What Is the Appropriate Use of Renal Sonography in an Inner-City Population With New-Onset Acute Kidney Injury?
OBJECTIVE
We aimed to determine the prevalence of hydronephrosis in patients who underwent renal sonography for new-onset acute kidney injury (AKI) and to identify clinical factors predictive of hydronephrosis. In patients with hydronephrosis, we sought to investigate how routine renal sonography affects patient treatment, including performance of interventional procedures.


METHODS
A retrospective chart review identified 274 adults with AKI who underwent renal sonography at an urban teaching hospital from January through July 2011. The prevalence of hydronephrosis was determined. Electronic medical records were reviewed for comorbidities, including risk factors for hydronephrosis such as a pelvic mass, prior renal or pelvic surgery, and neurogenic bladder, and for subsequent interventions and outcomes.


RESULTS
Sonography showed hydronephrosis in 28 patients (10%); 5 (18%) had subsequent interventions. In a multivariable logistic regression model with the outcome being hydronephrosis, all considered risk factors (pelvic mass, prior renal or pelvic surgery, and neurogenic bladder) were significantly associated with hydronephrosis (odds ratio, 6.4; 95% confidence interval, 2.7-15.4; P < .001) when adjusting for age and diabetes mellitus. Diabetes had a negative predictive value for hydronephrosis. No diabetic patients younger than 85 years and without clinical risk factors had hydronephrosis.


CONCLUSIONS
Hydronephrosis is infrequently seen on sonograms in hospitalized patients with AKI who lack risk factors for urinary tract obstruction. Deferral of sonography pending a trial of medical treatment is safe and will reduce medical costs. Adoption of clinical guidelines to assess patients' risk levels for hydronephrosis is critical to avoid unnecessary imaging.
Department of Radiology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York USA (R.G., M.W.S., J.M.R., J.H.R., M.K., F.S.M.); and Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, New York USA (H.W.C.).
Rebecca
R
Gamss
Department of Radiology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York USA (R.G., M.W.S., J.M.R., J.H.R., M.K., F.S.M.); and Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, New York USA (H.W.C.).
Marjorie W
MW
Stein
Department of Radiology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York USA (R.G., M.W.S., J.M.R., J.H.R., M.K., F.S.M.); and Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, New York USA (H.W.C.).
Joanne M
JM
Rispoli
Department of Radiology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York USA (R.G., M.W.S., J.M.R., J.H.R., M.K., F.S.M.); and Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, New York USA (H.W.C.).
Hillel W
HW
Cohen
Department of Radiology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York USA (R.G., M.W.S., J.M.R., J.H.R., M.K., F.S.M.); and Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, New York USA (H.W.C.).
Jeffrey H
JH
Roberts
Department of Radiology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York USA (R.G., M.W.S., J.M.R., J.H.R., M.K., F.S.M.); and Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, New York USA (H.W.C.).
Mordecai
M
Koenigsberg
Department of Radiology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York USA (R.G., M.W.S., J.M.R., J.H.R., M.K., F.S.M.); and Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, New York USA (H.W.C.). fmazzari@montefiore.org.
Fernanda S
FS
Mazzariol
D058186:Acute Kidney Injury / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D000368:Aged; D000369:Aged, 80 and over; D015984:Causality; D015897:Comorbidity; D042241:Early Diagnosis; D005260:Female; D006786:Hospitals, Urban; D006801:Humans; D006869:Hydronephrosis / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D015994:Incidence; D007668:Kidney / Q000000981:diagnostic imaging; D008297:Male; D000069342:Medical Overuse / Q000706:statistics & numerical data; D008875:Middle Aged; D009518:New York; D012307:Risk Factors; D014463:Ultrasonography / Q000706:statistics & numerical data*; D014505:Urban Population / Q000706:statistics & numerical data*; D014600:Utilization Review
acute kidney injury; genitourinary ultrasound; hydronephrosis; renal sonography; urinary tract obstruction