Correlation Between Vancomycin Trough Concentrations and C-Reactive Protein in Neonates: A Retrospective Observational Study from a Tertiary Hospital in China.

Background: Low initial trough concentrations of vancomycin (TCV) are prevalent among neonatal patients receiving this medication. Prior research has identified significant correlations between initial TCV and various clinical parameters, including postnatal age, gestational age, body weight, estimated glomerular filtration rate (eGFR), and serum albumin levels. However, few studies have addressed the relationship between C-reactive protein (CRP) and initial TCV in neonates. This study aimed to explore the correlation between CRP and initial TCV in a Chinese neonatal population.

Methods: A retrospective observational study was conducted on neonates who received intravenous vancomycin at Northwest Women's and Children's Hospital, China, from October 2018 to December 2023. Clinical characteristics and laboratory data were extracted from medical records, focusing on data obtained within 24 hours prior to the first vancomycin administration. The primary outcomes measured were CRP levels and initial TCV.

Results: A total of 112 neonates with available therapeutic drug monitoring (TDM) data for intravenous vancomycin treatment were included. After adjusting for potential confounders, a non-linear relationship between CRP and initial TCV was identified, with an inflection point at 88.28 mg/L. The effect sizes and corresponding confidence intervals for the regions below and above this inflection point were 0.036 (95% CI: -0.005 to 0.078) and -0.084 (95% CI: -0.142 to -0.027), respectively.

Conclusion: A non-linear relationship between CRP and initial TCV was identified, with a negative correlation when CRP levels exceed 88.28 mg/L.