Predictors for Distinguishing Renal Infarction From Urolithiasis in the Emergency Department: A Randomly Matched...

Emergency department (ED) clinicians may misdiagnose renal infarction (RI) as urolithiasis because RI is a rare disease with presenting symptoms similar to the symptoms of urolithiasis. However, earlier diagnosis of RI can improve patient prognosis.

We investigated potential predictors for distinguishing RI from urolithiasis based on clinical findings and laboratory results.

This randomly matched retrospective case-control study included patients who had been diagnosed with acute RI or acute urolithiasis between January 2016 and March 2020. Patients were excluded if they were aged under 18 years, had a history of trauma, or had incomplete medical records. Using a matching ratio of 1:4, RI patients were randomly matched to urolithiasis patients. Multivariable logistic regression was performed to identify factors that could distinguish RI from urolithiasis.

In total, 48 patients were included in the RI group and 192 patients were included in the urolithiasis group. Multivariable logistic regression showed that age ≥ 65 years (odds ratio [OR] 6.155; p = 0.022), atrial fibrillation (OR 18.472; p = 0.045), current smoking (OR 17.070; p = 0.001), costovertebral angle tenderness (OR 0.179; p = 0.037), aspartate aminotransferase level ≥ 27.5 U/L (OR 6.932; p = 0.009), sodium level ≥ 138.5 mEq/L (OR 0.079; p = 0.004), and hematuria (OR 0.042; p = 0.001) were significant predictors that could distinguish RI from urolithiasis. Based on these results, a nomogram was constructed.

Age ≥ 65 years, atrial fibrillation, current smoking, absence of costovertebral angle tenderness, aspartate aminotransferase level ≥ 27.5 U/L, sodium level < 138.5 mEq/L, and absence of hematuria were predictors that can distinguish between RI and urolithiasis.