Renal POCUS may Detect Hydronephrosis, Predict Nephrolithiasis, Study Finds
USA: Researchers have found in a new study that renal point-of-care ultrasound (rPOCUS) showing hydronephrosis in adults presenting to the emergency department with suspected renal colic is significantly associated with the presence of kidney stones, supporting its diagnostic value.
Renal colic remains one of the most frequent reasons for emergency department (ED) visits, yet imaging strategies continue to vary widely across clinical settings. In this context, a study published in the Journal of Emergency Medicine by Mark D. Scheatzle and colleagues explored how rPOCUS findings influence further imaging decisions, patient flow, and clinical outcomes.
The investigators conducted a retrospective cohort study including adult patients who underwent rPOCUS for suspected renal colic between January 2020 and January 2022. A total of 188 patients were analyzed, with nearly half (47%) demonstrating hydronephrosis on bedside ultrasound. The study used structured chart reviews and statistical modeling to evaluate associations between ultrasound findings and subsequent care pathways, including computed tomography (CT) use, urologic interventions, and ED length of stay.
The following were the key findings:
- CT imaging was performed in 57% of patients overall.
- CT use was higher in patients with hydronephrosis on rPOCUS (72%) compared to those without hydronephrosis (44%).
- Presence of hydronephrosis on rPOCUS was associated with increased likelihood of undergoing CT imaging.
- Hydronephrosis on rPOCUS was strongly associated with ureteral stone detection on CT (74% vs 30%).
- Patients with hydronephrosis had a higher likelihood of requiring urologic intervention within 24 hours (26% vs 6%).
- The presence of hydronephrosis did not reduce emergency department length of stay.
- Mean ED length of stay was similar regardless of hydronephrosis status.
- Patients undergoing CT imaging had significantly longer ED stays.
- CT utilization was identified as a major contributor to prolonged ED throughput.
- Abdominal tenderness and CT use were associated with increased length of stay on multivariable analysis.
- Hydronephrosis itself was not associated with longer ED stay.
The study also noted that alternative diagnoses of clinical significance were rare, occurring in only 1.6% of cases, and exclusively among patients without hydronephrosis. This finding suggests that the absence of hydronephrosis may warrant closer evaluation for other potential causes of symptoms.
Overall, the findings indicate that while rPOCUS is a valuable tool for identifying patients with a high likelihood of kidney stones and need for early intervention, its impact on reducing CT use and improving ED efficiency appears limited. The continued reliance on CT imaging, even in the presence of clear ultrasound findings, highlights the need for more streamlined imaging protocols to optimize patient care and resource utilization in emergency settings.
Reference:
Scheatzle, M. D., Johnjulio, W., Li, J., Lieurance, R., O’Neill, J., & McGahan, M. (2026). Renal point-of-care ultrasound findings and downstream CT use, urologic intervention, and ED length of stay in renal colic. The Journal of Emergency Medicine. https://doi.org/10.1016/j.jemermed.2026.04.013
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