Performance analysis of the Flutter VRP1 under different flows and angles.

BACKGROUND: The Flutter VRP1 device is used for airway clearance. Its performance is based on 4 basic effects: positive expiratory pressure (PEP), forced exhalations (huff), high-frequency airway flow oscillation, and modification of mucus viscoelasticity. The purpose of this study was to determine the flow and angle conditions in which these effects are optimized. METHODS: In an experimental setting, a Flutter VRP1 was fixed at angles of -30 degrees , -15 degrees , 0 degrees , +15 degrees , and +30 degrees , and submitted to flows ranging from 0.2 L/s to 2.0 L/s. The flows and angles that resulted in higher and lower values of mean pressure, mean flow, oscillation frequency, and flow amplitude were determined. In addition, it was defined which angles facilitated achieving "ideal" mean pressure of 10 cm H2O and 20 cm H2O and oscillation frequency of 12 Hz. RESULTS: At all flows, +15 degrees produced higher mean pressure (p < 0.01), whereas lower values were produced at -30 degrees at lower flows, 0 degrees at intermediate flows, and +30 degrees at higher flows (p < 0.01). Higher oscillation frequencies were produced at +30 degrees and +15 degrees (p < 0.01), and lower values were produced at -30 degrees and -15 degrees at all flows (p < 0.01). Higher flow-amplitude values were produced at +30 degrees , +15 degrees , and 0 degrees (p < 0.01), and lower values were produced at -30 degrees and -15 degrees (p < 0.01). Mean pressure of 10 cm H2O was reached with the lowest flow (0.2 L/s) at +30 degrees , and mean pressure of 20 cm H2O was produced at +15 degrees (1.0 L/s), whereas an oscillation frequency of 12 Hz was reached at 0 degrees , +30 degrees , and +15 degrees , at 0.2 L/s. CONCLUSIONS: Positive inclinations optimize positive expiratory pressure and flow-amplitude effects, whereas negative inclinations optimize huff effect. This theoretical knowledge may help optimize the use of the device when applied to different conditions.

[Cardiac autonomic responses to head-up tilt in obese adolescents]. / Respostas autonômicas cardíacas à manobra de tilt em adolescentes obesos.

INTRODUCTION: Obesity is associated with alterations of the autonomic nervous system. Previous studies in adults have shown that obese individuals present a decreased cardiac autonomic response to postural challenges. However, little is known about the impact of overweight on autonomic responses to passive postural stress in adolescents. OBJECTIVE: to compare cardiac autonomic responses to the head-up tilt maneuver between obese and non-obese adolescents by analyzing heart rate variability. METHODS: Fourteen obese adolescents (15.5+/-1.6 years) were compared with twenty non-obese subjects (15.4+/-0.8 years). Cardiac autonomic modulation was studied by heart rate variability (HRV) analysis of 5 minute RR interval recordings before and after a 70 masculine head-up tilt maneuver. HRV was analyzed according to the time domain (TD) and frequency-domain (FD) methods. The power spectral components were studied at low (LF) and high (HF) frequencies and as the LF/HF ratio. RESULTS: Obese adolescents demonstrated significantly lower HF normalized units (38.2+/-11.1 vs 53.9+/-15.5, p<0.05) and higher LF normalized units (60.7+/-11.3 vs 44.6+/-15.7, p<0.05) in the supine position. No difference was found in any HRV parameters after head-up tilt. When comparing differences between the orthostatic and supine positions, obese adolescents showed lesser changes of LF normalized units (22.4+/-12.6 vs 38+/-16.4, p<0.05) and HF normalized units (-21.9+/-12.4 vs -37.3+/-16.3, p<0.05). CONCLUSIONS: Obese adolescents have an abnormal cardiac autonomic response to the head-up tilt maneuver, characterized principally by a decreased parasympathetic response.

Diurnal variations in the parameters of pulmonary function and respiratory muscle strength in patients with COPD.

OBJECTIVE: To evaluate the magnitude of diurnal changes in the parameters of pulmonary function and respiratory muscle strength/endurance in a sample of patients with COPD. METHODS: A group of 7 patients underwent spirometry, together with determination of MIP and MEP, at two distinct times (between 8:00 and 8:30 a.m. and between 4:30 and 5:00 p.m.) on a single day. Between assessments, the patients remained at rest in the laboratory. RESULTS: In accordance with the Global Initiative for Chronic Obstructive Pulmonary Disease staging system, COPD was classified as moderate, severe, and very severe in 1, 3, and 3 of the patients, respectively. From the first to the second assessment, there were significant decreases in FVC, FEV1, and MEP (of 13%, 15%, and 10%, respectively), as well as (less than significant) decreases in PEF, MIP, and maximal voluntary ventilation (of 9%, 3%, and 11%, respectively). CONCLUSIONS: In this sample of COPD patients, there were diurnal variations in the parameters of pulmonary function and respiratory muscle strength. The values of FEV1, FVC, and MEP were significantly lower in the afternoon than in the morning.

Nutritional status is related to fat-free mass, exercise capacity and inspiratory strength in severe chronic obstructive pulmonary disease patients.

INTRODUCTION: Being overweight or obese is associated with a higher rate of survival in patients with advanced chronic obstructive pulmonary disease (COPD). This paradoxical relationship indicates that the influence of nutritional status on functional parameters should be further investigated. OBJECTIVE: To investigate the impact of nutritional status on body composition, exercise capacity and respiratory muscle strength in severe chronic obstructive pulmonary disease patients. METHODS: Thirty-two patients (nine women) were divided into three groups according to their body mass indices (BMI): overweight/obese (25 < or = BMI < or = 34.9 kg/m(2), n=8), normal weight (18.5 < or = BMI < or = 24.9 kg/m(2), n=17) and underweight (BMI <18.5 kg/m(2), n=7). Spirometry, bioelectrical impedance, a six-minute walking distance test and maximal inspiratory and expiratory pressures were assessed. RESULTS: Airway obstruction was similar among the groups (p=0.30); however, overweight/obese patients had a higher fat-free mass (FFM) index [FFMI=FFM/body weight(2) (mean+/-SEM: 17+/-0.3 vs. 15+/-0.3 vs. 14+/-0.5 m/kg(2), p<0.01)], exercise capacity (90+/-8 vs. 79+/-6 vs. 57+/-8 m, p=0.02) and maximal inspiratory pressure (63+/-7 vs. 57+/-5 vs. 35+/-8 % predicted, p=0.03) in comparison to normal weight and underweight patients, respectively. In addition, on backward multiple regression analysis, FFMI was the unique independent predictor of exercise capacity (partial r=0.52, p<0.01). CONCLUSIONS: Severe chronic obstructive pulmonary disease (COPD) patients who were overweight or obese had a greater FFM, exercise capacity and inspiratory muscle strength than patients with the same degree of airflow obstruction who were of normal weight or underweight, and higher FFM was independently associated with higher exercise capacity. These characteristics of overweight or obese patients might counteract the drawbacks of excess weight and lead to an improved prognosis in COPD.

