Citrate Anticoagulation in Continuous Renal Replacement Therapy: Multicenter PICU Study of Filter-Related Outcomes

Objectives: To examine citrate anticoagulation in continuous renal replacement therapy (CRRT) in the PICU. Design: Post hoc analysis of a curated, multicenter dataset collected from January 1, 2022, to June 1, 2023. Setting: Seven PICUs in Turkey. Patients: PICU admissions in need of CRRT, 28 days to 18 years old. Interventions: None. Measurements and Main Results: In 128 filters used in 73 patients, the effective filter life (EFL) restricted to 72 hours was a median (interquartile range [IQR]) of 40.5 hours (IQR, 21–58 hr); total EFL was a median of 59 hours (IQR, 28–89 hr). Analysis of the receiver operating characteristic curve for initial citrate infusion dose (CID) and whether EFL reached 72 hours identified a cutoff level for initial CID of greater than 2.64 mmol citrate per liter of patient blood flow (mmol/L-bf). As expected, the two filter groups categorized by initial CID (≥ 2.7 vs. < 2.7 mmol/L-bf) showed filters in children receiving higher initial dosing had longer total EFL (72 hr [IQR, 48–104 hr] vs. 38.5 hr [IQR, 18–84 hr]; p = 0.03). We failed to identify an association between CRRT for over 24 or 48 hours and greater odds (odds ratio [OR], 95% CI) of citrate accumulation (OR, 2.23; 95% CI, 0.82–6.13; p = 0.118 or OR, 1.78; 95% CI, 0.84–3.8; p = 0.134, respectively). However, we cannot exclude up to 6.1- or 3.8-fold odds of citrate accumulation; of note, CRRT over 72 hours was associated with greater odds of citrate accumulation (OR, 2.17; 95% CI, 1.01–4.68; p = 0.04). Citrate lock syndrome occurred in eight of 128 (6.3%; 95% CI, 3–11.4%) filters, and resolved without termination of CRRT. On multivariable analysis, a higher patient initial lactate concentration was associated with an 18% (95% CI, 7–30%) greater hazard of developing citrate accumulation. Conclusions: Citrate anticoagulation for CRRT is an option for children. Choosing an initial CID greater than or equal to 2.7 mmol/L-bf provides longer EFL but with the associated potential of citrate accumulation. Further studies are needed on initial CID and duration of EFL.