[Ketamine as a broncholytic agent in status asthmaticus and as an anesthetic for patients with bronchial asthma]

Ketamine was introduced into clinical anaesthesia in 1965. Since then it has been demonstrated to lower airway resistance and to increase lung compliance in the asthmatic patient. It has also proved useful in anesthetizing asthmatic patients with or without symptoms. In several case reports it has been used successfully in the management of status asthmaticus resistant to conventional therapy but so far no controlled clinical trial has been carried out to support this empirical use of ketamine. The limited magnitude of the side effects permits the use in status asthmaticus when all other treatment has failed. Experiments with animals and with human preparations have suggested one or more of the following mechanisms of action: a sympathomimetic effect, a direct relaxant effect, an antagonism to histamine and acetylcholine and a membrane stabilizing effect as with local analgesics. Until investigations have been published ketamine is recommended as an anaesthetic for the asthmatic patient and for the patient who has previously reacted with bronchospasm when intubated or anaesthetized. Prospective clinical trials should be planned.