What does the nurse identify as the most common cause of acute kidney injury in a critically ill patient?

Rationale: A. Advanced age is incorrect because, while older patients are at higher risk for acute kidney injury (AKI) due to decreased renal reserve, age itself is not the most common cause of AKI in critically ill patients. It is a predisposing factor, not a direct cause. B. Medications is incorrect because nephrotoxic drugs (like aminoglycosides, NSAIDs, or contrast agents) can cause AKI, but in critically ill patients, medications are a less frequent primary cause compared to systemic insults like sepsis. C. Sepsis is correct because sepsis is the leading cause of AKI in critically ill patients. The systemic infection and associated inflammatory response, hypotension, and hypoperfusion lead to ischemic injury of the kidneys. Sepsis-induced AKI often involves both prerenal factors (low perfusion) and intrinsic renal injury (acute tubular necrosis). Early recognition and aggressive management of sepsis are critical to prevent progression of AKI. D. Fluid overload is incorrect because fluid overload is a complication of AKI rather than a cause. AKI can lead to reduced urine output, causing fluid accumulation, but it is not the initiating factor in most cases.