Therapeutic antibiotic serum concentrations by two blood collection methods within the pediatric patient: A...

Area of Science:

• Pediatric pharmacology
• Clinical chemistry
• Patient safety

Background:

• Repeated venipunctures and fingersticks for serum drug concentration monitoring cause pain and dissatisfaction in pediatric patients.
• Current standard of care often involves additional blood draws even when patients have indwelling catheters (peripheral intravenous or central venous).

Purpose of the Study:

• To assess the agreement between serum drug concentrations obtained from existing peripheral intravenous (PIV) or central venous catheters (CVC) versus traditional venipuncture or fingerstick methods in pediatric patients.
• To evaluate if samples from indwelling catheters can reliably replace separate blood draws for monitoring tobramycin and vancomycin levels.

Main Methods:

• Paired blood samples were collected from 36 hospitalized pediatric patients (3 months to 22 years).
• Serum trough vancomycin and random tobramycin concentrations were compared between PIV/CVC and venipuncture/fingerstick samples.
• A strict protocol ensured PIV/CVC samples were drawn first, with minimal time between collections and specific flush/waste volumes.

Main Results:

• Concordant correlation coefficients showed substantial agreement between PIV/CVC and venipuncture/fingerstick concentrations for both vancomycin (Rc=0.982) and tobramycin (Rc=0.982).
• Bland-Altman analyses indicated good agreement within subjects and minimal bias between the two sampling methods.
• The results suggest high reliability of drug concentrations obtained from indwelling catheters.

Conclusions:

• Utilizing a lumen volume-based flush and waste protocol, drug concentrations can be accurately measured from indwelling catheters (PIV/CVC) in pediatric patients.
• This approach may eliminate the need for additional venipunctures or fingersticks, thereby enhancing patient comfort and satisfaction.
• Implementing this method can improve the quality of care for hospitalized children requiring therapeutic drug monitoring.