The Renal Ultrasound in Patients with Acute Kidney Injury

Aims: Acute Kidney Injury (AKI) is seen in 15% of hospitalized patients and a renal ultrasound (RUS) is often ordered to exclude an obstructive cause in the initial evaluation of AKI. This study was done to evaluate the usefulness of a RUS in patients with AKI in a developing country.

Methods: This was a retrospective study on all patients who were referred to nephrology with AKI and had a RUS, over a one-year period at a tertiary care teaching hospital of Karachi, Pakistan. The patients’ charts were reviewed for clinical characteristics and the RUS findings were documented.

Results: A significant number of patients did not have documented risk factors for obstruction based on the medical history. Hydronephrosis was found in 22.5% (25 out of 111) of patients, and in 14 of these cases, the etiology of the acute kidney injury was found to be obstructive uropathy. The presence of nephrolithiasis and/or benign prostatic hypertrophy was associated with and increased likelihood of finding hydronephrosis on RUS.

Conclusions: We thus recommend doing a renal ultrasound in all cases of AKI due to the fact that most of the time in a developing country, an accurate history is not available, and the prevalence of stone disease and obstructive uropathy is high.