Development of a predictive nomogram for sepsis in patients with urolithiasis-related obstructive pyelonephritis

Abstract Background: In patients with urolithiasis-related obstructive pyelonephritis (UROP), sepsis represents a critical and concerning complication that can substantially increase the mortality rate. This study aimed to identify the risk factors for sepsis in UROP patients and to develop a predictive nomogram model. Methods: We analyzed data from 148 patients who met the UROP criteria and were admitted to Chang Gung Memorial Hospital between January 1, 2016, and December 31, 2021. The primary outcome evaluated was the incidence of sepsis, as defined by the most recent Sepsis-3 guidelines. To identify potential risk factors for sepsis, we employed the Least Absolute Shrinkage and Selection Operator (LASSO) regression technique. Subsequently, we utilized multivariable logistic regression to construct the predictive model. Results: There were a total of 102 non-sepsis cases and 46 sepsis cases. The sepsis group showed significantly lower systolic blood pressure (p < 0.001), a higher heart rate (p = 0.002), a higher shock index (SI) (p < 0.001), a more prevalent history of diabetes mellitus (DM) (p = 0.015), and the mean hospital length of stay was significantly longer (p < 0.001). The laboratory results indicated a higher rate of positive blood culture in the sepsis group (60.9% vs 33.3%, p = 0.002), increased serum white blood cell counts (17.2 ± 10.9 103/uL vs 12.8 ± 6.4 103/uL, p = 0.014), a higher proportion of bandemia (26.1% vs 4.1%, p < 0.001), elevated CRP levels (19.9 ± 9.8 mg/dL vs 9.9 ± 9.9 mg/dL, p < 0.001), and a higher neutrophil to lymphocyte ratio (NLR) (23.6 ± 20.3 vs 12.9 ± 10.1, p < 0.001). Risk factors for sepsis in multivariable analysis were a history of DM (OR = 4.24, p = 0.007), SI (x10-1) (OR = 1.55, p < 0.001), CRP (mg/dL) (OR = 1.08, p = 0.005), and NLR (x10) (OR = 1.58, p = 0.007). Conclusions: Our study demonstrated that patients with UROP who have DM, higher SI, higher NLR, and elevated CRP levels are significantly more likely to develop sepsis. These insights may aid in risk stratification, and it is imperative that clinicians promptly initiate treatment for those identified as high risk.