Determinants of pyelonephritis onset in patients with obstructive urolithiasis

Abstract

Background: Acute obstructive pyelonephritis due to urolithiasis represents a medico-surgical emergency that can lead to life-threatening complications. There are still no established factors that reliably predict progression toward acute pyelonephritis in patients presenting with a simple renal colic. Objective: To investigate clinical and paraclinical factors that are associated with the onset of acute obstructive pyelonephritis. Methods: Patients presenting to the emergency department for renal colic with obstructive urolithiasis on imaging were enrolled in the study. Demographic data, vital signs, medical comorbidities, blood test results, urinalysis, and radiological findings were recorded. Obstructive pyelonephritis was defined by the presence of two or more of the following criteria: fever, flank pain or costovertebral angle tenderness, and a positive urine culture. Results: Seventeen patients out of 120 presenting with renal colic, were diagnosed with acute obstructive pyelonephritis (14%). Parameters that were associated with the onset of obstructive pyelonephritis were: diabetes ( p = 0.03), elevated CRP ( p = 0.01), stone size (>5 mm) ( p = 0.03), dilatation of renal pelvis ( p = 0.01), peri-renal fat stranding ( p = 0.02), and positive nitrites on urinalysis ( p < 0.01). Hyperleukocytosis, acute kidney injury, multiple stones, pyuria (>10/mm3), hypertension, and were not associated with the onset of obstructive pyelonephritis. Conclusion: This study showed that known diabetic status, elevated CRP, positive urine nitrites, stone size (>5 mm), pyelic dilatation, and peri-renal fat stranding were associated with the onset of pyelonephritis in patients presenting to the emergency department with obstructive urolithiasis.

Is conservative management safe in patients with acute ureterolithiasis and perirenal stranding?

“…Perirenal stranding on non-contrasted CT can be observed as a secondary radiological sign mainly in patients with pyelonephritis or ureteral obstruction [ 11 ]. While perirenal stranding in patients with pyelonephritis is associated with fever and elevated laboratory inflammatory markers, the role in patients with ureteral obstruction without inflammatory markers is ambiguous [ 12 ]. Perirenal stranding in this setting results from increased upper urinary tract pressure by pyelo-venous/lymphatic reflux, whereby an incipient infection cannot be clearly excluded [ 2 , 12 ].…”

“…While perirenal stranding in patients with pyelonephritis is associated with fever and elevated laboratory inflammatory markers, the role in patients with ureteral obstruction without inflammatory markers is ambiguous [ 12 ]. Perirenal stranding in this setting results from increased upper urinary tract pressure by pyelo-venous/lymphatic reflux, whereby an incipient infection cannot be clearly excluded [ 2 , 12 ]. Thus, several previous studies investigated the association of perirenal stranding with urinary tract infections and the impact on outcomes after different therapeutic approaches.…”

“…Thus, several previous studies investigated the association of perirenal stranding with urinary tract infections and the impact on outcomes after different therapeutic approaches. Indeed, studies reported conflicting findings about the association of perirenal stranding with the risk of concomitant urinary tract infection [ 12 , 13 ]. Authors reported an increased risk of infection after ureterorenoscopic stone removal or after ureteral stent insertion in patients with ureteral stone and perirenal stranding [ 14 , 15 ].…”

Differences in Urinary Calculi Characteristics among the Three Main Racial Groups in KwaZulu-Natal, South Africa

“…Acute disease might require hospitalization or emergency surgery (7). Its long-term consequences are more severe, and include pyelonephritis and chronic kidney disease (8,9). Given the serious implications of urolithiasis and the growing burden of the condition, much attention has been given to understanding the underlying pathology of the disease.…”

The association between C-reactive protein levels and the risk of kidney stones: a population-based study

“…In preterm neonates with acute kidney injury (AKI), elevated CRP emerged as a critical factor influencing AKI [ 12 ]. The association of CRP with pyelonephritis caused by obstructive renal stones has been demonstrated [ 13 ]. CRP is also considered to be a valid parameter for assessing whether to undergo urethral stenting in patients with renal colic caused by urinary stones, and is more informative than serum creatinine and leukocyte levels [ 14 ].…”