Analysis of risk factors for postoperative fever in patients with negative preoperative urine culture after flexible ureteroscopy and construction of a nomogram model
10.3760/cma.j.cn112330-20230922-00086
- VernacularTitle:术前尿培养阴性患者输尿管软镜碎石术后发热的危险因素分析及预测发热列线图模型的构建
- Author:
Shuo WANG
1
;
Xinyu SHI
;
Xiaofu WANG
;
Yuan LYU
;
Jinhao HU
;
Changbao XU
Author Information
1. 郑州大学第二附属医院泌尿外科，郑州 450000
- Keywords:
Kidney calculi;
Ureteral calculi;
Flexible ureteroscopy;
Fever;
Negative preoperative urine culture;
Risk factors
- From:
Chinese Journal of Urology
2024;45(3):202-207
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the risk factors for postoperative fever in patients with negative preoperative urine culture undergoing flexible ureteroscopy (fURS), and construct a nomogram prediction model to predict the risk of postoperative fever.Methods:The clinical data of 308 patients who underwent flexible ureteroscopy (fURS) at the Second Affiliated Hospital of Zhengzhou University from January 2019 to March2023, were retrospectively analyzed. Among these patients, there were 235 males and 73 females, with an average age of (46.4±12.1) years old. Additionally, 86 cases had concomitant hypertension, 41 cases had diabetes, and 12 cases had coronary heart disease. A history of urinary stone surgery was present in 57 cases, and 91 cases exhibited severe hydronephrosis. The distribution of stones included 164 cases on the left side and 144 cases on the right side, with 88 cases of renal stones, 124 cases of ureteral stones, and 96 cases of renal-ureteral stones. Among them, 243 cases had ≤2 stones, while 65 cases had >2 stones, with a maximum stone diameter of 12.0 (9.0, 15.0) mm. Urine leukocyte-positive cases were 109, and urine leukocyte-negative cases were 199. Two cases were positive for nitrite, and 308 cases were negative. The occurrence of postoperative fever within 48 hours was recorded, and differences between the fever and non-fever groups were compared. Logistic regression analysis was employed to identify risk factors for post-fURS fever. A nomogram prediction model based on independent risk factors was constructed, and internal validation was conducted using 1 000 bootstrap resamples. The predictive performance of the model was evaluated using receiver operating characteristic (ROC) curves and the area under the curve (AUC). Model stability was assessed using calibration curves.Results:The surgeries for all 308 cases were successfully completed with a median operative time of 60.0 (40.0, 75.0) minutes. Complete stone clearance was achieved in 221 cases. Among them, 14 cases (4.5%) experienced postoperative fever, while 294 cases did not. The fever group had a higher proportion of females [57.1% (8/14) vs. 22.1% (65/294), P=0.007], more cases with comorbid diabetes [50.0% (7/14) vs. 11.6% (34/294), P<0.001], a higher proportion of renal stones [64.3% (9/14) vs. 26.9% (79/294), P=0.022], a lower intraoperative stone clearance rate [42.9% (6/14) vs. 73.1% (215/294), P=0.031], larger stone diameter [15.5 (12.5, 19.3) mm vs. 11.0 (9.0, 15.0) mm, P=0.004], longer operative time [87.5 (58.8, 106.3) min vs. 55.0 (40.0, 75.0) min, P<0.001], higher platelet count [267.0 (225.8, 354.0) ×10 9/L vs. 233.0 (197.8, 272.0) ×10 9/L, P=0.026], lower creatinine levels [67.5 (52.5, 72.3) umol/L vs. 73.0 (62.0, 84.0) umol/L, P=0.026], and a higher platelet lymphocyte ratio [148.8 (118.3, 189.3) vs. 119.5 (93.2, 156.0), P=0.030]. Results of univariate analysis showed that female gender, diabetes, stone location, incomplete stone clearance, maximum stone diameter, operative time, platelet count, creatinine, platelet lymphocyte ratio, and positive nitrite in urine (all P<0.05)were risk factors for postoperative fever. Multivariate regression analysis revealed that female gender ( OR=11.073, 95% CI 1.623-75.521, P=0.014), diabetes ( OR=5.995, 95% CI 1.441-24.952, P=0.014), and operative time ( OR=1.024, 95% CI 1.003-1.046, P=0.024) were independent risk factors for post-fURS fever. The nomogram exhibited excellent predictive performance (AUC=0.866, 95% CI 0.781-0.935), and the calibration curve demonstrated good consistency. Conclusions:Female gender, longer operative time, and diabetes are risk factors for post-fURS fever in patients with preoperative negative urine culture. The nomogram demonstrates excellent predictive performance.
