Abstract: Ｏｂｊｅｃｔｉｖｅ：To retrospectively observe short and longterm prognosis and risk factors of severe posttraumatic acute kidney injury (AKI) patients receiving continuous renal replacement therapy (CRRT).
Ｍｅｔｈｏｄｏｌｏｇｙ：A retrospective analysis of 77 adult patients with severe posttraumatic AKI receiving CRRT from January 2014 to December 2019 was conducted. The deadline for followup is December 2020. 28day and 90day mortality of patients and their risk factors were analyzed, as well as recovery of renal function.
Ｒｅｓｕｌｔｓ：Of the 77 patients enrolled, all patients had severe trauma, with acute physiology and chronic health evaluation Ⅱ(APACHE Ⅱ) score of 179±62, injury severity score(ISS) of 25(18,36). 66(883％) of them requiring mechanical ventilation, 62 (805％) requiring vasoactive drugs, and 44 (571％) suffered sepsis. Renal injury was mainly in the AKI stage 3 (57 cases,74％), the remaining 11 cases (143％) in the AKI stage 2 and 9 cases (117％) in the AKI stage 1. The median interval between occurrence of AKI and start of CRRT was 6 (15, 125) days. The dose of CRRT was 364±078 L／h, and the cumulative treatment time of CRRT was 126(655,3118)h. The 28day hospitalized mortality rate was 247％(19 cases). Blood phosphorus level at the beginning of CRRT is an independent risk factor for 28day death (HR=0137, 95％CI 0038-0491, P=0002). The cutoff value of blood phosphorus predicting patients 28day death was 10 mmol／L. The survival rates of serum phosphorus>10 and≤10 mmol／L were 872％ and 556％ respectively (P=001). The 90day hospitalized mortality rate was 545％(42 cases), total bilirubin was an independent risk factor for 90day death(HR=1007, 95％CI 1002~1011, P=0003).The cutoff value of total bilirubin predicting patients 90day death is 1416 μmol／L. None of the patients with total bilirubin>1416 μmol／L survived. Among the 35 surviving patients, renal function recovered in 28 patients, 5 cases progressed to chronic renal insufficiency, 1 case required maintenance hemodialysis.
Ｃｏｎｃｌｕｓｉｏｎ：Posttraumatic AKI patients receiving CRRT are in critical condition and have a high mortality rate. Serum phosphate levels and total bilirubin levels at initiation of CRRT are independent risk factors for 28day and 90day death, some patients will progress to chronic kidney disease.

Key words: trauma, acute kidney injury, continuous renal replacement therapy, prognosis, risk factors