Continuous-infusion oxacillin for the treatment of burn wound cellulitis.

BACKGROUND

Burn cellulitis is an infection of the unburned skin at the margin of a burn wound or graft donor site, typically caused by group A beta-hemolytic streptococci and Staphylococcus aureus. beta-Lactam antibiotics exhibit time-dependent killing and, because of their narrow spectrum, minimize bacterial resistance. We therefore use continuous-infusion oxacillin in the treatment of burn cellulitis.

METHODS

Patients at a regional burn center who were treated for burn cellulitis from January 2003 to December 2005 were included. Charts were reviewed for all pertinent data regarding the antibiotic treatment methods and outcomes. Successful treatment was defined as resolution of physical findings, fever, and leukocytosis and intravenous antibiotic cessation.

RESULTS

Thirty-seven patients were treated for burn cellulitis, 26 (70%) of whom were treated initially with continuous-infusion oxacillin. Other initial antibiotics were chosen because of concomitant infections, penicillin allergy, or development of cellulitis during treatment with a beta-lactam antibiotic. Oxacillin treatment was successful in 19 patients (73%). Success required an average of 5.16 days, with 1.53 days required for fever resolution and 0.89 days for resolution of leukocytosis. Seven patients who did not respond rapidly were switched to intravenous vancomycin an average of 2.4 days after starting oxacillin, leading to a 100% success rate. There were no deaths, and only one suspected case of allergic reaction to oxacillin. In eleven patients treated with other antibiotics, the success rate was 75%. Success with these drugs required a longer treatment course of 6.45 days. Leukocytosis resolved significantly more slowly at 4.45 days (p = 0.02), and fever resolution was also slower at 3.18 days.

CONCLUSIONS

Continuous-infusion oxacillin was successful in the treatment of 73% of patients, a success rate that might have been higher with clinical patience, and leukocytosis resolved faster than with other antibiotics. Failure of continuous-infusion oxacillin can be managed without clinical consequence by conversion to intravenous vancomycin.