Cephalosporin prophylaxis for total hip replacement

A randomized, double-blind study of 110 subjects was undertaken to determine the adequacy of recommended antibiotic prophylaxis regimens for total hip replacement. Patients received either cephalothin or cefamandole preoperatively at anesthesia induction, and every four hours for 48 hours postoperatively. Samples of eight tissue types, excised in surgery, and serum and wound drainage were assayed for antibiotic levels. These levels were averaged for each drug group and time interval taken and compared with the MICs for Staphylococcus aureus and S. epidermidis. Cefamandole maintained consistently higher levels in all tissues, and penetrated bone and deep tissues better than cephalothin (P < .001). Our study supports the following recommendations for total hip replacement prophylaxis: the initial dose should be given 15 minutes prior to incision; a second dose should be given one hour after the first dose; and cephalothin, if used for prophylaxis, should be given in the maximum recommended dosage due to its poor tissue penetration.