title: Impact of timing of renal replacement therapy initiation on outcome of septic acute kidney injury.
abstract: BACKGROUND
  Sepsis is the leading cause of acute kidney injury (AKI) in critical patients. The optimal timing of initiating renal replacement therapy (RRT) in septic AKI patients remains controversial. The objective of this study is to determine the impact of early or late initiation of RRT, as defined using the simplified RIFLE (risk, injury, failure, loss of kidney function, and end-stage renal failure) classification (sRIFLE), on hospital mortality among septic AKI patients.
  
  
  METHODS
  Patient with sepsis and AKI requiring RRT in surgical intensive care units were enrolled between January 2002 and October 2009. The patients were divided into early (sRIFLE-0 or -Risk) or late (sRIFLE-Injury or -Failure) initiation of RRT by sRIFLE criteria. Cox proportional hazard ratios for in hospital mortality were determined to assess the impact of timing of RRT.
  
  
  RESULTS
  Among the 370 patients, 192 (51.9%) underwent early RRT and 259 (70.0%) died during hospitalization. The mortality rate in early and late RRT groups were 70.8% and 69.7% respectively (P > 0.05). Early dialysis did not relate to hospital mortality by Cox proportional hazard model (P > 0.05). Patients with heart failure, male gender, higher admission creatinine, and operation were more likely to be in the late RRT group. Cox proportional hazard model, after adjustment with propensity score including all patients based on the probability of late RRT, showed early dialysis was not related to hospital mortality. Further model matched patients by 1:1 fashion according to each patient's propensity to late RRT showed no differences in hospital mortality according to head-to-head comparison of demographic data (P > 0.05).
  
  
  CONCLUSIONS
  Use of sRIFLE classification as a marker poorly predicted the benefits of early or late RRT in the context of septic AKI. In the future, more physiologically meaningful markers with which to determine the optimal timing of RRT initiation should be identified.
authors.affiliation: Department of Surgery, National Taiwan University Hospital, 7 Chung-Shan South Road, Taipei 100, Taiwan.
authors.forename: Yu-Hsiang
authors.initials: YH
authors.lastname: Chou
authors.forename: Tao-Min
authors.initials: TM
authors.lastname: Huang
authors.forename: Vin-Cent
authors.initials: VC
authors.lastname: Wu
authors.forename: Cheng-Yi
authors.initials: CY
authors.lastname: Wang
authors.forename: Chih-Chung
authors.initials: CC
authors.lastname: Shiao
authors.forename: Chun-Fu
authors.initials: CF
authors.lastname: Lai
authors.forename: Hung-Bin
authors.initials: HB
authors.lastname: Tsai
authors.forename: Chia-Ter
authors.initials: CT
authors.lastname: Chao
authors.forename: Guang-Huar
authors.initials: GH
authors.lastname: Young
authors.forename: Wei-Jei
authors.initials: WJ
authors.lastname: Wang
authors.forename: Tze-Wah
authors.initials: TW
authors.lastname: Kao
authors.forename: Shuei-Liong
authors.initials: SL
authors.lastname: Lin
authors.forename: Yin-Yi
authors.initials: YY
authors.lastname: Han
authors.forename: Anne
authors.initials: A
authors.lastname: Chou
authors.forename: Tzu-Hsin
authors.initials: TH
authors.lastname: Lin
authors.forename: Ya-Wen
authors.initials: YW
authors.lastname: Yang
authors.forename: Yung-Ming
authors.initials: YM
authors.lastname: Chen
authors.forename: Pi-Ru
authors.initials: PR
authors.lastname: Tsai
authors.forename: Yu-Feng
authors.initials: YF
authors.lastname: Lin
authors.forename: Jenq-Wen
authors.initials: JW
authors.lastname: Huang
authors.forename: Wen-Chih
authors.initials: WC
authors.lastname: Chiang
authors.forename: Nai-Kuan
authors.initials: NK
authors.lastname: Chou
authors.forename: Wen-Je
authors.initials: WJ
authors.lastname: Ko
authors.forename: Kwan-Dun
authors.initials: KD
authors.lastname: Wu
authors.forename: Tun-Jun
authors.initials: TJ
authors.lastname: Tsai
mesh_terms: D058186:Acute Kidney Injury / Q000209:etiology / Q000401:mortality / Q000628:therapy*; D000368:Aged; D000369:Aged, 80 and over; D003422:Critical Care / Q000379:methods*; D005260:Female; D006305:Health Status Indicators; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D017582:Renal Replacement Therapy / Q000379:methods*; D012189:Retrospective Studies; D018805:Sepsis / Q000150:complications* / Q000401:mortality / Q000628:therapy; D013997:Time Factors; D016896:Treatment Outcome