**Core Concept**
Compartment syndrome is a condition that occurs when increased pressure within a muscle compartment compromises blood flow and function, leading to ischemic pain, paresthesias, and potentially permanent damage.

**Why the Correct Answer is Right**
Fasciotomy is the surgical release of the fascia surrounding a muscle compartment to relieve pressure and restore blood flow. In the scenario described, the child has developed compartment syndrome, as evidenced by pain, swelling, paresthesias, and stretch pain in the upper limb, despite normal peripheral pulses. Fasciotomy is the definitive treatment for compartment syndrome to prevent further damage and permanent disability. The procedure involves making an incision in the affected compartment to release the fascia and allow the muscle to expand and reperfuse.

**Why Each Wrong Option is Incorrect**
**Option A:** Aspiration is not indicated in this scenario, as compartment syndrome is a condition of increased pressure within the muscle compartment, not an infectious process. Aspiration would not address the underlying issue of increased pressure.

**Option B:** Anti-Inflammatory medications may provide temporary relief from pain and swelling but do not address the underlying issue of increased pressure within the muscle compartment. In the case of compartment syndrome, the increased pressure requires a more definitive treatment, such as fasciotomy.

**Option C:** Observation is not an appropriate management strategy for compartment syndrome, as delaying treatment can lead to permanent muscle and nerve damage. Prompt surgical intervention is necessary to prevent long-term consequences.

**Clinical Pearl / High-Yield Fact**
Compartment syndrome is a medical emergency that requires prompt recognition and treatment to prevent permanent damage. The classic symptoms of compartment syndrome include pain, swelling, paresthesias, and stretch pain, despite normal peripheral pulses.

**✓ Correct Answer: D. Fasciotomy**