In their review of the recent advances in the management of self
poisoning, Jones and Volans describe ketamine as a veterinary
anaesthetic1. Although commonly used in animals, ketamine was first
synthesised and used in humans in 1964 and has been used in human
anaesthetic practice ever since.
Ketamine has several advantages over
other induction agents used in anaesthesia; maintenance of blood pressure
and cardiac output (even in hypovolaemic patients), preservation of
laryngeal and pharyngeal reflexes, maintenance of alveolar ventilation,
bronchodilation and profound analgesia are all features unique to
ketamine.
Despite these attractive properties, the use of ketamine in
Western countries is limited because of the high incidence of unpleasant
dreams and post-operative nausea and vomiting.
I use ketamine in elderly patients requiring fixation of fractured neck of
femur. The operation itself is performed under spinal anaesthesia, but
ketamine is useful to provide the 5 minutes of profound analgesia and
amnesia required to position the patient and perform the spinal injection.
Ketamine is also used as caudal anaesthesia for post-operative analgesia,
to provide analgesia for change of burns dressings and as a bronchodilator
in severe asthmatics.
Ketamine is used more frequently in developing countries where anaesthetic
equipment and trained staff may not be readily available and it has also
been used in remote situations to provide profound analgesia for the
victims of accidents or the casualties of war. The wide margin of safety
of ketamine makes it a particularly useful agent in these situations.
The misuse of ketamine or 'Special K' developed during the 1990's.
Ketamine, previously readily available in most anaesthetic rooms, is now
locked away with the controlled drugs although its safe storage is not
demanded by the Misuse of Drugs Act. The use of ketamine in date rape is
not widely described and is not confirmed by the reference used by Jones
and Volans1. Although there are several references to flunitrazepam
(Rohypnol) and gamma hydroxybutyrate (GHB) associated with 'date rape'2, a
search of Medline and Embase did not confirm that ketamine has been abused
in a similar fashion.
Ketamine continues to be used in human anaesthetic practice. The
production of the S enantiomer, which has a better recovery profile3, may
provide ketamine with a new lease of life and limit its misuse.
James M S Macdonald specialist registrar in anaesthesia,
Department of Anaesthesia, Fairfield General Hospital, Rochdale Old Road,
Bury, Lancashire. BL9 7TD
1. Jones AL and Volans G. Management of self poisoning. BMJ
1999;319:1414-7. (27 November)
2. Hindmarch I and Brinkmann R. Trends in the use of alcohol and
other drugs in cases of sexual assault. Human Psychopharmacology
1999;14(4):225-31.
3. Adams HA and Werner C. From racemate to eutomer: (S)-Ketamine.
Renaissance of a substance? Anaesthetist 1997;46(12) :1026-42. (In German)
Rapid Response:
Veterinary anaesthetic used in humans
In their review of the recent advances in the management of self
poisoning, Jones and Volans describe ketamine as a veterinary
anaesthetic1. Although commonly used in animals, ketamine was first
synthesised and used in humans in 1964 and has been used in human
anaesthetic practice ever since.
Ketamine has several advantages over
other induction agents used in anaesthesia; maintenance of blood pressure
and cardiac output (even in hypovolaemic patients), preservation of
laryngeal and pharyngeal reflexes, maintenance of alveolar ventilation,
bronchodilation and profound analgesia are all features unique to
ketamine.
Despite these attractive properties, the use of ketamine in
Western countries is limited because of the high incidence of unpleasant
dreams and post-operative nausea and vomiting.
I use ketamine in elderly patients requiring fixation of fractured neck of
femur. The operation itself is performed under spinal anaesthesia, but
ketamine is useful to provide the 5 minutes of profound analgesia and
amnesia required to position the patient and perform the spinal injection.
Ketamine is also used as caudal anaesthesia for post-operative analgesia,
to provide analgesia for change of burns dressings and as a bronchodilator
in severe asthmatics.
Ketamine is used more frequently in developing countries where anaesthetic
equipment and trained staff may not be readily available and it has also
been used in remote situations to provide profound analgesia for the
victims of accidents or the casualties of war. The wide margin of safety
of ketamine makes it a particularly useful agent in these situations.
The misuse of ketamine or 'Special K' developed during the 1990's.
Ketamine, previously readily available in most anaesthetic rooms, is now
locked away with the controlled drugs although its safe storage is not
demanded by the Misuse of Drugs Act. The use of ketamine in date rape is
not widely described and is not confirmed by the reference used by Jones
and Volans1. Although there are several references to flunitrazepam
(Rohypnol) and gamma hydroxybutyrate (GHB) associated with 'date rape'2, a
search of Medline and Embase did not confirm that ketamine has been abused
in a similar fashion.
Ketamine continues to be used in human anaesthetic practice. The
production of the S enantiomer, which has a better recovery profile3, may
provide ketamine with a new lease of life and limit its misuse.
James M S Macdonald
specialist registrar in anaesthesia,
Department of Anaesthesia, Fairfield General Hospital, Rochdale Old Road,
Bury, Lancashire. BL9 7TD
1. Jones AL and Volans G. Management of self poisoning. BMJ
1999;319:1414-7. (27 November)
2. Hindmarch I and Brinkmann R. Trends in the use of alcohol and
other drugs in cases of sexual assault. Human Psychopharmacology
1999;14(4):225-31.
3. Adams HA and Werner C. From racemate to eutomer: (S)-Ketamine.
Renaissance of a substance? Anaesthetist 1997;46(12) :1026-42. (In German)
Competing interests: No competing interests