The following is a summary of “Clinical factors distinguishing renal infarction from acute pyelonephritis: A randomly matched retrospective case-control study,” published in the October 2023 issue of Emergency Medicine by Woo, et al.
Renal infarction (RI) is a rare but clinically significant condition often challenging to differentiate from acute pyelonephritis (APN) due to overlapping nonspecific symptoms. The timely and accurate diagnosis of RI is crucial for appropriate treatment. For a study, researchers sought to identify predictors that could effectively distinguish between RI and APN.
Data from patients presenting to the emergency department with diagnoses of RI or APN between March 2016 and May 2020 were prospectively collected and retrospectively analyzed. Exclusions were made for patients under 18 years old, those with a history of trauma, or incomplete medical records. RI patients were randomly matched to APN patients in a 1:5 ratio. Multivariable logistic regression analysis was employed to identify factors differentiating RI from APN. A decision tree was also constructed to identify risk factor patterns and develop prediction algorithms.
The study included 55 RI patients and 275 APN patients. Multivariable logistic regression analysis revealed that male sex (OR, 6.161; P = 0.009), atrial fibrillation (AF) (OR, 14.303; P = 0.021), absence of costovertebral angle tenderness (CVAT) (OR, 0.106; P < 0.001), aspartate transaminase (AST) level > 21.50 U/L (OR, 19.820; P < 0.001), C-reactive protein (CRP) level < 19.75 mg/L (OR, 10.167; P < 0.001), and no pyuria (OR, 0.037; P < 0.001) were significantly associated with RI over APN.
Male sex, atrial fibrillation, absence of CVAT, elevated AST (> 21.50 U/L), lower CRP (< 19.75 mg/L), and no pyuria emerged as significant factors for effectively distinguishing between RI and APN. The findings improved the accuracy of differential diagnoses in cases presenting with flank or abdominal pain.
Source: sciencedirect.com/science/article/abs/pii/S0735675723003960
