A randomized trial of surgical antimicrobial prophylaxis with and without vancomycin in organ transplant patients

Background. Gram-positive organisms, including vancomycin-resistant enteroc occi (VRE), have emerged as major pathogens on the organ transplant service at our institution. We hypothesized that our use of vancomycin as part of routine surgical prophylaxis increased the risk of VRE colonization and inf ection; conversely, there was concern that failure to use vancomycin prophy laxis would increase peri-operative morbidity due to gram-positive organism s. Methods. Renal transplant recipients (n = 88) were randomized to receive ei ther a) vancomycin/ceftriaxone or b) cefazolin; and pancreas transplants (n = 24) to receive either a) vancomycin/gentamicin or b) cefazolin/gentamici n. Stool samples or rectal swabs were obtained for culture for enterococci within 24 h of transplantation and weekly while hospitalized. Results. Enterococci were isolated on stool culture from 38 (34%) of 102 pa tients at the time of transplantation; 4 (11%) of the isolates were VRE. Th e percentage of patients who subsequently acquired VRE was low (1-7% per wk ) but remained constant during hospitalization. There was no association be tween new VRE detection and vancomycin use for either prophylactic or thera peutic purposes. Forty-four patients (39%) had a post-operative infection w ith 46% of these infections due to gram-positive organisms; rates were unaf fected by prophylactic vancomycin use. Pancreas transplant patients who did not receive vancomycin prophylaxis had a significantly longer initial hosp italization (p = 0.03); however, differences were not statistically signifi cant when total length of stay (LOS) within the first 90 d of transplantati on was compared. Conclusions. Vancomycin surgical prophylaxis does not appear to have an eff ect on VRE colonization or infection, or on rates of infection with gram-po sitive bacteria. Elimination of vancomycin prophylaxis in renal transplant patients may be a reasonable part of an overall program to limit vancomycin usage, although as a single measure, its impact may be minimal. Vancomycin surgical prophylaxis may be of greater importance in pancreas transplants.