Dissociation of lung function, dyspnea ratings and pulmonary extension in bronchiectasis.

UNLABELLED: Bronchiectasis is a heterogeneous disease in terms of its clinical and functional presentation. Some isolated parameters have been used to assess the severity of bronchiectasis or its response to treatment. A study was undertaken to evaluate whether lung function, dyspnea and extension of the disease are separate entities in the impact of bronchiectasis upon patients using factor analysis. Patients with bronchiectasis diagnosed by high-resolution computed tomography (HRCT) and airflow obstruction defined by FEV1/FVC<70% were included. Data were collected relating to clinical history, three different clinical ratings of dyspnea (Medical Research Council (MRC), Borg scale and Basal Dyspnea Index), the extent of bronchiectasis and functional variables. A total of 81 patients (mean age (SD): 69.5 (8.7)) years were included. The degree of dyspnea (MRC) was 1.9 (0.8). Mean FEV1 was 1301 ml (56.9% pred.). Four factors were found that accounted for 84.1% of the total data variance. Factor 1 (45.6% of the data variance) included the three measurements of dyspnea. Factor 2 (16% variance) comprised airflow obstruction parameters (FEV1, FEV1/FVC and PEF). Factor 3 (13.8% variance) included RV/TLC and RV (lung hyperinflation). Factor 4 (8.6% variance) included bronchiectasis extent. Dyspnea was more closely correlated with lung hyperinflation (r:0.33-0.54) than with airflow obstruction parameters (r:0.17-0.26). CONCLUSIONS: Airflow obstruction, dyspnea, lung hyperinflation and the lung extent of the bronchiectasis are four independent entities in the impact of bronchiectasis upon patients.

[Can home prophylaxis for venous thromboembolism reduce mortality rates in patients with chronic obstructive pulmonary disease?]. / Puede reducir la mortalidad de los pacientes con EPOC la profilaxis domiciliaria de la enfermedad tromboembólica venosa?

OBJECTIVE: The incidence of venous thromboembolism (VTE) in patients with chronic obstructive pulmonary disease (COPD) ranges from 20% to 60% in different studies and the mortality rates are higher for patients with both conditions. Heparin prophylaxis is therefore usually prescribed for COPD patients who are hospitalized for exacerbation. Once their situation becomes stable, however, they are discharged to home without prophylaxis even though the low level of physical activity their disease allows continues to put them at risk for VTE. The aim of this study was to test the efficacy of home heparin prophylaxis on reducing the incidence of VTE and on the overall mortality rate in patients with severe COPD. PATIENTS AND METHODS: We conducted a prospective, randomized controlled trial of 87 patients with severe COPD who required home oxygen therapy (> or =18 h/d) and whose physical activity was highly restricted. A total of 44 patients received low molecular weight heparin (3500 IU/d of bemiparin) subcutaneously for 6 months. The outcome measures were incidence of VTE and mortality at 3 and 6 months. RESULTS: Four patients (9.1%) died in the heparin group and 9 (20.4%) died in the control group; the difference was not statistically significant (P=.23). VTE without pulmonary embolism developed in 1 patient (2%) in each group. Slight bleeding complications appeared in 9 patients (20.4%) in the heparin group and 1 patient (2.3%) in the control group, a difference that was statistically significant (P=.015). CONCLUSIONS: Home prophylaxis with heparin does not reduce the incidence of VTE or overall mortality in patients with severe COPD.

[Internal consistency and validity of the Spanish version of the St. George's respiratory questionnaire for use in patients with clinically stable bronchiectasis]. / Consistencia interna y validez de la versión española del St. George's Respiratory Questionnaire para su uso en pacientes afectados de bronquiectasias clínicamente estables.

