title: Prognosis of emergency department patients with suspected infection and intermediate lactate levels: a systematic review.
abstract: OBJECTIVE
  Previous studies have shown a correlation between blood lactate greater than 4.0 mmol/L and mortality in patients with suspected infection in the emergency department (ED), but data are more limited regarding the prognosis of intermediate blood lactate (2.0-3.9 mmol/L), particularly in the absence of hemodynamic instability. We sought to quantify the prognostic significance of intermediate blood lactate levels in ED patients with suspected infection, emphasizing patients without hypotension.
  
  
  METHODS
  A systematic review of 4 databases was conducted to identify studies using a comprehensive search strategy. All studies performed on adult ED patients with suspected infection and available data on hemodynamics, intermediate lactate levels, and mortality rates were included.
  
  
  RESULTS
  We identified 20 potential publications, 8 of which were included. Intermediate lactate elevation was found in 11,062 patients with suspected or confirmed infection, 1672 (15.1%) of whom died. Subgroup analysis of normotensive patients demonstrated a mortality of 1561 (14.9%) of 10,442, with rates from individual studies between 3.2% and 16.4%.
  
  
  CONCLUSIONS
  This systematic review found that among ED patients with suspected infection, intermediate lactate elevation is associated with a moderate to high risk of mortality, even among patients without hypotension. Physicians should consider close monitoring and aggressive treatment for such patients.
authors.affiliation: Department of Emergency Medicine, University of Mississippi Medical Center, Jackson, MS.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Puskarich
authors.affiliation: Department of Emergency Medicine, University of Mississippi Medical Center, Jackson, MS.
authors.forename: Benjamin M
authors.initials: BM
authors.lastname: Illich
authors.affiliation: Department of Emergency Medicine, University of Mississippi Medical Center, Jackson, MS. Electronic address: aejones@umc.edu.
authors.forename: Alan E
authors.initials: AE
authors.lastname: Jones
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D007239:Infections / Q000097:blood* / Q000401:mortality*; D019344:Lactic Acid / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D018570:Risk Assessment
chemical_list: D015415:Biomarkers; D019344:Lactic Acid
keywords: Infection; Lactate; Prognosis; Review