Article: The role of emergency ultrasound for evaluating acute pyelonephritis in the ED. The American Journal of Emergency Medicine. 2011; 29:721-724.
Objective: To determine the efficacy of ultrasound in the diagnosis and management of patients presented to the ED with acute pyelonephritis
Design: Prospective data collection with retrospective review of medical records, protocol-driven, single center observational study
Inclusion Criteria: Adult patients diagnosed with acute pyelonephritis in the ED
Exclusion Criteria: Pregnant women and patients referred from other healthcare facilities
Methods: Data was collected including patient characteristics, medical history, laboratory findings, renal imaging modes and findings (according to ED protocol, any patient with severe flank tenderness, fever, chills, and leukocytosis would be evaluated with renal imaging with choice of imaging modality based on clinical judgement), organisms yielded from urine and blood cultures, length of stay in hospital, and patient disposition. EUS findings were categorized as significant (moderate to severe hydronephrosis, polycystic kidney disease, renal abscess, abnormal mass or gas in renal parenchyma, and overdistended bladder), mild (simple renal cysts, renal stones <.5 cm, and renal swelling), and no abnormalities.
Results: Of 243 patients (94% women), 200 patients were admitted for further treatment (11 of which were admitted to the ICU) and 43 were discharged on oral antibiotics. 206 (85%) patients received at least one form of renal imaging: 51% had KUB, 55% had EUS, 14% had CT, and 7.3% had IVP. Abnormal imaging findings were found in 96 (39.5%) patients, of which 63 (26%) patients had significant abnormalities. The ability to detect structural abnormalities were as followed: KUB was 16.3%, EUS was 39.6%, KUB + EUS was 56.6%, and CT was 58.8%. Up to 60.9% of patients with complicated acute pyelonephritis were found to have structural abnormalities on EUS, and the presence of significant sonographic abnormalities diverted 46 (34.3%) patients to receive surgical intervention.
Takeaway: Ultrasound can be useful in diagnosing acute pyelonephritis and can be used to detect hydronephrosis, cysts, calculi, masses, abscesses, and abnormal fluid or gas collections around the kidney. Ultrasound is noninvasive, can be performed at bedside, is cost-effective, and does not require exposure to radiation or contrast medium. This study showed that EUS was able to detect significant abnormalities in 39.6% of ED patients with acute pyelonephritis, and EUS + KUB approached a similar rate of detecting abnormalities in acute pyelonephritis compared to CT (56.6% vs. 58.8%, respectively). In addition, the early use of EUS for acute pyelonephritis could avoid delayed diagnosis of major urologic abnormalities that may require surgical intervention.
Author: McKayla Mawn, MS4