Predicting septic shock in obstructive pyelonephritis associated with ureteral stones: A retrospective study

To identify the best combination of potential predictors of septic shock in patients with obstructive acute pyelonephritis associated with ureteral stones (OAPN-US) according to Sepsis-3 criteria. Patients who underwent percutaneous nephrostomy (PCN) with OAPN-US were retrospectively evaluated. Recursive feature elimination (RFE) was applied to patients with and without septic shock to identify factors associated with the prediction of progression to septic shock. We compared combinations of the selected features based on area under the receiver operating curve (AUROC) to determine which combination was most effective. This study included 81 patients who were treated with PCN due to OAPN-US. A comparison was made between 37 patients with septic shock (SS) and 44 patients without septic shock (NSS). SS group had a higher age, poorer Eastern Cooperative Oncology Group status, and significantly higher levels of positivity in urine cultures and blood cultures. There were also differences in laboratory tests between the 2 groups. Procalcitonin (PCT), international normalized ratio (INR), and absolute lymphocyte count (ALC) were selected based on RFE. We compared the predictive power for SS when each marker was used alone, when 2 markers were combined, and when all 3 markers were combined. Among these combinations, using all 3 variables together yielded the highest AUROC of 0.942. Of the 3 variables, PCT had the highest Gini importance score, indicating that it was the most influential factor. Clinical characteristics were different between the SS and the NSS groups. In patients with OAPN-US, the combination of PCT, ALC, and INR was an excellent predictor of septic shock.