R. Álvarez-Sala

A bibliometric evaluation of European Union research of the respiratory system from 1987–1998

This study analyses the evolution of the bibliometric indicators of productivity and repercussion of European Union (EU) research into the respiratory system during the period from 1987-1998, describing the geographical distribution. Using MedLine, a selection was made of those articles by EU authors published between 1987-1998 in 38 respiratory system journals (classification from the Institute for Scientific Information). The journals, country of origin, number of articles and the relation to socioeconomic data, productivity index, visibility index, expected impact factor (EIF) and relative impact factor (RIF) were all analysed. The number of EU publications in respiratory system journals experienced an exponential increase, going from 606 articles (14.3% of world production) in 1987, to 2,325 (33.2%) in 1998. During this same period, the EIF increased from 1,258 to 2,111. The greatest gross productivities were those of the UK, France, Italy and Germany, although when corrected for number of inhabitants, Sweden, the Netherlands, Belgium and Denmark headed the list. The countries with the greatest mean EIF were the Netherlands, the UK, Spain and Belgium. In conclusion, productivity and repercussions of European Union research of the respiratory system experienced an important increase during this period.

Evolución de la producción científica española en revistas internacionales de sistema respiratorio de 1987 a 1998

Fundamento En los ultimos anos, el area del sistema respiratorio ha adquirido gran relevancia clinica por la prevalencia de sus enfermedades y por los recursos sanitarios que consume. Los objetivos de este trabajo fueron analizar la evolucion de la produccion y repercusion de la actividad cientifica espanola en el area de sistema respiratorio durante el periodo 1987-1998 y valorar la participacion de las distintas comunidades autonomas. Metodologia Se seleccionaron los articulos publicados durante el periodo 1987-1998 en las 38 revistas internacionales del area de respiratorio de mayor visibilidad a traves del sistema MedLine, delimitando la produccion espanola. Los articulos se clasificaron por revistas de publicacion, tipo de documento y especialidad y procedencia geografica e institucional del primer autor. Se calcularon los indicadores bibliometricos de produccion y de repercusion. Resultados El numero de documentos se octuplico entre 1987 y 1998. En porcentaje, paso del 0,66% al 1,49% de la produccion mundial. No obstante, el patron de crecimiento de la produccion cientifica espanola en respiratorio durante estos anos fue lineal. Los indicadores de repercusion experimentaron un incremento paralelo, alcanzando un factor de impacto esperado de 2,206 en 1998. En un 42% de los documentos, el primer firmante era neumologo. Entre las instituciones productoras, se aprecio una hegemonia de los hospitales. Las comunidades autonomas con mayor productividad fueron Cataluna, Cantabria y Madrid. La repercusion mas elevada correspondio a Baleares y Cataluna. Conclusiones La productividad y la repercusion de la investigacion espanola en el area del sistema respiratorio experimento un importante incremento durante el periodo 1987-1998.

Breathing pattern and central ventilatory drive in mild and moderate generalised myasthenia gravis.

BACKGROUND--Myasthenia gravis is a specific autoimmune disease characterised by weakness and fatigue. Respiratory muscle weakness has been studied using the determination of maximal respiratory pressures, but the response of respiratory centres is not well characterised. This study was undertaken to determine the breathing pattern and the central ventilatory drive in patients with mild and moderate generalised myasthenia gravis. METHODS--Twenty four patients with myasthenia gravis were studied, divided into two groups. Group 1 included 13 subjects (eight women and five men aged 23-64) with mild generalised myasthenia gravis, and group 2 was composed of 15 patients (11 women and four men aged 23-69) with moderate generalised myasthenia gravis. A control group comprised 15 healthy persons with a similar age and sex distribution. Spirometric measurements and maximal respiratory pressures were performed under basal conditions in all subjects, and the rate and depth of breathing and the inspiratory occlusion pressure in the mouth in the first 0.1 second (P0.1) were measured. RESULTS--No difference was detected for parameters of breathing pattern between patients in group 1 and control subjects, although P0.1 was higher in those in group 1. Subjects in group 2 had a lower tidal ventilation, shorter inspiratory time, and a higher frequency with a higher P0.1 than control subjects. CONCLUSIONS--Mild myasthenia gravis causes increased neuromuscular drive with a normal breathing pattern. Moderate myasthenia gravis is characterised by a more rapid shallow breathing pattern.

