A 6 year old boy taken for ophthalmic examination under anaesthesia. His father told that he has lower limb weakness & his elder brother died at 14 years of age. Which anaesthetic drug has to be avoided.
**Core Concept**
The question is testing the knowledge of the metabolism of certain anaesthetic drugs and their potential to accumulate in individuals with genetic disorders such as Pompe disease, which can lead to severe muscle weakness and cardiomyopathy.
**Why the Correct Answer is Right**
The correct answer is associated with succinylcholine, a depolarizing muscle relaxant that is metabolized by the enzyme butyrylcholinesterase. However, in individuals with Pompe disease, this enzyme is deficient, leading to a prolonged duration of action and potential severe hyperkalemia. This is a classic example of a pharmacogenetic interaction.
**Why Each Wrong Option is Incorrect**
**Option A:** Halothane is not associated with a risk of hyperkalemia or muscle weakness in patients with Pompe disease.
**Option B:** Propofol is not metabolized by butyrylcholinesterase and is not contraindicated in patients with Pompe disease.
**Option C:** Isoflurane is a volatile anaesthetic that is not metabolized by butyrylcholinesterase and is not associated with a risk of hyperkalemia or muscle weakness in patients with Pompe disease.
**Option D:** Fentanyl is an opioid anaesthetic that is not metabolized by butyrylcholinesterase and is not contraindicated in patients with Pompe disease.
**Clinical Pearl / High-Yield Fact**
When administering succinylcholine, it is essential to consider the patient's genetic background and the potential for butyrylcholinesterase deficiency, which can lead to severe hyperkalemia and cardiac arrest.
**Correct Answer: A. Succinylcholine. Succinylcholine should be avoided in patients with Pompe disease due to the risk of severe hyperkalemia and cardiac arrest.**