Antibiotic prophylaxis and therapy in colorectal surgery
Authors: Lalović Nenad , Sokolović Dragana , Popović Marko , Dukić Nikolina , Mašić Jelena , Joksimović Bojan 
Published: September 2023

Complications in colorectal surgery carry a high risk of morbidity and mortality, prolong hospitalization time and increase treatment costs, and the largest number of postoperative complications is related to surgical site infection (SSI). Antibiotic prophylaxis started in the fifties of the last century and changed with each new antibiotic. The following were used in order: aminoglycosides (1943), macrolides (1952), polymyxins (1958), and cephalosporins (1965). With the discovery of metronidazole in 1970, the prophylactic spectrum was extended to include anaerobic bacteria, which are an indispensable part of the flora in this anatomical region. Due to the nature of the gastrointestinal tract, it was believed that oral antibiotic prophylaxis and mechanical bowel preparation (MBP) could achieve intestinal sterilization and thus ensure a safe surgical intervention. However, studies have shown that MBP did not have an overall beneficial effect on postoperative complications and caused significant patient discomfort, so it was almost abandoned. Today, it is known that about 16% of surgical infections are caused by multiresistant bacteria, and only oral antibiotic prophylaxis is not sufficient to prevent these infections. Namely, in the race between bacterial resistance and the development of new antibiotics, antibiotics are increasingly lagging, and the treatment of complications remains a nightmare for surgeons. For this reason, the prevention of SSI in colorectal surgery is a challenge for 21st-century medicine. In modern surgery, both open and laparoscopic, the first and second generations of intravenous cephalosporins are most often used for prophylactic purposes, as antibiotics of a sufficiently broad spectrum, with favorable pharmacokinetics and rare side effects. New research indicates that in colorectal surgery, the combination of standard intravenous prophylaxis with the addition of an oral antimicrobial the day before surgery is superior when it comes to SSI prevention. However, there are still no clear recommendations on the regimen and type of antibiotics and they should be given in institutional guides and protocols, taking into account the bacterial spectrum in the local environment, as well as resistance, and the availability of appropriate drugs. Therapeutic use of antibiotics is reserved for acute conditions in colorectal surgery and its complications. For therapeutic purposes, more potent antibiotics are used against the expected pathogens, usually a combination of several antibiotics, such as third or fourth-generation cephalosporins, metronidazole, fluoroquinolones, or piperacillin/tazobactam and others. When it comes to the therapeutic use of antibiotics in colorectal surgery, research indicates that the most important thing is to recognize the infection in time and immediately start treatment, correct the therapy according to the causative agent, and also to stop the administration of antibiotics in time, to avoid unwanted complications and already advanced bacterial resistance.