Clinical characteristics and risk factors for septic shock in patients receiving emergency drainage for acute pyelonephritis with upper urinary tract calculi

BACKGROUND Acute pyelonephritis (APN) is a common complication of ureteral obstruction caused by urolithiasis, and it can be lethal if it progresses to septic shock. We investigated the clinical characteristics of patients undergoing emergency drainage and assessed risk factors for septic shock. METHODS A retrospective study was performed of 98 patients (101 events) requiring emergency drainage at our urology department for obstructive APN associated with upper urinary tract calculi from January 2003 to January 2011. Clinical characteristics were summarized, and risk factors for septic shock were assessed by logistic regression analysis. RESULTS Objective evidence of sepsis was found in 64 (63.4%) events, and 21 events (20.8%) were categorized as septic shock. Ninety-six patients recovered, but 2 patients died of septic shock. Multivariate analysis revealed that age and the presence of paralysis were independent risk factors for septic shock. CONCLUSIONS APN associated with upper urinary tract calculi is a severe disease that should be treated with caution, particularly when risk factors are present.