A six year old boy is scheduled for examination of the eye under anaesthesia. The father informed that for the past six months the child is developing progressive weakness of both legs. His elder sibling had died at the age of 14 years. Which drug would you definitely avoid during the anaesthetic management?

**Core Concept**
Muscle weakness in a child with a family history of early mortality could be indicative of a neuromuscular disorder, such as Duchenne Muscular Dystrophy (DMD). DMD is caused by mutations in the dystrophin gene, leading to progressive muscle degeneration.

**Why the Correct Answer is Right**
In patients with DMD, the dystrophin protein is absent or defective, leading to muscle damage and weakness. Succinylcholine, a depolarizing muscle relaxant, can cause severe hyperkalemia in these patients due to the release of potassium ions from damaged muscle cells. This can lead to cardiac arrhythmias and even cardiac arrest. Therefore, succinylcholine is contraindicated in patients with DMD.

**Why Each Wrong Option is Incorrect**
* **Option A:** Vecuronium is a non-depolarizing muscle relaxant, which is not contraindicated in DMD patients. It works by competitively blocking the nicotinic acetylcholine receptors at the neuromuscular junction.
* **Option B:** Fentanyl is an opioid analgesic and is not contraindicated in DMD patients. It can be used for pain management during anesthesia.
* **Option C:** Propofol is a sedative-hypnotic agent and is not contraindicated in DMD patients. It can be used for induction and maintenance of anesthesia.

**Clinical Pearl / High-Yield Fact**
Duchenne Muscular Dystrophy patients are prone to malignant hyperthermia when exposed to volatile anesthetics and succinylcholine. Early recognition and management of malignant hyperthermia are crucial to prevent severe morbidity and mortality.

**Correct Answer:** C. Propofol is a safe choice in DMD patients.

✓ Correct Answer: A. Succinylcholine