The following is a summary of the “Predictors for Distinguishing Renal Infarction From Urolithiasis in the Emergency Department: A Randomly Matched Retrospective Case-Control Study,” published in the January 2023 issue of Emergency Medicine by Woo, et al.

Urolithiasis is a common condition that emergency room doctors may incorrectly diagnose as renal infarction (RI) because the symptoms of both conditions are similar. However, earlier diagnosis of RI can improve patient prognosis. Therefore, they looked into clinical and laboratory findings as possible predictors for separating RI from urolithiasis. This retrospective case-control study included patients diagnosed with acute urolithiasis or RI between January 2016 and March 2020. 

Patients were not included if they were younger than 18, had a history of trauma, or had insufficient medical documentation. Using a matching ratio of 1:4, RI patients were randomly matched to urolithiasis patients. A multivariate logistic regression analysis was carried out to identify factors that differentiate RI from urolithiasis. There were a total of 48 people placed in the RI group and 192 people placed 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.

Source: sciencedirect.com/science/article/abs/pii/S0736467922005765