All are features of hemolytic uremic syndrome, EXCEPT:
**Core Concept**
Hemolytic uremic syndrome (HUS) is a complex disorder characterized by the triad of microangiopathic hemolytic anemia, acute kidney injury, and thrombocytopenia. It typically results from the abnormal activation of the complement system, leading to endothelial damage and the formation of microthrombi.
**Why the Correct Answer is Right**
HUS is classically associated with the following features:
- Microangiopathic hemolytic anemia: This is due to the mechanical destruction of red blood cells as they pass through the damaged endothelium, leading to schistocyte formation and elevated lactate dehydrogenase (LDH) levels.
- Acute kidney injury: The microthrombi formed in the small vessels of the kidneys impair renal function, leading to oliguria, hyperkalemia, and elevated creatinine levels.
- Thrombocytopenia: The consumption of platelets in the formation of microthrombi results in a low platelet count.
- Coagulopathy: Although not a primary feature, coagulopathy can occur in severe cases of HUS.
- Neurological symptoms: Some patients may experience neurological symptoms such as seizures, confusion, and coma.
**Why Each Wrong Option is Incorrect**
**Option A:** Not a feature of HUS. While hypertension can be present in some cases, it is not a defining characteristic of the syndrome.
**Option B:** This is a feature of HUS. Coagulopathy can occur in severe cases of the syndrome.
**Option C:** This is a feature of HUS. Neurological symptoms can occur in some patients.
**Option D:** This is a feature of HUS. Coagulopathy can occur in severe cases of the syndrome.
**Clinical Pearl / High-Yield Fact**
It's essential to note that HUS is often associated with E. coli O157:H7 infections, particularly in children. A high index of suspicion and prompt recognition are crucial in managing this potentially life-threatening condition.
**Correct Answer: A.**