Evaluation of respiratory dysfunction and disability

The determination of functional consequences (dysfunction) and their impact on daily life (incapacitation) is central to the evaluation of patients with occupational respiratory diseases. The present review addresses the fundamentals underlying the instruments used to determine the degree of dysfunction, including clinical aspects, as well as those related to pulmonary function and, in some circumstances, exercise tolerance. In particular, a multifactorial system of classifying the degree of dysfunction is presented, with the objective of informing decisions related to the awarding of retirement benefits in Brazil.A determinaçâo das conseqüências funcionais (disfunção) e do seu impacto na vida diária (incapacidade) são aspectos centrais da avalição de pacientes com doença ocupacional respiratória. A presente revisão apresenta as bases fundamentais para o entendimento dos instrumentos utilizados para a definição do grau de disfunção, incluindo aspectos clínicos, funcionais pulmonares e, em algumas circunstâncias, da capacidade de exercício. Em especial, apresenta-se uma classificação multifatorial do grau de disfunção com o intuito de nortear a concessão ou não de benefícios previdenciários em nosso meio.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaUniversidade Estadual de Campinas Faculdade de Ciências Médicas DMPSUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de MedicinaUNIFESP, EPM, Depto. de MedicinaSciEL

Reference values for lung function tests: III. Carbon monoxide diffusing capacity (transfer factor)

Carbon monoxide diffusing capacity (DLCO) or transfer factor (TLCO) is a particularly useful test of the appropriateness of gas exchange across the lung alveolocapillary membrane. With the purpose of establishing predictive equations for DLCO using a non-smoking sample of the adult Brazilian population, we prospectively evaluated 100 subjects (50 males and 50 females aged 20 to 80 years), randomly selected from more than 8,000 individuals. Gender-specific linear prediction equations were developed by multiple regression analysis with single breath (SB) absolute and volume-corrected (VA) DLCO values as dependent variables. In the prediction equations, age (years) and height (cm) had opposite effects on DLCOSB (ml min-1 mmHg-1), independent of gender (-0.13 (age) + 0.32 (height) - 13.07 in males and -0.075 (age) + 0.18 (height) + 0.20 in females). On the other hand, height had a positive effect on DLCOSB but a negative one on DLCOSB/VA (P0.05). Our results therefore provide an original frame of reference for either DLCOSB or DLCOSB/VA in Brazilian males and females aged 20 to 80 years, obtained from the standardized single-breath technique.University of LondonUniversidade Federal de São Paulo (UNIFESP)UNIFESPSciEL

Asbestos-related diseases

This chapter presents a bibliographic review of asbestos-related diseases. The latest diagnostic, radiological, computed tomography and lung function aspects of benign pleural disease, asbestosis, occupational lung cancer and mesothelioma are discussed.Apresenta-se uma revisão bibliográfica das doenças asbesto-relacionadas. São discutidos e atualizados os critérios diagnósticos, as características radiológicas, tomográficas e funcionais das alterações benignas de pleura, da asbestose, do câncer de pulmão ocupacional e do mesotelioma maligno de pleura.Universidade de São Paulo Faculdade de Medicina Hospital das ClínicasSanta Casa de São Paulo Faculdade de Ciências Médicas Departamento de Medicina SocialUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaUNIFESP, EPMSciEL

Iron stores and coagulation parameters in patients with hypoxemic polycythemia secondary to chronic obstructive pulmonary disease: the effect of phlebotomies

