Uric acid and acute kidney injury in high-risk patients for developing acute kidney injury undergoing cardiac surgery: A prospective multicenter study.

PURPOSE: It is unclear whether preoperative serum uric acid (SUA) elevation may play a role in the development of acute kidney injury (AKI) associated with cardiac surgery (CSA-AKI). We conducted a cohort study to evaluate the influence of preoperative hyperuricemia on AKI in patients at high risk for developing SC-AKI. DESIGN: Multicenter prospective international cohort study. SETTING: Fourteen university hospitals in Spain and the United Kingdom. PARTICIPANTS: We studied 261 consecutive patients at high risk of developing CSA-AKI, according to a Cleveland score ≥ 4 points, from July to December 2017. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: AKIN criteria were used for the definition of AKI. Multivariable logistic regression models and propensity score-matched pairwise analysis were used to determine the adjusted association between preoperative hyperuricemia (≥7 mg/dL) and AKI. Elevated preoperative AUS (≥7 mg/dL) was present in 190 patients (72.8%), whereas CSA-AKI occurred in 145 patients (55.5%). In multivariable logistic regression models, hyperuricemia was not associated with a significantly increased risk of AKI (adjusted Odds Ratio [OR]: 1.58; 95% confidence interval [CI]: 0.81-3; P = .17). In propensity score-matched analysis of 140 patients, the hyperuricemia group experienced similar adjusted odds of AKI (OR 1.05, 95%CI 0.93-1.19, P = .37). CONCLUSIONS: Hyperuricemia was not associated with an increased risk of AKI in this cohort of patients undergoing cardiac surgery at high risk of developing CSA-AKI.

Erratum: Ratchet universality in the bidirectional escape from a symmetric potential well [Phys. Rev. E 103, 022203 (2021)].

This corrects the article DOI: 10.1103/PhysRevE.103.022203.

Spreading fronts of wetting liquid droplets: Microscopic simulations and universal fluctuations.

We have used kinetic Monte Carlo (kMC) simulations of a lattice gas to study front fluctuations in the spreading of a nonvolatile liquid droplet onto a solid substrate. Our results are consistent with a diffusive growth law for the radius of the precursor layer, R∼t^{δ}, with δ≈1/2 in all the conditions considered for temperature and substrate wettability, in good agreement with previous studies. The fluctuations of the front exhibit kinetic roughening properties with exponent values which depend on temperature T, but become T independent for sufficiently high T. Moreover, strong evidence of intrinsic anomalous scaling has been found, characterized by different values of the roughness exponent at short and large length scales. Although such a behavior differs from the scaling properties of the one-dimensional Kardar-Parisi-Zhang (KPZ) universality class, the front covariance and the probability distribution function of front fluctuations found in our kMC simulations do display KPZ behavior, agreeing with simulations of a continuum height equation proposed in this context. However, this equation does not feature intrinsic anomalous scaling, at variance with the discrete model.

Two new species of geckos of the genus Phyllopezus Peters, 1878 (Squamata: Gekkota: Phyllodactylidae) from northeastern Brazil.

We describe two new species of Brazilian geckos of the genus Phyllopezus based on morphological and molecular data. The first species is currently known from a relictual Cerrado enclavecampos rupestres, in the mountains of the Serra do Espinhao in the state of Bahia. The second species is known from northeastern Atlantic Forest and transitional areas with Caatinga biome in the state of Alagoas. The two new species are sister taxa and together are the sister clade to the remaining species in the Phyllopezus pollicaris species complex. These new species can be morphologically distinguished from their congeners by meristic and morphometric characters, in addition to color pattern and genetic differentiation.

Ratchet universality in the bidirectional escape from a symmetric potential well.

The present work discusses symmetry-breaking-induced bidirectional escape from a symmetric metastable potential well by the application of zero-average periodic forces in the presence of dissipation. We characterized the interplay between heteroclinic instabilities leading to chaotic escape and breaking of a generalized parity symmetry leading to directed ratchet escape to an attractor either at ∞ or at -∞. Optimal enhancement of directed ratchet escape is found to occur when the wave form of the zero-average periodic force acting on the damped driven oscillator matches as closely as possible to a universal wave form, as predicted by the theory of ratchet universality. Specifically, the optimal approximation to the universal force triggers the almost complete destruction of the nonescaping basin for driving amplitudes which are systematically lower than those corresponding to a symmetric periodic force having the same period. We expect that this work could be potentially useful in the control of elementary dynamic processes characterized by multidirectional escape from a potential well, such as forced chaotic scattering and laser-induced dissociation of molecular systems, among others.

