Selecting patients requiring antibiotics in biliary surgery by immediate gram stains of bile at operation.

The value of selecting patients for antibiotic cover during biliary surgery by the use of immediate gram stains of bile was determined in a nonrandomized prospective study which compared two groups of patients. Group A consisted of 119 consecutive patients in whom antibiotics were administered during operation according to the results of immediate gram stains on bile. Group B included 101 patients, none of whom received antibiotics. In Group A gentamicin was given for gram-negative bacteria, ampicillin for gram-positive organisms, and no antibiotics were given if no bacteria were seen on the gram stain. In Group A the incidence of wound sepsis was 7 percent, compared with 22 percent in Group B (p less than 0.005). Septicemia occured in 2 percent of Group A, compared with 8 percent in Group B. It is concluded that immediate gram stains of bile will provide a means of selecting patients requiring antibiotic cover during biliary surgery; furthermore, this procedure is a practical way of reducing postoperative sepsis while avoiding unnecessary antibiotic administration.