OPTIMIZING ANTIMICROBIAL PROPHYLAXIS IN RECONSTRUCTIVE VASCULAR-SURGERY

The combinations of cefuroxime and metronidazole, and amoxycillin/clav ulanate (Augmentin) are useful as prophylactic drugs during vascular s urgery. In this study the pharmacokinetic profiles of different dosing regimens utilizing these drugs during reconstructive vascular procedu res are presented. Three groups of patients, undergoing aorto-bifemora l or femoropopliteal prosthetic surgery, received one of the following regimens: Group I: 1500 mg metronidazole plus 1500 mg cefuroxime At p remedication, Group II: 1500 mg metronidazole at premedication plus 15 00 mg cefuroxime at the time of induction anaesthesia, followed by 750 mg of cefuroxime 2 h later, Group III: 2000 mg amoxycillin/200 mg cla vulanate at time of induction anaesthesia, followed by 1000 mg amoxyci llin/200 mg clavulanate, 3 h later. For determination of the antibioti c concentrations, arterial blood samples were obtained at 30-minute in tervals during the entire procedure. An additional sample was collecte d at the time of inguinal graft site anastomosis. Cefuroxime concentra tions in these additional samples were 29.3 +/- 11.2 mg/l in group I a nd 44.7 +/- 15.9 mg/l in group II. Metronidazole concentrations were s atisfactorily high in all patients (38.4 +/- 4.5 mg/l). Amoxycillin/cl avulanate concentrations were 35.1 +/- 21.5 mg/l and 4.4 +/- 3.7 mg/l respectively. We recommend a multiple dose administration scheme for p rophylaxis in high-risk prosthetic vascular surgery, if the procedure takes more than 2-3 h and antimicrobial agents with a rapid eliminatio n time are used. A multiple dosing scheme ensures sufficiently high an tibiotic concentrations, exceeding the MIC of staphylococci and entero bacteria approximately twice, at the time of inguinal graft site anast omosis.