Effects of Antibiotic Timing on Culture Results and Clinical Outcomes in Pediatric Musculoskeletal Infection.

INTRODUCTION: Musculoskeletal infection (MSI) is a common cause of morbidity and hospital resource utilization in the pediatric population. Many physicians prefer to withhold antibiotics until tissue cultures can be taken in an effort to improve culture yields. However, there is little evidence that this practice improves culture results or outcomes in pediatric MSI. Therefore, investigating the effects of antibiotic timing may lead to improved clinical practice guidelines for treating children with MSI.

METHODS: An IRB-approved retrospective review was conducted that identified 113 patients aged 0 to 18 who presented to the pediatric emergency room at a tertiary care children's hospital with MSI from 2008 to 2013. Demographic data, culture results, severity markers, and intervention timing were obtained from the medical record. Logistic regression and Cox survival analysis were performed to determine the relationship of antibiotic timing with culture sensitivity and time to discharge.

RESULTS: No difference was seen in culture sensitivity antibiotic administration in either the local (55% culture before antibiotics vs. 89% after antibiotics) or disseminated group (76% before vs. 79% after), which persisted when further accounting for disease severity with C-reactive protein. However, later administration of antibiotics in the local infection group correlated with a decreased likelihood of discharge (3.91 d when cultured before antibiotics vs. 2.93 d when cultured after antibiotics; hazard ratio, 0.53; P<0.05). In patients with disseminated infection, antibiotic administration was not shown to correlate with any difference in time to discharge (hazard ratio, 1.08).

CONCLUSIONS: The authors were surprised to find that tissue culture sensitivities were not decreased by antibiotic administration in either local or disseminated MSI, suggesting that antibiotic administration should not be delayed to obtain tissue cultures. The correlation of earlier antibiotic administration with shorter length of stay in children with local MSI led the authors to conclude that antibiotics should be initiated as quickly as possible. Further study is necessary to confirm these findings and establish clinical practice guidelines.

LEVEL OF EVIDENCE: Level III-retrospective cohort.