858. Preoperative “Dirty” Urinalysis Leads to Antibiotic Use Without Benefit

BACKGROUND: Pyuria is often used as a surrogate for bacteriuria and may trigger antibiotic use even in the setting of negative cultures. The impact of preoperative pyuria on empirical antibiotic use and on postoperative outcomes has not been evaluated in large multisite studies. Thus, we investigated rates and outcomes associated with treated versus untreated preoperative pyuria in a national cohort of surgical patients. METHODS: All patients who underwent standardized Surgical Quality review after cardiac, orthopedic implant, or vascular surgery within the national VA health care system from October 1, 2008 to September 30, 2013 and had a urinalysis performed in the 30 days before surgery were eligible. Rates of preoperative pyuria (≥5 WBCs and/or positive leukocyte esterase) and antibiotics were measured. Adjusted rates of 30-day postoperative surgical (SSI) and urinary tract (UTI) infections were determined by a trained nurse reviewer using CDC definitions and compared between pyuria patients who did or did not receive antibiotics before surgery. RESULTS: Among 17,749 preoperative urinalyses, 755 were culture-positive and 16,994 were culture-negative. Among culture negative patients, 1,812/16,994 (10.7%) had urinalyses diagnostic of pyuria. Antibiotics were prescribed to 574 (32%) of pyuria-positive, culture-negative patients. After adjusting for diabetes, smoking, age, and ASA score, the rate of post-op SSI was similar among antibiotic-treated pyuria patients (13/574, 2.3%) compared with those not treated (21/1,238, 1.7%), aOR 1.33, 95% (0.66–2.69, P = 0.41). Post-op UTI was also not reduced among pyuria treated (17/351, 4.8%) vs. untreated (39/893, 4.4%), aOR 1.09, 95% (0.60–1.96, P = 0.76). CONCLUSION: In this large national study cohort, almost 1/3 of pyuria-positive preoperative patients received antibiotics despite negative cultures. Antibiotic treatment was not associated with clinical benefits, including no reduction in post-operative SSI or UTI. There is an opportunity for diagnostic stewardship to reduce preoperative urinalysis testing and unnecessary antibiotic exposure. DISCLOSURES: K. Itani, Pfizer: Grant Investigator, Research grant. Sanofi: Grant Investigator, Research grant. K. Gupta, Iterum Therapeutics: Consultant, Consulting fee. Paratek Pharmaceutical: Consultant, Consulting fee. Tetraphase: Consultant, Consulting fee.