title: Oxygen Uptake Efficiency Slope, an Objective Submaximal Parameter in Evaluating Exercise Capacity in Pulmonary Thromboembolism.
abstract: The objective of this article was to study the oxygen uptake efficiency, an index of cardiopulmonary functional reserve that can be based upon a submaximal exercise effort, in pulmonary thromboembolism (PE) by performing the cardiopulmonary exercise test.
  
  
  
  The cardiopulmonary exercise test with simultaneous respiratory gas measurement was performed in 50 patients with PE and in 50 healthy individuals. All subjects also underwent the pulmonary function test. Peak oxygen uptake (peak VO2), anaerobic threshold (AT), oxygen uptake efficiency slope (OUES), oxygen uptake efficiency plateau (OUEP) and oxygen uptake efficiency at anaerobic threshold (OUE@AT), were determined.
  
  
  
  (1) Compared with the controls, the patients with PE had lower peak VO2, AT, OUES, OUEP and OUE@AT (P < 0.001). (2) In patients with PE, oxygen uptake efficiency (OUE = VO2/VE) at warming up, AT and peak exercise but not rest, were indicated statistically lower than the controls. The OUE in normal subjects increased as unloaded exercise began, and then increased further to OUEP just before the AT. Thereafter, the OUE decreased gradually until peak exercise. In contrast, the rate of changes of the OUE in patients with PE was relatively mild during exercise. (3) Of all the submaximal parameters, OUES correlated best with peak VO2 (r = 0.712, P < 0.001).
  
  
  
  The oxygen uptake efficiency of patients with PE was lower than the controls during exercise. The OUE is an objective measure of cardiopulmonary reserve that does not require a maximal exercise effort. Therefore, OUES could be helpful to assess exercise performance in patients with PE who are unable to perform a maximal exercise test in early recovery stage.
authors.affiliation: Department of Pulmonary Function Test, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Guo
authors.affiliation: Department of Pulmonary Function Test, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China; Department of Respiratory Medicine, Changzhou Tumor Hospital Soochow University, Changzhou, China.
authors.forename: Shujuan
authors.initials: S
authors.lastname: Chen
authors.affiliation: Department of Pulmonary Function Test, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China.
authors.forename: Bigyan
authors.initials: B
authors.lastname: Pudasaini
authors.affiliation: Department of Pulmonary Circulation, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China.
authors.forename: Qinhua
authors.initials: Q
authors.lastname: Zhao
authors.affiliation: Department of Pulmonary Function Test, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China.
authors.forename: Wenlan
authors.initials: W
authors.lastname: Yang
authors.affiliation: Department of Pulmonary Circulation, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China.
authors.forename: Lan
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Pulmonary Circulation, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China.
authors.forename: Sugang
authors.initials: S
authors.lastname: Gong
authors.affiliation: Department of Pulmonary Function Test, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China; Department of Pulmonary Circulation, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China. Electronic address: jinmingliu2013@126.com.
authors.forename: Jinming
authors.initials: J
authors.lastname: Liu
mesh_terms: D000328:Adult; D000368:Aged; D002681:China; D015444:Exercise; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000378:metabolism*; D011655:Pulmonary Embolism / Q000209:etiology / Q000378:metabolism*; D012129:Respiratory Function Tests
chemical_list: D010100:Oxygen
keywords: Cardiopulmonary exercise testing; Oxygen uptake efficiency; Pulmonary thromboembolism