Dynamics of chest wall volume regulation during constant work rate exercise in patients with chronic obstructive pulmonary disease

This study evaluated the dynamic behavior of total and compartmental chest wall volumes [(V CW) = rib cage (V RC) + abdomen (V AB)] as measured breath-by-breath by optoelectronic plethysmography during constant-load exercise in patients with stable chronic obstructive pulmonary disease. Thirty males (GOLD stages II-III) underwent a cardiopulmonary exercise test to the limit of tolerance (Tlim) at 75% of peak work rate on an electronically braked cycle ergometer. Exercise-induced dynamic hyperinflation was considered to be present when end-expiratory (EE) V CW increased in relation to resting values. There was a noticeable heterogeneity in the patterns of V CW regulation as EEV CW increased non-linearly in 17/30 "hyperinflators" and decreased in 13/30 "non-hyperinflators" (P < 0.05). EEV AB decreased slightly in 8 of the "hyperinflators", thereby reducing and slowing the rate of increase in end-inspiratory (EI) V CW (P < 0.05). In contrast, decreases in EEV CW in the "non-hyperinflators" were due to the combination of stable EEV RC with marked reductions in EEV AB. These patients showed lower EIV CW and end-exercise dyspnea scores but longer Tlim than their counterparts (P < 0.05). Dyspnea increased and Tlim decreased non-linearly with a faster rate of increase in EIV CW regardless of the presence or absence of dynamic hyperinflation (P < 0.001). However, no significant between-group differences were observed in metabolic, pulmonary gas exchange and cardiovascular responses to exercise. Chest wall volumes are continuously regulated during exercise in order to postpone (or even avoid) their migration to higher operating volumes in patients with COPD, a dynamic process that is strongly dependent on the behavior of the abdominal compartment.

Eficácia da reabilitação pulmonar uma vez na semana em portadores de doença pulmonar obstrutiva / Effectiveness of pulmonary rehabilitation once a week for patients with obstructive pulmonary disease

CONTEXTUALIZAÇÃO: As doenças pulmonares obstrutivas podem interferir negativamente na qualidade de vida (QV) dos pacientes, sendo que questionários específicos, como o Chronic Respiratory Questionnaire (CRQ), são aplicados para quantificar o impacto da doença e para mensurar os efeitos de diferentes protocolos de reabilitação. OBJETIVOS: Avaliar a eficácia da reabilitação pulmonar uma vez por semana associada a exercícios domiciliares em pacientes com doença pulmonar obstrutiva por meio das comparações do CRQ, das pressões respiratórias máximas (PImáx e PEmáx) e da distância percorrida no teste de caminhada de seis minutos (TC6) pré e pós-tratamento. MÉTODO: O estudo foi desenvolvido no Ambulatório de Fisioterapia do hospital. Foram avaliados 34 portadores de doença pulmonar obstrutiva de ambos os sexos, sendo incluídos, no estudo, 19 pacientes, com idade média de 60,8 ± 14,2 anos. Todos realizaram avaliação e reavaliação fisioterapêutica contendo medidas de PImáx, PEmáx, TC6, e questionário CRQ. A fisioterapia era composta de exercícios respiratórios, aeróbios e resistidos, com freqüência de uma vez por semana, durante 12 semanas, associados a exercícios domiciliares duas vezes na semana. RESULTADOS: Foram utilizados os testes de Wilcoxon e de correlação de Spearman. Verificou-se diferença estatisticamente significativa nos períodos pré e pós-reabilitação para todos os domínios do CRQ (p< 0,05), na PImáx (p= 0,01) e PEmáx (p= 0,002). CONCLUSÃO: O programa proposto melhorou a qualidade de vida e promoveu incrementos nas pressões respiratórias máximas de pneumopatas obstrutivos, apesar de a literatura atual sugerir maior freqüência de treinamento.

BACKGROUND: Obstructive pulmonary diseases may interfere negatively with patients' quality of life (QOL). Specific QOL questionnaires such as the Chronic Respiratory Questionnaire (CRQ) have been used to quantify the impact of the disease and measure the effects of different rehabilitation protocols. OBJECTIVE: To evaluate the effectiveness of pulmonary rehabilitation performed once a week in association with exercises at home among patients with obstructive pulmonary disease, by means of CRQ comparisons, maximum respiratory pressures (MIP and MEP) and six-minute walking distance test (6MWD), before and after treatment. METHODS: This study was developed in the physical therapy outpatient clinic of the hospital. Thirty-four patients of both sexes with obstructive pulmonary disease were evaluated, and nineteen (mean age: 60.8 ± 14.2 years) were included in the study. These subjects all underwent physiotherapeutic evaluation and reevaluation with the CRQ and measurements of MIP, MEP and 6MWD. The physical therapy consisted of respiratory, aerobic and resistance exercises once a week for 12 weeks, together with home exercises twice a week. RESULTS: The Wilcoxon test and Spearman correlation were used. Statistically significant differences between evaluations before and after rehabilitation were found for all CRQ domains (p< 0.05), MIP (p= 0.01) and MEP (p= 0.002). CONCLUSION: The proposed program improved QOL and promoted increases in maximum respiratory pressures among these patients with obstructive pulmonary disease, even though the current literature suggests that higher frequency of training is needed.