Profile of the level of physical activity in the daily lives of patients with COPD in Brazil.

OBJECTIVE: To evaluate characteristics of physical activities in daily life in COPD patients in Brazil, correlating those characteristics with physiological variables. METHODS: Physical activities in daily life were evaluated in 40 COPD patients (18 males; 66 + or - 8 years of age; FEV(1) = 46 + or - 16 % of predicted; body mass index = 27 + or - 6 kg/m(2)) and 30 healthy age- and gender-matched subjects, using a multiaxial accelerometer-based sensor for 12 h/day on two consecutive days. We also assessed maximal and functional exercise capacity, using the incremental exercise test and the six-minute walk test (6MWT), respectively; MIP and MEP; peripheral muscle force, using the one-repetition maximum test and the handgrip test; quality of life, using the Saint George's Respiratory Questionnaire (SGRQ); functional status, using the London Chest Activity of Daily Living questionnaire; and dyspnea sensation, using the Medical Research Council (MRC) scale. RESULTS: Mean walking time/day was shorter for COPD patients than for the controls (55 + or - 33 vs. 80 + or - 28 min/day; p = 0.001), as movement intensity was lower (1.9 + or - 0.4 vs. 2.3 + or - 0.6 m/s(2); p = 0.004). The COPD patients also tended to spend more time seated (294 + or - 114 vs. 246 + or - 122 min/day, p = 0.08). Walking time/day correlated with the 6MWT (r = 0.42; p = 0.007) and maximal workload (r = 0.41; p = 0.009), as well as with age, MRC scale score and SGRQ activity domain score (-0.31 < or = r < or = -0.43; p < or = 0.05 for all). CONCLUSIONS: This sample of Brazilian patients with COPD, although more active than those evaluated in studies conducted in Europe, were less active than were the controls. Walking time/day correlated only moderately with maximal and functional exercise capacity.

Portuguese-language version of the Chronic Respiratory Questionnaire: a validity and reproducibility study.

OBJECTIVE: To determine the validity and reproducibility of a Portuguese-language version of the Chronic Respiratory Questionnaire (CRQ) in patients with COPD. METHODS: A Portuguese-language version of the CRQ (provided by McMaster University, the holder of the questionnaire copyright) was applied to 50 patients with COPD (70 +/- 8 years of age; 32 males; FEV1 = 47 +/- 18% of predicted) on two occasions, one week apart. The CRQ has four domains (dyspnea, fatigue, emotional function, and mastery) and was applied as an interviewer-administered instrument. The Saint George's Respiratory Questionnaire (SGRQ), already validated for use in Brazil, was used as the criterion for validation. Spirometry and the six-minute walk test (6MWT) were performed to analyze the correlations with the CRQ scores. RESULTS: There were no significant CRQ test-retest differences (p > 0.05 for all domains). The test-retest intraclass correlation coefficient was 0.98, 0.97, 0.98 and 0.95 for the dyspnea, fatigue, emotional function and mastery domains, respectively. The Cronbach's alpha coefficient was 0.91. The CRQ domains correlated significantly with the SGRQ domains (-0.30 < r < -0.67; p < 0.05). There were no significant correlations between spirometric variables and the CRQ domains or between the CRQ domains and the 6MWT, with the exception of the fatigue domain (r = 0.30; p = 0.04). CONCLUSIONS: The Portuguese-language version of the CRQ proved to be reproducible and valid for use in Brazilian patients with COPD.

Validation of the Modified Pulmonary Functional Status and Dyspnea Questionnaire and the Medical Research Council scale for use in Brazilian patients with chronic obstructive pulmonary disease.

OBJECTIVE: To determine the validity and reproducibility of two subjective instruments to assess limitations in activities of daily living (ADLs) in patients with chronic obstructive pulmonary disease (COPD) in Brazil: the Pulmonary Functional Status and Dyspnea Questionnaire - Modified version (PFSDQ-M) and the Medical Research Council (MRC) scale. METHODS: Thirty patients with COPD (age, 67 +/- 10 years; males, 17; forced expiratory volume in one second, 42% +/- 13% of predicted) completed the Portuguese-language versions of the two instruments on two occasions, one week apart. The PFSDQ-M has three components: influence of dyspnea on ADLs, influence of fatigue on ADLs change in ADLs experienced by the patient. The MRC scale is simple, with only five items, in which patients report the degree to which dyspnea limits their performance of ADLs. The traditional Saint George's Respiratory Questionnaire (SGRQ), previously validated for use in Brazil, was used as a validation criterion. RESULTS: The test-retest reliability (intraclass correlation coefficient) of the PFSDQ-M was 0.93, 0.92 and 0.90 for dyspnea, fatigue and change components, respectively, compared with 0.83 for the MRC scale. Bland-Altman plots showed good test-retest agreement for the PFSDQ-M. The components of the PFSDQ-M and the MRC scale correlated significantly with all of the domains and the total score of the SGRQ (0.49 < r < 0.80; p < 0.01 for all). CONCLUSIONS: The Portuguese-language versions of the PFSDQ-M and the MRC scale proved reproducible and valid for use in patients with COPD in Brazil.

Pulmonary function and respiratory muscle strength in chronic renal failure patients on hemodialysis.

