Determining the Role of Dynamic Hyperinflation in Patients with Severe Chronic Obstructive Pulmonary Disease

作者：Klooster Karin^*; ten Hacken Nick H T; Hartman Jorine E; Sciurba Frank C; Kerstjens Huib A M; Slebos Dirk Jan

来源：Respiration, 2015, 90(4): 306-313.

DOI：10.1159/000439056

• Chronic obstructive pulmonary disease
• Dynamic hyperinflation
• Static hyperinflation
• Inspiratory capacity
• Exercise capacity

Background: Dynamic hyperinflation due to increased respiratory frequency during exercise is associated with limitations in exercise capacity in patients with moderately severe chronic obstructive pulmonary disease (COPD). Objectives: The present study assessed whether the manually paced tachypnea (MPT) test, sitting at rest, induces dynamic hyperinflation correlating with exercise capacity in patients with very severe COPD. Methods: Dynamic hyperinflation was induced by the MPT test, using a breathing frequency of 40/min for 1 min. Dynamic hyperinflation was defined as a 'change' in inspiratory capacity (IC) before and directly after the MPT test. At baseline, static hyperinflation by body plethysmography was measured, as well as the 6-min walking test and spirometry. Results: We studied 74 patients with severe COPD (age 59 +/- 9 years, FEV1 28 +/- 10% predicted). All patients tolerated the MPT test well. It induced a significant decrease in IC: -0.65 +/- 0.33 liters, p < 0.001, correlating with the 6-min walking distance (rho = -0.246, p = 0.034). Static hyperinflation [IC/total lung capacity (TLC)] at baseline correlated stronger with the 6-min walking distance (r = 0.582, p < 0.001). Multiple regression analysis showed that IC/TLC, but not dynamic hyperinflation, was the only independent predictor of walking distance. Conclusions: In patients with very severe COPD, dynamic hyperinflation measurement by the MPT test is feasible and contributes less importantly to exercise performance than static hyperinflation.

• 出版日期2015