title: A prospective study of fever in the intensive care unit.
abstract: OBJECTIVE
  To determine the epidemiology of fever on the intensive care unit (ICU).
  
  
  METHODS
  Prospective, observational study.
  
  
  METHODS
  Nine-bed general ICU in a 500-bed tertiary care inner city institution.
  
  
  METHODS
  100 consecutive admissions of 93 patients over a 4-month period between July and October 1996.
  
  
  METHODS
  All patients were seen and examined by one investigator within 24 h of ICU admission. Patients were followed up on a daily basis throughout their ICU stay, and all clinical and laboratory data were recorded during the admission.
  
  
  RESULTS
  Fever (core temperature > or = 38.4 degrees C) was present in 70% of admissions, and it was caused by infective and non-infective processes in approximately equal number. Most fevers occurred early in the course of the admission, within the first 1-2 days, and most lasted less than 5 days. The median Acute Physiology and Chronic Health Evaluation (APACHE) II score was 15 (+/- 0.6). The 70 episodes associated with fever at any time were associated with a significantly higher APACHE II score on admission than the afebrile episodes (15.8 +/- 6.1 vs 12.1 +/- 6.7, p = 0.04). The most common cause of non-infective fever was in the group designated post-operative fever (n = 34). All the patients in the post-operative fever group were febrile on day 0 or day 1; their mean admission APACHE score was 12.4 (+/- 4.4) compared to 15.9 (+/- 7.1) for the remaining patients (p = 0.01). Fever alone was not associated with a higher mortality: 26/70 (37%) of febrile patients died, compared to 8/30 (27%) of afebrile patients, (chi 2 = 1.23, p = 0.38). Prolonged fever (> 5 days) occurred in 16 patients. In 13 cases, fever was due to infection, and in the remaining 3 both infective and non-infective processes occurred concurrently. The mortality in the group with prolonged fever was 62.5% (10/16) compared to 29.6% (16/54) in patients with fever of less than 5 days' duration, a highly significant difference (p < 0.0001).
  
  
  CONCLUSIONS
  Fever is a common event on the intensive care unit. It usually occurs early in the course, is frequently non-infective and is often benign. Prolonged fever is associated with a poor outcome. Post-operative fever is a well-recognised but poorly defined syndrome which requires further study.
authors.affiliation: Department of Infectious Diseases, Imperial College School of Medicine, Hammersmith Hospital, London, UK.
authors.forename: B
authors.initials: B
authors.lastname: Circiumaru
authors.forename: G
authors.initials: G
authors.lastname: Baldock
authors.forename: J
authors.initials: J
authors.lastname: Cohen
mesh_terms: D018806:APACHE; D001424:Bacterial Infections / Q000150:complications; D003422:Critical Care; D016638:Critical Illness; D005260:Female; D005334:Fever / Q000209:etiology*; D006801:Humans; D007362:Intensive Care Units; D008131:London; D008297:Male; D008875:Middle Aged; D009181:Mycoses / Q000150:complications; D011183:Postoperative Complications / Q000209:etiology; D011446:Prospective Studies