OBJECTIVE: To evaluate pulmonary function and respiratory muscle strength in chronic renal failure patients, correlating these variables with hemodialysis-related weight fluctuation; to study the correlation between the duration hemodialysis and potential respiratory alterations. METHODS: Seventeen patients (median age, 47 years; interquartile range, 41-52 years), submitted to three weekly hemodialysis sessions for a median of 27 months (interquartile range, 14-55) were evaluated. Twelve of the patients were male. The patients underwent spirometry. Maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) were measured prior to and after the first hemodialysis session of the week. Body weight was quantified prior to and after each of the three weekly sessions. RESULTS: Before the first hemodialysis session of the week, 8 patients presented mild restrictive defect, which normalized after the session in 2 of those patients. After dialysis, there was a significant increase in forced vital capacity (p = 0.02) and a significant decrease in body weight (p = 0.0001). Weight fluctuation over 3 days without hemodialysis tended to correlate with the variation in forced vital capacity in the first weekly session (r = 0.47; p = 0.055). Duration of hemodialysis correlated with predialysis MIP (r = -0.3; p = 0.03) and MEP (r = -0.63; p = 0.006). CONCLUSIONS: More pronounced weight gain in the interdialytic period is associated with worsening of lung function, which is almost fully reversible by hemodialysis. In addition, longer duration of hemodialysis is associated with decreased respiratory muscle strength.

Variação diurna de parâmetros de função pulmonar e de força muscular respiratória em pacientes com DPOC / Diurnal variations in the parameters of pulmonary function and respiratory muscle strength in patients with COPD

OBJETIVO: Avaliar a magnitude de mudanças diurnas em parâmetros de função pulmonar e de força e resistência dos músculos respiratórios em uma amostra de pacientes com DPOC. MÉTODOS: Um grupo com 7 pacientes foi submetido a espirometria e a determinação de PImáx e PEmáx em dois momentos (entre 8h00 e 8h30 e entre 16h30 e 17h00) em um único dia. Os pacientes permaneceram em repouso na área do laboratório entre as avaliações. RESULTADOS: De acordo com o sistema de estadiamento da Global Initiative for Chronic Obstructive Pulmonary Disease, a doença foi classificada em moderada, grave e muito grave em 1, 3 e 3 pacientes, respectivamente. Da primeira para a segunda avaliação, houve uma queda significativa em CVF, VEF1 e PEmáx (de 13%, 15% e 10%, respectivamente), bem como uma queda não significativa em PFE, PImáx e ventilação voluntária máxima (de 9%, 3% e 11%, respectivamente). CONCLUSÕES: Nesta amostra de pacientes com DPOC, houve variações diurnas nos parâmetros de função pulmonar e de força de músculos respiratórios. Os valores de VEF1, CVF e PEmáx foram significativamente menores à tarde do que de manhã.

OBJECTIVE: To evaluate the magnitude of diurnal changes in the parameters of pulmonary function and respiratory muscle strength/endurance in a sample of patients with COPD. METHODS: A group of 7 patients underwent spirometry, together with determination of MIP and MEP, at two distinct times (between 8:00 and 8:30 a.m. and between 4:30 and 5:00 p.m.) on a single day. Between assessments, the patients remained at rest in the laboratory. RESULTS: In accordance with the Global Initiative for Chronic Obstructive Pulmonary Disease staging system, COPD was classified as moderate, severe, and very severe in 1, 3, and 3 of the patients, respectively. From the first to the second assessment, there were significant decreases in FVC, FEV1, and MEP (of 13%, 15%, and 10%, respectively), as well as (less than significant) decreases in PEF, MIP, and maximal voluntary ventilation (of 9%, 3%, and 11%, respectively). CONCLUSIONS: In this sample of COPD patients, there were diurnal variations in the parameters of pulmonary function and respiratory muscle strength. The values of FEV1, FVC, and MEP were significantly lower in the afternoon than in the morning.

Profile of physical activity in daily life in physically independent elderly men and women / Perfil da atividade física na vida diária de homens e mulheres idosos fisicamente independentes / Perfil de la actividad física en la vida diaria de hombres y mujeres mayores físicamente independientes

This study compared the profile of daily activities and variables of functional fitness between elderly men and women, as well as the relation of their time spent walking per day with the remaining study variables concerning each gender. Thirty healthy elderly (15 men; 66 ± 6 years), sedentary and physically independent, had their daily activities evaluated objectively by a multi-axial accelerometer as well as their metabolic and functional fitness variables by means of specific protocols. Both men and women presented similar time spent in walking per day, even though men had higher intensity during walking. Women spent longer time standing, and men, sitting. A better performance was achieved by men in most physical tests in regard to absolute values but not in relative values. In conclusion, despite their different patterns of daily activities, elderly men and women do not differ in time spent walking per day.

Este estudo comparou o perfil da atividade da vida diária e variáveis de aptidão funcional entre homens e mulheres idosos, bem como a relação de seu tempo de caminhada por dia com as demais variáveis estudadas em cada gênero. Trinta idosos saudáveis (15 homens, 66 ± 6 anos), sedentários e fisicamente independentes, tiveram suas atividades diárias avaliadas objetivamente por um acelerômetro multi-axial, bem como variáveis de aptidão física e funcional avaliadas por protocolos específicos. Homens e mulheres apresentaram tempo gasto andando por dia semelhantes, apesar dos homens se movimentarem com maior intensidade. As mulheres permaneceram mais tempo em pé e os homens mais tempo sentados. Os homens apresentaram melhor desempenho em valores absolutos na maioria dos testes físicos, mas não em valores relativos. Em conclusão, apesar de seus diferentes padrões de atividades diárias, os homens idosos e mulheres não diferem em tempo de caminhada por dia.

Este estudio comparó el perfil de la actividad de la vida diaria y variables de aptitud funcional entre hombres y mujeres mayores, así como la relación de su tiempo de caminata por día con las demás variables estudiadas en cada género. Treinta mayores saludables (15 hombres, 66±6 años), sedentarios y físicamente independientes, tuvieron sus actividades diarias evaluadas objetivamente por un acelerómetro multi-axial, así como variables de aptitud física y funcional evaluados por protocolos específicos. Todos presentaron tiempo gasto andando por día semejantes, a pesar de que los hombres se muevan con mayor intensidad. Las mujeres permanecieron más tiempo en pie y los hombres más tiempo sentados. Los hombres presentaron mejor desempeño en valores absolutos en la mayoría de los testes físicos, perono en valores relativos. Se concluyó que los hombres y las mujeres mayores no se difieren en tiempo de caminata por día.

