Risk factors for septic shock in acute obstructive pyelonephritis requiring emergency drainage of the upper urinary tract.

PURPOSE: To assess the risk factors for septic shock in patients with acute obstructive pyelonephritis requiring emergency drainage of the upper urinary tract.
METHODS: We retrospectively reviewed the records of 48 patients who underwent emergency drainage of the upper urinary tract for sepsis associated with acute obstructive pyelonephritis at our institute. Univariate and multivariate analyses were performed to identify the risk factors.
RESULTS: Among 54 events of sepsis, we identified 20 events of septic shock requiring vasopressor therapy. Cases with shock were more likely than those without shock to have ureteral stone (70 vs 38%, p = 0.024) and positive blood culture results (81 vs 28%, p = 0.006). They received drainage significantly earlier than those without shock (1.0 vs 3.5 days, p < 0.001). Univariate analysis demonstrated that acute obstructive pyelonephritis by ureteral stone, rapid progression (the occurrence of symptoms to drainage ≤ 1 day), positive blood culture, leukocytopenia (<4,000/mm(3)), thrombocytopenia (<120,000/mm(3)), and prothrombin time international normalized ratio ≥ 1.20 were correlated with septic shock. Multivariate logistic regression analysis identified thrombocytopenia (p = 0.005) and positive blood culture (p = 0.040) as independent risk factors for septic shock.
CONCLUSIONS: Thrombocytopenia and positive blood culture were independent risk factors for septic shock in acute obstructive pyelonephritis requiring emergency drainage. Thrombocytopenia would be practically useful as a predictor of septic shock.