Redescription of the tadpole of Leptodactylus natalensis Lutz (Anura: Leptodactylidae), an inhabitant of the Brazilian Atlantic Forest.

The Neotropical foam-nesting genus Leptodactylus Fitzinger is currently composed of 75 species (Frost 2019) divided into four monophyletic species groups (De Sá et al. 2014). The L. melanonotus species group includes 17 species delimited by five adult osteological character-states (De Sá et al. 2014). Leptodactylus natalensis Lutz is the only species of the L. melanonotus species group that occurs in north of the Brazilian Atlantic Rain Forest (De Sá et al. 2014; Almeida et al. 2016) and whose type locality is the municipality of Natal, state of Rio Grande do Norte, Brazil (Lutz 1930). The tadpole of this species was briefly described by Oliveira Lírio-Júnior (2000) based on a single individual from the municipality of Aracaju, state of Sergipe, Brazil. Herein, we present a complete redescription of the tadpole of this species, including morphometric data and interpopulational variation. Besides, we provide comparisons with all members of the L. melanonotus group.

Helpers at the nest compensate for reduced maternal investment in egg size in carrion crows.

Life history theory predicts that mothers should trade off current and future reproductive attempts to maximize lifetime fitness. When breeding conditions are favourable, mothers may either increase investment in the eggs to improve the quality of the offspring or save resources for future reproduction as the good raising environment is likely to compensate for a 'bad start'. In cooperatively breeding birds, the presence of helpers improves breeding conditions so that mothers may vary the number, size and quality of the eggs in response to the composition of the group. Here, we show that in cooperatively breeding carrion crows Corvus corone corone, where nonbreeding males are more philopatric and more helpful at the nest than females, breeding females decreased egg size as the number of subordinate males in the group increased. However, despite the smaller investment in egg size, fledglings' weight increased in groups with more male subordinates, improving post-fledging survival and indicating that helpers fully compensated for the initial 'bad start'. These results highlight a 'hidden effect' of helpers that bears profound implications for understanding the ultimate function of helping.

Infección por Chlamydia trachomatis en el primer año de vida / Chlamydia trachomatis infection in the first year of life

Introducción: En la embarazada el rastreo de Chlamydia trachomatis (C. trachomatis) es controvertido. La colonización asintomática ocurre en el 2—20%. El 40—70% de los recién-nacidos son infectados. Objetivo: Caracterizar la infección por C. trachomatis en los niños con menos de 1 año de edad. Material y métodos: Estudio retrospectivo de 13 años (enero de 1997 a diciembre de 2009)de las infecciones diagnosticadas en lactantes por immunofluorescencia del raspado ocular o inmunoglobulina M sérica. Se analizaron datos demográficos, clínicos, radiológicos y la evolución clínica. Resultados: Fueron incluidos 46 niños, con una incidencia de 0,7/1.000 recién nacidos vivos. Lae dad media fue de 2 meses (rango: 7 días-11 meses). Siete madres presentaban otras coinfecciones: virus de la inmunodeficiencia 1 (1), antígeno HBs (AgHBs) (1) y Streptococcus del grupo B (5). El parto fue vaginal en el 81,4% y en el 13,0% hubo rotura de bolsa amniótica superior a 12 h. Cinco niños fueron prematuros. Ocurrió infección respiratoria en 41 pacientes (89,1%) y conjuntivitis en 17 (36,9%). La conjuntivitis se manifestó a los primeros 30 días de vida (rango: 7—52 días) y la infección respiratoria a los 45 días de vida (rango: 8 días-11 meses). Diez (29,4%) niños presentaron complicaciones: hipoxemia (9), otitis media aguda (2), apnea (3) y atelectasia (1). La radiografía de tórax mostró infiltrado intersticial en 25 casos (65,8%) y fue normal en 4 niños. La mayoría (80,5%) tuvo una evolución favorable, pero 5 niños fueron reingresados y 8 (17,4%) desarrollaron broncospasmo recurrente. Conclusiones: En el primer año de vida la C. trachomatis debe considerarse entre los agentes etiológicos de conjuntivitis e infecciones respiratorias. En Portugal, la prevalencia es desconocida, pero probablemente es subdiagnosticada (AU)

