EVALUATION OF POINT OF CARE URINARY ULTRASOUND IN THE DIAGNOSIS OF HYDRONEPHROSIS

Abstract

Hydronephrosis, characterized by dilation of the renal collecting system due to urine accumulation, often results from an obstruction in the urinary tract. Early identification of this condition is crucial to prevent permanent kidney damage. Historically, diagnosis has relied on imaging tests such as conventional ultrasound performed by radiologists or computed tomography. However, point-of-care ultrasound (POCUS) has emerged as an affordable and rapid diagnostic tool performed at the bedside by non-radiologists. This modality has gained significant traction in emergency and intensive care settings, allowing for immediate assessment and guidance of therapeutic approaches, especially in scenarios where time is critical and transport of the patient to the radiology department may be complex or time-consuming. The noninvasive nature and absence of ionizing radiation have made urinary POCUS particularly attractive for renal and bladder assessments. Objective: The objective of this systematic review was to analyze and synthesize the available evidence in the scientific literature on the accuracy and clinical utility of point-of-care urinary ultrasonography specifically for the diagnosis of hydronephrosis, comparing its performance with traditional imaging methods. Methodology: A systematic review of the literature was conducted, following the PRISMA checklist guidelines. Searches were conducted in the PubMed, Scielo, and Web of Science databases for articles published in the last 10 years. The following descriptors (or their English equivalents) were used: "Point-of-care ultrasonography", "Hydronephrosis", "Urinary tract", "Diagnostic imaging", and "Urinary obstruction". Inclusion criteria included studies that directly evaluated the use of POCUS for the diagnosis of hydronephrosis in patients, studies that presented data on the accuracy of the method (sensitivity/specificity), and original research. Review articles, case reports, and studies that did not use a standard imaging method as a comparator or that evaluated only other urological conditions without a focus on hydronephrosis were excluded. Results: The aggregate results of the analyzed studies indicated that point-of-care ultrasound showed good overall accuracy for the detection of hydronephrosis, especially for moderate to severe degrees. It was found that POCUS was particularly useful in emergency departments for rapid triage of patients with suspected renal colic or acute urinary obstruction, speeding up the diagnostic process. However, sensitivity was variable, being lower for mild hydronephrosis, and the ability to identify the underlying cause of obstruction (such as small stones or strictures) was limited compared with formal ultrasound or CT. Operator experience and training were consistently indicated as crucial factors influencing the performance of the exam. Conclusion: It was concluded that point-of-care urinary ultrasound has established itself as a valuable complementary diagnostic tool in the initial evaluation of hydronephrosis. Its application has allowed for faster clinical decision-making in acute scenarios, optimizing patient management. Despite its advantages in terms of accessibility and speed, limitations related to operator dependence and lower sensitivity for mild cases or for etiological definition have reinforced the idea that POCUS does not completely replace conventional imaging exams, but rather acts effectively as a screening exam and targeted initial assessment.