The Accuracy of Point-of-Care Ultrasound Performed by Emergency Physicians in Detecting Hydronephrosis in Patients with Renal Colic

Objectives: This study aimed to determine the accuracy of renal point-of-care ultrasound (POCUS) performed by emergency physicians in detecting hydronephrosis in patients with renal colic. Methods: This prospective cross-sectional diagnostic study was conducted at the Emergency Department (ED) of Sultan Qaboos University Hospital from February 2017 to February 2018. All adult patients with suspected renal colic and who could give informed consent were included. The emergency physicians performed POCUS on both kidneys and graded hydronephrosis as none, mild, moderate or severe. The POCUS grade was compared to the non-contrast computed tomography (NCCT) grade. Results: A total of 303 participants were enrolled in the analysis. The majority of the study population comprised adult males (247 [81.5%]), and the mean age was 39 years. Among the samples, 71.3% of the patients exhibited a degree of hydronephrosis based on CT findings. Ultrasounds performed by emergency physicians had a sensitivity of 75.8% (95% CI: 69.5‒81.4), specificity of 55.2% (95% CI: 44.1‒65.8), a positive likelihood ratio of 1.69 (95% CI: 1.32‒2.16) and a negative likelihood ratio of 0.43 (95% CI: 0.32‒0.59) for hydronephrosis using CT as the criterion standard. Conclusion: When evaluating patients with suspected renal colic, a bedside renal POCUS performed by emergency physicians has a moderate sensitivity to detect hydronephrosis and grade its severity. Therefore, it should be utilised in the ED to screen patients for hydronephrosis; however, more training is required to improve the test’s accuracy.