Inspiratory drive is related to dynamic pulmonary hyperinflation in COPD patients

• Published in: International journal of chronic obstructive pulmonary disease 2013-01, Vol.8 (default), p.169-173
• Main Authors: Gatta, Diego, Fredi, Marco, Aliprandi, Giovanni, Pini, Laura, Tantucci, Claudio
• Format: Article
• Language: English
• Subjects: Aged; Albuterol - therapeutic use; Bronchodilator agents; Bronchodilator Agents - therapeutic use; Care and treatment; Complications and side effects; Dosage and administration; Female; Humans; Inflammation; Inspiratory Capacity - physiology; Lung diseases, Obstructive; Lung Volume Measurements; Male; Metered Dose Inhalers; Neuromuscular Junction - physiology; Original Research; Prospective Studies; Pulmonary Disease, Chronic Obstructive - drug therapy; Pulmonary Disease, Chronic Obstructive - physiopathology; Respiratory Muscles - physiology; Risk factors; Severity of Illness Index
• ISSN: 1178-2005; 1176-9106; 1178-2005
• DOI: 10.2147/COPD.S38320

Baseline high neuromuscular drive is present in chronic obstructive pulmonary disease (COPD). In moderate-to-very severe COPD patients, both static and/or dynamic pulmonary hyperinflation have been demonstrated at rest. To assess the influence of dynamic hyperinflation on neuromuscular drive at rest. We recruited 22 patients with severe-to-very severe COPD showing resting dynamic pulmonary hyperinflation, as assessed by the baseline reduction of inspiratory capacity (IC) (12% of baseline and at least 200 mL) after bronchodilator, resting P0.1 showed a clinically significant decrease, despite the EELV diminution (P < 0.001). MIP was augmented following EELV reduction and therefore the P₀.₁/MIP ratio was markedly decreased (P < 0.001). In contrast, no changes in these indices were found after bronchodilator in COPD patients with insignificant variations of IC. Breathing pattern parameters did not vary in both sub-groups after albuterol. Following bronchodilator, significant P₀.₁ decrease, MIP increase, and reduction of the P₀.₁/MIP ratio were found only in COPD patients with a marked IC increase and these changes were closely related. These findings suggest that bronchodilators, by decreasing dynamic hyperinflation, may control exertional and/or chronic dyspnea partly through a reduction of central neuromuscular drive.