Not a feature of maintenance phase of acute kidney injury
**Core Concept**
The maintenance phase of acute kidney injury (AKI) is characterized by a stable or slowly declining glomerular filtration rate (GFR), indicating a transition from the initial insult to a more chronic state. This phase is crucial for minimizing further kidney damage and promoting recovery.
**Why the Correct Answer is Right**
During the maintenance phase, the priority is to maintain GFR, prevent further damage, and promote renal recovery. This involves careful management of fluid balance, electrolytes, and blood pressure. The use of renin-angiotensin-aldosterone system (RAAS) inhibitors, such as ACE inhibitors or ARBs, is a key feature of this phase, as they help to reduce intraglomerular pressure and promote sodium excretion.
**Why Each Wrong Option is Incorrect**
**Option A:** Hyperkalemia is a common feature of AKI, particularly during the initiation phase, due to impaired potassium excretion. It is not a characteristic of the maintenance phase, where the focus is on stabilizing and recovering renal function.
**Option B:** Fluid overload is a hallmark of AKI, particularly in the context of acute tubular necrosis. While fluid management is crucial during the maintenance phase, fluid overload is not a defining feature of this phase.
**Option C:** Oliguria is often seen in AKI, especially during the initiation phase, due to reduced renal blood flow and GFR. However, during the maintenance phase, efforts are made to optimize fluid balance and promote diuresis, making oliguria less characteristic of this phase.
**Clinical Pearl / High-Yield Fact**
To remember the features of the maintenance phase of AKI, recall the acronym "MAINTAIN": Maintain GFR, Avoid further insult, Initiate RAAS inhibitors, Normalize electrolytes, Inhibit inflammatory pathways, and Treat underlying causes.
**Correct Answer:** B. Fluid overload is a common feature of AKI, particularly in the context of acute tubular necrosis, and not a defining characteristic of the maintenance phase.