[Predicting model based on risk factors for urosepsis after percutaneous nephrolithotomy].

OBJECTIVE: To analyze the potential perioperative risk factors that affect the development of urosepsis following percutaneous nephrolithotomy (PCNL) for upper urinary tract calculi with a regression model, and to develop a nomogram for predicting the probability of postoperative urosepsis after PCNL according to the identified independent risk factors.

METHODS: We retrospectively analyzed the clinical data from consecutive 405 cases of upper urinary tract calculi treated by one-phase PCNL between January 2013 and December 2016 in our clinical department. According to whether the patients developed urosepsis or not after the surgery, the patients were divided into two groups. Perioperative risk factors that could potentially contribute to urosepsis were compared between the two groups. By a Logistic regression model, univariate and multivariate statistical analyses were carried out for the occurrence of postoperative urosepsis, to identify the independent risk factors affecting the development of postoperative urosepsis. From this model, a nomogram was built based on regression coefficients.

RESULTS: The PCNL procedures of the 405 cases were performed successfully, and there were 32 cases that developed urosepsis after the PCNL, and the incidence of urosepsis was 7.9% (32/405). A multivariate Logistic regression model was built, excluding the factors with values of P>0.05 in the univariate analysis. Multivariable Logistic regression analysis identified the following factors as independent risk factors for urosepsis after PCNL: diabetes mellitus history (OR=4.511, P=0.001), larger stone burden (OR=2.588, P=0.043), longer operation time (OR=2.353, P=0.036), increased irrigation rate (OR=5.862, P<0.001), and infectious stone composition (OR=2.677, P=0.036). The nomogram based on these results was well fitted to predict a probability, and the concordance index (C-index) was 0.834 in the nomogram model sample and 0.802 in the validation sample.

CONCLUSION: Diabetes mellitus history, higher stone burden, longer operation time, increased intraoperative irrigation rate, and infectious stone composition are identified as independent risk factors to affect the development of urosepsis after one-phase percutaneous nephrolithotomy for upper urinary tract calculi. A nomogram based on these perioperative clinical independent risk factors for urosepsis could be used to predict the risk of urosepsis following PCNL.