OBJECTIVE: To analyze the reliability and validity of the St. George's Respiratory Questionnaire (SGRQ) for use in patients with clinically stable bronchiectasis. MATERIAL AND METHODS: The SGRQ (50 items on 3 scales--symptoms, activity, and impact) was administered to 102 patients (mean [SD] age, 69.5 [8.7] years; 63% men) with clinically stable bronchiectasis. Disease severity was classified according parameters such as airflow obstruction (forced expiratory volume in 1 second), colonization by Pseudomonas aeruginosa, extent of bronchiectasis, symptoms, daily quantity of sputum, and number of exacerbations. Internal consistency (Cronbach's alpha and correlation between items and between item and scale), concurrent validity (correlation between items and clinical variables), predictive validity (correlation between items and severity), and construct validity (factorial analysis of main components) were assessed. RESULTS: The internal consistency of the SGRQ was excellent (Cronbach's alpha between 0.81 and 0.87 for the different scales, and 0.90 for the overall score). Concurrent validity was high, as correlations between items and clinical variables were significant and followed the expected distribution. The SGRQ differentiated between degrees of disease severity, regardless of the clinical variable used. The factorial analysis showed a construct of 4 factors that were only moderately similar to the original structure of the questionnaire, due mainly to inclusion of a small number of questions with conditioned response and others with low discriminatory capacity. CONCLUSIONS: The SGRQ shows excellent concurrent and predictive internal consistency and validity, though restructuring of the original construct would be advisable before use in patients with stable bronchiectasis.

[Changes in spirometric parameters and arterial oxygen saturation during a mountain ascent to over 3000 meters]. / Cambios espirométricos y en la saturación arterial de oxígeno durante la ascensión a una montaña de más de 3.000 metros.

OBJECTIVE: To ascertain whether climbing a mountain over 3000 meters high produces any alterations in ventilation, whether such alterations are modified by acclimatization, and whether they correlate with changes in arterial oxygen saturation (SaO2) or the development of acute mountain sickness (AMS). SUBJECTS AND METHODS: The following parameters were measured in 8 unacclimatized mountaineers who climbed Aneto (3404 m) and spent 3 days at the summit: forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), airway response to inhaled terbutaline, SaO2, and the symptoms of AMS. RESULTS: At the summit, mean (SD) FEV1 declined by 12.3% (5.7%) and mean FVC by 7.6% (6.7%) while the ratio of FEV1 to FVC remained normal. The means for both parameters were higher on the following day. No airway response to bronchodilator treatment was observed. The restriction disappeared entirely on descent. At the peak, SaO2 increased progressively as the climbers became acclimatized. During the ascent, FEV1 correlated with SaO2 (r=0.79). One participant who suffered from AMS had a ratio of FEV1 to FVC less than 70% and the worst SaO2 during the 3 days on the summit. Obstruction preceded the AMS symptoms, did not respond to bronchodilator treatment, and disappeared when the climber descended. CONCLUSIONS: The mountaineers who climbed over 3000 meters presented restriction that correlated with hypoxemia. This restriction did not respond to bronchodilator treatment, improved with acclimatization, and disappeared on descent. One person with AMS presented obstruction that did not respond to terbutaline and disappeared on descent.

Screening of tuberculous pleural effusion by discriminant analysis.

SETTING: Pneumology Department of a 635-bed acute-care teaching hospital in Valencia, Spain. OBJECTIVE: To assess the value of discriminant analysis as a method of optimizing the discriminant power of routine radiographic features and a panel of laboratory parameters including biochemical analyses of pleural fluid for differentiation between tuberculous and non-tuberculous pleural effusion. DESIGN: A series of 47 variables were retrospectively obtained from the medical records of 189 patients with exudative pleural effusion (tuberculous pleurisy, n = 78; non-tuberculous pleurisy, n = 111). A backward elimination method was applied until the best discriminant function was found. RESULTS: The most powerful predictor of tuberculous pleural effusion was a function that consisted of four variables, as follows: age (years); tuberculin skin test (mm of induration at 48 hours); white blood cell count (cells/mm3); and bloodstained exudate (coded as yes = 1, no = 2). This function showed a sensitivity of 90%, specificity of 87%, positive predictive value of 83%, negative predictive value of 92%, and was able to give an 88% rate of correct classification. CONCLUSION: The calculated discriminant function based on the patient's age, peripheral leukocyte count, tuberculin skin test and blood in the exudate is a simple, rapid and inexpensive method for screening tuberculous etiology in patients with pleural effusion.

Screening of malignant pleural effusion by discriminant analysis.

