What is a dissociative anaesthetic agent?

A class of psychedelic drugs characterised by distorted sensory perception and feelings of detachment from the environment and oneself. These drugs, such as ketamine, induce a state of sedation, immobility, amnesia and marked analgesia. Ketamine is a rapidly acting general anaesthetic and a Glutamatergic NDMA receptor antagonist that can be used to induce anaesthesia typically in combination with a muscle relaxant. It has also been shown to have antidepressant effects at low doses. These doses are not sufficient to be anaesthetic.