Prevalence of Recent Antimicrobial Exposure among Elective Surgical Patients.

BACKGROUND: The annual prevalence of antimicrobial exposure is high in the outpatient setting and should be a common exposure for surgical patients. Antimicrobials have negative side effects and may be associated with poor outcomes. Logically, one would expect surgical patients to be particularly susceptible to any negative effects of recent antimicrobial exposure. Despite these observations, however, the prevalence of recent antimicrobial exposure among surgical patients remains undefined. The purpose of this study is to define the prevalence of antimicrobial exposure in patients undergoing elective surgical procedures.

METHODS: Patients presenting for elective operations between August 4, 2015 and August 3, 2016 at our institution were asked prospectively about any antimicrobial exposure in the previous three months. Answers were recorded as either Yes, No, or Unsure. Patients were grouped according to age, American Society of Anesthesiologists (ASA) score, primary operative service, and post-operative destination. Descriptive statistics were employed using simple percentages and chi-square analysis when appropriate. Cochrane-Armitage test was used to evaluate temporal trends.

RESULTS: There were 21,473 elective surgical procedures performed during the study period across 13 operative services. Answers were recorded for 91.2% cases. The overall prevalence of exposure during this period was 28.6%. Exposure varied with age, ASA score, and surgical specialty. Vascular and transplant operations had the highest prevalence of exposure while ophthalmology and pediatric orthopedic procedures had the lowest. Patients with recent antimicrobial exposure were less likely to be discharged home on the same day and more likely to be admitted to an intensive care or intermediate care unit than those who denied recent exposure.

CONCLUSION: In this descriptive analysis, the prevalence of recent antimicrobial exposure is overall approximately 28.6% and is higher than anticipated. Further work is needed to determine to what extent, if any, recent antimicrobial exposure impacts post-operative outcomes.