This study was designed to determine the effects of phlebotomy on iron body contents and coagulation tests of COPD patients with polycythemia secondary to hypoxemia. Seventeen patients with COPD and hematocrits higher than 54 percent (mean Hct: 57 ± 0.49 percent ), who had not received anti-inflammatory or antiplatelet aggregation agents recently. Their mean forced expiratory volume at 1 second (FEV1) was 0.92 ± 0.11 L. Intervention: Blood work was collected to evaluate the following: serum iron and ferritin levels, total iron binding capacity, transferrin saturation index, fibrinogen plasma levels, activated partial thromboplastin time, platelet count, platelet aggregation measurements, and thromboelastography coagulation parameters. The blood samples were obtained before and about 7 days after the hematocrit correction by 300-400 ml phlebotomies done every other day. The mean number of phlebotomies done for each patient was 4.4. Postphlebotomy iron serum levels decreased from 90.1 ± 14.8 to 59.7 ± 9.9 mg/dl and the ferritin serum levels from 133.8 ± 37.9 to 70.8 ± 32.7 ng/ml (p< 0.05). Regarding the coagulation studies, there were significant increases in the platelet count, from 227,300 ± 13,900 to 312,500 ± 30,200 per mm³, and in the maximum clot amplitude (a) obtained by thromboelastography ( from 53.6 ± 1.4 percent to 60.4 ± 1.1 percent). The coagulation time (k) of the thromboelastography also decreased significantly, from 7.5 ± 0.7mm prephlebotomy to 4.5 ± 0.3mm postphlebotomy. Although the coagulation changes were small amount, the observed significant decrease in iron contents may have important clinical implications.Determinar os efeitos das sangrias nas reservas corporais de ferro e em testes da coagulação sanguínea de pacientes com policitemia secundária a hipoxemia por doença pulmonar obstrutiva crônica (DPOC). Dezesete pacientes portadores de DPOC, com hematócritos superiores a 54%, ( Hct médio: 57± 0,49%) que não tinham feito uso recente de agentes antinflamatórios ou antiadesivos plaquetários, e cujo volume expirado forçado no primeiro segundo (VEF1), médio foi de 0,92 ± 0,11 L. Determinação dos níveis de ferro, ferritina, capacidade de ligação do ferro, índice de saturação da transferrina, fibrinogênio, tempo de tromboplastina parcial ativada, número de plaquetas, agregação plaquetária e de parâmetros da coagulação medidos pela tromboelastografia. Tais dosagens foram realizadas antes e em torno de sete dias após a normalização dos hematócritos através de sangrias de 300-400ml cada, realizadas em dias alternados, resultando num número médio de 4,4 sangrias por paciente. Com as sangrias os níveis séricos do ferro caíram de 90,1± 14,8 mg/dl a 59,7 ± 9,9 mg/dl, e os níveis da ferritina sérica de 133,8 ± 37,9 ng/ml a 70,8 ± 32,7 ng/ml (p<0.05). Em relação aos estudos da coagulação, houve um aumento significante na contagem plaquetária de 227.300 ± 13.900 a 312.500 ± 30,200 elementos/mm³, e na amplitude máxima do coágulo obtida pela tromboelastografia (a), de 53,6 ± 1,4% para 60,4 1 ± 1,1%. O tempo de coagulação (k) da tromboelastografia, também diminuiu significantemente de 7,5 ± 0,7 mm pré-flebotomias para 4,5 ± 0,3 mm pós-flebotomias. Os autores concluem que embora as alterações da coagulação tenham sido de pequena monta, os decréscimos nas reservas de ferro foram significantes podendo ter implicações clínicas importantes.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Respiratory and Hematology DivisionsUNIFESP, EPM, Respiratory and Hematology DivisionsSciEL

Identification of rounded atelectasis in workers exposed to asbestos by contrast helical computed tomography

Rounded atelectasis (RA) is a benign and unusual form of subpleural lung collapse that has been described mostly in asbestos-exposed workers. This form of atelectasis manifests as a lung nodule and can be confused with bronchogenic carcinoma upon conventional radiologic examination. the objective of the present study was to evaluate the variation in contrast uptake in computed tomography for the identification of asbestos-related RA in Brazil. Between January 1998 and December 2000, high-resolution computed tomography (HRCT) was performed in 1658 asbestos-exposed workers. the diagnosis was made in nine patients based on a history of prior asbestos exposure, the presence of characteristic (HRCT) findings and lesions unchanged in size over 2 years or more. in three of them the diagnosis was confirmed during surgery. the dynamic contrast enhancement study was modified to evaluate nodules and pulmonary masses. All nine patients with RA received iodide contrast according to weight. the average enhancement after iodide contrast was infused, reported as Hounsfield units (HU), increased from 62.5 +/- 9.7 to 125.4 +/- 20.7 (P < 0.05), with a mean enhancement of 62.5 +/- 19.7 (range 40 to 89) and with a uniform dense opacification. in conclusion, in this study all patients with RA showed contrast enhancement with uniform dense opacification. the main clinical implication of this finding is that this procedure does not permit differentiation between RA and malignant pulmonary neoplasm.Grp Interinst Estudos Doencas Relacionadas Amiant, São Paulo, BrazilUniv São Paulo, Fac Med, Hosp Clin, Inst Corcao,Disciplina Pneumol, São Paulo, BrazilUniv São Paulo, Fac Med, Disciplinas Radiol, São Paulo, BrazilUniv São Paulo, Fac Med, Disciplinas Patol, São Paulo, BrazilUniv Estadual Campinas, Fac Med, Area Med Ocupac, Campinas, SP, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Disciplinas Pneumol, São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Disciplinas Radiol, São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Disciplinas Pneumol, São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Disciplinas Radiol, São Paulo, BrazilWeb of Scienc

