title: The feasibility and accuracy of point-of-care lactate measurement in emergency department patients with suspected infection.
abstract: BACKGROUND
  Prior studies show that lactate is a useful prognostic marker in sepsis.
  
  
  OBJECTIVE
  To study the feasibility and accuracy of a point-of-care (POC) analyzer capable of performing bedside serum lactate measurements; and to determine if other measurements (pH, base excess) are predictive of mortality.
  
  
  METHODS
  
  
  
  METHODS
  prospective cohort study of adult (age 18 years or older) Emergency Department (ED) patients with suspected infection during the study period of May 2006 through March 2007.
  
  
  METHODS
  A 55,000-annual-visit urban tertiary care ED.
  
  
  METHODS
  A point-of-care device (i-STAT, Abbott Point of Care Inc., Princeton, NJ) was deployed using a standardized training and quality assurance process. Using POC testing, we measured serum lactate, pH, and base excess, as well as concomitant lactate measurement via a central laboratory.
  
  
  METHODS
  Area under the curve (AUC) for receiver operator characteristic curve, Bland-Altman statistics along with a correlation coefficient, and relative risk with 95% confidence intervals reported.
  
  
  RESULTS
  There were 699 patients enrolled, of whom 34 (4.9%) died. The AUCs for mortality prediction were: POC lactate 0.72, laboratory lactate 0.70, pH measurement 0.60, and base excess 0.60. Bland-Altman showed that POC lactate was, on average, 0.32 (95% confidence interval -0.35-0.98) lower than laboratory lactate, with agreement kappa = 0.97.
  
  
  CONCLUSIONS
  A point-of-care testing device provides a reliable and feasible way to measure serum lactate at the bedside. The pH and base excess were less helpful.
authors.affiliation: Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02116, USA.
authors.forename: Nathan I
authors.initials: NI
authors.lastname: Shapiro
authors.forename: Christopher
authors.initials: C
authors.lastname: Fisher
authors.forename: Michael
authors.initials: M
authors.lastname: Donnino
authors.forename: Lauren
authors.initials: L
authors.lastname: Cataldo
authors.forename: Aimee
authors.initials: A
authors.lastname: Tang
authors.forename: Stephen
authors.initials: S
authors.lastname: Trzeciak
authors.forename: Gary
authors.initials: G
authors.lastname: Horowitz
authors.forename: Richard E
authors.initials: RE
authors.lastname: Wolfe
mesh_terms: D000328:Adult; D000368:Aged; D019540:Area Under Curve; D004636:Emergency Service, Hospital; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D019344:Lactic Acid / Q000097:blood*; D008297:Male; D008875:Middle Aged; D019095:Point-of-Care Systems; D011379:Prognosis; D011446:Prospective Studies; D018805:Sepsis / Q000175:diagnosis*
chemical_list: D019344:Lactic Acid