Short-term prognosis and influencing factors of patients with acute kidney injury treated with prolonged intermittent renal replacement therapy.

Background: Studies assessing prognosis after prolonged intermittent renal replacement therapy (PIRRT) for acute kidney injury (AKI) are scarce.

Aim: To assess the impact of PIRRT on AKI and factors associated with short-term prognosis.

Methods: In this retrospective nested case-control study, AKI patients administered PIRRT in Shanghai General Hospital from 01/2012 to 10/2018 were assigned to the 30-day survivor and death groups. Surviving patients were further divided into the kidney recovery and non-recovery groups at 30 and 90 days post-discharge, respectively. Propensity score matching was performed.

Results: Totally 576 patients were included in the non-matched study population, mortality and kidney recovery rates were 51.7% and 33.4%, respectively. After propensity score matching, there were 250 patients in each of the death and survival groups. Low PIRRT frequency (OR = 2.165, 95% CI = 1.178-3.978), infection (OR = 0.447, 95% CI = 0.251-0.795), number of damaged vital organs (OR = 0.478, 95% CI = 0.346-0.661), sodium (OR = 0.958, 95% CI = 0.928-0.988), total protein (OR = 1.047, 95% CI = 1.022-1.072), pre-dialysis thrombin time (TT; OR = 0.959, 95% CI = 0.936-0.983), pre-discharge glomerular filtration rate (GFR; OR = 1.024, 95% CI = 1.017-1.031) and admission ward [reference: renal ward; intensive care unit (OR = 0.042, 95% CI = 0.008-0.211); surgery (OR = 0.092, 95% CI = 0.018-0.465); medical (OR = 0.049, 95% C% CI = 0.009-0.259); other (OR = 0.097, 95% CI = 0.016-0.572)] independently predicted 30-day mortality. Peripherally inserted central catheter (OR = 13.970, 95% CI = 1.439-135.589), urea nitrogen (OR = 0.961, 95% CI = 0.933-0.990) and pre-discharge GFR (OR = 1.102, 95% CI = 1.067-1.137) independently predicted 30-day kidney recovery. Pre-dialysis Scr (OR = 0.997, 95% CI = 0.995-0.999), urea nitrogen (OR = 0.948, 95% CI = 0.912-0.986) and pre-discharge GFR (OR = 1.137 95% CI = 1.088-1.189) independently predicted 90-day kidney recovery.

Conclusions: PIRRT improves survival and kidney function recovery in AKI patients. In patients with previous GFR ≥ 30 mL/(min-1.73 m ) and no prior maintenance dialysis, PIRRT at 3-5 sessions/week might be appropriate.