Determinants of abnormal maximum oxygen uptake after lung transplantation for chronic obstructive pulmonary disease.
BACKGROUND
Single lung transplantation for chronic obstructive pulmonary disease relieves a ventilatory limit to incremental exercise, but maximum oxygen uptake remains abnormal. The purpose of this study was to define the relative contributions of Fick principle variables to abnormal aerobic capacity after lung transplantation.


METHODS
Twelve paired incremental cardiopulmonary exercise test results obtained before and 3 to 6 months after single lung transplantation for chronic obstructive pulmonary disease were compared.


RESULTS
Maximum workload nearly doubled after operation (42.5+/-4.2 vs 25.5+/-4.7 watts, P < .05). Peak exercise minute ventilation increased (32.8+/-3.3 vs 21+/-2.4 L/min, n = 11, P < .05), but maximum oxygen uptake remained markedly abnormal after transplantation (46.6%+/-4.4% vs 32.1%+/-2.9% predicted, P < .05, n = 8). Peak exercise cardiac output was normal (11.0+/-1.4 L/min, 89% predicted), but arterial-mixed venous oxygen content difference at peak exercise was only half of normal (7.2+/-0.61 mL/dL), as a result in part of the failure of mixed venous oxygen saturation to fall normally (peak exercise SvO2 = 49.8%+/-2.8%).


CONCLUSIONS
Lung transplantation for chronic obstructive pulmonary disease relieves a ventilatory limit to exercise, but maximum aerobic capacity remains abnormal, in part because of abnormal systemic O2 extraction.
Systrom
D M
DM
Pulmonary and Critical Care Unit, Massachusetts General Hospital, Harvard Medical School, Boston 02114, USA. systrom@helix.mgh.harvard.edu
Pappagianopoulos
P
P
Fishman
R S
RS
Wain
J C
JC
Ginns
L C
LC
D000328:Adult; D000332:Aerobiosis; D002302:Cardiac Output; D005080:Exercise Test; D006801:Humans; D008173:Lung Diseases, Obstructive / Q000503:physiopathology / Q000601:surgery*; D016040:Lung Transplantation; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D010101:Oxygen Consumption; D011659:Pulmonary Gas Exchange; D012123:Pulmonary Ventilation; D013318:Stroke Volume; D014797:Vital Capacity
D010100:Oxygen