Flow limitation and dynamic hyperinflation during exercise in COPD patients after single lung transplantation.
OBJECTIVE
Using the negative expiratory pressure (NEP) method, we have previously shown that patients receiving single lung transplantation (SLT) for COPD do not exhibit expiratory flow limitation and have little dyspnea at rest. In the present study, we assessed whether SLT patients exhibit flow limitation, overall hyperinflation, and dyspnea during exercise.


METHODS
Expiratory flow limitation assessed by the NEP method and inspiratory capacity maneuvers used to determine end-expiratory lung volume (EELV) and end-inspiratory lung volume (EILV) were performed at rest and during symptom-limited incremental cycle exercise in eight SLT patients.


RESULTS
At the time of the study, the mean (+/- SD) FEV(1), FVC, functional residual capacity, and total lung capacity (TLC) amounted to 55 +/- 14%, 67 +/- 12%, 137 +/- 16%, and 110 +/- 11% of predicted, respectively. At rest, all patients did not experience expiratory flow limitation and were without dyspnea. At peak exercise, the maximal mechanical power output and maximal oxygen consumption amounted to 72 +/- 20% and 65 +/- 8% of predicted, respectively, with a maximal dyspnea Borg score of 6 +/- 3. All but one patient exhibited flow limitation and dynamic hyperinflation; the EELV and EILV amounted to 74 +/- 5% and 95 +/- 9% TLC, respectively. The patient who did not exhibit flow limitation during exercise had the lowest dyspnea score.


CONCLUSIONS
Most SLT patients for COPD exhibit expiratory flow limitation and dynamic hyperinflation during exercise, whereas maximal dyspnea is variable.
Murciano
D
D
INSERM U408, Service de Pneumologie, Hopital Beaujon, Clichy, France. daniele.murciano@bjn.ap-hop-paris.fr
Ferretti
A
A
Boczkowski
J
J
Sleiman
C
C
Fournier
M
M
Milic-Emili
J
J
D000368:Aged; D000704:Analysis of Variance; D004417:Dyspnea / Q000503:physiopathology; D005080:Exercise Test; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D005544:Forecasting; D005652:Functional Residual Capacity / Q000502:physiology; D006801:Humans; D007320:Inspiratory Capacity / Q000502:physiology; D016018:Least-Squares Analysis; D016014:Linear Models; D008168:Lung / Q000503:physiopathology*; D008173:Lung Diseases, Obstructive / Q000503:physiopathology / Q000601:surgery*; D016040:Lung Transplantation / Q000502:physiology*; D008176:Lung Volume Measurements; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology; D005082:Physical Exertion / Q000502:physiology*; D011312:Pressure; D015656:Respiratory Mechanics / Q000502:physiology; D012143:Respiratory Physiological Phenomena; D012146:Rest / Q000502:physiology; D014109:Total Lung Capacity / Q000502:physiology; D014797:Vital Capacity / Q000502:physiology