Pediatr Int. 2025 Jan-Dec;67(1):e70041. doi: 10.1111/ped.70041.
ABSTRACT
BACKGROUND: Therapeutic monitoring is recommended for aminoglycoside drugs, which are often used in neonatal care. In this study, we examined whether it is possible to estimate the trough value after administration using serum creatinine (Cr) and serum cystatin C (CysC) values of umbilical cord artery blood in infants, which can be measured without increasing risks due to invasive tests.
METHODS: Subjects included infants who were hospitalized between March 2022 and March 2023 and treated with tobramycin (TOB) from 0 days old. In addition to cord blood Cr and CysC, TOB blood concentration (trough value) was measured at 3 days. The correlation coefficient (r) between serum Cr and CysC values and TOB trough value was calculated.
RESULTS: Sixteen cases were included in the study. Cord blood Cr and CysC values were divided by gestational week (GW), birth weight (BW), and body surface area (BSA), respectively, and the correlations with TOB trough values were determined. Cord blood CysC/GW/BSA showed a strong correlation with TOB trough value (r = 0.77). The receiver operating characteristic curve for the relationship between cord blood CysC/GW/BSA and TOB trough values ≥1 mg/mL revealed a cut-off value of 0.29 (area under the curve: 0.927, sensitivity: 1.00, specificity: 0.75).
CONCLUSION: Umbilical cord blood CysC/GW/BSA values were strongly correlated with TOB trough values. Cord blood samples can be used to estimate trough values before drug administration without increasing the risk to infants associated with invasive tests, enabling determination of the dosage that will not cause nephrotoxicity.
PMID:40365876 | DOI:10.1111/ped.70041