Background: Chlamydia trachomatis (C. trachomatis) is the most frequent bacterial sexual infection in women. Pregnant women screening is controversial, with asymptomatic colonization occurring in 2—20%, and 40—70% newborns can be infected. Objectives: The aim of this work is to characterise C. trachomatis infections in children under 12 months. Material and methods: Retrospective study was carried out from January 1997 to December 2009 (13 years), on Chlamydia infections, diagnosed by immunofluorescence of ocular scraping or serum immunoglobulin M (IgM). Demographic, clinical features, imaging findings, and outcomes were analysed. Results: A total of 46 children were identified, with an overall incidence of 0.7/1,000 deliveries. Mean age was 2 months (range from 7 days to 11 months). Seven mothers had co-infections: Human Immunodeficiency Virus (HIV) (1), HBs antigen (HBsAg) (1) and group B Streptococcus (5). Most (81.4%) children had a vaginal delivery, with membrane rupture over 12 hours in 13.0%. Respiratory infection occurred in 41 (89.1%) cases and conjunctivitis in 17 (36.9%). Conjunctivitis manifested in the first 30 days of life (range from 7 days to 52 days). Respiratory symptoms occurred at age 45 days (range from 8 days to 11 months). Ten (29.4%) children had complications: hypoxemia (9), acute medial otitis (2), apnoea (3) and atelectasis (1). Chest X-ray revealed interstitial infiltrate in 25 (65.8%), and was normal in 4 children. Most children (80.5%) had a good outcome. Conclusions: C. trachomatis should be considered as an aetiologic agent of conjunctivitis and respiratory infections in the first year of life. The prevalence of C. trachomatis infection in Portugal is unknown, and is probably an underdiagnosed disease (AU)

[Chlamydia trachomatis infection in the first year of life]. / Infección por Chlamydia trachomatis en el primer año de vida.

BACKGROUND: Chlamydia trachomatis (C. trachomatis) is the most frequent bacterial sexual infection in women. Pregnant women screening is controversial, with asymptomatic colonization occurring in 2-20%, and 40-70% newborns can be infected. OBJECTIVES: The aim of this work is to characterise C. trachomatis infections in children under 12 months. MATERIAL AND METHODS: Retrospective study was carried out from January 1997 to December 2009 (13 years), on Chlamydia infections, diagnosed by immunofluorescence of ocular scraping or serum immunoglobulin M (IgM). Demographic, clinical features, imaging findings, and outcomes were analysed. RESULTS: A total of 46 children were identified, with an overall incidence of 0.7/1,000 deliveries. Mean age was 2 months (range from 7 days to 11 months). Seven mothers had co-infections: Human Immunodeficiency Virus (HIV) (1), HBs antigen (HBsAg) (1) and group B Streptococcus (5). Most (81.4%) children had a vaginal delivery, with membrane rupture over 12 hours in 13.0%. Respiratory infection occurred in 41 (89.1%) cases and conjunctivitis in 17 (36.9%). Conjunctivitis manifested in the first 30 days of life (range from 7 days to 52 days). Respiratory symptoms occurred at age 45 days (range from 8 days to 11 months). Ten (29.4%) children had complications: hypoxemia (9), acute medial otitis (2), apnoea (3) and atelectasis (1). Chest X-ray revealed interstitial infiltrate in 25 (65.8%), and was normal in 4 children. Most children (80.5%) had a good outcome. CONCLUSIONS: C. trachomatis should be considered as an aetiologic agent of conjunctivitis and respiratory infections in the first year of life. The prevalence of C. trachomatis infection in Portugal is unknown, and is probably an underdiagnosed disease.

[Management of COPD according to severity by respiratory specialists in France]. / Prise en charge de la BPCO en pneumologie selon le stade de sévérité.

INTRODUCTION: The diagnosis and treatment of chronic obstructive pulmonary disease (COPD) is suboptimal in many patients, which may impact on morbidity, mortality, use of healthcare resources and patients' overall quality of life. OBJECTIVES: To describe the management of COPD by respiratory physicians from the French mainland according to severity. METHODS: Observational cross-sectional survey performed in France in 2006-2007. 515 pulmonologists located throughout the national territory were involved and each of them had to recruit 5 patients with stable COPD. RESULTS: The study included 2494 patients (mean age 67 years, 78% males), of whom nearly 50% had severe to very severe COPD (GOLD stage III-IV). At inclusion, 93.2% of patients were receiving pharmacological treatment, most often non-nebulised bronchodilators (91.2%) and/or inhaled corticosteroids (73.7%). Pulmonary rehabilitation was scheduled or had been performed within the last 2 years in 26.9% of patients. Investigations and treatments were more frequent when the disease was more severe, but there was considerable overlap between severity grades. CONCLUSIONS: Differences in decisions about the investigation and treatment of COPD by pulmonologists can not be explained only by the severity of disease. Efforts must be made to identify other patient characteristics associated with these decisions, in order to help developing future recommendations.

