BACKGROUND:
Guidelines on perioperative antimicrobial prophylaxis advocate administering only one dose of antibiotics, if any, without continuation postoperatively. However, in practice, surgeons performing endoscopic urologic procedures may, based on intraoperative findings, send urine culture samples or initiate treatment due to concerns about postoperative symptomatic infections, even if there are no symptoms present. This study describes the use of intraoperative point of care urinalysis obtained cystoscopically to predict positive urine cultures and symptomatic postoperative infections. The aim is to eliminate the routine use of urine cultures and/or unwarranted antimicrobial treatment while providing clinicians with information to support pre-emptive treatment when necessary.
METHODS: Intraoperative urine samples were prospectively collected over an eight month period during the cystoscopic procedures to test for leukocyte and nitrite positivity. These results were used to calculate the two-point Leukocyte+Nitrite score. This group was analyzed in comparison to cystoscopy patients who had only routine urine cultures performed.. We monitored for urine culture positivity as well as the development of symptomatic urinary tract infections. The score’s accuracy, sensitivity, and specificity in predicting postoperative UTI were evaluated against urine cultures using ROC curve analysis and logistic regression. The analysis excluded patients with an active infection or those who were on ongoing treatment.
RESULTS: Of patients who underwent cystoscopy over eight months, we evaluated 210 patients who had only urine cultures, and 62 patients who had both an intraoperative urinalysis and a culture. The leukocyte+nitrite score exhibited accuracy as a diagnostic tool with an Area under the Curve (AUC) of 0.087 (Figure 1, Table 1), demonstrating its use in comparison to the standard diagnostic which is a positive urine culture. None of the patients with a negative score developed a symptomatic UTI. The data demonstrates that as many as 40% of routine urine cultures may be omitted with the use of the Leukocyte+Nitrite score to predict postoperative UTI.
CONCLUSIONS: Our findings suggest that an intraoperative point of care urinalysis, which considers both leukocyte and nitrite dip positivity, is a reliable tool to predict symptomatic UTI postoperatively. This should aid the performing urologist in prompt decision making around pre-emptive treatment of infections, without needing to wait for a positive urine culture prior to discharging patients with treatment dose antimicrobials.
| Asymptotic 95% Confidence Interval | |||||
| Test Result Variable(s) | Area | Std. Errora | Asymptotic Sig.b | Lower Bound | Upper Bound |
| Leuk positive - 1 yes, 0 no | .821 | .070 | .000 | .684 | .959 |
| Nitrites positive - 1 yes, 0 no | .735 | .086 | .008 | .566 | .903 |
| Leuk_Nitr | .887 | .051 | .000 | .787 | .987 |
