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 musc les in patients with severe chronic obstructive pulmonary disease (COP D). 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 patient s with severe COPD, by using diaphragmatic surface electromyograms. Du ring threshold loading, the patients had to generate 80% of their maxi mal transdiaphragmatic pressure with each breath. The endurance of ins piratory muscles was defined as the time from the beginning of resisti ve breathing trial until exhaustion (tlim). In DLT recipients and even in SLT recipients (an both sides), neural activation of the diaphragm was significantly lower than in COPD patients (p<0.05). However, no s tatistically significant difference in tlim was seen between LT recipi ents and COPD patients. The data suggest that single-lung and double-l ung transplantations cause a significant decrease of the neural drive to the diaphragm, while the endurance of inspiratory muscles is well-p reserved in patients with advanced chronic obstructive pulmonary disea se, This may contribute to reduced sensation of inspiratory effort dur ing ventilatory stress, thus improving the quality of life.