This investigation was designed to compare cephalothin sodium (Keflin) to penicillin G when used as chemoprophylaxis of postoperative wound infections incurred during potentially contaminated operations and to determine the incidence of bacterial superinfection following either of these forms of treatment.
Either cephalothin or penicillin G was administered randomly, as indicated in Table 1, to 169 patients undergoing serious abdominal operations which involved the probable incision of an organ potentially contaminated by bacteria. Relabeled, disguised vials of the antimicrobials were dispensed by the pharmacy staff who recorded their exact composition. The double-blind nature of the trial was maintained until a determination was made of the presence or absence of infection upon final review of the hospital record following discharge of the patient from the hospital. An attempt was made to culture the external nares and the skin of the operative site on each patient prior to operation with reculture of the