A Randomized, Controlled Trial on the Efficacy of Perioperative Antibiotics in Grafting After Thermal Injury

Author(s):
Lauren Nosanov; Robert Ball; Melissa McLawhorn; Anna Day; Lauren Moffatt; Jeffrey Shupp

Background:

After thermal injury, the limited use of antibiotics for clear signs of infection is well accepted among burn care providers. Use of perioperative antibiotics for grafting procedures in an uninfected wound, however, remains largely institution and surgeon specific. Although previous studies have proposed increased graft take with perioperative antibiotics, these conclusions rely on small patient populations. Unnecessary use of perioperative antibiotics can lead to patient specific complications and will contribute to the development of drug resistant organisms. The primary objective of this study is to quantify the effects of a single dose of perioperative antibiotics on the bacterial concentration of a graft site following thermal injury.

Hypothesis:

Perioperative antibiotics do not significantly reduce bacterial concentration in a thermal wound bed after grafting procedure.

Methods:

Patients expected to undergo a single grafting procedure after thermal injury less than 10% TBSA were approached for enrollment. Patients were randomized to receive weight-based cefazolin perioperatively or to receive no antibiotics. Patients with infected wounds were excluded from the study. Skin biopsies (3mm) and swabs for culture from the wound bed were obtained intraoperatively before and after excision of unviable tissue. Repeat biopsies and swabs of the site after grafting were taken at the first dressing takedown. A final culture swab was obtained at the postoperative follow-up visit.

Results:

Eight patients have completed the study thus far, and enrollment is ongoing. Three patients were randomized to receive antibiotics. In the antibiotic group, 2/3 patients had no growth of bacterial in both swab and culture at the first dressing takedown, while one patient had an increase from no growth intraoperatively to 6.0×10⁴ CFU/g in the biopsy. In the control group, 2/5 patients had no growth at the dressing takedown with three patients having an increase (average 1.2×10⁹ CFU/g in biopsies). All eight patients had clinically insignificant concentrations of bacteria from wound swabs obtained at the follow-up visit with no appreciable difference in graft take.

Conclusions:

Although a trend towards temporary reduction of bacterial concentration with antibiotics was noted, preliminary data does not support a clinically significant difference in bacterial load of burn wounds after grafting regardless of the use of perioperative antibiotics. Continued enrollment and analyses will support or refute this conclusion and allow for investigation of secondary outcomes, such as the effect of antibiotics on donor sites and the microbiome of the patient.