Nutritional status is related to fat-free mass, exercise capacity and inspiratory strength in severe chronic obstructive pulmonary disease patients

INTRODUCTION: Being overweight or obese is associated with a higher rate of survival in patients with advanced chronic obstructive pulmonary disease (COPD). This paradoxical relationship indicates that the influence of nutritional status on functional parameters should be further investigated. OBJECTIVE: To investigate the impact of nutritional status on body composition, exercise capacity and respiratory muscle strength in severe chronic obstructive pulmonary disease patients. METHODS: Thirty-two patients (nine women) were divided into three groups according to their body mass indices (BMI): overweight/obese (25 < BMI < 34.9 kg/m², n=8), normal weight (18.5 < BMI < 24.9 kg/m², n=17) and underweight (BMI <18.5 kg/m², n=7). Spirometry, bioelectrical impedance, a six-minute walking distance test and maximal inspiratory and expiratory pressures were assessed. RESULTS: Airway obstruction was similar among the groups (p=0.30); however, overweight/obese patients had a higher fat-free mass (FFM) index [FFMI=FFM/body weight² (mean±SEM: 17±0.3 vs. 15±0.3 vs. 14±0.5 m/kg², p<0.01)], exercise capacity (90±8 vs. 79±6 vs. 57±8 m, p=0.02) and maximal inspiratory pressure (63±7 vs. 57±5 vs. 35±8 percent predicted, p=0.03) in comparison to normal weight and underweight patients, respectively. In addition, on backward multiple regression analysis, FFMI was the unique independent predictor of exercise capacity (partial r=0.52, p<0.01). CONCLUSIONS: Severe chronic obstructive pulmonary disease (COPD) patients who were overweight or obese had a greater FFM, exercise capacity and inspiratory muscle strength than patients with the same degree of airflow obstruction who were of normal weight or underweight, and higher FFM was independently associated with higher exercise capacity. These characteristics of overweight or obese patients might counteract the drawbacks of excess weight and lead to an improved prognosis in COPD.

Taxa metabólica basal em universitários: comparação entre valores medidos e preditos / Basal metabolic rate of university students: comparison between measured and predicted values

OBJETIVO: Comparar a taxa metabólica basal medida por recursos de calorimetria indireta com a taxa metabólica basal estimada por equações de predição em universitários. MÉTODOS: A amostra foi constituída por 48 voluntários (23 moças e 25 rapazes) na faixa etária entre 20 e 25 anos. A taxa metabólica basal medida por calorimetria indireta foi comparada à taxa metabólica basal estimada pelas equações de predição propostas pela World Health Organization e por Henry & Rees. As informações foram analisadas mediante o teste t pareado, coeficiente de correlação intraclasse, desvio-padrão das diferenças e técnica de Bland-Altman. RESULTADOS: Não ocorreram diferenças significativas entre os valores da taxa metabólica basal medidos e estimados por ambas as equações de predição. Os coeficientes de correlação intraclasse entre os valores medidos e estimados foram significativos em linguagem estatística nos dois gêneros e mais elevados nos rapazes, e a magnitude do desvio-padrão das diferenças foi similar em ambos os gêneros. A técnica de Bland-Altman sugere comportamento de variabilidade similar entre a taxa metabólica basal medida e predita por ambas as equações, porém a taxa metabólica basal predita pela equação de Henry & Rees apresentou coincidências mais elevadas, sobretudo entre as moças. CONCLUSÃO: Mediante indicadores estatísticos mais conservadores, conclui-se que a taxa metabólica basal medida por recursos de calorimetria indireta e predita por ambas as equações não apresentam diferenças significativas. No entanto, ao considerar procedimentos estatísticos aparentemente de maior sensibilidade na detecção de eventuais diferenças entre os valores medidos e preditos, verificou-se algum comprometimento quanto à potencialidade das equações para estimar a taxa metabólica basal, apresentando viés entre 12,5 por cento e 15,6 por cento em comparação com a taxa metabólica basal medida por recursos de calorimetria indireta.

OBJECTIVE: The aim of this work is to compare the basal metabolic rate determined by indirect calorimetry with the basal metabolic rate estimated by prediction equations in university students. METHODS: The sample consisted of 48 Brazilian volunteers (23 women and 25 men), aged 20-25 years. The basal metabolic rate determined by indirect calorimetry was compared with the basal metabolic rate estimated by the World Health Organization and Henry & Rees equations. The data was analyzed by the paired t-test, intra-class correlation coefficients, standard deviation of differences and Bland and Altman technique. RESULTS: There were no statistically significant differences between measured and estimated basal metabolic rates by both equations. Correlation coefficients between measured and estimated values were higher in men, however statistically significant in both genders. The magnitude of the standard deviation of differences was similar in both genders. The Bland and Altman technique suggests a similar variability behavior between the measured basal metabolic rate and that estimated by both equations. However, basal metabolic rate predicted by the Henry & Rees equation showed greater concordance than that predicted by the World Health Organization equation, especially in women. CONCLUSION: Due to the use of more conservative statistical indicators, it appears that the basal metabolic rates measured by indirect calorimetry and predicted by both equations do not differ significantly. However, when statistical procedures with an apparently higher sensitivity for detecting differences between measured and predicted rates are used, the potential of the equations to estimate the basal metabolic rate was somewhat compromised. There was a bias of 12.5 percent to 15.6 percent in comparison with the basal metabolic rate determined by indirect calorimetry.

