[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.

[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.

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.

[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.

[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.

[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.

[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.

Pulmonary involvement in leptospirosis.

The objective of this study was to assess the incidence of pulmonary involvement in a cohort of 26 patients in whom a diagnosis of leptospirosis had been made. Seventeen of the 26 patients had respiratory symptoms. Of these 17 patients, 13 had radiographs showing pulmonary abnormality. The most frequent finding was a bilateral patchy alveolar-acinar pattern in six patients. Three patients developed acute respiratory distress syndrome and died due to multiorgan failure. Only cigarette smoking was significantly associated with respiratory involvement (odds ratio, 19.2; 95% CI, 1.7-250; P < 0.001). The results indicate that pulmonary manifestations are observed in a high percentage of patients with leptospirosis. Cigarette smoking is a risk factor for the development of pulmonary involvement in human leptospirosis.

[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.

Effects of air pollution and weather conditions on asthma exacerbation.

BACKGROUND: Meteorological conditions and a high concentration of air pollutants have been associated with increased respiratory morbidity. However, few studies have examined the association between asthma exacerbation and air pollution. OBJECTIVES: In the present study, the possible relationship of the concentration of black smoke and SO2 in the air, the local weather conditions and emergency room visits for asthma is investigated. METHODS: The weekly total of emergency room admissions for asthmatic adults during a 1-year period was recorded together with daily metereological conditions (average temperature, humidity, rainfall, wind speed and barometric pressure) and average weekly levels of daily pollutant concentrations (black smoke and SO2). The relationship was assessed by stepwise regression linear models and analysis of variance. The analysis took into account season and metereological variables. RESULTS: Both air pollutants correlated significantly with emergency room admissions for asthma (SO2 [r = 0. 32], black smoke [r = 0.35]); however, multiple regression analysis showed that black smoke was the only significant predictor of weekly visits. There were approximately 3.5 admissions a week per SD of change (34.6 microg.m-3). There were no significant correlations between weekly emergency room visits and the weather variables. Analysis of the data stratified by season and weather conditions demonstrated that the association of black smoke with asthma exacerbation was more pronounced in autumn (r = 0.67) or when temperatures were higher than average. CONCLUSION: In our city, a high concentration of certain air pollutants is indeed associated with an increase in the number of hospital emergency room admissions for asthma.

[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.