Differences between Risk Factors for Sepsis and Septic Shock in Obstructive Urolithiasis

BACKGROUND: Complicated acute pyelonephritis (APN) is a life-threatening condition that requires immediate intervention. This study examined the characteristics of APN occurring as a complication of ureteral stone. METHODS: We retrospectively reviewed 85 patients diagnosed with APN complicated by ureteral stone between December 2006 and July 2017 at our institution. Patients with concomitant renal stone, multiple ureteral stones, ureteral strictures, ureteral cancer, and urogenital anomalies, including vesicoureteral reflux were excluded. Clinical characteristics including age, sex, underlying disease, medical history, stone characteristics, initial laboratory data, and the procedure used to correct urinary obstruction were summarized, and the risk factors associated with sepsis and septic shock were analyzed. RESULTS: Sepsis was diagnosed at initial presentation in 62 patients, 17 of whom suffered from septic shock. Disease-related death did not occur in any patient. Previous history of stone (P = 0.015), leukocytosis (P < 0.001), elevated C-reactive protein levels (P = 0.006), and low albumin (P = 0.038) were significant risk factors for progression to sepsis. The absence of hypertension (P = 0.047), thrombocytopenia (P = 0.006), decreased erythrocyte sedimentation rate (ESR) (P = 0.003), elevated blood urea nitrogen (P = 0.016), and positive blood culture (P = 0.018) were significant predictors for progression to septic shock. Multivariate analysis revealed that previous history of stone (P = 0.015) was an independent risk factor for sepsis, while the absence of hypertension (P = 0.047), thrombocytopenia (P = 0.013), and decreased ESR (P = 0.009) were risk factors for shock. CONCLUSION: The risk factors associated with the progression from APN to sepsis differed from those associated with the progression from sepsis to septic shock. Various factors should be considered while selecting treatment options based on the severity of APN associated with ureteral stone. It should be managed with aggressive treatment and close observation, especially in the presence of risk factors.