The effect of lung transplantation on the neural drive to the diaphragm in patients with severe COPD

Little is known about the effects of lung transplantation (LT) on the neural drive to the diaphragm and on the endurance of respiratory muscles in patients with severe chronic obstructive pulmonary disease (COPD). The aim of this study was to evaluate these effects of single-lung (SLT) and double-lung transplantation (DLT). The neural drive to the diaphragm was assessed during fatiguing inspiratory threshold loading manoeuvres in six SLT recipients, six DLT recipients and seven patients with severe COPD, by using diaphragmatic surface electromyograms. During threshold loading, the patients had to generate 80% of their maximal transdiaphragmatic pressure with each breath. The endurance of inspiratory muscles was defined as the time from the beginning of a resistive breathing trial until exhaustion (t lim). In DLT recipients and even in SLT recipients (on both sides), neural activation of the diaphragm was significantly lower than in COPD patients (p