Microvascular oxygen delivery-to-utilization mismatch at the onset of heavy-intensity exercise in optimally treated patients with CHF

Sperandio PA, Borghi-Silva A, Barroco A, Nery LE, Almeida DR, Neder JA. Microvascular oxygen delivery-to-utilization mismatch at the onset of heavy-intensity exercise in optimally treated patients with CHF. Am J Physiol Heart Circ Physiol 297: H1720-H1728, 2009. First published September 4, 2009; doi:10.1152/ajpheart.00596.2009.-Impaired muscle blood flow at the onset of heavy-intensity exercise may transiently reduce microvascular O(2) pressure and decrease the rate of O(2) transfer from capillary to mitochondria in chronic heart failure (CHF). However, advances in the pharmacological treatment of CHF (e. g., angiotensin-converting enzyme inhibitors and third-generation beta-blockers) may have improved microvascular O(2) delivery to an extent that intramyocyte metabolic inertia might become the main locus of limitation of O(2) uptake ((V)over dot(O2)) kinetics. We assessed the rate of change of pulmonary (V)over dot(O2) ((V)over dot(O2p)), (estimated) fractional O(2) extraction in the vastus lateralis (similar to Delta[deoxy-Hb + Mb] by near-infrared spectroscopy), and cardiac output ((Q)over dot(T)) during high-intensity exercise performed to the limit of tolerance (Tlim) in 10 optimally treated sedentary patients (ejection fraction = 29 +/- 8%) and 11 controls. Sluggish (V)over dot(O2p) and (Q)over dot(T) kinetics in patients were significantly related to lower Tlim values (P < 0.05). the dynamics of Delta[deoxy-Hb + Mb], however, were faster in patients than controls [mean response time (MRT) = 15.9 +/- 2.0 s vs. 19.0 +/- 2.9 s; P < 0.05] with a subsequent response overshoot being found only in patients (7/10). Moreover, tau(V)over dot(O2)/MRT-[deoxy-Hb + Mb] ratio was greater in patients (4.69 +/- 1.42 s vs. 2.25 +/- 0.77 s; P < 0.05) and related to (Q)over dot(T) kinetics and Tlim (R = 0.89 and -0.78, respectively; P < 0.01). We conclude that despite the advances in the pharmacological treatment of CHF, disturbances in central and peripheral circulatory adjustments still play a prominent role in limiting (V)over dot(O2p) kinetics and tolerance to heavy-intensity exercise in nontrained patients.Fed Univ São Paulo UNIFESP, Dept Med, Div Resp Med, Pulm Funct & Clin Exercise Physiol Unit SEFICE, São Paulo, BrazilFed Univ São Paulo UNIFESP, Dept Med, Div Cardiol, São Paulo, BrazilFed Univ Sao Carlos UFSCar, Nucleus Res Phys Exercise, Cardiopulm Lab, Sao Carlos, SP, BrazilFed Univ São Paulo UNIFESP, Dept Med, Div Resp Med, Pulm Funct & Clin Exercise Physiol Unit SEFICE, São Paulo, BrazilFed Univ São Paulo UNIFESP, Dept Med, Div Cardiol, São Paulo, BrazilWeb of Scienc

Differences between remaining ability and loss of capacity in maximum aerobic impairment

In the evaluation of exercise intolerance of patients with respiratory diseases the American Medical Association (AMA) and the American Thoracic Society (ATS) have proposed similar classifications for rating aerobic impairment using maximum oxygen uptake (VO2max) normalized for total body weight (ml min-1 kg-1). However, subjects with the same VO2max weight-corrected values may have considerably different losses of aerobic performance (VO2max expressed as % predicted). We have proposed a new, specific method for rating loss of aerobic capacity (VO2max, % predicted) and we have compared the two classifications in a prospective study involving 75 silicotic claimants. Logistic regression analysis showed that the disagreement between rating systems (higher dysfunction by the AMA/ATS classification) was associated with age >50 years (P<0.005) and overweight (P = 0.04). Interestingly, clinical (dyspnea score) and spirometric (FEV1) normality were only associated with the VO2max, % predicted, normal values (P<0.01); therefore, in older and obese subjects the AMA/ATS classification tended to overestimate the aerobic dysfunction. We conclude that in the evaluation of aerobic impairment in patients with respiratory diseases, the loss of aerobic capacity (VO2max, % predicted) should be used instead of the traditional method (remaining aerobic ability, VO2max, in ml min-1 kg-1).Universidade Federal de São Paulo (UNIFESP)Universidade Estadual de CampinasHarbor-UCLA Medical CenterUNIFESPSciEL