[General principles of choice of antibiotics for antibiotic prophylaxis in surgery]

A large amount of knowledge has been obtained in the field of prophylactic antibiotics over the past few years. Only procedures with a reasonable risk (incidence or severity) ought to be covered. Antibiotics must be present not only in plasma but also in the tissues during the surgical procedure. In most cases a very short prophylaxis, usually using a single bolus, is convenient. The best cost/benefit ratio has to be obtained. Several points remain unclear and require further investigations: what is the best dosage? What is the adequate timing for reinjections according to the duration of surgical procedure, and to the risk of postoperative infection using a "risk index"? Must we modulate the type of prophylaxis according to the duration of hospital stay before surgery? What is the value of selective decontamination of the digestive tract?