Treatment of severe acute pyelonephritis associated with upper urinary tract calculi

We treated 37 patients with severe acute pyelonephritis associated with upper urinary tract calculi between January 2008 and December 2011. We examined the patient characteristics and clinical courses of these patients retrospectively. The average age was 74.9 years-old, and there were 11 male (30%) and 26 female (70%) patients. Calculi were located on the right side in 15 patients (41%), on the left side in 19 patients (51%), and on the both sides in 3 patients (8%). The average size of the calculi was 9.5 mm. The most common organism isolated was Escherichia coli (15 strains, 41%). Twenty-one patients (57%) required emergency drainage (ureteral stent, 18 cases ; nephrostomy, 3 cases). Ten patients (27%) required vasopressor agents, and 7 patients (20%) developed disseminated intravascular coagulation (DIC). There were no fatalities among the patients. Average hospital stay and performance status (PS) showed significant differences between the drainage group and the no-drainage group. The Japanese Association for Acute Medicine QAAM) scoring system for DIC was thought to be a useful indication regarding urinary drainage.