Versão em português do Chronic Respiratory Questionnaire: estudo da validade e reprodutibilidade / Portuguese-language version of the Chronic Respiratory Questionnaire: a validity and reproducibility study

OBJETIVO: Verificar a validade e a reprodutibilidade de uma versão em português do Chronic Respiratory Questionnaire (CRQ) em pacientes com DPOC. MÉTODOS: A versão em português do CRQ (fornecida pela Universidade de McMaster, detentora dos direitos do questionário) foi aplicada a 50 pacientes portadores de DPOC (32 homens; 70 ± 8 anos; VEF1 = 47 ± 18 por cento predito) em dois momentos, com intervalo de uma semana. O CRQ tem quatro domínios (dispneia, fadiga, função emocional e autocontrole) e foi aplicado em formato de entrevista. O Saint George's Respiratory Questionnaire (SGRQ), já validado em português, foi utilizado como o critério de validação. A espirometria e o teste da caminhada de seis minutos (TC6) foram realizados para a análise das correlações com os valores do CRQ. RESULTADOS: Não foram observadas diferenças significativas entre a aplicação e a reaplicação do CRQ (p > 0.05 para todos os domínios). O coeficiente de correlação intraclasse entre a aplicação e a reaplicação foi de 0,98; 0,97; 0,98 e 0,95 para os domínios dispneia, fadiga, função emocional e autocontrole, respectivamente. O coeficiente alfa de Cronbach foi 0,91. Os domínios do CRQ se correlacionaram significativamente com os domínios do SGRQ (-0.30 < r < -0.67; p < 0,05). Não houve correlação entre as variáveis espirométricas e os domínios do CRQ e nem entre esses domínios e o TC6, exceto para o domínio fadiga (r = 0,30; p = 0,04). CONCLUSÕES: A versão em português do CRQ demonstrou ser reprodutível e válida em pacientes brasileiros portadores de DPOC.

OBJECTIVE: To determine the validity and reproducibility of a Portuguese-language version of the Chronic Respiratory Questionnaire (CRQ) in patients with COPD. METHODS: A Portuguese-language version of the CRQ (provided by McMaster University, the holder of the questionnaire copyright) was applied to 50 patients with COPD (70 ± 8 years of age; 32 males; FEV1 = 47 ± 18 percent of predicted) on two occasions, one week apart. The CRQ has four domains (dyspnea, fatigue, emotional function, and mastery) and was applied as an interviewer-administered instrument. The Saint George's Respiratory Questionnaire (SGRQ), already validated for use in Brazil, was used as the criterion for validation. Spirometry and the six-minute walk test (6MWT) were performed to analyze the correlations with the CRQ scores. RESULTS: There were no significant CRQ test-retest differences (p > 0.05 for all domains). The test-retest intraclass correlation coefficient was 0.98, 0.97, 0.98 and 0.95 for the dyspnea, fatigue, emotional function and mastery domains, respectively. The Cronbach's alpha coefficient was 0.91. The CRQ domains correlated significantly with the SGRQ domains (-0.30 < r < -0.67; p < 0.05). There were no significant correlations between spirometric variables and the CRQ domains or between the CRQ domains and the 6MWT, with the exception of the fatigue domain (r = 0.30; p = 0.04). CONCLUSIONS: The Portuguese-language version of the CRQ proved to be reproducible and valid for use in Brazilian patients with COPD.

Perfil do nível de atividade física na vida diária de pacientes portadores de DPOC no Brasil / Profile of the level of physical activity in the daily lives of patients with COPD in Brazil

OBJETIVO: Avaliar as características de atividades físicas na vida diária de pacientes portadores de DPOC no Brasil e sua relação com diferentes variáveis fisiológicas. MÉTODOS: Foram avaliados 40 pacientes portadores de DPOC (18 homens; 66 ± 8 anos; VEF1 = 46 ± 16 por cento predito; índice de massa corpórea = 27 ± 6 kg/m²) e 30 idosos saudáveis pareados por gênero e idade quanto às atividades físicas na vida diária, utilizando-se um acelerômetro multiaxial por 12 h/dia durante dois dias consecutivos. Foram ainda avaliados as capacidades máxima e funcional de exercício através do teste incremental máximo e do teste de caminhada de seis minutos (TC6), respectivamente; PImáx e PEmáx; força muscular periférica através dos testes de uma repetição máxima e de força de preensão manual; qualidade de vida através de Saint George's Respiratory Questionnaire (SGRQ); estado funcional através do questionário London Chest Activity of Daily Living; e sensação de dispneia através da escala do Medical Research Council (MRC). RESULTADOS: Os pacientes portadores de DPOC apresentaram menor tempo de caminhada/dia quando comparados aos idosos saudáveis (55 ± 33 vs. 80 ± 28 min/dia; p = 0,001) e menor intensidade de movimento (1,9 ± 0,4 vs. 2,3 ± 0,6 m/s²; p = 0,004). Os pacientes com DPOC também tenderam a passar mais tempo sentados (294 ± 114 vs. 246 ± 122 min/dia; p = 0,08). O tempo de caminhada/dia correlacionou-se com TC6 (r = 0,42; p = 0,007), carga máxima de trabalho (r = 0,41; p = 0,009), idade, escala MRC e domínio atividade do SGRQ (-0,31 < r < -0,43; p < 0,05 para todos). CONCLUSÕES: Apesar de serem mais ativos do que pacientes europeus estudados previamente, pacientes portadores de DPOC no Brasil foram menos ativos em comparação a idosos saudáveis. O tempo de caminhada/dia desses pacientes correlacionou-se apenas moderadamente com a capacidade máxima e funcional de exercício.

OBJECTIVE: To evaluate characteristics of physical activities in daily life in COPD patients in Brazil, correlating those characteristics with physiological variables. METHODS: Physical activities in daily life were evaluated in 40 COPD patients (18 males; 66 ± 8 years of age; FEV1 = 46 ± 16 percent of predicted; body mass index = 27 ± 6 kg/m²) and 30 healthy age- and gender-matched subjects, using a multiaxial accelerometer-based sensor for 12 h/day on two consecutive days. We also assessed maximal and functional exercise capacity, using the incremental exercise test and the six-minute walk test (6MWT), respectively; MIP and MEP; peripheral muscle force, using the one-repetition maximum test and the handgrip test; quality of life, using the Saint George's Respiratory Questionnaire (SGRQ); functional status, using the London Chest Activity of Daily Living questionnaire; and dyspnea sensation, using the Medical Research Council (MRC) scale. RESULTS: Mean walking time/day was shorter for COPD patients than for the controls (55 ± 33 vs. 80 ± 28 min/day; p = 0.001), as movement intensity was lower (1.9 ± 0.4 vs. 2.3 ± 0.6 m/s²; p = 0.004). The COPD patients also tended to spend more time seated (294 ± 114 vs. 246 ± 122 min/day, p = 0.08). Walking time/day correlated with the 6MWT (r = 0.42; p = 0.007) and maximal workload (r = 0.41; p = 0.009), as well as with age, MRC scale score and SGRQ activity domain score (-0.31 < r < -0.43; p < 0.05 for all). CONCLUSIONS: This sample of Brazilian patients with COPD, although more active than those evaluated in studies conducted in Europe, were less active than were the controls. Walking time/day correlated only moderately with maximal and functional exercise capacity.

