title: Effect of oxygen on postoperative cardiovascular response to exercise.
abstract: OBJECTIVE
  To evaluate the effect of supplemental oxygen on postoperative cardiovascular response to submaximal exercise.
  
  
  METHODS
  Randomised, controlled study.
  
  
  METHODS
  University hospital, Denmark.
  
  
  METHODS
  16 patients having major abdominal operations.
  
  
  METHODS
  A submaximal exercise test (heart rate up to 120 min(-1)) done twice on the third day after operation. Patients were given either 100% oxygen (4 L min(-1)) or air (21% oxygen, 4 L min(-1)) 30 minutes before and during the test in randomised order. During the tests they were monitored with a Holter tape recorder and a pulse oximeter.
  
  
  METHODS
  Heart rate during exercise.
  
  
  RESULTS
  At similar workloads there were significantly lower heart rates (median decrease 3 min(-1)) during exercise tests with oxygen compared with air (p < 0.05). Holter monitoring showed signs of myocardial ischaemia in 6 patients in relation to exercise testing, 4 of them related to both tests, 2 of them only when breathing air. Signs of myocardial ischaemia disappeared when the exercise ended.
  
  
  CONCLUSIONS
  During the late postoperative period supplementary oxygen reduced heart rate in response to exercise to the same degree as observed previously in non-surgical patients and surgical patients not taking exercise. These findings do not suggest that decreased peripheral tissue oxygenation is responsible for the impaired cardiovascular response to exercise in postoperative patients.
authors.affiliation: Department of Surgical Gastroenterology, Hvidovre University Hospital, Denmark.
authors.forename: M
authors.initials: M
authors.lastname: Kjaersgaard
authors.forename: C
authors.initials: C
authors.lastname: Lie
authors.forename: T
authors.initials: T
authors.lastname: Bisgaard
authors.forename: H
authors.initials: H
authors.lastname: Kehlet
authors.forename: J
authors.initials: J
authors.lastname: Rosenberg
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000378:metabolism*; D011184:Postoperative Period; D011446:Prospective Studies; D013514:Surgical Procedures, Operative
chemical_list: D010100:Oxygen