Background: At our clinic, total hip arthroplasties with an acute postoperative infection are treated with surgical debridement and application of several gentamicin-loaded sponges, each with an equivalent of 130 mg gentamicin. We studied the possible systemic effect of this local application of gentamicin.
Patients and methods: All 12 patients treated during 1997-2001 were included. 4-6 sponges were used in each case. We measured the serum gentamicin levels daily, from the first postoperative day until gentamicin was no longer measurable. The creatinine levels were monitored daily and the creatinine clearance was calculated according the Cockcroft-Gault formula.
Results: In 7 of the 12 patients, we found toxic serum levels of gentamicin (range 2-13 mg/L). In 3 cases there was a significant drop in renal clearance, which persisted. In 3 other cases there was a temporary decrease in renal clearance.
Interpretation: We found toxic serum levels after local administration of gentamicin. We even found a persistent decrease in renal clearance in some patients. Because of the alarming results, we have reduced the number of sponges used for this purpose.