Traqueopatía osteocondroplásica / Osteochondroplastic tracheopathy

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Características de los pacientes ingresados por exacerbación de enfermedad pulmonar obstructiva crónica (EPOC): diferencias entre varones y mujeres / Characteristics of patients hospitalized due to worsening of chronic obstructive pulmonary disease (COPD): differences between men and women

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Vascular endothelial growth factor serum concentrations in hypercholesterolemic patients.

OBJECTIVE: Vascular endothelial growth factor (VEGF) promotes normal and pathological angiogenesis. VEGF is a chemotactic factor for macrophages and vascular smooth muscle cells, and induces synthesis of metalloproteinases and adhesion molecules. VEGF expression is regulated by hypoxia, cytokines, oncogenes, and oxidized low-density lipoprotein (LDL). The purpose of this study was to determine the relationship between levels of lipid parameters and VEGF, to investigate whether pravastatin treatment influences VEGF serum concentrations, and to examine the relationship between VEGF and the variations in post-treatment lipid and inflammatory parameters. MATERIAL AND METHODS: Eighteen patients aged 48+/-6.8 years with total cholesterol (TC) >6.1 mmol/L comprised the hypercholesterolemic group. The controls included 12 individuals aged 50+/-7.4 years with TC <5.1 mmol/L. TC, high-density lipoprotein cholesterol (HDLC), triglycerides, LDLC, C-reactive protein (CRP), and VEGF were determined in both groups at baseline, and in the hypercholesterolemic group after 4 months of treatment with 20 mg/day pravastatin. RESULTS: A significant correlation was observed between concentrations of VEGF and TC, LDLC and TG, and a significant difference in VEGF concentration was observed between the control group (mean 142 ng/L) and the hypercholesterolemic group (mean 272.9 ng/L). A significant decrease was observed in TC (14.7 %), LDLC (21.5 %), CRP (22.7 %), and VEGF (14.8 %) after 4 months of treatment with pravastatin. CONCLUSIONS: A relationship was found between serum levels of VEGF and most atherogenic lipoproteins. In patients with hypercholesterolemia treated with pravastatin, a reduction in VEGF and CRP was seen in addition to lipid decreases.

Right renal vein elongation with the inferior vena cava for cadaveric kidney transplants: an old neglected surgical approach

INTRODUCTION: Short right renal vein is a frequent and well-known technical inconvenience that is commonly observed during transplantation of the right kidney. We present our experience with the elongation of short cadaveric right renal veins using the contiguous vena cava during cadaveric renal transplants. METHODS: We performed 34 kidney transplantations with a short right renal vein requiring elongation using the inferior vena cava, to make the venous anastomosis technically feasible. The elongated right renal vein was anastomosed end to side to the external iliac vein in 24 patients, to the common iliac vein in 8 patients and to the inferior vena cava in 2 patients. The right renal artery with an aortic patch was implanted end to side in 33 patients, and end to end without aortic patch to the internal iliac artery in one patient. RESULTS: In all cases, the vascular anastomoses were easily performed in the recipient and no thrombosis was observed. CONCLUSION: Elongation of a short right renal vein with the inferior vena cava is a feasible mean to overcome technical problems that may compromise the results of cadaveric renal transplantation.

Right renal vein elongation with the inferior vena cava for cadaveric kidney transplants. An old neglected surgical approach.

INTRODUCTION: Short right renal vein is a frequent and well-known technical inconvenience that is commonly observed during transplantation of the right kidney. We present our experience with the elongation of short cadaveric right renal veins using the contiguous vena cava during cadaveric renal transplants. METHODS: We performed 34 kidney transplantations with a short right renal vein requiring elongation using the inferior vena cava, to make the venous anastomosis technically feasible. The elongated right renal vein was anastomosed end to side to the external iliac vein in 24 patients, to the common iliac vein in 8 patients and to the inferior vena cava in 2 patients. The right renal artery with an aortic patch was implanted end to side in 33 patients, and end to end without aortic patch to the internal iliac artery in one patient. RESULTS: In all cases, the vascular anastomoses were easily performed in the recipient and no thrombosis was observed. CONCLUSION: Elongation of a short right renal vein with the inferior vena cava is a feasible mean to overcome technical problems that may compromise the results of cadaveric renal transplantation.

