Upper Limb Anaerobic Metabolism Capacity is Reduced in Mild and Moderate COPD Patients.

Limited information is available regarding the role of anaerobic metabolism capacity on GOLD 1 and 2 COPD patients during upper limb exercise. We aimed to compare the upper limb anaerobic power capacity, blood lactate concentration, cardiovascular and respiratory responses, in male COPD patients versus healthy subjects during the 30-s Wingate anaerobic test (WAnT). The rate of fatigue and time constant of the power output decay (τ, tau) were also calculated and a regression analysis model was built to assess the predictors of τ in these patients. Twenty-four male COPD patients (post-bronchodilator FEV1 73.2 ± 15.3% of predicted) and 17 healthy subjects (FEV1 103.5 ± 10.1% of predicted) underwent the WAnT. Measurements were performed at rest, at the end of the WAnT, and during 3' and 5' of recovery time. Peak power (p = 0.04), low power (p = 0.002), and mean power output (p = 0.008) were significantly lower in COPD patients than in healthy subjects. Power output decreased exponentially in both groups, but at a significantly faster rate (p = 0.007) in COPD patients. The time constant of power decay was associated with resistance (in ohms) and fat-free mass (r2 = 0.604, adjusted r2 = 0.555, and p = 0.002). Blood lactate concentration was significantly higher in healthy subjects at the end of the test, as well as during 3' and 5' of recovery time (p < 0.01). Compared with healthy subjects, COPD patients with GOLD 1 and 2 presented lower upper limb anaerobic capacity and a faster rate of power output decrease during a maximal intensity exercise. Also, the WAnT proved to be a valid tool to measure the upper limb anaerobic capacity in these patients.

Replacement of the 6-min walk test with maximal oxygen consumption in the BODE Index applied to patients with COPD: an equivalency study.

INTRODUCTION: Patients with COPD have decreased exercise capacity and low oxygen consumption (Vo(2)) during formal cardiopulmonary exercise testing, and lower scores on health-related quality of life questionnaires. When isolated, these three variables show different correlations with COPD mortality. The multidimensional BODE (body mass index[BMI], airflow obstruction, dyspnea, and exercise capacity in COPD) index, which comprises four variables including the 6-min walk test (6MWT), predicts survival in COPD. OBJECTIVES: To evaluate the degree of association between the values of the BODE index using the 6MWT with the BODE index using maximal Vo(2) (Vo(2)max) obtained in a maximal incremental test. MATERIALS AND METHODS: Fifty patients with mild-to-severe COPD (average age, 63.5 +/- 9.9 years; FEV(1), 65.3 +/- 23.6% of predicted) [+/- SD] had BMI, spirometric function (FVC and FEV(1)), and dyspnea status (Medical Research Council) evaluated. Two BODE index scores were then completed: one with the 6MWT, and one with the Vo(2)max obtained during maximal incremental testing on a treadmill. RESULTS: Correlation between BODE index and Vo(2) in milliliters per minute per kilogram (r = - 0.41) was weak; the correlation was moderate (r = - 0.64) when Vo(2) percentage of predicted was used. The BODE index modified by replacing the 6MWT with Vo(2) showed excellent correlations with Vo(2) in milliliters per minute per kilogram (r = 0.92) and Vo(2) percentage of predicted (r = 0.95). CONCLUSION: The excellent correlation between the conventional BODE index and the modified BODE index with Vo(2) replacing the 6MWT enables us to reach the conclusion that the original BODE index is very effective in the evaluation of COPD patients.

Cough impairment and risk of postoperative pulmonary complications after open upper abdominal surgery.

BACKGROUND: Cough impairment is often described as part of the pathophysiological basis of postoperative pulmonary complications (PPCs). However, there have been few studies examining cough effectiveness and its relationship with PPCs following open upper abdominal surgery. The goal of this study was to estimate (1) changes in cough efficacy after upper abdominal surgery through the assessment of peak cough flow and (2) the extent to which cough impairment is associated with postoperative pain, FVC, and risk of PPCs. METHODS: This prospective cohort study assessed 101 subjects (45% male, 56 ± 16 y old) admitted for elective upper abdominal surgery. Measurements of peak cough flow and FVC were performed on the day before surgery and repeated on postoperative days 1, 3, and 5. PPCs were assessed daily by a pulmonologist blinded to the cough measurement results. RESULTS: Peak cough flow dropped to 54% of the preoperative value on postoperative day 1 and gradually increased on postoperative days 3 (65%) and 5 (72%) (P < .05). On all postoperative days, peak cough flow was strongly correlated with FVC (P < .001) and weakly correlated with pain (P = .006). Six subjects (6%) developed PPCs. The association between peak cough flow and risk of PPCs was not statistically significant (unadjusted odds ratio of 0.80, 95% CI 0.45-1.40, P = .44; adjusted odds ratio of 0.66, 95% CI 0.32-1.38, P = .41). CONCLUSIONS: Cough effectiveness is impaired after upper abdominal surgery. Postoperative restrictive lung dysfunction seems to be associated with this impairment. There is no significant association between peak cough flow and PPCs; however, cough impairment might result in clinically important consequences in a high-risk population.

Upper limb exercises using varied workloads and their association with dynamic hyperinflation in patients with COPD.

BACKGROUND: Increased ventilation during upper limb exercises (ULE) in patients with COPD is associated with dynamic hyperinflation (DH) and a decrease in inspiratory capacity (IC). The best level of ULE load training is still unknown. Our objective was to evaluate the dynamic hyperinflation development during ULE using three constant workloads. METHODS: This was a prospective, randomized protocol involving 24 patients with severe COPD (FEV(1) < 50%) performing an endurance symptom-limited arm exercise of up to 20 min in an arm cycloergometer with different workloads (50%, 65%, and 80% of the maximal load). Ventilation, metabolic, and lung function variables (static IC pre-exercise and postexercise) were measured. RESULTS: DH was observed during exercises with 65% (-0.23 L) and 80% (-0.29 L) workloads (P < .0001). Total time of exercise with 80% workload (7.6 min) was shorter than with 50% (12.5 min) (P < .0005) and with 65% (10.1 min; not significant). Oxygen consumption percent predicted (VO(2)) (P < .01) was lower with 50% workload than with 80%. Eighty percent workload showed lower work efficiency (VO(2) [mL/kg]/exercise time) than the other two workloads (P < .0001). CONCLUSION: Different workloads during upper limb exercises showed a direct influence over dynamic hyperinflation and the endurance exercise duration.