Predictors of outcome in emphysematous pyelonephritis

Purpose: We identified and quantified prognostic factors for emphysematous pyelonephritis. Materials and Methods: The clinical information, laboratory data and radiological findings from 38 patients with emphysematous pyelonephritis were retrospectively analyzed. Results: There were no significant differences between the nonsurvivor and survivor groups with respect to age, gender, diabetes mellitus history, presence of bacteremia, identity of infecting organisms, blood glucose level, leukocyte count, urinary white blood count, presence or absence of urinary tract obstruction or urolithiasis, and modes of treatment. There were significant differences between the nonsurvivor and survivor groups, however, with respect to platelet count (84,300 +/- 119,500 versus 220,400 +/- 161,800/mm.(3), p = 0.001), serum creatinine level (3.61 +/- 1.25 versus 2.19 +/- 1.32 mg./dl., p = 0.003) and urinary red blood counts (56.47 +/- 41.86 versus 27.65 +/- 36.14, p = 0.028). Patients with radiological type I emphysematous pyelonephritis were significantly more likely to die than those with type II (69 versus 18%, p = 0.002). Conclusions: Serum creatinine level is the most reliable predictor of outcome in patients with emphysematous pyelonephritis. By calculating likelihood ratios, patients with creatinine levels greater than 1.4 mg./dl. and platelet counts 60,000/mm.(3) or less were at high risk. The posttest probability of death increased from 69 and 18% to 92 and 53% for type I and II emphysematous pyelonephritis, respectively. Patients with creatinine levels 1.4 mg./dl. or less and platelet counts greater than 60,000/mm.(3) were at much lower risk. Posttest mortality risk in these patients dropped from 69 and 18% to 27 and 4% for type I and II emphysematous pyelonephritis, respectively.