PROPHYLACTIC USE OF ANTIBIOTICS Salam Daradkeh,MDDepartment of General Surgery
Introduction Infectious complications are the main cause of morbidity and mortality in surgery. In USA they cost 36 billion $ /year. Prevention of post-operative infections by all means is nowadays considered of paramount significance. It is impossible to create a predictably sterile wound.
Wound classification Clean surgery: 2-5% Clean-contaminated surgery 5-10% Contaminated surgery 10-20% Dirty surgery 30-70%This is without use of prophylactic antibiotics.
Definition of prophylactic antibiotic It refers to the administration of antibiotic agents to patients without evidence of established infection ,with the objective of reducing subsequent post-operative septic complications. Prophylaxis should be limited to patients in whom there is a high risk for the development of an infection or infection might be associated with a catastrophic end result .
Factors promoting……E- condition of patient : - advanced age. - impaired defenses.F- inadequate treatment: - delayed wound care. - failure to immobilize the wound. - inadequate hemostasis. - no antibiotic prophylaxis.
For prophylaxis of infections The following factors have to be taken in consideration :1- Surgical tactics.2- Surgical techniques.3- Pre and post-operative treatment.4- Antibiotics.
Prophylactic use of antibiotics Timing: should have adequate tissue level prior to skin incision. ideally 15mn -1 h prior to surgery. Route of administration: parenteral and IV is preferable. Duration: up to 72h. Choice of antibiotics: previous knowledge about micro-organisms responsible for the infection.
Prophylactic antibiotics Is statistically effective if infection rates are greater than 5% and suitable antimicrobials are chosen. Antibiotics are not substitute for asepsis. Antibiotics are not antipyretics or Doctor’s tranquilizers. Antibiotics do not substitute surgical knowledge and skill.
Antibiotic prophylaxis It is more cost-effective and safer to administer prophylactic antimicrobials than to treat infections that occur in patients who have not received these agents. The proper regimen of antibiotics for surgical prophylaxis decreases the total amount of chemotherapeutic agents used.
Antibiotic prophylaxis indications If post-operative infections occur frequently >5% e.g colonic surgery. May have major local consequences. e.g brain surgery.joint prosthesis,vascular prosthesis. May have major systemic consequences e.g patients at risk(age,DM). Might be lethal: e.g heart valve replacement.
indications Antibiotic prophylaxis in Clean surgical operations is usually unnecessary. Clean-contaminated surgery with entry to the lower respiratory tract,GIT ,and genito-urinary tract requires prophylactic antibiotics. In contaminated surgery with serious spillage (e.g colon) pophylaxis is mandatory.
indications The effectiveness of chemoprophylaxis has been documented in controlled trials in:- Maxillofacial surgery.- Cardiac surgery.- Vascular grafts.- Cancer surgery of the esophagus and stomach.
indications Antimicrobial prophylaxis is essential when the operation has a significant risk of post- operative infection. Or the infection might be lethal.(e.g cardiac valve replacement). Or the infection might cause an irreparable damage.(e.g hip joint replacement).
indications- Elective colorectal surgery.- Vaginal and abdominal hysterectomy.- Prostatectomy.- Orthopedic surgery- Traumatology The effectiveness of chemoprophylaxis has been documented for high-risk patients in:- Elective gastroduodenal surgery.- Biliary tract surgery.- Cesarean section.
indications Failure to maintain adequate serum and tissue levels throughout surgical procedures has been associated with increased infection rates. Antibiotics in effective concentration should cover the whole perioperative period of risk.
Single –dose prophylaxis has thefollowing advantages Reduced side effects. Reduced total amount of antibiotics used. Reduced work load for personnel. Reduced duration of hospitalization. Reduced amount of waste material. Reduced total costs.
Remember 40% of hospital- acquired infections are urinary tract infections. 20% respiratory tract infections. 20% wound infections.