Back to bedside: Renal point-of-care ultrasonography (POCUS) by internal medicine resident physicians for identification of hydronephrosis in patients with acute kidney injury

TL;DR

This study shows that internal medicine residents, after proper training, can effectively use ultrasound to detect kidney swelling in patients with sudden kidney problems.

Contribution

Demonstrates the diagnostic accuracy of resident-performed renal POCUS in a Middle Eastern setting for hydronephrosis detection in AKI patients.

Findings

POCUS performed by residents detected hydronephrosis with 83.3% sensitivity and 93% specificity.

Substantial agreement (Cohen’s kappa 0.7) was found between resident POCUS and radiologist ultrasounds.

Residents’ POCUS had high negative predictive value (98%) for hydronephrosis detection.

Abstract

Point-of-care ultrasonography (POCUS) has rapidly emerged as a valuable diagnostic tool in various medical conditions, including acute kidney injury (AKI) in the Western healthcare system. Its utility in the Middle East and Asian healthcare setups remains under-explored. This study aimed to assess the effectiveness of POCUS, performed by internal medicine residents (IMRs), in diagnosing hydronephrosis in AKI patients at a tertiary care training hospital in Qatar.

We conducted a pilot prospective cross-sectional study from June 2021 to September 2021, enrolling adult patients admitted with AKI in the acute medical assessment unit (AMAU) via convenience sampling. IMRs received mandatory POCUS training (including a 30-minute didactic teaching session and supervised performance of renal POCUS scans). The primary outcome was the detection of hydronephrosis, with findings compared to departmental renal ultrasound scans performed by the radiologists.

Fifty patients were included, with POCUS identifying hydronephrosis in five out of nine patients with confirmed hydronephrosis via official departmental renal ultrasound, demonstrating a sensitivity of 83.3% and specificity of 93% for POCUS performed by IMRs. Hydronephrosis via bedside POCUS scans had clinically reliable positive and negative predictive values (55.6% and 98%, respectively). Cohen’s kappa was 0.7 (0.45–0.94), indicating substantial agreement. One patient whose renal POCUS was reported as normal by IMR was identified to have hydronephrosis on an official departmental renal ultrasound.

This study demonstrated the effectiveness of adequate training in improving the diagnostic skills of residents using POCUS for bedside detection of hydronephrosis in patients with AKI in a residency program from the Middle East. Residency programs that include POCUS training have the potential to significantly increase bedside diagnostic capabilities with improved quality of training and patient care.