Utility of Routine Preoperative Urinalysis in the Prevention of Surgical Site Infections

OBJECTIVE: Preoperative assessment is important for neurosurgical risk stratification, but the level of evidence for individual screening tests is low. In preoperative uri-nalysis (UA), testing may significantly increase costs and lead to inappropriate antibiotic treatment. We prospec-tively evaluated whether eliminating preoperative UA was noninferior to routine preoperative UA as measured by 30-day readmission for surgical site infection in adult elective neurosurgical procedures. METHODS: A single-institution prospective, pragmatic study of patients receiving elective neurosurgical proced res from 2018 to 2020 was conducted. Patients were allocated based on same-day versus preoperative admis-sion status. Rates of preoperative UA and subsequent wound infection were measured along with detailed de-mographic, surgical, and laboratory data.RESULTS: The study included 879 patients. The most common types of surgery were cranial (54.7%), spine (17.4%), and stereotactic/functional (19.5%). No preopera-tive UA was performed in 315 patients, while 564 under-went UA. Of tested patients, 103 (18.3%) met criteria for suspected urinary tract infection, and 69 (12.2%) received subsequent antibiotic treatment. There were 14 patients readmitted within 30 days (7 without UA [2.2%] vs. 7 with UA [1.2%]) for subsequent wound infection with a risk difference of 0.98% (95% confidence interval L0.89% to 2.85%). The upper limit of the confidence interval exceeded the preselected noninferiority margin of 1%.CONCLUSIONS: In this prospective study of preopera-tive UA for lective neurosurgical procedures using a pragmatic, real-world design, risk of readmission due to surgical site infection was very low across the study cohort, suggesting a limited role of preoperative UA for elective neurosurgical procedures.