Blood concentrations of cefuroxime in cardiopulmonary bypass surgery

Patients with coronary artery bypass graft (CABG) surgery are at risk for severe postoperative infections. Prophylactic cefuroxime may help to reduce this risk, however sufficient concentrations, i.e. above the breakpoint (32 mg/L), are mandatory. The aim of this study is to evaluate the blood concentrations of cefuroxime during and after CABG surgery with cardiopulmonary bypass (CPB) and hypothermia, to determine the concentration of cefuroxime in sternum fluid and to evaluate possible factors of influence.

Seventeen patients were enrolled in this study, given 1.5 g cefuroxime at anaesthesia induction and an additional 1.5 g at start CPB. Blood samples were collected at skin incision, start CPB, every 30 min on CPB, end CPB, at wound closure and 1 h after surgery. Cefuroxime concentrations were determined by high performance liquid chromatography.

In 47 % of the patients the cefuroxime concentration was below the breakpoint at some point during the operation and in 59 % of the patients 1 h after surgery. A statistically significant inverse correlation between estimated glomerular filtration rate and plasma cefuroxime concentrations was found (P = 0.034). Cefuroxime levels in the sternum are not significantly different from blood levels from the radial artery catheter, taken at approximately the same time (P = 0.30).

The current antibiotic regimen used did not maintain cefuroxime concentrations above the breakpoint throughout the operation, suggesting insufficient antibiotic prophylaxis. Further research to other antibiotic regimes is therefore necessary.