title: Serum Lactate Predicts Adverse Outcomes in Emergency Department Patients With and Without Infection.
abstract: BACKGROUND
  Lactate levels are increasingly used to risk stratify emergency department (ED) patients with and without infection. Whether a serum lactate provides similar prognostic value across diseases is not fully elucidated. This study assesses the prognostic value of serum lactate in ED patients with and without infection to both report and compare relative predictive value across etiologies.
  
  
  METHODS
  We conducted a prospective, observational study of ED patients displaying abnormal vital signs (AVS) (heart rate ≥130 bpm, respiratory rate ≥24 bpm, shock index ≥1, and/or systolic blood pressure <90 mmHg). The primary outcome, deterioration, was a composite of acute renal failure, non-elective intubation, vasopressor administration or in-hospital mortality.
  
  
  RESULTS
  Of the 1,152 patients with AVS who were screened, 488 patients met the current study criteria: 34% deteriorated and 12.5% died. The deterioration rate was 88/342 (26%, 95% CI: 21 - 30%) for lactate < 2.5 mmol/L, 47/90 (52%, 42 - 63%) for lactate 2.5 - 4.0 mmol/L, and 33/46 (72%, 59 - 85%) for lactate >4.0mmol/L. Trended stratified lactate levels were associated with deterioration for both infected (p<0.01) and non-infected (p<0.01) patients. In the logistic regression models, lactate > 4mmol/L was an independent predictor of deterioration for patients with infection (OR 4.8, 95% CI: 1.7 - 14.1) and without infection (OR 4.4, 1.7 - 11.5).
  
  
  CONCLUSIONS
  Lactate levels can risk stratify patients with AVS who have increased risk of adverse outcomes regardless of infection status.
authors.affiliation: Beth Israel Deaconess Medical Center, Department of Emergency Medicine, Boston, Massachusetts; Aarhus University Hospital, Research Center for Emergency Medicine, Aarhus, Denmark.
authors.forename: Kimie
authors.initials: K
authors.lastname: Oedorf
authors.affiliation: Beth Israel Deaconess Medical Center, Department of Emergency Medicine, Boston, Massachusetts.
authors.forename: Danielle E
authors.initials: DE
authors.lastname: Day
authors.affiliation: Ben-Gurion University of the Negev, Clinical Research Center Soroka University Medical Center, and Faculty of Health Sciences, Beersheba, Israel.
authors.forename: Yotam
authors.initials: Y
authors.lastname: Lior
authors.affiliation: Ben-Gurion University of the Negev, Clinical Research Center Soroka University Medical Center, and Faculty of Health Sciences, Beersheba, Israel.
authors.forename: Victor
authors.initials: V
authors.lastname: Novack
authors.affiliation: Beth Israel Deaconess Medical Center, Department of Emergency Medicine, Boston, Massachusetts.
authors.forename: Leon D
authors.initials: LD
authors.lastname: Sanchez
authors.affiliation: Beth Israel Deaconess Medical Center, Department of Emergency Medicine, Boston, Massachusetts.
authors.forename: Richard E
authors.initials: RE
authors.lastname: Wolfe
authors.affiliation: Aarhus University Hospital, Research Center for Emergency Medicine, Aarhus, Denmark.
authors.forename: Hans
authors.initials: H
authors.lastname: Kirkegaard
authors.affiliation: Beth Israel Deaconess Medical Center, Department of Emergency Medicine, Boston, Massachusetts.
authors.forename: Nathan I
authors.initials: NI
authors.lastname: Shapiro
authors.affiliation: Beth Israel Deaconess Medical Center, Department of Emergency Medicine, Boston, Massachusetts.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Henning
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D016638:Critical Illness / Q000401:mortality; D003661:Decision Support Techniques; D004636:Emergency Service, Hospital; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D019344:Lactic Acid / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010043:Outcome and Process Assessment, Health Care; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D018805:Sepsis / Q000097:blood* / Q000175:diagnosis / Q000401:mortality; D014218:Triage; D014481:United States / Q000453:epidemiology
chemical_list: D015415:Biomarkers; D019344:Lactic Acid