Lactic acid levels in patients with chronic obstructive pulmonary disease accomplishing unsupported arm exercises.

Patients with chronic obstructive pulmonary disease (COPD) may suffer dyspnea when performing unsupported arm exercises (UAE). However, some factors related to the tolerance of the upper limbs during these exercises are not well understood. Our investigation was to determine if an unsupported arm exercise test in patients with COPD accomplishing diagonal movements increases lactic acid levels; also, we assessed the metabolic, ventilatory and cardiovascular responses obtained from the unsupported arm exercise test. The study used results of maximal symptom limited tests with unsupported arms and legs performed on 16 patients with COPD. In order to do the test, some metabolic, respiratory and cardiovascular parameters such as oxygen uptake (VO(2)), carbon dioxide production (VCO(2)), respiratory rate (RR), pulmonary ventilation (VE), heart rate (HR) and blood pressure (BP) were measured during the exercise tests. Furthermore, blood lactate concentration was measured during the arm test. We detected a significant increase in the mean blood lactate concentration, VO(2), VCO(2), VE and RR from the resting to the peak phase of the UAE test. The mean values of VO(2), VCO(2) and VE obtained at the peak of the UAE test corresponded to 52.5%, 50.0% and 61.2%, respectively, of the maximal values obtained at the peak of the leg exercise test. In comparison, the mean heart rate and systolic arterial blood pressure were significantly lower at the peak of the UAE test than at the peak leg exercise test and corresponded to 76.2% and 83.0%, respectively. Unsupported incremental arm exercises in patients with COPD increases blood lactic acid levels.

Variability in Quality of Life Outcomes Following a Pulmonary Rehabilitation Program in Patients With COPD.

PURPOSE: Pulmonary rehabilitation (PR) improves exercise tolerance in patients with chronic obstructive pulmonary disease. However, it is unclear why some patients do not improve quality of life during a training program. Our objective was to evaluate the differences between patients with chronic obstructive pulmonary disease who improve and those who do not improve quality of life during a pulmonary rehabilitation program. METHODS: Seventy-three patients underwent a PR program. All patients trained at 80% (legs) and 50% (arms) of their maximum load. Incremental and endurance tests, 6-min walk test, and health-related quality of life with the St George Respiratory Questionnaire (SGRQ) were measured. We subdivided the groups based on a decrease ≥4 points in the pre- and post-PR SGRQ total score (G1); <4-point change in the SGRQ total score (G2); and an increase in scores ≥4 points (G3). RESULTS: Exacerbation frequency (P = .004) and SGRQ total scores (P < .001) were lower in G1 and G2 than in G3. G1 (P = .0007) and G2 (P = .0005) significantly improved 6-min walk test distance. Before PR, G1 and G2 walked greater distances than G3 (P = .003); however, the difference was no longer significant after PR (P = .34). A significant load increase was seen after PR for the 3 groups (P < .05). We found a significant correlation between the SGRQ and the Charlson index (r = 0.78, P < .0001), exacerbation frequency (r = 0.72, P < .0001), and basal dyspnea index (r = -0.48, P < .0001). CONCLUSION: Patients whose quality of life did not improve after comprehensive PR presented a higher number of disease-related exacerbations with comorbidities.

Oxygen and ventilatory output during several activities of daily living performed by COPD patients stratified according to disease severity.

OBJECTIVES: To measure the oxygen and ventilatory output across all COPD stages performing 18 common ADL and identify the activities that present the highest metabolic and ventilatory output as well as to compare the energy expenditure within each disease severity. MATERIALS AND METHODS: Metabolic (VO2 and VCO2), ventilatory (f and VE), cardiovascular (HR) and dyspnea (Borg score) variables were assessed in one hundred COPD patients during the completion of eighteen ADL grouped into four activities domains: rest, personal care, labor activities and efforts. RESULTS: The activities with the highest proportional metabolic and ventilatory output (VO2/VO2max and VE/MVV) were walking with 2.5 Kg in each hand and walking with 5.0 Kg in one hand. Very severe patients presented the highest metabolic, ventilatory output and dyspnea than mild patients (p<0.05). CONCLUSIONS: COPD patients present an increased proportion of energy expenditure while performing activities of daily living. The activities that developed the highest metabolic and ventilatory output are the ones associated to upper and lower limbs movements combined. Very severe patients present the highest proportional estimated metabolic and ventilatory output and dyspnea. Activities of daily living are mainly limited by COPD's reduced ventilatory reserve.