[Effects of muscle training on breathing pattern in patients with severe chronic obstructive pulmonary disease]. / Efectos del entrenamiento muscular sobre el patrón ventilatorio en pacientes con enfermedad pulmonar obstuctiva crónica grave.

OBJECTIVE: During physical exertion, the ventilatory response of patients with severe chronic obstructive pulmonary disease (COPD) is more rapid and shallow than that of healthy subjects. There is evidence that exercise training can alter breathing pattern in COPD patients. The purpose of the present study was to observe the effects of physical training on patients with severe COPD and to determine whether or not any possible changes were maintained over time. MATERIAL AND METHODS: Patients with severe COPD without bronchial reversibility were enrolled in a randomized controlled trial of a peripheral muscle training program carried out in a hospital setting. All enrolled patients were clinically stable, without exacerbation, and were randomly assigned to a training program of high (group A) or low (group B) intensity. RESULTS: Thirty-five men with severe COPD in stable condition (mean [SD] forced expiratory volume in 1 second at 41%[7%]) were enrolled in the study. The mean age was 64(5) years. Group A underwent training at 70(22) W and group B at 35(10) W, such that the estimated total work was 8050(2882) kJ in group A and 4044(1205) kJ in group B. Breathing pattern changes were detected in exercise tests only for group A patients, but the changes were not maintained 12 months after the end of the program. CONCLUSIONS: Intense training produces changes in the breathing pattern of patients with severe COPD. The changes are not specific to the task performed, not dependent on lactate production, and not maintained over the long term.

Efectos del entrenamiento muscular sobre el patrón ventilatorio en pacientes con enfermedad pulmonar obstructiva crónica grave / Effects of muscle training on breathing pattern in patients with severe chronic obstructive pulmonary disease

OBJETIVO: Durante el esfuerzo físico la respuesta ventilatoria de los enfermos con enfermedad pulmonar obstructiva crónica (EPOC) grave es más rápida y superficial que la de los sujetos sanos, y existen indicios de que el entrenamiento físico podría cambiar el patrón ventilatorio de estos pacientes. El propósito del presente estudio fue comprobar los efectos que el entrenamiento físico de los pacientes con EPOC grave tiene sobre el patrón ventilatorio, así como determinar o no el mantenimiento de los posibles cambios producidos en el tiempo. MATERIAL Y MÉTODO: Se realizó un estudio aleatorio y controlado con pacientes con EPOC grave sin reversibilidad bronquial. En estos pacientes se efectuó una intervención mediante entrenamiento físico. Los pacientes fueron remitidos al hospital para entrenamiento muscular periférico, todos ellos en situación clínica estable, sin exacerbación, y fueron asignados a dos programas diferentes de entrenamiento físico. RESULTADOS: Se estudiaron 35 pacientes varones con EPOC grave, estables (volumen espiratorio forzado en el primer segundo del 41 ñ 7 por ciento), con una edad media de 64 ñ 5 años, divididos en dos grupos con diferente potencia media estimada de entrenamiento (grupo A: 70 ñ 22 W; grupo B: 35 ñ 10 W) y trabajo total desarrollado (grupo A: 8.050 ñ 2.882 kJ; grupo B: 4.044 ñ 1.205 kJ). Sólo se objetivaron cambios en el patrón ventilatorio durante el ejercicio realizado durante la prueba de esfuerzo en el grupo A, que no se mantuvieron a los 12 meses de finalizado el programa. CONCLUSIONES: El entrenamiento intenso produce cambios en el patrón ventilatorio de los pacientes con EPOC grave que son inespecíficos de la tarea e independientes de la producción de lactato, y que no se mantienen a largo plazo (AU)

[Analysis of withdrawal from noninvasive mechanical ventilation in patients with obesity-hypoventilation syndrome. Medium term results]. / Análisis de la retirada de la ventilación mecánica no invasiva en pacientes con síndrome de hipoventilación-obesidad. Resultados a medio plazo.