OBJECTIVE: To assess the value of discriminant analysis as a method of optimizing the discriminant power of routine parameters in differentiating between malignant and non-malignant pleural effusions. METHODS: Retrospective review of the medical records of 245 patients with exudative pleural effusion. RESULTS: The most powerful predictor of the malignant etiology of pleural effusion was a function that consisted of seven variables: age (years); effusion volume (coded as up to one third = 1, up to two thirds = 2, massive = 3); sedimentation rate (mm/h); monocyte count in the peripheral blood (cells/mm3); bloodstained exudate (coded as yes = 1, no = 2); and glucose (mg/dL) and iron (microg/dL) concentration in pleural fluid. This function showed a sensitivity of 77%, specificity of 85%, positive predictive value (PPV) of 76%, negative predictive value (NPV) of 86%, and was able to give an 82% rate of correct classification. In patients aged 50 years or younger, the NPV ranged between 91 and 98%, whereas in those older than 60 years, the PPV was 89%. CONCLUSION: The calculated discriminant function is a simple, rapid, and inexpensive method for screening patients with pleural effusion for malignant etiology.

Maximal static respiratory pressures in children and adolescents.

This study was designed to establish reference values of maximal static respiratory pressures in children and adolescents in our community, and compare them with previous studies. Participants were recruited from three schools (randomly chosen from those located in the metropolitan area of the city of Valencia) after appropriate consent. None of the participants had a previous history of pulmonary, cardiac, and/or skeletal abnormalities, and all of them had normal spirometry. Forced spirometry (Spirotrac III, Vitalograph) and maximal inspiratory (P(ImaxRV)) and expiratory (P(EmaxTLC)) pressure values (Sibelmed 163) were obtained by the same investigator, following national guidelines (SEPAR 1990).We studied 392 subjects (185 males, 207 females) whose ages ranged from 8-17 years. The reproducibility of measurements was investigated in a subgroup of 88 participants (randomly selected from the total sample, and stratified for age and gender) by means of the intraclass correlation coefficient (P(EmaxTLC), 0.98; P(ImaxRV), 0.95). P(EmaxTLC) and P(ImaxRV) values were significantly different between males and females (P < 0.0001) and were normally distributed. A stepwise, linear multiple regression model was built in each gender group (male/female) for the prediction of P(ImaxRV) and P(EmaxTLC) values. Independent variables (weight, height, and age) and their potential interactions were forced to enter the model in order to maximize the square of the multiple correlation coefficient of the resultant equation. This model turned out to be applicable (homoscedasticity, independence, and normality requirements) for P(ImaxRV) (in males and females) and for P(EmaxTLC) (in males but not in females). Variables included in the model were age and the product of weight and height. Their predictive power ranged between 0.21-0.51. In conclusion, P(ImaxRV) and P(EmaxTLC) values increase with age from 8 until 17 years. In all age groups, values were higher in males than in females. Weight, height, and age are included in the predictive equations for P(ImaxRV) (in males and females) and P(EmaxTLC) (in males). Their predictive value is similar to that reported by other authors and ranges between 0.21-0.51. This model is not suitable for the prediction of P(EmaxTLC) in females; the observed mean and range should be used instead.

Respiratory disorders in common variable immunodeficiency.

Common variable immunodeficiency (CVID) is a heterogeneous immunodeficiency syndrome characterized by hypogammaglobulinemia, recurrent bacterial infections, and various immunologic abnormalities. The clinical presentation is generally that of recurrent pyogenic sinopulmonary infections. Our objectives were to study the prevalence of lung involvement and the response to intravenous immunoglobulin replacement therapy in 19 patients with CVID. Nineteen patients (12 men) with a mean age (SD) of 33.1 (17.1) years had a previous diagnosis of CVID and were treated with intravenous immunoglobulin replacement. All patients underwent complete pulmonary function tests and high-resolution computed tomography (HRCT) examination. Bronchiectasis was diagnosed in 11 (58%) patients and eight (42%) were multi-lobar bronchiectasis. Chronic airflow limitation (CAL) was present in 10 (53%) patients and a restrictive pattern was seen in one case. Eleven patients (58%) presented a decrease in single-breath carbon monoxide diffusing capacity of the lung (DL(CO)). Before intravenous immunoglobulin replacement therapy (INIRT), 84% of patients had suffered from at least one episode of pneumonia. Episodes of lower respiratory tract infection decreased significantly from 0.28 per patient and year before replacement therapy to 0.16 per patient and year after treatment. The mean duration of replacement therapy was 7.5 years. In conclusion lung involvement was frequent in patients with CVID. Long-term administration of intravenous gammaglobulin resulted in a substantial reduction of pneumonic episodes.

