Acute Kidney Injury: A Blocked Diagnosis.

Acute kidney injury (AKI) is a common medical condition that we encounter in our daily clinical practice. However, in certain cases, ascertaining the underlying cause of the AKI could be challenging and requires a thorough history, focused investigations, and a high index of suspicion. We present the case of a 79-year-old gentleman who has been using a long-term urinary catheter and presented with AKI, which we found to be challenging to diagnose. In patients with a history of obstructive uropathy, particularly those using long-term catheters, a blocked catheter is the most probable cause of AKI. In this case, we found it challenging to establish a definitive diagnosis, given that the initial ultrasound scan of the kidneys failed to identify an obstruction. This necessitated broadening our differential diagnoses and resorting to second-line investigations such as a CT scan.  As the clinical suspicion remained high for an obstructive uropathy as the cause for the AKI, CT imaging was carried out, which revealed severe hydronephrosis with bilateral moderate hydroureter, a finding that was not picked up on routine sonography. This case report highlights the importance of determining an accurate etiology of AKI to prevent delayed treatment and underscores the importance of clinical judgment in formulating a valid differential diagnosis.