Role of emergency ultrasound screening in the management of acute pyelonephritis in emergency department: A large observational study from a tertiary care center of South India

Abstract

Background: Role of emergency ultrasound screening (EUS) in the evaluation of all patients with clinically suspected acute pyelonephritis (APN) in the emergency department (ED) remains unclear. The aim of the study was to describe the frequency of abnormal EUS findings in APN presenting to ED and ascertain the laboratory abnormalities associated with significant abnormal findings to identify the subgroup of patients who will benefit from EUS in ED. Methodology: In this retrospective study, electronic medical records were searched to identify all adult patients who underwent EUS screening from ED for initial clinical diagnosis of APN over 1 year. The EUS findings were categorized into normal, major abnormalities (hydronephrosis, renal abscess, and emphysematous pyelonephritis), and mild abnormalities (cysts, calculi, and renal edema). Results: A total of 1218 patients with initial clinically diagnosed APN underwent EUS. Nearly 49% had a normal EUS while 51% had at least one major or minor abnormality. The frequency of hydroureteronephrosis, renal calculi emphysematous changes, and renal abscess was 19.1%, 8.9%, 2.1%, and 1.9%, respectively. Only 72 (5.9%) patients required emergency percutaneous nephrostomy or drainage of an abscess. Among these patients, EUS was able to identify a major abnormality in sixty (83.3%) patients. Male gender, presence of diabetes mellitus, peripheral white blood cell (WBC) count >10,000 cells/cumm, serum creatinine >1.4 mg%, and urine WBC count >100 cells/hpf were found to independently predict the presence of an abnormality on an EUS. Conclusion: A large proportion of APN patients have only normal or minor abnormalities and do not need additional screening and intervention.