Prescripción electrónica asistida como nueva tecnología para la seguridad del paciente hospitalizado

Concern about patient safety is a priority in the quality policy of health systems. In the pharmacotherapeutic process, from prescription to administration of drugs, failures that cause unwanted effects in patients may occur. This is especially common in patients with multiple pathologies and polypharmacy, common in medical specialities services. To analyze and identify the causes that trigger medical errors is essential to prevent their occurrence. In this context, computerized physician order entry appear as an attractive tool for ensuring patients safety.

EPOC y estado nutricional

Las alteraciones nutricionales, entendidas como perdida de peso o desnutricion, son una complicacion muy frecuente en los pacientes con enfermedad pulmonar obstructiva cronica (EPOC) y afectan principalmente a su capacidad funcional y calidad de vida, ademas de constituir un indicador pronostico de morbilidad y mortalidad independientes. Los factores que contribuyen a la desnutricion son multiples; entre ellos cabe mencionar el aumento del gasto energetico en reposo, el descenso de la ingesta, el efecto de determinados farmacos y, quiza el mas importante, una elevada respuesta inflamatoria sistemica. En este articulo se pretende revisar los aspectos mas importantes sobre la prevalencia, etiopatogenia y efectos de la desnutricion en la EPOC, ademas de discutir los parametros de valoracion nutricional mas adecuados en la practica clinica diaria y la estrategia para que estos pacientes mantengan un correcto estado nutricional.

Comparison of helium dilution and plethysmographic lung volumes in pregnant women

The multibreath helium equilibration method is the technique recommended for routine measurement of static lung volumes in normal subjects. However, pregnancy could be an exception to this general rule, due to airway closure during the second half of gestation. The aim of this study was to compare the measurements of lung volumes by plethysmography and helium dilution during pregnancy. Twenty three healthy women were studied at 12, 24 and 36 weeks of pregnancy, and 4 months postpartum. Total lung capacity (TLC), functional residual capacity (FRC) and residual volume (RV) were measured by multibreath helium equilibration (TLCHe, FRCHe and RVHe) and by plethysmography (TLCbox, FRCbox and RVbox). Only at 36 weeks were there differences between the two methods. RVbox was significantly larger than RVHe (1.01+/-0.18 vs 0.77+/-0.21 L; p<0.001). FRCbox was larger than FRCHe (1.95+/-0.32 vs 1.60+/-0.32 L; p<0.001) and TLCbox was larger than TLCHe (4.83+/-0.52 vs 4.45+/-0.51 L; p<0.05). The 95% limits of agreement for differences between lung volumes measured by the two techniques (helium dilution - plethysmography) at 36 weeks were: -0.42 to -0.06 L for RV; -0.54 to -0.17 L for FRC; and -0.66 to -0.11 L for TLC. We conclude that using the multibreath helium equilibration method to measure lung volumes in at-term pregnant women results in underestimation of functional residual capacity and total lung capacity.

Dynamic Hyperinflation, Arterial Blood Oxygen, and Airway Oxidative Stress in Stable Patients With COPD

BACKGROUND There is considerable evidence that oxidative stress is increased in patients with COPD, although little information is available about its relationship with the structural and functional alterations produced by COPD. In this study, we evaluated the relationship between 8-isoprostane in exhaled breath condensate (EBC) of stable patients with COPD and the main parameters of the disease (such as dyspnea), stages of severity, lung parenchyma densities, lung function impairment, and exercise tolerance in order to identify the predictors of airway oxidative stress. METHODS In a cross-sectional study, we included 76 men with moderate to very severe COPD. 8-Isoprostane levels in EBC were measured by enzyme immunoassay. Regional lung densities were measured by lung densitometry with high-resolution CT scanning. Arterial blood gas levels, lung volumes, and diffusing capacity were determined. Patients performed a 6-min walk test and an incremental exercise test with measurement of breathing pattern and operating lung volumes. RESULTS Significant severity-related differences in 8-isoprostane were identified according to the BMI, obstruction, dyspnea, and exercise (BODE) index. 8-Isoprostane levels were related to smoking intensity, lung densities in expiration, static lung volumes, PaO(2), diffusion capacity, distance walked in 6 min, peak oxygen uptake, and anaerobic threshold. Concentration of 8-isoprostane was higher in the 60 patients (79%) who developed dynamic hyperinflation than in the remaining 16 (21%) who did not. In a multivariate linear regression analysis using 8-isoprostane as a dependent variable, end-expiratory lung volume change and PaO(2) were retained in the prediction model (r(2) = 0.734, P < .001). CONCLUSIONS In stable patients with COPD, oxygen level and dynamic hyperinflation are related to airway oxidative stress.

