Stratification and Management of Persistently Positive Urine Cultures in Urological Stone Surgery
Poster #: 089
Session/Time: B
Author:
Ang Li, BA
Mentor:
Ilya Sobol, MD
Research Type: Clinical Research
Abstract
INTRODUCTION:
Persistently positive urine cultures despite antibiotic treatment pose significant management challenges in urological stone surgery. Current guidelines recommend obtaining preoperative cultures and treating positive results with antibiotics, prior to surgery, however they provide limited guidance on managing persistent bacteriuria. While stone culture best predicts postoperative sepsis, this laboratory outcome arrives too late for preoperative risk mitigation. Literature reports sepsis rates up to 18% in patients with positive preoperative cultures, highlighting the substantial risk in this population. This study aimed to identify the prevalence and risk factors for persistent positive cultures, develop a risk stratification scoring system to guide selective re-culturing, and evaluate whether risk-stratified mitigation strategies could reduce postoperative infectious complications below expected rates.
METHODS:
A retrospective review analyzed 195 patients with positive preoperative urine cultures who underwent urological stone surgery. All patients received antibiotic treatment with re-culture prior to intervention. All cultures were obtained via catheterization to minimize contamination. Persistent positivity was defined as any growth measuring >10K on subsequent preoperative urinary culture. Specific demographic and clinical risk factors were assessed using univariate and multivariate logistic regression to develop a risk stratification scoring system. Secondary outcomes included immediate and 30-day postoperative sepsis rates.
RESULTS:
Despite antibiotic therapy, 26.2% of patients demonstrated persistent positive cultures. Significant risk factors in univariate analysis included the history of urosepsis upon previous stent placement (Odds ratio, OR=6.73, p<0.001), multi-drug-resistant organisms (MDRO) (OR=4.64, p=0.002), history of recurrent urinary tract infections (UTIs) (OR=2.93, p=0.002), and presence of indwelling devices (OR=2.69, p=0.004). Our scoring system achieved 72% sensitivity and 61% specificity at ≥2 risk factors, potentially reducing repeat cultures by 59%. High-risk patients received intensified mitigation strategies including additional antibiotic/anti-fungal therapy, strategic surgical delay with extended antimicrobials, and surgery cancellation with intravenous treatment.
CONCLUSION:
Despite treating a 100% culture-positive cohort with expected sepsis rates of 5-18% based on literature, our risk-stratified management approach achieved remarkably lower rates, maintaining comparable sepsis outcomes between persistent positive and no-growth groups (immediate: 3.92% vs 2.78%; 30-day: 5.88% vs 3.47%). This substantial reduction from expected rates suggests that tailored antibiotic strategies and vigilant perioperative management can effectively neutralize the elevated infection risk in patients with persistent positive cultures, particularly those with multiple risk factors or organism shifts following initial treatment. The protocol demonstrates that proportional risk mitigation based on culture persistence predictors may transform high-risk patients into standard-risk through targeted intervention.
Persistently positive urine cultures despite antibiotic treatment pose significant management challenges in urological stone surgery. Current guidelines recommend obtaining preoperative cultures and treating positive results with antibiotics, prior to surgery, however they provide limited guidance on managing persistent bacteriuria. While stone culture best predicts postoperative sepsis, this laboratory outcome arrives too late for preoperative risk mitigation. Literature reports sepsis rates up to 18% in patients with positive preoperative cultures, highlighting the substantial risk in this population. This study aimed to identify the prevalence and risk factors for persistent positive cultures, develop a risk stratification scoring system to guide selective re-culturing, and evaluate whether risk-stratified mitigation strategies could reduce postoperative infectious complications below expected rates.
METHODS:
A retrospective review analyzed 195 patients with positive preoperative urine cultures who underwent urological stone surgery. All patients received antibiotic treatment with re-culture prior to intervention. All cultures were obtained via catheterization to minimize contamination. Persistent positivity was defined as any growth measuring >10K on subsequent preoperative urinary culture. Specific demographic and clinical risk factors were assessed using univariate and multivariate logistic regression to develop a risk stratification scoring system. Secondary outcomes included immediate and 30-day postoperative sepsis rates.
RESULTS:
Despite antibiotic therapy, 26.2% of patients demonstrated persistent positive cultures. Significant risk factors in univariate analysis included the history of urosepsis upon previous stent placement (Odds ratio, OR=6.73, p<0.001), multi-drug-resistant organisms (MDRO) (OR=4.64, p=0.002), history of recurrent urinary tract infections (UTIs) (OR=2.93, p=0.002), and presence of indwelling devices (OR=2.69, p=0.004). Our scoring system achieved 72% sensitivity and 61% specificity at ≥2 risk factors, potentially reducing repeat cultures by 59%. High-risk patients received intensified mitigation strategies including additional antibiotic/anti-fungal therapy, strategic surgical delay with extended antimicrobials, and surgery cancellation with intravenous treatment.
CONCLUSION:
Despite treating a 100% culture-positive cohort with expected sepsis rates of 5-18% based on literature, our risk-stratified management approach achieved remarkably lower rates, maintaining comparable sepsis outcomes between persistent positive and no-growth groups (immediate: 3.92% vs 2.78%; 30-day: 5.88% vs 3.47%). This substantial reduction from expected rates suggests that tailored antibiotic strategies and vigilant perioperative management can effectively neutralize the elevated infection risk in patients with persistent positive cultures, particularly those with multiple risk factors or organism shifts following initial treatment. The protocol demonstrates that proportional risk mitigation based on culture persistence predictors may transform high-risk patients into standard-risk through targeted intervention.