Clinical Differences in Acute Kidney Injury between Unilateral Acute Pyelonephritis and Bilateral Acute Pyelonephritis

Jang, Suk Hyun; Lee, Chung Seop; Lee, Mi Young; Hwang, Won Min; Yun, Sung Ro

Abstract

BACKGROUND/AIMS
Acute pyelonephritis (APN) can involve a single kidney or both kidneys. The aim of this study was to define the clinical characteristics of unilateral and bilateral APN and compare their differences in acute kidney injury (AKI).
METHODS
This was a retrospective study of patients admitted to Konyang University Hospital from January, 2006 to December, 2010 with APN diagnosed by the presence of definitive APN lesions on abdominal CT. Patients with a history of renal disease or anatomical predisposing factors were excluded. The patients were divided into two groups: unilateral and bilateral APN. BUN, creatinine, MDRD eGFR, and FENa were evaluated.
RESULTS
Of the 177 patients, 130 had unilateral APN and 47 had bilateral APN. Significant differences were noticed in BUN, creatinine, and MDRD eGFR between the two groups. According to RIFLE criteria, 51 patients were at "risk" and six were in "failure." Compared with unilateral APN, bilateral APN patients had lower eGFR (65.2 vs. 61.7, p = 0.042) and higher FENa (0.81 vs. 1.43, p = 0.04), and "failure" was more frequent (4 vs. 2, p = 0.044).
CONCLUSIONS
Our study showed a significant correlation between bilateral APN and decreased renal function. AKI in bilateral APN was more likely than AKI in unilateral APN to result in severe renal dysfunction. The pathophysiology of AKI may differ between unilateral and bilateral APN.