Desaturation – distance ratio: a new concept for a functional assessment of interstitial lung diseases

INTRODUCTION: The functional evaluation has become increasingly important in the understanding and management of patients with interstitial lung diseases. The cardiopulmonary exercise test and the six-minute walk test (6MWT), through their isolated variables, have been used to do this evaluation, with some limitations. OBJECTIVES: We proposed a new composite index (desaturation distance ratio using continuous peripheral oxygen saturation (SpO2) and the distance walked as a more reliable tool for doing a functional evaluation of these patients. METHODS: 6MWT was performed by interstitial lung diseases patients and controls. Analyzed parameters were walked distance and desaturation area (DAO2), obtained by taking the difference between maximal SpO2 possible (100%) and patient's SpO2 every 2 seconds. desaturation distance ratio was calculated using the ratio between DAO2 and distance walked. RESULTS: Forty-nine interstitial lung diseases patients and 11 control subjects completed the protocol. The mean (SD) age was 60 (12) years and 65 (9) years, respectively (p:NS). Data obtained from 6MWT showed a significant statistical difference between interstitial lung diseases patients and controls: mean walked distance (430 and 602 meters, respectively); SpO2 minimal maintained at least 10 seconds - SpO2 min (85% and 94%, respectively), and median desaturation distance ratio (10 and 2.5, respectively). A correlation analysis, considering interstitial lung diseases patients, revealed the best correlation between desaturation distance ratio and DLco (r= - 0.72; p<0.001), being the correlation between SpO2 min and DLco of 0.61 (p<0.001) and among walked distance and DLco of 0.58 (p<0.05). CONCLUSION: Desaturation distance ratio is a promising concept and a more reliable physiologic tool to assess pulmonary diseases characterized by involvement of the alveolar-capillary membrane, such as interstitial lung diseases

Spirometry among rheumatoid arthritis patients and its association with epidemiological, clinical, radiographic and treatment aspects

INTRODUÇÃO: Artrite reumatoide (AR) é uma doença inflamatória autoimune comum, de predomínio feminino e presente em 1% da população brasileira. O acometimento do sistema respiratório é frequente e ocorre em aproximadamente 50% desta população, principalmente as doenças de vias aéreas e as doenças pulmonares intersticiais. Pacientes tabagistas têm maior chance de desenvolver AR em relação aos não tabagistas, mas o papel do tabaco na doença pulmonar da AR ainda está indefinido. Este trabalho foi dividido em 2 partes. Na primeira avaliamos as características epidemiológicas, clínicas, radiográficas e espirométricas dos pacientes com AR, e comparamos o grupo de pacientes com alterações em qualquer dos exames realizados com grupo onde os exames foram normais. Na segunda parte, fizemos uma avaliação mais aprofundada do sistema respiratório dos pacientes com alteração à espirometria e os comparamos de acordo com a exposição ao tabagismo: elevada (carga tabágica > 10 anos.maço) contra baixa ou ausente. MÉTODOS: Pacientes acompanhados no ambulatório de Artrite Reumatoide do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo foram submetidos a um estudo de corte transversal com avaliação clínica, oximetria de pulso em repouso, radiografia de tórax e espirometria. Aqueles que apresentavam espirometria alterada foram submetidos a tomografia de alta resolução do tórax (TCAR) e função pulmonar com espirometria, pletismografia, difusão de monóxido de carbono (DLCO) e teste de washout de nitrogênio por respiração única. RESULTADOS: Um total de 246 pacientes foram analisados. História de tabagismo prévio ou atual foi visto em metade da amostra. Houve baixa prevalência de nódulos reumatoides e Síndrome de Sjögren. Alterações à espirometria foram vistas em 30% dos pacientes, radiografia de tórax em 45% e oximetria de pulso em 13%. Exames normais estavam simultaneamente presentes em apenas 41% dos casos. Houve fraca correlação negativa entre carga tabágica e diferentes parâmetros da espirometria. No grupo de pacientes com elevada exposição ao tabaco, observamos uma maior frequência de enfisema à TCAR de tórax e menor DLCO, enquanto que no grupo com exposição baixa ou ausente houve maior prevalência de bronquiolite. CONCLUSÕES: Alteração combinada em radiografia de tórax, espirometria e oximetria de pulso foi mais frequentemente observada em pacientes com mais idade, história de tabagismo e uso prévio de metotrexate e biológicos. Apesar de frequentes, a maioria das alterações à radiografia de tórax e espirometria foram leves. A exposição ao tabagismo consegue explicar apenas uma pequena parte das alterações espirométricas da doença pulmonar da AR. A maioria dos pacientes com alteração à espirometria apresentou TCAR de tórax e função pulmonar sugestivas de doença pulmonar obstrutiva, principalmente bronquiolite. A presença de enfisema à TCAR é um marcador altamente específico de exposição ao tabacoINTRODUCTION: Rheumatoid Arthritis (RA) is a frequent connective tissue disorder, occurring mainly in women, with a 1% prevalence in Brazil. Pulmonary disease, which is present in up to 50% of patients, manifests most commonly as interstitial lung disease (ILD) and airways disease. A high frequency of smoking is observed among RA patients, but its role on pulmonary involvement is unknown. This work was divided in 2 parts. At the first part, we analyzed epidemiological, clinical, radiographic and spirometric RA patients´ characteristics, and compared the group of patients with any abnormality on complementary medical tests against the group with normal tests. At the second part, patients with abnormal spirometry were submitted to a more complex respiratory evaluation, and we compared RA patients with high tobacco exposure ( > 10 pack-years) versus absent or low tobacco exposure. METHODS: RA patients undergoing regular follow-ups at the rheumatoid arthritis clinic of the Rheumatology Division, University of Sao Paulo Medical School, Brazil, were submitted to a cross-sectional clinical pulmonary evaluation, rest pulse oximetry, chest radiograph and spirometry. Those with abnormal spirometry were submitted to chest high-resolution computed tomography (HRCT) and pulmonary function tests with spirometry, plethysmography, carbon monoxide diffusion capacity (DLCO) and single breath nitrogen washout. RESULTS: A total of 246 RA patients underwent complete assessments. Half of the population reported tobacco exposure. Rheumatoid nodules and Sjögren Syndrome were uncommon. Spirometry was abnormal in 30% of the patients; CXR was abnormal in 45%, and pulse oximetry was abnormal in 13%. Normal CXR, spirometry and oximetry were observed simultaneously in only 41% of the RA patients. A weak negative correlation was found between tobacco exposure and spirometric parameters. Thorax HRCT emphysema and lower DLCO were more frequent in patients with high tobacco exposure, while patients with absent or low tobacco exposure had a higher frequency of bronchiolitis. CONCLUSIONS: A significant difference was observed in age, smoking status, and ever methotrexate or biologic treatments when comparing patients with normal and abnormal complementary medical tests. Even though radiographic and spirometric abnormalities were frequent, most of them were mild. Tobacco exposure was slightly responsible for RA patients´ spirometric abnormalities. HRCT and pulmonary function tests compatible with obstructive lung disease, mainly bronchiolitis, were the most frequent patterns among RA patients with abnormal spirometry. HRCT emphysema was a highly specific marker of tobacco exposur

