Antimicrobial dose adjustment by renal function in adult Intensive Care Unit

Abstract

Objective: to identify antimicrobial dose adjustments according to renal function in prescriptions for patients hospitalized in an adult ICU of a general hospital in southern Brazil. Methods: observational, retrospective cross-sectional study, carried out in an adult ICU of a general hospital in southern Brazil from January to December 2021. All adult patients with ≥48 hours of ICU stay, creatinine clearance (CrCl) ≤60 mL/min/1.73 m2 and use of one or more of the following antimicrobials: amikacin, ampicillin, ampicillin/sulbactam, cefepime, ceftazidime/avibactam, fluconazole, levofloxacin, meropenem, piperacillin/tazobactam and/or voriconazole. Renal function was estimated from serum creatinine using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation, and dose appropriateness was determined by comparing practice to specific guidelines. Sociodemographic variables (gender, age, ethnicity) were evaluated, in addition to the influence of possible determinants, such as: duration of antimicrobial use, length of stay, mortality, among others. Results: 151 patients were included, totaling 906 possibilities for adjusting the dose of antimicrobials based on renal function. Among the 906 possibilities, 546 (60.3%) were properly adjusted, 69 (7.6%) were inadequately adjusted, and 291 (32.1%) were not adjusted. Voriconazole was associated with a greater proportion of unadjusted doses 6/6 (100%), while piperacillin/tazobactam was associated with a greater proportion of adjustments not recommended in the literature 41/268 (15.3%). Fluconazole had its doses properly adjusted according to renal function in all situations 21/21 (100%). The duration of antimicrobial use between patients with dose adjustment and those treated with the usual dose was 10 and 11 days, respectively (p <0.001), and the length of ICU stay in the respective groups was 14 and 18 days ( p<0.001). Conclusions: Our findings revealed a high percentage of antimicrobial dose adjustment according to renal function for ICU patients compared to other studies that evaluated non-critical patients. The data suggest that the involvement of physicians and pharmacists to ensure adequate dosage of nephrotoxic antimicrobials according to renal function has significantly contributed to more favorable patient outcomes.