[Cloxacillin concentration in suction fluid following flash antibiotic therapy during insertion of a hip prosthesis]

Since 1982 we have administered cloxacillin intraoperatively during total hip replacement. 1 g cloxacillin is injected intravenously at induction of anesthesia, followed by 1g every hour until the end of the procedure or a total of 6 g. In our study, cloxacillin concentrations were determined in the fluid collected from the deep suction catheter inserted at the end of the surgical procedure. Fluid samples were collected 2 h, 4 h, 6 h, 8 h and 24 hours after the last injection of cloxacillin. Serum samples were taken 2 h, 6 h and 24 hours after the last injection. Cloxacillin was assayed using an agar-diffusion microbiologic method. 18 patients were studied. Each had received 3 to 5 g cloxacillin over 3 to 5 hours. Mean suction catheter fluid concentrations were to 69.7 micrograms/ml, 37.6 micrograms/ml, 24.2 micrograms/ml, 15.5 micrograms/ml, and 6.8 micrograms/ml respectively in the samples collected 2 h, 4 h, 6 h, 8 h and 24 hours after the last injection of cloxacillin. Mean serum concentrations were 34.1 micrograms/ml, 4.2 micrograms/ml, and 0 microgram/ml respectively 2 h, 6 h and 24 hours after the last injection. Our results indicate that cloxacillin concentrations within the hip joint are probably effective against staphylococci for 8 to 12 hours.