[Usefulness of the IUATLD respiratory symptoms questionnaire for the differential diagnosis of bronchial asthma and chronic bronchitis]. / Utilidad del cuestionario de síntomas respiratorios IUATLD para el diagnóstico diferencial del asma bronquial y la bronquitis crónica.

Our objective was to determine the diagnostic value of the questionnaire devised by the International Union against Tuberculosis and Lung Disease (IUATLD) for distinguishing between bronchial asthma and chronic bronchitis. We therefore compared clinical diagnoses established independently by two pneumologists for 211 patients to the patients' responses to the IUATLD questionnaire. The questions were analyzed for their ability to discriminate using the responses as independent variables and the diagnosis as the dependent variable. The individual predictive capacity of each question and the discriminating functions that identified the best clusters of questions were calculated using bayesian analysis. Finally, we compared IUATLD results to tests that assessed lung function (spirometry), obstruction variability (bronchodilator test, peak flow, bronchial challenge test), atopy (prick test, serum IgE), and clinical and biological markers (eosinophilia). The questionnaire correctly diagnosed 91% of the patients and a cluster of five questions registered a sensitivity of 85.6%, specificity of 91.4%, a positive predictive value of 93.1% and a negative predictive value of 82.2%, thus proving superior to the other tests. These results, along with the ease of administering the questionnaire allows us to consider the IUATLD instrument to be a good tool for the differential diagnosis of bronchial asthma and chronic bronchitis.

[Identification of new diagnostic categories within bronchial asthma and COPD. A review of traditional classifications]. / Identificación de nuevas categorías diagnósticas dentro del asma bronquial y la EPOC. Una revisión de las clasificaciones tradicionales.

The overlapping of function test results and clinical symptoms of airway diseases makes it difficult to differentiate sub-categories of diagnoses. Our aim was to identify "occult" categories within the traditional diagnostic labels for bronchial asthma and chronic bronchitis. We studied 211 patients with those diagnoses by lung function testing (spirometry), variability of obstruction (bronchodilator test, peak expiratory flow, and bronchial challenge testing), atopy (prick test, total serum IgE), biological parameters (eosinophil count), frequency of smoking and symptoms. Multivariant analysis was used to group the data (Quick Cluster) and reclassify the subjects based on the selected parametric clusters with factorial analysis of the principal components. This analysis allowed us to identify four types of patients by diagnosis (atopic asthma, asthmatic bronchitis, simple chronic bronchitis and hyperresponsive chronic bronchitis) which we consider to represent the diagnostic categories with clinical relevance and which would overlap and be partially overshadowed by the diagnoses of bronchial asthma and chronic bronchitis.

[Development of a new instrument for the evaluation of the desire for information and decision making in patients with asthma]. / Desarrollo de un nuevo instrumento para evaluar el deseo de información y la toma de decisiones de los pacientes con asma.

The aim of this study was to design a new instrument for determining the asthmatic's desire for information as well as his or her active search for it and ability to make decisions about his or her disease. A questionnaire titled Information and Decisions in Asthma (IDEA) was compiled by writing a list of preliminary questions related to each of the three aforementioned aspects. The list was revised and the length reduced vased on the responses and signs of comprehension from a first group of patients. The draft under study then consisted of 36 items in the following subscales: desire for information (DI), active search for information (AS) and decision making (DM) in three scenarios describing stable asthma, mild exacerbation and severe exacerbation. The questionnaire was then administered to 120 adult asthmatic of both sexes whose disease was stable and at different levels of severity. Cronbach alpha coefficients were satisfactory for DI and AS (0.86 and 0.77, respectively) and did not improve with the elimination of any items. Factorial analysis overall for DI and AS (total explained variance = 44.16%) detected two correlated factors (r = 0.34, p < 0.01). The DM subscale contained problems of internal consistency which were solved by removing five items. Factorial analysis for DM then revealed a tri-factorial structure in which each factor adjusted well to each of the scenarios. Analysis of these results indicates that the final version of the IDEA shows very acceptable internal consistency and validity, suggesting that it could be used to assess the aspects it is intended to measure.

