All of the following are common examples of inhalation anaesthesia, EXCEPT:

BTSC 3 August 2025

Pharmacology

Easy

Appeared in: BTSC 3 August 2025

Explanation

Propofol is classified as a parenteral or intravenous (IV) general anesthetic, not an inhalational one.
It is administered directly into the bloodstream via injection, leading to rapid induction of anesthesia.
Its route of administration is fundamentally different from inhalational agents, which are delivered as a gas or vapor through the respiratory system.
Due to its rapid onset and recovery, along with antiemetic properties, it is a popular choice for outpatient (day care) surgeries.

Option A: Isoflurane is a classic example of an inhalational anesthetic. It is a volatile liquid that is vaporized and inhaled to maintain anesthesia.
Option B: Halothane is a potent volatile liquid used as an inhalational anesthetic. It was a very common agent for many years.
Option D: Nitrous oxide, also known as 'laughing gas', is an anesthetic gas administered by inhalation. It is the only anesthetic gas in common use.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Classification of General Anesthetics as background academic context rather than a clinical decision trigger.
Understanding the route of administration (inhalational vs. intravenous) is fundamental for safe anesthetic delivery, patient preparation, and monitoring.
Nurses must be aware of the distinct side effect profiles. Inhalational agents carry a risk of malignant hyperthermia and airway irritation, while IV agents like propofol can cause pain on injection and require lipid monitoring with prolonged use.
What if? If a patient has a known personal or family history of malignant hyperthermia, all volatile inhalational anesthetics (like isoflurane and halothane) are strictly contraindicated. Anesthesia would need to be managed using an IV-based technique, making agents like propofol a primary choice.

How to Approach the Question

First, identify the key instruction in the question stem, which is the word 'EXCEPT'. This tells you to look for the option that does not belong to the specified category.
The category is 'inhalation anaesthesia'. Your task is to find the drug that is NOT administered via inhalation.
Recall the two main classes of general anesthetics: Inhalational (breathed in) and Intravenous (injected).
Systematically evaluate each option: Isoflurane (inhaled volatile liquid), Halothane (inhaled volatile liquid), and Nitrous oxide (inhaled gas). These three fit the category.
Identify Propofol. Recall that it is a milky white liquid given by IV injection for inducing and maintaining anesthesia.
Since Propofol is administered intravenously, it is the exception and therefore the correct answer.

Concept Tested & Keywords

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