Utility of Routine Pre-Operative Urinalysis in the Prevention of Surgical Site Infections

Preoperative assessment is important for neurosurgical risk stratification, but the level of evidence for individual screening tests is low. In pre-operative urinalysis (UA), testing may significantly increase costs and lead to inappropriate antibiotic treatment. We prospectively evaluated whether eliminating pre-operative UA was non-inferior to routine pre-operative UA as measured by 30-day readmission for surgical site infection (SSI) in adult elective neurosurgical procedures. A single-institution prospective, pragmatic study of patients receiving elective neurosurgical procedures from 2018-2020 was conducted. Patients were allocated based on same-day versus pre-operative admission status. Rates of pre-operative urinalysis and subsequent wound infection were measured, along with detailed demographic, surgical, and laboratory data. A total of 879 patients were included in the study. The most common surgery types were cranial (54.7%), spine (17.4%), and stereotactic/functional (19.5%). Three-hundred and fifteen patients had no pre-operative UA, while 564 received testing. Of tested patients, 103 (18.3%) met criteria for suspected UTI and 69 (12.2%) received subsequent antibiotic treatment. Fourteen patients were readmitted within 30 days (7 without UA [2.2%] vs 7 with UA [1.2%]) for subsequent wound infection with a risk difference (RD) of 0.98% (95% CI -0.89% - 2.85%). The upper limit of the CI exceeded the pre-selected non-inferiority margin of 1%. We performed the first prospective study of pre-operative urinalysis for elective neurosurgical procedures using a pragmatic, real-world design. Risk of readmission due to SSI was very low across the study cohort, suggesting a limited role of pre-operative urinalysis for elective neurosurgical procedures.