OBJECTIVE: To evaluate the possibility of cessation of noninvasive mechanical ventilation or noninvasive positive pressure ventilation (NPPV) treatment in patients with obesity-hypoventilation syndrome (OHS). MATERIAL AND METHODS: A study was carried out on 22 OHS patients who had received NPPV for a minimum of 1 year. Prior to evaluation of the cessation of ventilatory support, all patients underwent the following tests: diurnal and nocturnal arterial blood gases, nocturnal oximetry, nocturnal cardiorespiratory polygraphy, and lung function tests. Based on the results obtained, 12 patients who met the NPPV cessation criteria were selected. This group was liberated from ventilatory support for 3 months. At the end of this period, all of the tests initially carried out were repeated on all patients and the results were compared with those obtained at the time of NPPV cessation. RESULTS: Three months after liberation from NPPV, no significant variations were observed in arterial blood gases or in lung function tests in comparison with the values found at the time of cessation. In terms of individual development, only 1 patient showed blood gas deterioration requiring a return to NPPV. In 7 cases, a polygraph showed obstructive sleep apnea syndrome (OSAS), 4 at the time of cessation and 3 at the follow-up examination carried out at the end of the 3 months. Finally, in 4 patients the respiratory situation remained stable, with no significant variations in the tests done before or after cessation of NPPV. CONCLUSIONS: The majority of the OHS patients who receive prolonged treatment with NPPV continue to be stable 3 months after liberation from ventilatory support. A high percentage of these patients can be seen to have OSAS once the hypercapnia situation is corrected.

Estado actual de la ventilación mecánica domiciliaria en España: resultados de una encuesta de ámbito nacional / Home mechanical ventilation in Spain today: results of a national survey

La ventilación mecánica domiciliaria constituye una modalidad de tratamiento de la insuficiencia respiratoria crónica para aquellos pacientes en situación clínica estable que precisan un soporte ventilatorio parcial o total. Con el objetivo de conocer el estado de la ventilación mecánica domiciliaria en España, se envió una encuesta a los servicios de neumología de todos los hospitales de la red sanitaria pública, cerrándose la recogida de datos en abril de 1999. Se han obtenido respuestas de 43 hospitales que pertenecen a 14 comunidades autónomas. La ventilación mecánica domiciliaria se inició en 1987 y el número total de pacientes actualmente en ventilación se eleva a 1.821. Los diagnósticos corresponden a enfermedad restrictiva toracógena en el 44 por ciento, enfermedades neuromusculares en el 25 por ciento, síndrome de hipoventilación-obesidad en el 15 por ciento, EPOC en el 9 por ciento y otras enfermedades en el 7 por ciento. De los 1.821 pacientes, 856 utilizan respiradores volumétricos y 965 diferentes modelos de soporte de presión. En cuanto a la forma de conexión al respirador, un 90 por ciento lo hacen mediante máscara nasal, un 6 por ciento a través de traqueotomía, un 2 por ciento utilizan máscaras faciales y menos de un 1 por ciento a través de piezas bucales. En conclusión, la ventilación mecánica domiciliaria se encuentra ampliamente introducida en nuestro país, siendo la forma más habitual la ventilación no invasiva mediante máscara nasal. Además de las indicaciones clásicas, enfermedades de la caja torácica y neuromusculares, otros procesos como el síndrome de hipoventilación-obesidad y la EPOC son causa de indicación de ventilación mecánica domiciliaria. (AU)

[A comparison of several measurement scales for assessing dyspnea in their daily activities in patients with chronic obstructive lung disease]. / Comparación de varias escalas de medición para valorar la disnea en las actividades diarias en los pacientes con enfermedad pulmonar obstructiva crónica.

The objective of this study was to compare two instruments for measuring dyspnea to functional capacity, defined as maximal oxygen uptake in a stress test limited by symptoms. We carried out a descriptive study to determine correlation between the methods. Subjects with severe chronic obstructive pulmonary disease were enrolled and dyspnea during daily activities was evaluated using the Medical Research Council (MRC) scale and the chronic respiratory disease health perception questionnaire (CRQ). Dyspnea was also assessed on a visual analog scale (VAS) and the Borg scale. Patients performed a progressive treadmill test limited by symptoms to measure peak VO2 and VE. Correlation analysis of the two measures of dyspnea and the objective measures of functional capacity (peak VO2 and VE) showed that the clinical dyspnea measures (CRQ and MRC) correlated well with peak aerobic capacity and with maximal ventilation, whereas the VAS and Borg scale were not significantly related to the aforementioned variables. We also observed that the clinical scales for dyspnea correlated with each other, as did the VAS and Borg scale, but that there was no correlation between the two types of measurement. We conclude that clinical dyspnea indexes (CRQ and MRC) correlate well with maximal aerobic capacity and with each other. However, the VAS and Borg scale do not correlate with functional capacity measured by peak VO2 and VE.