[Construct validity of the Information and Decisions in Asthma questionnaire]. / Validez de constructo del cuestionario Información y Decisiones en el Asma.

OBJECTIVE: To establish the construct validity of a new scale based on the Information and Decisions in Asthma (IDEA) questionnaire, which was designed to detect an asthmatic's desire to receive information, active seeking out of information and ability to make decisions about his or her disease. METHODOLOGY: The IDEA questionnaire containing 31 items in three subscales: desire for information (DI), seeking out information (SI) and decision making (DM) was answered by 120 asthmatic adults (54 men and 66 women; 86 intrinsic and 44 extrinsic) in stable condition and with varying levels of severity of disease. After interviews to take down medical histories (age of onset, years of evolution, visits to the emergency room within the past year), educational level and economic status, all patients completed a battery of tests assessing the following: quality of life (QL), alexithymia (TAS-20), health opinions (HOS), state-trait anxiety (STAI-E/R), asthma symptoms control (ASC), health locus control (HLC), somatosensory amplification (SAS) and personality (NEO-PI). RESULTS: Although most patients expressed interest in obtaining information, their level of active seeking and decision making were much lower. DI and SI were associated with higher educational levels and economic status, whereas DM correlated with the presence of atopy, age (young patients), sex (women) and few visits to the emergency room. Multiple regression analysis of psychological variables showed that DI and SI were accounted for mainly by the absence of alexithymia, whereas DM depended on an individual's behavioral involvement with his or her disease. CONCLUSION: The global analysis of these results indicate that the IDEA questionnaire has satisfactory construct validity, given that its dimensions are associated with sociodemographic and psychological characteristics that can be expected given its conceptual content.

[Contribution of the bronchodilator test in the study of bronchial reversibility]. / Aportación del test broncodilatador al estudio de la reversibilidad bronquial.

This study sought to determine the optimum dose of salbutamol and the most useful method for calculating bronchodilator response. Changes in FEV1 after inhalation of 3 doses of salbutamol 200 micrograms were measured in 150 adults (64 healthy individuals, 18 with rhinitis, 53 with asthma and 15 with bronchitis). Bronchodilator response was calculated by 4 different methods: absolute value, percent change form baseline FEV1, from theoretical value and from weighted value. Significant differences in response were observed among the various methods of assessment. Patients with asthma and bronchitis showed the greatest response to salbutamol and their results were used to analyze the usefulness of the reversibility indices. The index that discriminated best was percent of theoretical reference value, although the sensitivity of this index was low and specificity varied from 0.73 to 1 depending on the cut-off point used. This index of reversibility along with absolute value proved to be the least dependent on baseline FEV1. We conclude that bronchodilator response is best assessed by calculating changes in FEV1 in relation to a theoretical reference value. This bronchomotor test, however, does not adequately assess patients with asthma and bronchitis.

[Relationship between peak expiratory flow and clinical exploration and arterial gas analysis in assessing the severity of an asthma attack]. / Relación del flujo espiratorio máximo con la exploración clínica y la gasometría arterial en la valoración de gravedad de la crisis asmática.

Protocols for treating acute asthma presently rely on measurement of peak expiratory flow (PEF) to orient treatment and evaluate progress. Other clinical or functional parameters have also been considered for use in the assessment of severity of attack. In order to investigate the usefulness of these criteria we analyzed their relation to degree of air flow obstruction expressed by PEF in a sample of 48 asthmatics who came to the emergency room for treatment of disease exacerbation, excluding 6 who presented imminent risk of death at the time of admission. Among the clinical parameters analyzed, only presentation of cyanosis or diaphoresis was related to degree of obstruction. The pattern of accessory muscle use or vital signs such as heart, breathing rate or blood pressure were similar in patients with (PEF < 50%) or without (PEF > 50%) severe exacerbation. Among gasometric readings only PaO2 was significantly lower in patients with PEF < 50% and we were able to identify a cutoff point useful as a screen for respiratory insufficiency: when the initial PEF was above 50% of theoretical value, no patient had PaO2 < 60 mmHg. We conclude that: 1) clinical parameters do not always reflect severity of attack established by degree of air flow obstruction, and 2) PEF > 50% at the start of asthmatic exacerbation allows respiratory insufficiency to be ruled out, making performance of gasometric measurement unnecessary.

