Renal Dose-Adjustment Concordance in Critically Ill Patients with AKI and CKD: A Cross-sectional Study

Kidney dysfunction complicates drug dosing in the intensive care unit (ICU). Guidance is well established for stable chronic kidney disease (CKD) but is less certain in acute kidney injury (AKI), in which renal function can change rapidly.

To assess concordance between prescribed maintenance regimens and reference-based renal dose-adjustment recommendations for adults with AKI, CKD, or AKI superimposed on CKD.

This cross-sectional study included 80 adults admitted to four ICUs in 2024. Acute kidney injury was classified according to the Risk, Injury, Failure, Loss, and end-stage renal disease (RIFLE) criteria using serial creatinine measurements and/or urine output, whereas CKD required documented chronicity. Cockcroft-Gault creatinine clearance (CrCl) was used to match patients to dosing-reference categories. Each patient-medication pair was classified once according to maintenance-dose amount and dosing interval, using UpToDate as the primary reference and the Sanford Guide as a supplementary source.

Among 414 patient-medication pairs, 211 (51.0%; patient-level cluster-bootstrap 95% CI, 46.2%-55.8%) were discordant: 125 were lower and 86 were higher than recommended. Vancomycin (41.4%), ciprofloxacin (40.0%), and levofloxacin (40.0%) had the highest drug-specific discordance proportions. Nephrology and pulmonology had the highest patient-level service proportions (62.5% and 61.5%, respectively).

Reference discordance was frequent, particularly for antimicrobials. Because measured exposure and clinical outcomes were unavailable, these findings identify regimens requiring review rather than confirming prescribing errors.