Interpretation of autoantibody positivity in interstitial lung disease and lung-dominant connective tissue disease

The initial evaluation of patients with interstitial lung disease (ILD) primarily involves a comprehensive, active search for the cause. Autoantibody assays, which can suggest the presence of a rheumatic disease, are routinely performed at various referral centers. When interstitial lung involvement is the condition that allows the definitive diagnosis of connective tissue disease and the classical criteria are met, there is little debate. However, there is still debate regarding the significance, relevance, specificity, and pathophysiological role of autoimmunity in patients with predominant pulmonary involvement and only mild symptoms or formes frustes of connective tissue disease. The purpose of this article was to review the current knowledge of autoantibody positivity and to discuss its possible interpretations in patients with ILD and without clear etiologic associations, as well as to enhance the understanding of the natural history of an allegedly new disease and to describe the possible prognostic implications. We also discuss the proposition of a new term to be used in the classification of ILDs: lung-dominant connective tissue disease

Lymphadenopathy and fever in a chef during a stay in Europe

This case illustrates a rare presentation (as lymphadenopathy and fever) of one of the most common zoonotic diseases worldwide-brucellosis-in a 22-year-old Brazilian male (a chef) who had recently returned to Brazil after having lived in and traveled around Europe for one year. The histopathology, clinical history, and response to treatment were all consistent with a diagnosis of brucellosis, which was confirmed by PCR in a urine sample. We also review some aspects of brucellosis, such as the clinical features, diagnosis, and management

Pulmonary involvement in rheumatoid arthritis: evaluation by radiography and spirometry

AbstractObjective: To determine whether simple diagnostic methods can yield relevant disease information in patients with rheumatoid arthritis (RA).Methods: Patients with RA were randomly selected for inclusion in a cross-sectional study involving clinical evaluation of pulmonary function, including pulse oximetry (determination of SpO2, at rest), chest X-ray, and spirometry.Results: A total of 246 RA patients underwent complete assessments. Half of the patients in our sample reported a history of smoking. Spirometry was abnormal in 30% of the patients; the chest X-ray was abnormal in 45%; and the SpO2 was abnormal in 13%. Normal chest X-ray, spirometry, and SpO2 were observed simultaneously in only 41% of the RA patients. A history of smoking was associated with abnormal spirometry findings, including evidence of obstructive or restrictive lung disease, and with abnormal chest X-ray findings, as well as with an interstitial pattern on the chest X-ray. Comparing the patients in whom all test results were normal (n = 101) with those in whom abnormal test results were obtained (n = 145), we found a statistically significant difference between the two groups, in terms of age and smoking status. Notably, there were signs of airway disease in nearly half of the patients with minimal or no history of tobacco smoke exposure.Conclusions: Pulmonary involvement in RA can be identified through the use of a combination of diagnostic methods that are simple, safe, and inexpensive. Our results lead us to suggest that RA patients with signs of lung involvement should be screened for lung abnormalities, even if presenting with no respiratory symptoms