[Characteristics of tuberculosis in a tertiary hospital during the years 1993-1996. Influence of the coinfection with HIV]. / Características de la tuberculosis en un hospital terciario durante los años 1993-1996. Influencia de la coinfección por el VIH.

To assess and compare epidemiological factors, clinical and radiological signs, laboratory results and drug resistance in patients with tuberculosis (TB) with and without AIDS. Retrospective study of TB diagnosed bacteriologically between January 1993 and December 1996 at Hospital Universitario La Fe. Annual rates were 41.7, 47.1, 34.6 and 43.8 per 100,000 inhabitants in 1993 to 1996, respectively. AIDS was present in 22.4%. TB was pulmonary in 87% and 49.4% in patients without and with AIDS, respectively. Incidence was higher in the 25 to 34 age range. Prior contact with TB patients was established in 19.2% of cases. Pulmonary TB in patients with AIDS presented with normal lung X-rays in 30.1%; 16.2% of these had positive sputum cultures. Pulmonary cavitation was evident in 32.6% of TB patients without AIDS and 6.8% of those with AIDS. Pulmonary TB was diagnosed by culture of sputum taken at the time of admission in 25.9% of non AIDS patients and in 12.4% of patients with AIDS. Extrapulmonary TB was diagnosed by culture in most cases. Such forms predominated among TB plus AIDS patients, with most cases being ganglial and urogenital. Overall drug resistance was 8.3% (7.4% non-AIDS/11.5% AIDS). Primary resistance (PR) was 6.3% and 7.1%, PR to hydrazides was 5% and 5.4%, and secondary resistance was 32.4% and 33.3%. Drug resistance in non-AIDS and AIDS patients, was associated with a history of TB and past treatment (p < 0.009), prior contact with TB patients (p < 0.004) and pulmonary cavitatin (p < 0.02). TB with AIDS tends to occur in a younger population, is often extrapulmonary or with atypical lung involvement. Drug resistance is similar in patients with and without AIDS.

[How can we assess the perception of induced dyspnea in chronic obstructive pulmonary disease?]. / Cómo valorar la percepción de la disnea inducida en la EPOC?

OBJECTIVE: To evaluate various methods for studying the perception of dyspnea in chronic obstructive pulmonary disease (COPD) using a new parameter, the change in Borg scale rating, and others already in use: the linear regression slope and the application of Stevens' law to the response perception curve--ie change in forced expiratory volume in 1 second (delta FEV1)--change in dyspnea (delta dyspnea). PATIENTS AND METHODS: A bronchial challenge test was performed on 70 patients with stable COPD and no contraindications for performing the test (European Respiratory Society criteria), during which dyspnea was measured (Borg scale) after each nebulization. Perception was analyzed using: a) the linear regression slope of delta FEV1 plotted against (delta dyspnea); b) the exponent n of Stevens' law (psi=k phi n, in which psi is delta dyspnea and phi is delta FEV1, with perception being poor when n<1 and good when n>1), and c) change in Borg: difference between dyspnea when FEV1 has fallen 20% and dyspnea after saline inhalation. Subjects were classified according to the slope and change in Borg as hypoperceivers, normal perceivers, or hyperperceivers. These 2 methods of classification were compared using the kappa statistic. RESULTS: According to the exponent n, all patients were hypoperceivers (n<1). According to the slope, there were 33 hypoperceivers, 28 normal perceivers, and 9 hyperperceivers. The change in Borg classified 37 subjects as hypoperceivers, 23 as normal perceivers, and 10 as hyperperceivers. All except 5 subjects were classified in the same way by the slope and the change in Borg (kappa=0.88). In most of the 5 cases of discrepancy, the slope classified subjects as better perceivers. CONCLUSIONS: The n exponent is not valid for evaluating the perception of dyspnea induced by a bronchial challenge test in COPD. Change in Borg is at least as useful as the slope for evaluating perception of dyspnea. The percentage of patients with this disease who are hyperperceivers is high.