Influência do posicionamento de membros superiores sobre os efeitos do treinamento / Influence of arm positioning on the effects of a short-term high intensity inspiratory muscle training protocol in health young subjects

O objetivo do estudo foi analisar os efeitos de um treinamento muscular inspiratório (TMI) de curta duração e alta intensidade, com e sem o apoio de membros superiores, sobre as pressões respiratórias máximas em jovens saudáveis. Trinta jovens do sexo feminino foram aleatoriamente distribuídas em três grupos: o grupo controle (GC) fez treinamento placebo na posição sentada...

The purpose of this study was to analyse the effects of a short-term, high-intensity inspiratory muscle training (IMT) on health youth maximal respiratory pressures, with and without arm bracing postures. Thirty young women were randomly assigned to three groups: control group (CG); group training with the arm bracing (AB)...

Validação do Modified Pulmonary Functional Status and Dyspnea Questionnaire e da escala do Medical Research Council para o uso em pacientes com doença pulmonar obstrutiva crônica no Brasil / Validation of the Modified Pulmonary Functional Status and Dyspnea Questionnaire and the Medical Research Council scale for use in Brazilian patients with chronic obstructive pulmonary disease

OBJETIVO: Verificar a validade e a reprodutibilidade do uso de dois instrumentos subjetivos para avaliar a limitação nas atividades da vida diária (AVD) em pacientes com doença pulmonar obstrutiva crônica (DPOC) no Brasil: o Pulmonary Functional Status and Dyspnea Questionnaire - Modified version (PFSDQ-M) e a escala do Medical Research Council (MRC). MÉTODOS: Trinta pacientes com DPOC (17 homens; idade, 67 ± 10 anos; volume expiratório forçado no primeiro segundo, 42 por cento ± 13 por cento do predito) responderam por duas vezes às versões em português dos dois instrumentos com intervalo de uma semana. O PFSDQ-M contém três componentes: influência da dispnéia nas AVD, influência da fadiga nas AVD, e mudança nas AVD em comparação ao período anterior à doença. A escala do MRC é simples, com apenas cinco itens, dentre os quais o paciente escolhe qual o seu nível de limitação nas AVD devido à dispnéia. O tradicional questionário Saint George's Respiratory Questionnaire (SGRQ), já validado para o uso no Brasil, foi utilizado como critério de validação. RESULTADOS: A confiabilidade em reteste do PFSDQ-M utilizando o coeficiente de correlação intraclasse foi de 0,93, 0,92 e 0,90 para os componentes dispnéia, fadiga e mudança, respectivamente, enquanto que esta foi de 0,83 para a escala do MRC. A análise dos gráficos de Bland e Altman mostrou boa concordância entre a aplicação e a reaplicação do PFSDQ-M. Os componentes do PFSDQ-M e a escala do MRC se correlacionaram significativamente com os domínios e o escore total do SGRQ (0,49 < r < 0,80; p < 0,01 para todos). CONCLUSÕES: As versões em língua portuguesa do PFSDQ-M e da escala do MRC demonstraram ser reprodutíveis e válidas para o uso em pacientes com DPOC no Brasil.

OBJECTIVE: To determine the validity and reproducibility of two subjective instruments to assess limitations in activities of daily living (ADLs) in patients with chronic obstructive pulmonary disease (COPD) in Brazil: the Pulmonary Functional Status and Dyspnea Questionnaire - Modified version (PFSDQ-M) and the Medical Research Council (MRC) scale. METHODS: Thirty patients with COPD (age, 67 ± 10 years; males, 17; forced expiratory volume in one second, 42 percent ± 13 percent of predicted) completed the Portuguese-language versions of the two instruments on two occasions, one week apart. The PFSDQ-M has three components: influence of dyspnea on ADLs, influence of fatigue on ADLs change in ADLs experienced by the patient. The MRC scale is simple, with only five items, in which patients report the degree to which dyspnea limits their performance of ADLs. The traditional Saint George's Respiratory Questionnaire (SGRQ), previously validated for use in Brazil, was used as a validation criterion. RESULTS: The test-retest reliability (intraclass correlation coefficient) of the PFSDQ-M was 0.93, 0.92 and 0.90 for dyspnea, fatigue and change components, respectively, compared with 0.83 for the MRC scale. Bland-Altman plots showed good test-retest agreement for the PFSDQ-M. The components of the PFSDQ-M and the MRC scale correlated significantly with all of the domains and the total score of the SGRQ (0.49 < r < 0.80; p < 0.01 for all). CONCLUSIONS: The Portuguese-language versions of the PFSDQ-M and the MRC scale proved reproducible and valid for use in patients with COPD in Brazil.

