title: Epidemiology and outcomes of acute kidney injury in critically ill surgical patients.
abstract: OBJECTIVE
  Acute kidney injury (AKI) is common in critically ill patients but is poorly defined in surgical patients. We studied AKI in a representative cohort of critically ill surgical patients.
  
  
  METHODS
  This was a retrospective 1-year cohort study of general surgical intensive care unit patients. Patients were identified from a prospective database, and clinical data were reviewed. Acute kidney injury events were defined by risk, injury, failure, loss, and end-stage renal classification criteria. Outcomes were inpatient and 1-year mortality, inpatient lengths of stay, and discharge renal function. Risk factors for AKI and outcomes were compared by univariate and multivariate analyses.
  
  
  RESULTS
  Of 624 patients, 296 (47%) developed AKI. Forty-two percent of events were present upon admission, whereas 36% occurred postoperatively. Risk, injury, failure, loss, and end-stage renal classification distributions by grade were as follows: risk, 152 (51%); injury, 69 (23%); and failure, 75 (25%). Comorbid diabetes, emergency admission, major surgery, sepsis, and illness severity were independently associated with renal dysfunction. Patients with AKI had significantly worse outcomes, including increased inpatient and 1-year mortality. Acute kidney injury starting before admission was associated with worse renal dysfunction and greater renal morbidity than de novo inpatient events.
  
  
  CONCLUSIONS
  Acute kidney injury is common in critically ill surgical patients and is associated with increased mortality, persisting renal impairment and greater resource use.
authors.affiliation: Division of General Surgery, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD. Electronic address: dharris@smail.umaryland.edu.
authors.forename: Donald G
authors.initials: DG
authors.lastname: Harris
authors.affiliation: Division of General Surgery, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD.
authors.forename: Michelle P
authors.initials: MP
authors.lastname: McCrone
authors.affiliation: Division of General Surgery, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD.
authors.forename: Grace
authors.initials: G
authors.lastname: Koo
authors.affiliation: Division of General Surgery, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD.
authors.forename: Adam S
authors.initials: AS
authors.lastname: Weltz
authors.affiliation: R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, Baltimore, MD.
authors.forename: William C
authors.initials: WC
authors.lastname: Chiu
authors.affiliation: R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, Baltimore, MD.
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Scalea
authors.affiliation: R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, Baltimore, MD.
authors.forename: Jose J
authors.initials: JJ
authors.lastname: Diaz
authors.affiliation: R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, Baltimore, MD; Department of Surgery, Rutgers - Robert Wood Johnson Medical School, New Brunswick, NJ.
authors.forename: Matthew E
authors.initials: ME
authors.lastname: Lissauer
mesh_terms: D058186:Acute Kidney Injury / Q000453:epidemiology* / Q000209:etiology / Q000401:mortality; D000368:Aged; D000704:Analysis of Variance; D015897:Comorbidity; D016638:Critical Illness / Q000401:mortality; D005260:Female; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D010351:Patient Discharge; D011183:Postoperative Complications / Q000453:epidemiology / Q000401:mortality; D051437:Renal Insufficiency / Q000453:epidemiology* / Q000209:etiology / Q000401:mortality; D012189:Retrospective Studies; D012307:Risk Factors; D018805:Sepsis / Q000453:epidemiology; D013514:Surgical Procedures, Operative
keywords: Acute kidney injury; Organ failure; Outcomes; Renal replacement therapy; Surgical critical care