Comparison between non-septic and septic cases in stone-related obstructive acute pyelonephritis and risk factors for septic shock: A multi-center retrospective study.

PURPOSE

This study assessed risk factors for septic shock in patients with obstructive acute pyelonephritis (APN) associated with upper urinary tract calculi in a multi-center retrospective study.

METHODS

We studied 143 patients admitted to 4 hospitals in Japan with obstructive APN associated with upper urinary tract calculi. Data on gender, age, hypertension, diabetes, neurological disease or malignant disease, laboratory data (white blood cell (WBC) and C-reactive protein (CRP)), drainage, and bacterial strains including Escherichia coli in the non-septic and septic groups were collected. Risk factors for septic shock were analyzed by univariate and multivariate statistical analyses.

RESULTS

There were a total of 107 non-septic cases (74.8%) and 36 septic cases (25.2%). The commonest strains of urinary tract infection-causative bacteria were E. coli in the non-septic group (23 cases, 21.5%) and septic group (13 cases, 36.1%) (p > 0.05). Emergency drainage was administered in 74.8% of the non-septic group and 97.2% of the septic group (p > 0.05). Meropenem was most often used as the initial treatment in the non-septic group (20 cases, 18.7%) and septic group (22 cases, 61.1%) (p < 0.0001). Risk factors for septic shock in multivariate analyses were diabetic mellitus (odds ratio (OR) = 3.591, p = 0.0098) and CRP ≥ 10 (OR = 1.057, p = 0.0119) as significant independent factors in this multicenter study.

CONCLUSIONS

APN is a common infectious disease, especially in the cases with urinary tract obstruction where patients easily acquire bacteremia or sepsis. Stone-associated obstructed APN can cause fatal septic shock in cases with diabetes and CRP ≥ 10. Further prospective studies will be undertaken to draw definitive conclusions.