Serious acute pyelonephritis: a predictive score for evaluation of deterioration of treatment based on clinical and radiologic findings using CT

Background: Acute pyelonephritis (APN) requires prompt diagnosis and immediate treatment. Purpose: To develop a simple score to assist in diagnosing treatment deterioration in patients with serious APN. Material and Methods: Using data from a retrospective cohort of 193 patients with APN, we developed scores based on multivariate logistic regression after the jackknife procedure. We validated the scores in a prospective cohort of 40 patients. Results: Nine criteria were independently associated with our investigation: Abscess (adjusted odds ratio [OR], 19.8; 95% confidence interval [95% Cl] 4.5-72.1), pyonephrosis with or without stone (18.3; 4.8-70.9), pelvicalyceal air (15.5; 3.2-26.9), poor global excretion of contrast (12.3; 2.9-68.5), tachycardia or hypotension (10.1; 2.5-28.0), obliteration of the renal sinus (9.6; 2.5-45.2), persistent fever or pyuria (9.8; 1.9-25.8), diabetes (9.4; 2.0-31.8), and global renal enlargement (7.5; 2.1-35.8). The APN score was based on these nine criteria. Low-risk and high-risk groups were derived from the score (probability, 3.5% [95% Cl 0-7.5] and 67% [51-83]). Application of these criteria to the prospective cohort confirmed the diagnostic accuracy of the score (probability 0% [0-15] and 71% [25-100] in the low-risk and high-risk groups, respectively). Conclusion: This easy-to-calculate score may prove useful for diagnosing patients with serious APN who deteriorate with treatment.