Estimación de los indicadores bibliométricos de repercusión de Archivos de Bronconeumología

Se estiman los principales indicadores bibliometricos de repercusion de A rchivos de B ronconeumologia de los ultimos dos anos. Para ello se han revisado las citas de A rchivos de B ronconeumologia emitidas en 1996 y 1997 por Medicina Clinica y por todas las revistas con capacidad citadora que, en el Science Citation index, aparecen agrupadas bajo el epigrafe Respiratory System. Se registro el ano de emision de la cita, el ano de publicacion del articulo de A rchivos de B ronconeumologia que resultaba citado y la revista citadora. Tambien se contabilizaron los articulos publicados por A rchivos de B ronconeumologia entre 1994 y 1996. A partir de estos datos se determinaron el indice de visibilidad, el semiperiodo de las citas y el factor de impacto de A rchivos de B ronconeumologia en cada uno de los anos estudiados. A su vez se calculo el factor de impacto relativo de la revista. En 1996, A rchivos de B ronconeumologia alcanzo un indice de visibilidad de 1,602, un semiperiodo de las citas de 2,00 anos, un factor de impacto de 0,069 y un factor de impacto relativo de 1,371. En 1997, el indice de visibilidad fue de 1,477, el semiperiodo de las citas de 3,00 anos y el factor de impacto de 0,030. En conclusion, la repercusion internacional de A rchivos de B ronconeumologia es discreta, aun cuando alcanza un factor de impacto relativo superior al de otras publicaciones de medicina interna o de especialidades medicas contenidas en el Journal Citation Reports.

Prediction Equations for Single-Breath Diffusing Capacity in Subjects Aged 65 to 85 Years

BACKGROUND In senior subjects, diffusing capacity of the lung for carbon monoxide (Dlco) is interpreted using prediction equations derived from primarily younger adult populations. Our objectives were to provide reference equations for single-breath Dlco for a cohort of healthy, never-smoking, white, European adults between 65 and 85 years of age and to compare the predicted values of this sample with those from other studies involving middle-aged adults. METHODS Reference equations were derived from a randomly selected sample from the general population of 431 healthy never smoker subjects aged 65 to 85 years (262 women and 169 men). Spirometry, lung volume determinations by plethysmography, and single-breath Dlco (corrected for hemoglobin) were performed following the American Thoracic Society/European Respiratory Society guidelines. Reference values and lower and upper limits of normal were derived using a piecewise polynomial model. RESULTS In addition to age, our reference equations confirmed the height and body size dependence of Dlco and diffusing capacity for alveolar volume (Dlco/Va) in older subjects. Practically all of the reference values obtained by extrapolating reference equations of middle-aged adults underestimated the true diffusing capacity of the healthy elderly volunteers. Middle-aged reference equations underestimated Dlco by 2.1% to 22.3% in women and 2.8% to 37.8% in men. In addition, Dlco/Va was overestimated up to 18% and 39.8% in women and men, respectively, whereas other equations underestimated Dlco/Va up to 22.2% and 11.9% in women and men, respectively. CONCLUSIONS These results underscore the importance of using prediction equations appropriate to the origin and age characteristics of the subjects being studied.

Amyloid goitre and hypothyroidism secondary to cystic fibrosis.

Although cystic fibrosis (CF) is still the most frequently fatal childhood disease, many adults now survive into their third and fourth decades. Uncommon complications of chronic diseases, such as amyloidosis, while infrequent, may now appear during the course of CF in adulthood. We present a case of a patient with CF who was diagnosed with hypothyroidism due to amyloid deposits in the thyroid.