Prophylactic antibiotic in general surgery

Abstract

Postoperative infections are one of the most important causes of morbidity and mortality and it's widely accepted that postoperative wound infections lead to increased hospital stay and direct cost of hospitalization. The term 'prophylactic antibiotics' implies that a microorganism is attacked by an antimicrobial agent at the time of its lodgement in a surgical wound or body cavity before colonization takes place, certainly before suppuration or invasive infection begins. In other words, the aim is to prevent the development of clinical surgical infections. There are many factors that influence postoperative wound infection rate. These include blood supply, tissue oxygenation, organic and inorganic foreign bodies, seroma, hematoma, nutrition, inherent and iatrogenic factors, duration of operation, duration of preoperative hospitalization, skin preparition. During prophylactic use of antibiotics, there are some rules. Prophylactic antibiotics should not be used in clean operations, except some cardiac, and orthopaedic operations, because in this group, expected incidence of infection is less than 2-5 per cent. Prophylactic antibiotic use is especially recommended for clean-contaminated operations, for example gastrointestinal operations, where the most likely source of bacteria leading to infection is from with in the bowel itself, microorganisms spilled at the time of operation. Prophylactic antibiotic is administered during induction of anesthesia, namely just before initial surgical incision and it should be given by parenterally. Postoperative and early antibiotic administration is significantly associated with an increased rate of infection. In upper gastrointestinal operations, prophylaxis with antimicrobials effective against aerobic Gram negative rods is usually sufficient and first or second generation cephalosporins is preferred. In colorectal operations, most likely pathogens are Gram negative roods and anaerobic Gram negative bacilli. So, in these group operations an anaerobic antimicrobial is added. Antimicrobials for prophlaxis are selected on the basis of their spectrum of activity against these pathogens with consideration given to the toxicity, side effects, pharmacologic half-life, and cost of the pharmaceutic agents.