Felipe Cortopassi

Effects of hyperinflation on the oxygen pulse as a marker of cardiac performance in COPD

A decreased inspiratory capacity (IC)/total lung capacity (TLC) ratio is associated with dynamic hyperinflation and decreased exercise capacity. The present authors hypothesised that static (low IC/TLC) and dynamic hyperinflation impair cardiac function as assessed by oxygen pulse at rest and during cardiopulmonary exercise testing (CPET). Lung function, body mass index, hand grip strength and CPET parameters were measured (oxygen uptake (mL·kg−1·min−1) and oxygen pulse (mL·beat−1)) in 87 chronic obstructive pulmonary disease (COPD) patients (American Thoracic Society/European Respiratory Society/Global Initiative for Chronic Obstructive Lung Disease stage 3–4) and 46 controls. The patients were divided into those with IC/TLC >25% or ≤25%. The IC/TLC ratio at rest and at peak exercise was associated significantly with oxygen pulse. Patients with IC/TLC ≤25% (n = 45) had significantly lower exercise capacity, peak oxygen pulse, peak minus baseline oxygen pulse, peak IC, peak IC/TLC ratio and % change from baseline to peak IC/TLC ratio compared with patients with IC/TLC >25% and controls. During CPET, the oxygen pulse was lower at iso-work in patients with IC/TLC ≤25% than in those with IC/TLC >25%. Resting hyperinflation (inspiratory capacity/total lung capacity) is associated with lower oxygen pulse, peak exercise inspiratory capacity/total lung capacity and exercise capacity in patients with severe chronic obstructive pulmonary disease. The present results support an interaction between hyperinflation and decreased cardiac function that may contribute to exercise limitation in these patients.

Inflammatory and Repair Serum Biomarker Pattern. Association to Clinical Outcomes in COPD

BackgroundThe relationship between serum biomarkers and clinical expressions of COPD is limited. We planned to further describe this association using markers of inflammation and injury and repair.MethodsWe studied lung function, comorbidities, exercise tolerance, BODE index, and quality of life in 253 COPD patients and recorded mortality over three years. Serum levels of Interleukins 6,8 and16, tumor necrosis factor alpha (TNF α) [inflammatory panel], vascular endothelial growth factor (VEGF), and matrix metalloproteinase 9 (MMP-9) [injury and repair panel] and pulmonary and activation-regulated chemokine (PARC/CCL-18) and monocyte chemotactic protein 1 (MCP-1/CCL2) [chemoattractant panel] were measured. We related the pattern of the biomarker levels to minimal clinically important differences (MCID) using a novel visualization method [ObServed Clinical Association Results (OSCAR) plot].ResultsLevels of the inflammatory markers IL-6, TNF α were higher and those of injury and repair lower (p < 0.01) with more advanced disease (GOLD 1 vs. 4). Using the OSCAR plot, we found that patients in the highest quartile of inflammatory and lowest quartile of injury and repair biomarkers level were more clinically compromised and had higher mortality (p < 0.05).ConclusionsIn COPD, serum biomarkers of inflammation and repair are distinctly associated with important clinical parameters and survival.

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.