Antibiotic Concentrations in Serum and Wound Fluid after Local Gentamicin or Intravenous Dicloxacillin Prophylaxis in Cardiac Surgery

Abstract

One important aim of antibiotic prophylaxis in cardiac surgery is preventing mediastinitis and thus it would appear to be relevant to study the antibiotic concentrations in pericardial/mediastinal fluid. Local administration of gentamicin in the wound before sternal closure is a novel way of antibiotic prophylaxis and could be effective against bacteria resistant to intravenous antibiotics. This study measured dicloxacillin concentrations in 101 patients in serum and wound fluid following intravenous administration of dicloxacillin. Similarly, concentrations of gentamicin in serum and wound fluid were determined in 30 patients after administration of 260 mg gentamicin in the wound at sternal closure. Median dicloxacillin concentrations in serum and wound fluid at sternal closure were 59.4 and 55.35 mg/l, respectively. Gentamicin levels in the wound were very high (median 304 mg/l), whereas serum concentrations were low (peak median 2.05 mg/l). Dicloxacillin, 1 g given intravenously, according to the clinical protocol, resulted in levels in serum and wound fluid at sternal closure likely to prevent Staphylococcus aureus infections. Locally administered gentamicin resulted in high local concentrations, potentially effective against agents normally considered resistant.

Local collagen‐gentamicin for prevention of sternal wound infections: the LOGIP trial

“…However, although frequently practised (10), all prophylactic use of vancomycin should be restrictive, for the reasons previously mentioned. The high gentamicin concentration in the wound achieved by local application of gentamicin may be effective against bacteria that are normally considered resistant according to the MIC values (11).…”

Gentamicin–Collagen Sponge for Infection Prophylaxis in Colorectal Surgery

“…In support of this hypothesis are data showing low wound and local levels of gentamicin 12 hours after sponge insertion. 21 We found what appeared to be a transient early benefit of the sponge (Fig. 2), with a subsequent reversal in that effect, which may be consistent with the failure of the sponge to provide a sustained local level of gentamicin.…”

TOPICALLY-USED GENTAMICIN ATTACHED TO NANOFIBRE MDOCTM COMPARED WITH GARAMYCIN SCHWAMM^® IN AN ACUTE WOUND INFECTION MODEL. AN EXPERIMENTAL STUDY.

“…The other advantages of topicallyadministered gentamicin are its high concentration in wound fluid and minimum concentration in serum. High local gentamicin levels, about 75-200 times higher than minimum inhibition concentration (MIC), 4mg/l, were observed in wound fluid compared to that in serum (1-4 mg/l after 24 hours): both levels being safely below the toxic threshold of 10 mg/l [5,[7][8][9].…”

“…Most published articles involving topicallyadministered gentamicin with a collagen carrier describe results of the prophylaxis of SSI in a cardiac surgery [5][6][7][8][9][10][11]. Gentamicin-collagen implants of various brand names (Collatamp-G ® , Gentacoll ® , Sulmycin Implant ® ) that contain 130 mg of gentamicin and 280 mg of collagen were put underneath the sternum or between its edges before sternotomy closure.…”