title: Hypothermia does not increase the risk of infection: a case control study.
abstract: BACKGROUND
  Hypothermia may improve outcome in patients after traumatic brain injury, especially when hypothermia is maintained for more than 48 hours. In the acute phase, patients with severe brain injury are more vulnerable to infections. Prolonged hypothermic treatment may further enhance the risk of infection. Selective decontamination of the digestive tract (SDD) reduces the risk of respiratory tract infections. The aim of this study was to investigate the incidence of infections in patients treated with hypothermia and normothermia while receiving SDD.
  
  
  METHODS
  In this retrospective case control study 35 patients treated with prolonged hypothermia (cases) were identified and 169 patients with severe brain injury were included (controls). Propensity score matching was performed to correct for differences in baseline characteristics and clinical parameters. Primary outcome was the incidence of infection. The secondary endpoints were the micro-organisms found in the surveillance cultures and infection. In addition, a number of clinical characteristics were assessed.
  
  
  RESULTS
  The demographic and clinical data indicated that the cases and controls were well matched. The overall risk of infection during ICU stay was 20% in the hypothermia groups versus 34.4% in the normothermia group (P = 0.388). Pneumonia was diagnosed in 11.4% of patients in both groups (P = 1.000). The incidence of meningitis, wound infection, bacteremia, and urinary tract infection was low and comparable between the groups. SDD surveillance cultures indicated a higher colonization with gram-negative bacteria in the rectal samples of the hypothermia patients.
  
  
  CONCLUSIONS
  Hypothermia does not increase the risk of infection in patients treated with SDD.
authors.affiliation: Department of Intensive Care, Radboud University Nijmegen Medical Centre PO Box 9101, 6500 HB Nijmegen, The Netherlands.
authors.forename: Marlijn
authors.initials: M
authors.lastname: Kamps
authors.forename: Laurens A
authors.initials: LA
authors.lastname: Bisschops
authors.forename: Johannes G
authors.initials: JG
authors.lastname: van der Hoeven
authors.forename: Cornelia W E
authors.initials: CW
authors.lastname: Hoedemaekers
mesh_terms: D000328:Adult; D001930:Brain Injuries / Q000628:therapy*; D016022:Case-Control Studies; D003666:Decontamination / Q000379:methods*; D004064:Digestive System / Q000382:microbiology*; D005260:Female; D006801:Humans; D007036:Hypothermia, Induced / Q000009:adverse effects / Q000379:methods*; D007239:Infections / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D013997:Time Factors; D016896:Treatment Outcome