title: Pyrexia after cardiac surgery: natural history and association with infection.
abstract: BACKGROUND
  Pyrexia is common after major surgery, and infection is often an important consideration. To investigate the natural history and association with infection, we performed a prospective observational study.
  
  
  METHODS
  From November 2000 to January 2001, we studied 219 patients undergoing cardiac surgery screening daily for wound, respiratory, urinary tract, and other infections. Pyrexia was defined as temperature above 37.5 degrees C.
  
  
  RESULTS
  Of 219 patients, 7 intraoperative deaths occurred and 1 patient was excluded because of preoperative endocarditis, leaving 211. The mean age (SD) was 64 (10) years, consisting of 172 male patients (81.5%). The proportion pyrexial on days 1, 2, and 5 was 30.0%, 25.8%, and 10.3%, respectively. More patients undergoing urgent or emergency procedures (17.7% versus 7.8%; P =.03) subsequently developed pyrexia. However, there were no differences in wound infection (3.4% versus 8.3%; P =.13), positive cultures for respiratory (14.7% versus 11.4%; P =.16), urinary tract (5.2% versus 2.0%; P =.09), or other infection (8.6% versus 7.3%; P =.71) in patients experiencing postoperative pyrexia compared with those who did not.
  
  
  CONCLUSIONS
  Pyrexia is common after cardiac surgery and resolves in the majority of patients by day 5. Because there is no association between early pyrexia and infection, diagnosis of early postoperative infection by pyrexia alone is insufficient and is better established by clinical assessment with microbiological evidence.
authors.affiliation: Department of Cardiothoracic Surgery, Royal Brompton Hospital, Sydney Street, London SW3 6NP, United Kingdom. ericlim2@hotmail.com
authors.forename: Eric
authors.initials: E
authors.lastname: Lim
authors.forename: Reza
authors.initials: R
authors.lastname: Motalleb-Zadeh
authors.forename: Matthew
authors.initials: M
authors.lastname: Wallard
authors.forename: Nikhil
authors.initials: N
authors.lastname: Misra
authors.forename: Enoch
authors.initials: E
authors.lastname: Akowuah
authors.forename: Ishtiaq
authors.initials: I
authors.lastname: Ahmed
authors.forename: James C
authors.initials: JC
authors.lastname: Halstead
authors.forename: Fiona
authors.initials: F
authors.lastname: Murphy
authors.forename: Juliet
authors.initials: J
authors.lastname: Foweraker
authors.forename: Steven
authors.initials: S
authors.lastname: Tsui
mesh_terms: D006348:Cardiac Surgical Procedures; D004630:Emergencies; D005260:Female; D005334:Fever / Q000209:etiology*; D006801:Humans; D007239:Infections / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D019370:Observation; D011183:Postoperative Complications; D011446:Prospective Studies; D012141:Respiratory Tract Infections / Q000209:etiology; D013997:Time Factors; D014552:Urinary Tract Infections / Q000209:etiology