ORLANDO Most dermatologic surgery patients don't need perioperative antibiotics, and the routine use of antibiotics to prevent surgical site infection or infective endocarditis should be discouraged, Dr. Steve Spencer said at the annual meeting of the Florida Society of Dermatologic Surgeons.
Healthy individuals, those who undergo surgery of a clean site, and those who undergo procedures of limited duration typically do not need prophylactic antibiotics. As for determining which patients do need prophylaxis, a number of variable risk factors should be considered, including HIV-positive status, chronic immunosuppression, age, occupation, and temperature/humidity, all of which could affect infection risk, said Dr. Spencer of Port Charlotte, Fla., noting that these are gray areas that require individualized decision making.
It is clearer, however, that those who are immunocompromised; those undergoing surgery of riskier areas such as the mouth, groin, or axillae, or sites that are already infected; and those who are at high risk of infective endocarditis (see sidebar) should receive prophylaxis, he said. Dr. Spencer cited guidelines on prevention of infective endocarditis published by the American Heart Association last year (Circulation 2007;116:173654).
Although the guidelines mainly address dental issues, the AHA noted that infectious endocarditis is more likely to result from frequent exposure to random bacteremias associated with daily activities than from bacteremia caused by dental or medical procedures and that prophylaxis is likely to prevent a very small number of cases of infectious endocarditis, if any.
The guidelines also point out that the risks of antibiotic prophylaxis in terms of adverse events exceed the benefits, if any, from antibiotic prophylaxis and recommend that only those with the highest risk of adverse outcomes from endocarditis should undergo antibiotic prophylaxis.
As for procedures on infected skin, skin structures, or musculoskeletal tissue, the AHA noted that, while these infections are typically polymicrobial, only staphylococci and β-hemolytic streptococci are likely to cause infective endocarditis. Therefore, when antibiotic prophylaxis is needed, the drug selected should target the most likely organisms to be encountered and be given prior to the procedure.
Broad-spectrum antibioticsmost often first-generation cephalosporinsare commonly used to treat these species.
Semisynthetic penicillinase-resistant penicillins are good for gram-positive cocci, Klebsiella, Escherichia coli, and Proteus organisms. Clindamycin is an alternative option in penicillin-allergic patients. Erythromycin is almost never used because it is associated with very high staphylococcal resistance, Dr. Spencer said.
Clindamycin also is a good option for patients undergoing surgery of the oral mucosal areas, but cephalosporins may have less cross-reactivity in penicillin-allergic patients. Although trimethoprim-sulfamethoxazole coverage is similar to these, with excellent gram-positive coverage, it does not provide Pseudomonas coverage, he added.
When antibiotic prophylaxis is determined to be necessary, it should be delivered 3060 minutes before surgery. Since surgical factors are at least as important for preventing infection, sterile techniques and proper sterilization of instruments, avoidance of excess tension on closures, avoidance of excessive suture material, and avoidance of charring also require careful attention, he said.
Conditions With Endocarditis Risk
The American Heart Association guidelines state that the following cardiac conditions have the highest risk of adverse outcomes from endocarditis:
▸ Prosthetic cardiac valve.
▸ Previous infective endocarditis.
▸ Congenital heart disease.
▸ Unrepaired cyanotic CHD, including palliative shunts and conduits.
▸ Completely repaired (with prosthetic material or device) congenital heart defect during first 6 months after the repair.
▸ Repaired CHD with residual defect (at or adjacent to the site of the prosthetic patch or device) that inhibits endothelialization.
▸ Postcardiac transplant cardiac valvulopathy.