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Persistent acute agitation after partial response to rapid tranquillisation, with prolonged QTc and amphetamin

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HardMental health and behavioural emergenciesPersistent acute agitation after partial response to rapid tranquillisation, with prolonged QTc and amphetamine useMRCEM SBA

A 32-year-old man is brought to the emergency department after taking amphetamine. He is frightened by perceived threats and repeatedly attempts to strike staff. Verbal de-escalation has failed and he refuses oral medication. An earlier ECG shows a QTc of 520 ms. He received a single dose of intramuscular lorazepam one hour ago. On review, he is less agitated but still intermittently lashes out; he is awake, breathing normally and has stable observations. Intravenous access cannot be obtained safely. Trained staff and resuscitation equipment are available. What is the most appropriate next plan?

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Correct answer: A — Give a further single intramuscular lorazepam dose; monitor physiological observations every 15 minutes in the emergency department.

He still poses an immediate risk despite de-escalation, and oral medication is not possible, so further rapid tranquillisation is appropriate. The first intramuscular lorazepam dose has been reviewed and produced a partial response without evident respiratory compromise. NICE recommends considering a further dose in this situation. His prolonged QTc weighs against the alternative NICE regimen of intramuscular haloperidol with promethazine. Because he has taken an illicit drug, post-tranquillisation monitoring of physiological observations is required every 15 minutes, alongside continued emergency-department assessment of the intoxication and his physical health. B is attractive because haloperidol with promethazine is another recommended intramuscular regimen, but the prolonged QTc is the decisive contraindicating feature here. C selects an appropriate repeat medicine but uses the usual minimum hourly observation frequency rather than the 15-minute frequency specified after illicit drug use. D retains the benzodiazepine but would delay treatment to obtain access that cannot currently be established safely; intravenous rapid tranquillisation is exceptional. E provides behavioural observation but substitutes it for the required physiological monitoring and moves him out of emergency-department assessment prematurely. Psychiatric assessment and disposition can be arranged once his immediate safety and physical health needs are addressed.

Reference: NICE NG10: Violence and aggression — recommendations 1.4.37–1.4.44 (2015) — https://www.nice.org.uk/guidance/NG10/chapter/recommendations NICE NG10: Violence and aggression — recommendation 1.4.45 (2015) — https://www.nice.org.uk/guidance/NG10/chapter/recommendations NICE NG10: Violence and aggression — section 1.5 (2015) — https://www.nice.org.uk/guidance/NG10/chapter/recommendations