22-year-old lady, with a history of epilepsy is undergoing the pre-anaesthetic review. The use of which inhalational agent is contraindicated in this patient?
**Core Concept**
Enflurane is an inhalational anesthetic agent that can induce seizures in susceptible individuals, such as those with a history of epilepsy. This is due to its potential to lower the seizure threshold.
**Why the Correct Answer is Right**
Enflurane is metabolized by the liver to inorganic fluoride ions, which can accumulate in the body and lead to neurotoxicity. This neurotoxicity can manifest as seizures, particularly in individuals with a predisposition to seizure disorders, such as those with a history of epilepsy. In addition, Enflurane can also induce seizures through its direct effect on the central nervous system.
**Why Each Wrong Option is Incorrect**
**Option A:** Halothane is not contraindicated in patients with a history of epilepsy. While it can cause hepatotoxicity and myocardial depression, it is not known to lower the seizure threshold.
**Option C:** Sevoflurane is often used in pediatric anesthesia and is generally considered safe in patients with a history of epilepsy. It does not have the same neurotoxic properties as Enflurane.
**Option D:** Isoflurane is a commonly used inhalational anesthetic agent that is not contraindicated in patients with epilepsy. It does not have the same potential to induce seizures as Enflurane.
**Clinical Pearl / High-Yield Fact**
When managing patients with a history of epilepsy, it's essential to carefully select anesthetic agents that do not lower the seizure threshold. In such cases, intravenous anesthetics like propofol or etomidate may be preferred over inhalational agents.
**✓ Correct Answer: B. Enflurane**