title: Early acute kidney injury in military casualties.
abstract: BACKGROUND
  While acute kidney injury (AKI) has been well studied in a variety of patient settings, there is a paucity of data in patients injured in the course of the recent wars in Iraq and Afghanistan. We sought to establish the rate of early AKI in this population and to define risk factors for its development.
  
  
  METHODS
  We combined the results of two studies performed at combat support hospitals in Afghanistan. Only US service members who required care in the intensive care unit were included for analysis. Data on age, race, sex, Injury Severity Score (ISS), first available lactate, and requirement for massive transfusion were collected. Univariate analyses were performed to identify factors associated with the subsequent development of early AKI. Multivariable Cox regression was used to adjust for potential confounders.
  
  
  RESULTS
  The two observational cohorts yielded 134 subjects for analysis. The studies had broadly similar populations but differed in terms of age and need for massive transfusion. The rate of early AKI in the combined cohort was 34.3%, with the majority (80.5%) occurring within the first two hospital days. Patients with AKI had higher unadjusted mortality rates than those without AKI (21.7% vs. 2.3%, p < 0.001). After adjustment, ISS (hazard ratio, 1.02; 95% confidence interval, 1.00-1.03; p = 0.046) and initial lactate (hazard ratio, 1.16; 95% confidence interval, 1.03-1.31; p = 0.015) were independently associated with the development of AKI.
  
  
  CONCLUSIONS
  AKI is common in combat casualties enrolled in two prospective intensive care unit studies, occurring in 34.3%, and is associated with crude mortality. ISS and initial lactate are independently associated with the subsequent development of early AKI.
  
  
  METHODS
  Prognostic and epidemiologic study, level III.
authors.affiliation: From the Department of Medicine (K.D.H.), Eglin Hospital, Eglin Air Force Base, Florida; Department of Medicine (I.J.S., J.A.S., H.K.K., K.R.G., B.D.M., A.T.H., K.K.S.), San Antonio Military Medical Center; and Burn Center (K.K.C.), and Blood Task Area (A.P.C.), United States Army Institute of Surgical Research, Fort Sam Houston, Texas; Department of Medicine (W.L.), Kessler Medical Center, Biloxi, Mississippi; Department of Medicine (E.D.S., T.A.I), Vanderbilt University Medical Center, Nashville, Tennessee; and Department of Medicine (I.J.S., J.A.S., K.R.G., B.D.M., K.K.C.), Uniformed Services University of the Health Sciences, Bethesda, Maryland.
authors.forename: Kelly D
authors.initials: KD
authors.lastname: Heegard
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Stewart
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Cap
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Sosnov
authors.forename: Hana K
authors.initials: HK
authors.lastname: Kwan
authors.forename: Kristen R
authors.initials: KR
authors.lastname: Glass
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Morrow
authors.forename: Wayne
authors.initials: W
authors.lastname: Latack
authors.forename: Aaron T
authors.initials: AT
authors.lastname: Henderson
authors.forename: Kristin K
authors.initials: KK
authors.lastname: Saenz
authors.forename: Edward D
authors.initials: ED
authors.lastname: Siew
authors.forename: T Alp
authors.initials: TA
authors.lastname: Ikizler
authors.forename: Kevin K
authors.initials: KK
authors.lastname: Chung
mesh_terms: D058186:Acute Kidney Injury / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D000328:Adult; D055826:Afghan Campaign 2001-; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007362:Intensive Care Units; D008297:Male; D008889:Military Personnel; D016016:Proportional Hazards Models; D011446:Prospective Studies; D013997:Time Factors; D014481:United States / Q000453:epidemiology; D014947:Wounds and Injuries / Q000150:complications* / Q000175:diagnosis; D055815:Young Adult