The activity of the chosen prophylactic agent should encompass the majority of pathogens likely to contaminate the wound or operative site. When more than one choice is given as a prophylactic agent, the agents or agents selected should be based on the most likely contaminating organisms. The prophylactic agent must be administered in a dose which provides an effective tissue concentration prior to intraoperative bacterial contamination. The effective dose should be governed by the patient's weight. In procedures lasting 3 hour or less, a single prophylactic dose is usually sufficient.
Procedures lasting greater than three hours require an additional effective dose.
Under no circumstance should any prophylactic agent be given on-call because it often results in less than effective tissue levels at the time of incision. An effective and thoughtful prophylactic regimen is no substitute for exquisite surgical technique and competent postsurgical management. I. General Surgery a. Under most circumstances antimicrobial prophylaxis is not required when performing a clean surgical procedure. Cefazolin or cefuroxime.