title: Cardiopulmonary exercise testing before and after blood transfusion: a prospective clinical study.
abstract: BACKGROUND
  Cardiopulmonary exercise testing (CPET) is used to risk-stratify patients undergoing major elective surgery, with a poor exercise capacity being associated with an increased risk of complications and death. Patients with anaemia have a decreased exercise capacity and an increased risk of morbidity and mortality after major surgery. Blood transfusion is often used to correct anaemia in the perioperative period but the effect of this intervention on exercise capacity is not well described. We sought to measure the effect of blood transfusion on exercise capacity measured objectively with CPET.
  
  
  METHODS
  Patients with stable haematological conditions requiring blood transfusion underwent CPET before and 2-6 days after transfusion.
  
  
  RESULTS
  Twenty patients were enrolled and completed both pre- and post-transfusion tests. The mean (sd) haemoglobin (Hb) concentration increased from 8.3 (1.2) to 11.2 (1.4) g dl(-1) after transfusion of a median (range) of 3 (1-4) units of packed red cells. The anaerobic threshold increased from a mean (sd) of 10.4 (2.4) to 11.6 (2.5) ml kg(-1) min(-1) (P=0.018), a mean difference of 1.2 ml kg(-1) min(-1) (95% confidence interval (CI)=0.2-2.2). When corrected for the change in Hb concentration, the anaerobic threshold increased by a mean (sd) of 0.39 (0.74) ml kg(-1) min(-1) per g dl(-1) Hb.
  
  
  CONCLUSIONS
  Transfusion of allogeneic packed red cells in anaemic adults led to a significant increase in their capacity to exercise. This increase was seen in the anaerobic threshold, and other CPET variables.
authors.affiliation: Perioperative and Critical Care Directorate, Freeman Hospital, High Heaton, Newcastle upon Tyne NE7 7DN, UK stephen.wright@nuth.nhs.uk.
authors.forename: S E
authors.initials: SE
authors.lastname: Wright
authors.affiliation: Perioperative and Critical Care Directorate, Freeman Hospital, High Heaton, Newcastle upon Tyne NE7 7DN, UK.
authors.forename: B
authors.initials: B
authors.lastname: Pearce
authors.affiliation: Perioperative and Critical Care Directorate, Freeman Hospital, High Heaton, Newcastle upon Tyne NE7 7DN, UK.
authors.forename: C P
authors.initials: CP
authors.lastname: Snowden
authors.affiliation: Perioperative and Critical Care Directorate, Freeman Hospital, High Heaton, Newcastle upon Tyne NE7 7DN, UK.
authors.forename: H
authors.initials: H
authors.lastname: Anderson
authors.affiliation: Department of Haematology, Freeman Hospital, High Heaton, Newcastle upon Tyne NE7 7DN, UK.
authors.forename: J P
authors.initials: JP
authors.lastname: Wallis
mesh_terms: D000328:Adult; D000368:Aged; D015308:Anaerobic Threshold / Q000502:physiology; D000740:Anemia / Q000097:blood / Q000503:physiopathology / Q000628:therapy*; D002908:Chronic Disease; D017707:Erythrocyte Transfusion; D005080:Exercise Test / Q000379:methods*; D017079:Exercise Tolerance / Q000502:physiology; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology; D011446:Prospective Studies
chemical_list: D006454:Hemoglobins
keywords: adult; anaemia; anaerobic threshold; erythrocyte transfusion; exercise test; humans; oxygen consumption; physical exertion; pulmonary gas exchange