Keisuke Okamoto, Naoki Ozu, Hidetada Fukushima, Masahiko Kawaguchi, Kazuhiko Tsuruya
In ICU patients starting CKRT, pre-CKRT urine output in AKI and dialysis vintage in ESKD were associated with short-term prognosis. Non-oliguric AKI was associated with a lower adjusted hazard of death than ESKD, and longer dialysis vintage was associated with a higher hazard of death within ESKD. These findings require external validation in contemporary multicenter cohorts.
BACKGROUND: Prognostic assessment at continuous kidney replacement therapy (CKRT) initiation remains challenging in ICU practice. CKRT recipients are heterogeneous; most have acute kidney injury (AKI), whereas a clinically important subset has end-stage kidney disease (ESKD). We evaluated whether pre-CKRT urine output in AKI and dialysis vintage in ESKD were associated with short-term prognosis after CKRT initiation.
METHODS: We conducted a single-center retrospective cohort study of consecutive adults who started CKRT in a combined medical-surgical ICU between 2012 and 2021. Patients were classified at CKRT initiation as ESKD, oliguric AKI, or non-oliguric AKI. ESKD was defined as maintenance hemodialysis or peritoneal dialysis before ICU admission. Among patients with AKI, oliguric and non-oliguric AKI were defined as pre-CKRT urine output <0.5 and ≥0.5 mL/kg/h, respectively. The primary outcome was time to all-cause death within 90 days after CKRT initiation. We used Cox proportional hazards models adjusted for prespecified covariates measured at CKRT initiation. Within ESKD, we modeled dialysis vintage as a continuous variable using Cox models adjusted for APACHE II score and sepsis.
RESULTS: Among 560 patients, 66 had ESKD, 305 had oliguric AKI, and 189 had non-oliguric AKI. Documented death within 90 days occurred in 236 patients (42.1%). Using ESKD as the reference, oliguric AKI was not associated with a different hazard of death within 90 days (adjusted hazard ratio [HR], 0.86; 95% confidence interval [CI], 0.58-1.29), whereas non-oliguric AKI was associated with a lower hazard (adjusted HR, 0.63; 95% CI 0.41-0.99). Among patients with ESKD, longer dialysis vintage was associated with a higher hazard of death within 90 days (adjusted HR per 1-year increase, 1.07; 95% CI 1.02-1.11).
CONCLUSIONS: In ICU patients starting CKRT, pre-CKRT urine output in AKI and dialysis vintage in ESKD were associated with short-term prognosis. Non-oliguric AKI was associated with a lower adjusted hazard of death than ESKD, and longer dialysis vintage was associated with a higher hazard of death within ESKD. These findings require external validation in contemporary multicenter cohorts.