Effects of continuous venovenous hemofiltration on vancomycin trough concentrations in critically ill children

Background: Vancomycin trough concentrations are associated with clinical outcomes and drug adverse effects. This study investigates the effects of continuous venovenous hemofiltration (CVVH) on vancomycin trough concentrations in critically ill children with a vancomycin dosage of 40-60 mg/kg/day. Methods: Children with steady-state vancomycin trough concentrations admitted to the pediatric intensive care unit (PICU) between January 2016 and December 2019 were retrospectively enrolled. Patients were divided into CVVH and non-CVVH groups according to treatment differences and renal function. Vancomycin trough concentrations were then compared between the groups, and risk factors for supratherapeutic trough concentrations (>20 mg/L) were analyzed with logistic regression. Results: Of the 119 patients included, 35 were enrolled in the CVVH group and 84 in the non-CVVH group. Median vancomycin trough concentrations were significantly higher in the CVVH group than those in the non-CVVH group [14.9 (IQR =9.6-19.6) vs. 9.3 (IQR =7.0-13.4), P<0.001] and the proportion of therapeutic trough concentrations (10-20 mg/L) was similar between CVVH and non-CVVH groups (54.3% vs. 39.3%, P=0.133). However, CVVH therapy patients had a significantly higher proportion of supratherapeutic trough concentrations (20.0% vs. 1.2%, P=0.001) compared to the non-CVVH group. Multivariate analysis demonstrated that the Pediatric Risk of Mortality (PRISM) III score >= 28 (OR =13.7; 95% CI, 1.4-137.0; P=0.026] was an independent risk factor for supratherapeutic trough concentrations in critically ill patients. Conclusions: CVVH therapy affects vancomycin trough concentrations and is associated with supratherapeutic concentrations with a 40-60 mg/kg/day vancomycin dosage. PRISM III scores >= 28 may serve as an independent risk factor for supratherapeutic trough concentrations in children receiving CVVH therapy.