (mean 256 ml) than the FRC estimated by other studies using gas dilution techniques, but showed an acceptable agreement with the plethysmographic measurements carried out in an independent sample of 94 healthy non-smokers (42 men and 52 women) from Barcelona using different equipment. The present study provides an internally consistent set of prediction equations for static lung volumes. Differences in predicted FRC between the present study and other reference values obtained using gas dilution measurements should be attributed to the method of measurement.

Lack of effects of moderate-high altitude upon lung function in healthy middle-aged volunteers.

This study investigates the effects of moderate-high altitude on lung function and exercise performance in 46 volunteers (19 females, 27 males), with a mean age of 42.4 +/- 1.4 years (+/- SEM) and varying smoking and exercise habits, who were not previously acclimatized. Measures obtained in the base camp (1140 m) and at altitude (2630 m), in random order, included forced spirometry, maximal voluntary ventilation, maximal inspiratory and expiratory pressures, arterial oxygen saturation and capillary lactate concentration after a standardized exercise test. The smoking history, Fagerström test and degree of habitual physical activity were also recorded for each participant. The percentage of smokers was similar in males (19%) and females (21%) (P = n.s.). Mean habitual physical activity index was 8.2 +/- 0.2 (range, 5.88-11.63). At the base camp, all lung function variables were within the normal range. Lactate concentration after exercise averaged 3.7 +/- 0.3 mm l-1. No significant change was observed at altitude, except for a higher heart rate and a lower arterial oxygen saturation (SaO2) (both at rest and after inspiratory manoeuvres). The smoking history and the degree of physical activity did not influence lung function or exercise performance at altitude. The results of this study show that in middle-aged, healthy, not particularly well-trained individuals, lung function is not significantly altered by moderate-high altitude, despite the absence of any acclimatization period and independent of their smoking history and previous exercise habits.

Assessment of chlorine exposure in swimmers during training.

The presence of a high prevalence of bronchial hyperresponsiveness and asthma-like symptoms in swimmers has been recently reported. Chlorine, a strong oxidizing agent, is an important toxic gas that the swimmer can breath during swimming. Measurements of the chlorine concentration at the breathing level (< 10 cm) were obtained randomly during five nonconsecutive days in four different swimming pool enclosures. The mean level in all the swimming pools was 0.42 +/- 0.24 mg.m-3, far below the threshold limited value (TLV) of 1.45 mg.m-3 for the work places for a day of work (8 h). The TLV could be reached and even exceeded if we consider the total amount of chlorine that a swimmer inhales in a daily training session of 2 h (4-6 g) compared with a worker during 8 h at the TLV (4-7 g). Low correlation was observed with the number of swimmers in the swimming pool during the measurements (0.446) and other variables as the water surface area of the pool, volume of the enclosure, and the chlorine-addition system in the swimming pool. A low turnover rate in the air with an increase of chlorine levels through the day (P < 0.05) was observed in all pools. The concentration of chlorine in the microenvironment where the swimmer is breathing is below the TLV concentration limit, but nevertheless results in a high total volume of chlorine inhaled by the swimmers in a given practice session. The possible role of chlorine in producing respiratory symptoms in swimmers needs further investigation.