Topical Vancomycin Paste Over the Sternal Edge During Cardiac Surgery: Effects of Renal Function and Body Size on Systemic Exposure

Purpose: Intraoperative topical vancomycin has been widely used in several surgical fields to prevent wound infection. However, there have been limited studies on the systemic exposure of topical vancomycin. The aim of this study was to investigate systemic exposure after topical vancomycin over the sternal edge in cardiac surgical patients. The impact of impaired renal function and body size on the exposure was also examined.

Methods: Topical vancomycin (2.5 g) was applied to the sternal edge in 129 adult cardiac surgical patients. Plasma concentrations were measured on postoperative days 0 through 7 and analyzed using linear mixed-effects models.

Findings: Sixty (46.5%) patients were in chronic kidney disease stages 3 to 5, including 20 patients in end-stage renal disease (ERSD) status with regular hemodialysis preoperatively. A total of 377 plasma vancomycin levels were modeled. It was reported that there was a 7.7% increase in vancomycin level per postoperative day for patients with ESRD in contrast to a decrease of 6.1% each day for patients without ESRD. Every increase of 1 mL/min/1.73 m² in the estimated glomerular filtration rate is associated with a 0.9% decline in vancomycin concentration. Increasing body surface area (BSA) by 0.1 m² reduces the vancomycin level by 6.3%. Model simulations using 10,000 replicates reported that the probability of vancomycin level >10 mg/L declines to near 0 within 1 week after surgery in patients without ESRD, even in subjects with low estimated glomerular filtration rate and BSA. For the ESRD group with a BSA <2 m², the chance of vancomycin >10 mg/L is up to 20% to 30%.

Implications: Plasma exposure after topical vancomycin for the sternal edge is influenced by renal function and body size. The low probability of significant plasma vancomycin levels supports the typical fixed-dose strategy. For patients with ESRD receiving hemodialysis, accumulation of plasma vancomycin is worth cautioning.