医学课件 感染--【汉魅HanMei—医学专区分享】【PPT课件】精选.pptVIP

Use of Antibiotics in Surgery  Prophylactic antibiotics. Antibiotics are frequently administered prophylactically to patients undergoing operation to prevent wound infection where the likelihood of infection is high (when the tissue have been exposed to bacteria such as occurs during colon surgery) or where the consequences of infection are great even though the risk of infection is low .Antibiotic prophylaxis should also be administered to many patients with previously placed prosthetic devices such as cardiac valves who are having operations or dental procedures. * Therapeutic Use of Antibiotics. Many infections can be successfully treated with oral antibiotics on an outpatient basis. Severe surgical infections should be treated with intravenous antibiotics. Initial antibiotic therapy is usually empiric since it should be postponed until microbiologic studies are complete . Antibiotic therapy should generally be initiated before cultures are obtained with peritonitis, abscesses, and necrotizing soft tissue infections. Since cultures are usually obtained promptly during operative procedures or when percutaneous drainage has been preformed, it is unlikely that prior antibiotic therapy will affect culture results for most surgical infections.  * Empiric Therapy Rational empiric antibiotic therapy requires familiarity with the microbes most likely to cause infection at the involved site and antibiotic susceptibility patterns in the hospital or unit. Intraabdominal surgical infections are virtually caused by mixed gram-negative and gram-positive aerobic and anaerobic bacteria. Initial antibiotic therapy should provide broad-spectrum activity against these bacteria * Most necrotizing soft tissue infections, especially those originating after an intraabdominal operation or occurring below the waist, are also due to a mixed bacteria flora, and broad-spectrum empiric therapy should be initiated. Because clostridia or streptococci therapy can also cause these in