Função pulmonar e força muscular respiratória em pacientes com doença renal crônica submetidos à hemodiálise / Pulmonary function and respiratory muscle strength in chronic renal failure patients on hemodialysis

OBJETIVO: Avaliar a função pulmonar e a força muscular respiratória de pacientes com doença renal crônica e correlacioná-las com a variação de peso ligada à realização de hemodiálise; estudar a correlação entre o tempo de hemodiálise e possíveis alterações respiratórias. MÉTODOS: Foram avaliados 17 pacientes (mediana de idade, 47 anos; intervalo interquartílico, 41-52 anos) submetidos a três sessões semanais de hemodiálise (mediana de tempo, 27 meses; intervalo interquartílico, 14-55). Doze eram do sexo masculino. Realizaram espirometria e mensuração das pressões máximas inspiratória (PImáx) e expiratória (PEmáx) antes e após a primeira sessão semanal de hemodiálise. O peso corporal foi quantificado antes e após as três sessões semanais. RESULTADOS: Oito pacientes apresentaram distúrbio restritivo leve antes da primeira sessão de hemodiálise. Desses, 2 normalizaram após a sessão. Houve aumento da capacidade vital forçada (p = 0,02) e diminuição de peso (p = 0,0001) ao final da primeira sessão semanal. A variação de peso durante três dias sem hemodiálise tendeu a se correlacionar com a variação da capacidade vital forçada na primeira sessão (r = 0,47; p = 0,055). O tempo de hemodiálise correlacionou-se com os valores da porcentagem do predito da PImáx (r = -0,53; p = 0,03) e com a PEmáx (r = -0,63; p = 0,006) pré-diálise. CONCLUSÕES: O maior ganho de peso no período interdialítico está associado com a piora da função pulmonar, que pode ser quase totalmente revertida com hemodiálise. Além disso, o maior tempo de hemodiálise está associado à diminuição da força muscular respiratória.

OBJECTIVE: To evaluate pulmonary function and respiratory muscle strength in chronic renal failure patients, correlating these variables with hemodialysis-related weight fluctuation; to study the correlation between the duration hemodialysis and potential respiratory alterations. METHODS: Seventeen patients (median age, 47 years; interquartile range, 41-52 years), submitted to three weekly hemodialysis sessions for a median of 27 months (interquartile range, 14-55) were evaluated. Twelve of the patients were male. The patients underwent spirometry. Maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) were measured prior to and after the first hemodialysis session of the week. Body weight was quantified prior to and after each of the three weekly sessions. RESULTS: Before the first hemodialysis session of the week, 8 patients presented mild restrictive defect, which normalized after the session in 2 of those patients. After dialysis, there was a significant increase in forced vital capacity (p = 0.02) and a significant decrease in body weight (p = 0.0001). Weight fluctuation over 3 days without hemodialysis tended to correlate with the variation in forced vital capacity in the first weekly session (r = 0.47; p = 0.055). Duration of hemodialysis correlated with predialysis MIP (r = -0.3; p = 0.03) and MEP (r = -0.63; p = 0.006). CONCLUSIONS: More pronounced weight gain in the interdialytic period is associated with worsening of lung function, which is almost fully reversible by hemodialysis. In addition, longer duration of hemodialysis is associated with decreased respiratory muscle strength.

Limiar de variabilidade da freqüência cardíaca em adolecentes obesos e não-obesos / Heart rate variability threshold in obese and non-obese adolescents

A obesidade na adolescência está associada à disfunção simpato-vagal cardíaca em repouso, embora existam poucas informações sobre a resposta autonômica durante o exercício nestes adolescentes. OBJETIVO: Comparar a modulação autonômica durante teste de esforço físico dinâmico incremental em amostras de adolescentes obesos e não-obesos, e analisar a relação entre o limiar de variabilidade da freqüência cardíaca (LiVFC) e o limar ventilatório (LV). MÉTODOS: Dez adolescentes obesos e 19 adolescentes não-obesos do sexo masculino com idades entre 13 e 18 anos foram submetidos à teste de esforço físico progressivo máximo em esteira rolante para estudo da variabilidade da freqüência cardíaca (VFC) e para identificação do LV. A VFC foi estudada mediante análise do desvio-padrão da variabilidade instantânea batimento-a-batimento (SD1) da Plotagem de Poincaré. O LiVFC foi identificado na intensidade de esforço físico em que o SD1 atingiu valor menor que 3 ms. RESULTADOS: O índice SD1 diminuiu progressivamente em ambos os grupos até aproximadamente 50-60 por cento do VO2pico, sendo que os adolescentes obesos apresentaram valores significativamente menores (p<0,001) somente na intensidade relativa a 20 por cento do VO2pico, Os adolescentes obesos apresentaram valores relativos (mL.kg-1.min-1) de VO2pico e LV significativamente menores (p<0,05) que os adolescentes não-obesos. Em ambos os grupos, não foram observadas diferenças significativas entre o ponto de ocorrência do LV e do LiVFC, expressos em valores relativos e absolutos de VO2. Contudo, não foram encontradas correlações significativas entre o ponto de ocorrência do LV e do LiVFC, tanto em valores relativos quanto em valores absolutos de VO2. CONCLUSÕES: A obesidade na adolescência parece não estar associada à alteração da modulação autonômica durante o exercício físico. Torna-se possível determinar o LiVFC mediante análise da Plotagem de Poincaré em adolescentes obesos e não-obesos. Entretanto, a ausência de associação estatística entre o LiVFC e o LV demonstra que parece não haver relação causal entre estes eventos.

Obesity in adolescence is associated with a cardiac sympathetic-parasympathetic dysfunction at rest. However, there is little information about the autonomic response during exercise in these adolescents. OBJECTIVE: To compare the cardiac autonomic modulation during a maximal exercise test in obese and non-obese adolescents and analyze the association between the Heart Rate Variability threshold (HRVT) and the Ventilatory threshold (VT). METHODS: Ten obese and 19 non-obese male adolescents with age between 13-18 years were submitted to a maximal progressive treadmill physical exercise test for Heart Rate Variability (HRV) study and VT determination. HRV was assessed through the study of Poincaré Plot, by the analysis of the standard deviation of instantaneous beat-to-beat variability (SD1). HRVT was defined as the effort intensity at which the SD1 reached less than 3 ms. RESULTS: The SD1 index reduced progressively in both groups until approximately 50-60 percent of VO2peak, while the obese adolescents showed lower significant values (p<0.001) only in the relative intensity of 20 percent of VO2peak. The obese adolescents showed relative values (mL.kg-1.min-1) of VO2peak and VT significantly lower (p<0.05) than non-obese ones. There were no significant differences between VT and HRVT, expressed in absolute and relative VO2 values for neither groups. However, no significant correlations between VT and HRVT were found, neither in absolute nor relative values. CONCLUSIONS: Obesity in adolescence does not seem to be associated with the autonomic modulation during physical exercise. It is possible to determine the HRVT by Poincaré Plot in obese and non-obese adolescents. Nonetheless, the absence of statistical association between HRVT and VT suggests a lack of causal relationship between these events.