[Cough-inducing capsaicin challenge test in a healthy population]. / Test de provocación tusígena con capsaicina: resultados en una población sana.

OBJECTIVE: Cough-inducing agents are used to study the cough reflex in both pharmacological and physiological research. Clinical use of cough challenge testing as a tool in diagnostic algorithms has been limited by the lack of either uniform methodology or reference values for healthy subjects. The objective of this study was to determine the cough threshold for capsaicin in a sample of healthy subjects, while also evaluating the influence of age, sex and smoking. We also assessed the reliability and repeatability of the test. MATERIAL AND METHODS: Ninety-two healthy subjects were enrolled and given a capsaicin challenge test using concentrations from 0.49 to 500mg. The concentrations of capsaicin that triggered two and five coughs, C2 and C5 respectively, were recorded. The test was repeated three days later in a sub-sample of 30 subjects. RESULTS: No subject showed clinical or functional signs of bronchoconstriction. The mean values obtained for the study population were log C2:1.5 +/- 0.69 mM. and log C5: 2.1 +/- 0.4 microM. The geometric means were 31.6 and 134.8 microM for C2 and C5, respectively. No significant differences were found for sex or smoking; however age was significantly related to log C5 (r: -0.27, p < 0.05). Repeatability of the capsaicin test was high, with intra-class correlation coefficients and 95% confidence intervals of 0.75 (0.53-0.87) and 0.88 (0.76-0.97)for C2 and C5, respectively. CONCLUSION: The capsaicin challenge test was safe and easy to administer,gave reproducible results and allowed us to obtain reference values for a healthy population in our community.

[Coexistence of bronchogenic carcinoma and active pulmonary tuberculosis]. / Coexistencia de carcinoma broncogénico y tuberculosis pulmonar activa.

We describe 9 patients with coincident active tuberculosis of the lung and bronchogenic carcinoma who were all diagnosed within a 5-year period. All were men, with a mean age of 55 +/- 10 years. The principal symptom was toxic syndrome lasting 1-3 months and the most common X-ray sign was alveolar consolidation. Analysis of tissue samples revealed squamous carcinoma (4 cases), adenocarcinoma (4 cases, one of which was bronchioloalveolar) and non-small cell carcinoma (1 case). Tumoral stage was often advanced: IV (44%) and III (33%). The tuberculosis bacillus was isolated in sputum (100%) and in bronchial aspirate (50%); no in vitro resistance was observed. Three patients were treated with radical surgery and three with radiotherapy. Average survival was 3 months in this series.

[Alveolar-arterial gradient of O2 in COPD with hypercapnia]. / Gradiente alveolo-arterial de O2 en la EPOC con hipercapnia.

OBJECTIVE: This study was conducted to assess whether or not calculation of the alveolar-arterial oxygen tension difference (AaPO2) from arterial blood gas measurements, breathing air, is useful to discriminate patients with hypecapnia associated with obstructive lung disease. PATIENTS AND METHODS: The effect of different values for the respiratory exchange ratio (R) was also analyzed. We calculated the AaPO2 in 45 patients with chronic airway obstruction and hypercapnia (PaCO2 in 45 mmHg) and hemodynamic stability using the standard alveolar gas equation, PAO2 = PIO2 - PACO2 [FIO2 + (1-FIO2)/R], with R assumed to vary from 0.6 to 1.1 and the simplified alveolar gas equation, PAO2 = PIO2 - PACO2/R, with R assumed to be 0.8. It was considered that a patient was correctly classified when the calculated AaPO2 was greater than predicted AaPO2. RESULTS: When the simplified alveolar gas equation was used, 9 (20%) of 45 patients were misclassified, whereas using the standard equation with R assumed to be 0.8, 41 (91%) of 45 patients were correctly classified. Modification of the value of R only allowed improving the classification of two further patients. CONCLUSIONS: We conclude that calculation of the AaPO2 using the standard equation and R = 0.8 can be used to classify hypercapnic COPD patients. This laboratory parameter is of sufficient discriminant value to be used for clinical purposes.