Analysis of bacterial spectrum and construction of a predictive model for postoperative sepsis in patients with upper urinary calculi and positive urinary cultures

To analyze bacterial profiles, antibiotic resistance, and urosepsis risk factors in urine culture-positive (UC+) patients post-endoscopic lithotripsy. Retrospectively, 806 UC+ patients (2016.3–2021.3) were stratified into urosepsis/non-urosepsis groups per Sepsis-3 criteria. Among 845 isolates (56 species), <i>Escherichia coli</i> dominated (46.8%), followed by <i>Enterococcus faecalis</i> ;(8.8%). Gram-negative bacteria exhibited high resistance to ampicillin, cefazolin, and cefuroxime. Multivariate analysis identified preoperative multidrug-resistant (MDR) bacteriuria (OR = 2.15), staghorn calculi (OR = 2.23), days of preoperative antibiotics use &lt; 3 (OR = 1.87), absence of nephrostomy (OR = 2.30), and postoperative WBC &gt; 9.8 × 10⁹/L (OR = 2.69) as independent sepsis predictors. A nomogram incorporating these factors achieved robust predictive accuracy. Preoperative antibiotic use for ≥3 days was inversely correlated with the risk of urinary sepsis as the duration of antibiotic administration increased. Urosepsis incidence was 13.1% post-lithotripsy. Early risk stratification, targeted infection control, and antibiotic stewardship guided by urine susceptibility testing are critical for prevention.