Acute pyelonephritis in ER

Symptoms and signs of acute pyelonephritis sometimes are subtle and emergency physicians attending overcrowded and busy institutions could easily miss the right diagnosis. The presence of a renal damage is decisive in the therapeutic choice. Aims of our study are: 1) to assess prevalence of renal damage in patients presenting to our ED with symptoms and signs of primary urinary tract infection (UTI); 2) to evaluate the reliability of such symptoms and signs in predicting a renal damage; 3) to assess accuracy of the contrast enhanced ultrasound (CEUS) in the ED diagnosis of renal damage due to acute uncomplicated pyelonephritis. We studied 54 patients with suspected UTI. Each patient underwent clinical examination, routine blood and urine sampling and conventional renal ultrasound (US). 23 patients had confirmation of acute primary UTI, and performed renal magnetic resonance (MR) to rule out renal parenchymal involvement. In 16 patients (69,6%) one or more parenchymal lesions were visualized at MR, and diagnosis of acute uncomplicated pyelonephritis was confirmed (group A). The other 7 patients had a diagnosis of UTI without renal involvement (group B). Some of 23 patients presented with few atypical symptoms. Lumbar pain was the most frequent symptom (n = 21), without a statistically significant difference between group A and B (P 0,958; p = 0,328). No other symptom or sign has demonstrated statistically valid in predicting the renal involvement. Renal US was positive in only 3 patients of group A (18,7%). During this first part of our study, CEUS was performed in a limited number of patients (n = 8), and in 7 examinations data were concordant with MR. In conclusion, analysis of our preliminary data confirms that a distinction between patients with different extension of the UTI is not possible through the simple clinical examination and routine tests. CEUS is very promising and its routine employment in the ED could simplify the diagnostic practice in suspected acute pyelonephritis.