Relação entre indicadores fisiológicos obtidos em teste ergoespirométrico em cicloergômetro de membros superiores e desempenho na canoagem / Relationship between physiological indicators obtained in ergospirometry test in cycle ergometer of upper extremities and performance in canoeing

A avaliação de indicadores de aptidão aeróbia em canoístas revela características funcionais adquiridas por treinamento específico, podendo estar relacionadas ao desempenho competitivo. Assim, o objetivo do presente estudo foi avaliar indicadores funcionais obtidos em teste ergoespirométrico de jovens canoístas, e verificar a relação destas variáveis com a performance em distâncias de 200, 500 e 1.000m. Foram avaliados 12 atletas do sexo masculino (17,6 ± 2,1 anos; 175,7 ± 2,5cm; 68,3 ± 6,3kg) por meio de teste em cicloergômetro de membros superiores para determinação do consumo de oxigênio no limiar ventilatório 1 (LV1 - 1,8 ± 0,4L/min), no limiar ventilatório 2 (LV2 - 2,9 ± 0,4L/min) e VO2pico (3,5 ± 0,4L/min). O teste tinha início com carga de 17W, com incrementos de 17W/min até a exaustão voluntária. Os atletas foram também submetidos a testes específicos em embarcação individual K-1 em um lago, objetivando alcançar os menores tempos nas distâncias referidas (tempos equivalentes a 47,6 ± 4,3, 122,0 ± 9,0 e 239,5 ± 12,6s, respectivamente). Foi utilizado o teste de correlação de Spearman-Rank (rs), com nível de significância fixado em 5 por cento. Observou-se correlação moderada entre LV2 e tempo nos 1.000m (rs = -0,685), VO2pico e tempo nos 500m (rs = -0,699) e VO2pico e tempo nos 1.000m (rs = -0,734). Portanto, conclui-se que LV2 e VO2pico obtidos em cicloergômetro de membros superiores, e expressos em termos absolutos, predizem o desempenho em provas de 500 e 1.000m de canoagem, podendo ser potencialmente empregados na avaliação de canoístas.

Evaluation of aerobic fitness indicators in canoers reveals functional characteristics acquired through specific training, which can be related to competitive performance. Thus, the aim of the present study was to evaluate functional evaluators obtained in ergospirometry test of young canoers, as well as to verify the relationship of these variables with performance in 200, 500 and 1000 m distances. The sample consisted of 12 male athletes (17.6 ± 2.1 years; 175.7 ± 2.5 cm; 68.3 ± 6.3 kg) through a test in cycle ergometer of upper extremities for determination of oxygen uptake in the ventilatory threshold 1 (VT1 - 1.8 ± 0.4 L/min), in the ventilatory threshold 2 (VT2 - 2.9 ± 0.4 L/min) and VO2peak (3.5 ± 0.4 L/min). The test began with a 17 W load, with 17 W/min increments until voluntary exhaustion. The athletes have been also submitted to specific tests in K-1 individual canoe in a lake, with the purpose to reach the lowest times in the referred distances (times equivalent to 47.6 ± 4.3, 122.0 ± 9.0 and 239.5 ± 12.6 s, respectively). The Spearman-Rank correlation test was used (rs), with significance level set at 5 percent. Moderate correlation was observed between VT2 and time in the 1000 m (rs = -0.685), VO2peak and time in the 500 m (rs = -0.699) and VO2peak and time in the 1000 m) rs = -0.734). Therefore, it is concluded that VT2 and VO2peak obtained in cycle ergometer of upper extremities, and expressed in absolute terms, predict performance in 500 and 1000 m canoeing events and can be potentially applied in evaluation of canoers.

Correlação entre os parâmetros do modelo de potência crítica no cicloergômetro de membros superiores e no caiaque / Correlation between critical power model parameters in the upper body cycle ergometer and in kayak

Este trabalho teve como objetivo correlacionar os parâmetros do modelo de potência crítica, obtidos por canoístas em cicloergômetro de membros superiores e em caique. Os parâmetros foram estimados, em ambas as situações, através de testes exaustivos de duração entre 1 e 15 minutos. A potência crítica (PCrit) no cicloergômetro de membros superiores variou entre 123 a 124 W entre as estimativas das três equações de predição do modelo. A capacidade de trabalho anaeróbio (CTAnaer) variou entre 10.551 a 10.831 J. Na água, a velocidade crítica (VCrit) ficou entre 3,06 a 3,10 m/s, ao passo que a capacidade anaeróbia na canoagem (CACanoagem) ficou entre 62,2 m a 74,0 m. As correlações entre as estimativas de PCrit e de VCrit foram de r = 0,79 - 0,91 (p < 0,05), enquanto as correlações entre as estimativas de CTAnaer e CACanoagem foram de r = -0,03 - 0,36 (p > 0,05). Com isso, concluiu-se que a capacidade aeróbia de canoístas em caiaque pode ser predita através de testes mais simples e controlados em cicloergômetro de membros superiores.

The objective of this study was to correlate the parameters of the critical power model obtained by canoeists in an upper body cycle ergometer and in kayak. The parameters were estimated, in both situations, through exhaustive tests lasting between 1 and 15 minutes. The critical power (PCrit) in the upper body cycle ergometer varied between 123 to 124 W among the three predictive equations estimates of the model. The anaerobic work capacity (CTAnaer) varied between 10.551 to 10.831 J. In the water, critical velocity (VCrit) was among 3,06 to 3,10 m/s, while the anaerobic work capacity in kayaking (CACanoagem) was in the 62,2 m to 74,0 m range values. The correlations among the estimates of PCrit and VCrit were of r = 0,79 - 0,91 (p <0,05), while the correlations between the estimates of CTAnaer and CACanoagem were of r = -0,03 - 0,36 (p> 0,05). Therefore, it was concluded that the aerobic capacity of canoeists in the kayak can be predicted through simpler and controlled tests in the upper body cycle ergometer.