Abstract
David C. Furrows, Royal Brisbane Hospital, Australia:
I was surprised when moving from New Zealand to Australia to discover that intravenous sedation with haloperidol is still practised. A recent article observed that the practice was used in 23 of 24 psychiatric wards in New South Wales and administered to one-quarter of patients involuntarily detained [1]. Doses frequently exceed the recommended guidelines for use.
Evidence has begun to emerge in recent years of a clear association between use of intravenous haloperidol and the ventricular tachycardia Torsades de Pointes [2]. Hunt and Stern postulated that this was due to the same pattern of cardiac output lengthening recognised with the antihistamine terfanadine which was created by a structural modification of haloperidol [3]. In a recent study of critically ill patients treated with intravenous haloperidol, Torsades de Pointes occurred in 33% of those who received 35 mg or more of haloperidol in 24 h and in some patients on lower doses [4].
The implications for psychiatric practice are considerable. It could be argued that cardiac monitoring should be a prerequisite for this practice and, given the difficulty in distinguishing Torsades de Pointes from other ventricular dysrhythmias, that a suitably trained medical specialist might need to be in attendance.
New Zealand's history of medical malpractice and medical manslaughter cases has effectively made the practice of intravenous rapid sedation unviable because the slight advantages over intramuscular administration in onset of action are largely out-weighed by the process of arranging suitable monitoring. There are also ethical issues relating to the use of intravenous medication without consent when less invasive (intramuscular) alternatives are of similar efficacy.
The practice of intravenous sedation without appropriate monitoring clearly needs review. Psychiatrists may risk serious consequences if they effectively anaesthetise patients without exercising the level of care that would be expected of an anaesthetist.