Anaesthesia amnesia

It may be used to produce light sedation and amnesia for unpleasant procedures by intravenous injection. It has also been used for induction and to supplement nitrous oxide anaesthesia. The benzodiazepines are further discussed in chapter Sedative and hypnotics in detail. 

Phencyclidine ( angel dust ) was made in a search for a better intravenous anaesthetic. It is structurally related to pethidine. Phencyclidine was found to induce analgesia without unconsciousness, but with amnesia, in man (dissociative anaesthesia). The postoperative course, however, was complicated... 

Dissociative anaesthesia is a state of profound analgesia and anterograde amnesia with minimal hypnosis during which the eyes may remain open (see ketamine, p. 353). It is particularly useful where modem equipment is lacking or where access to the patient is limited, e.g. at major accidents or on battlefields. 

Ketamine is a phencyclidine (hallucinogen) derivative and an antagonist of the NMDA-receptor. In anaesthetic doses it produces a trance-like state known as dissociative anaesthesia (sedation, amnesia, dissociation, analgesia). 

Ketamine produces a different effect to other intravenous anaesthetics analgesia, sensory loss, amnesia and muscle paralysis are produced without loss of consciousness, so-called dissociative anaesthesia, and with minimal respiratory depression. 

A study in 33 patients found that quazepam 15 or 30 mg given the night before induction of anaesthesia with propofol and fentanyl reduced the induction time when compared with a third group of patients not given a hypnotic. Quazepam did not affect blood pressure or heart rate, but the 30 mg dose of quazepam did increase anterograde amnesia. ... 

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