Which agent is associated with dissociative anaesthesia?

Dissociative anaesthesia is primarily characterized by a trance-like state, which includes analgesia, amnesia, and an altered sense of awareness, while preserving protective airway reflexes. Ketamine is the agent most commonly associated with this type of anaesthesia.

Ketamine acts as a non-competitive antagonist of the NMDA (N-methyl-D-aspartate) receptor in the central nervous system, which leads to its unique effects, including sedation and dissociation. Unlike other anaesthetic agents, Ketamine does not cause a complete loss of consciousness; instead, it creates a state where patients may experience a lack of connection with their surroundings, often referred to as a dissociative state.

In terms of the other agents mentioned, while Fentanyl is a potent opioid known for its analgesic properties, it does not produce dissociative anaesthesia. Midazolam is a benzodiazepine that provides sedation and amnesia but lacks the dissociative effects. Dexmedetomidine is an alpha-2 adrenergic agonist primarily used for sedation; it produces a calming effect but does not lead to dissociation. Thus, Ketamine stands out as the only agent that reliably induces dissociative anaesthesia, making