Picture this. You walk into the cubicle. Five security staff are struggling to restrain a post-ictal patient: six foot three, big and very strong. He’s face down, shouting that he can’t breathe, and panicking. Everyone turns to you for direction.

That’s a high-stress, critical moment, and not one you want to meet without knowing the acute behavioural disturbance guidance well. That’s why this guide matters, for the exam and beyond: it lets you run through scenarios like this in your head now, without the adrenaline of the exam or the real thing.

Acute behavioural disturbance (ABD) presents as behaviour, but the danger is physiological: a hyperadrenergic state, metabolic acidosis and cardiotoxicity. Ongoing sympathetic over-stimulation and excessive muscular activity can cause a “metabolic storm” and then cardiovascular collapse, and rapid tranquillisation in more severe ABD is associated with reduced mortality (Royal College of Emergency Medicine, RCEM).

The FRCEM Final assumes you can recognise an agitated patient. The questions are about the next steps: the stage the patient has reached, the right drug for this patient, what to do when the drug causes a problem, and what the law allows.

ABD is a clinical picture, not a diagnosis or syndrome. It’s an umbrella term for a presentation that may include abnormal physiology and/or behaviour, with a variety of presenting features and potential causes (RCEM). It has also been called excited delirium, acute behavioural disorder and agitated delirium. Excited delirium is a contested diagnosis that isn’t recognised in the UK, and the Royal College of Psychiatrists (RCPsych) advises against the term.

Like the post-ictal patient above: seizures are one of the listed causes, and unusual or unexpected strength is one of the ten presenting features.

What are the features of ABD?

One or more may be present, and they can be identified before the patient is on a monitor (RCEM):

• Agitation
• Constant physical activity
• Bizarre behaviour, including paranoia and hypervigilance
• Fear, panic
• Unusual or unexpected strength
• Sustained non-compliance with police or ambulance staff
• Tolerance of pain, or imperviousness to it
• Hot to touch, sweating
• Rapid breathing
• Tachycardia

There are no diagnostic criteria, no minimum number of features and no heart rate or temperature cut-offs. The list is drawn from the excited delirium literature, because there is little evidence on ABD in a UK context.

What if the features are missing?

The features may be absent if the patient has had rapid tranquillisation or anaesthesia before arrival, has reached exhaustion, or is peri-arrest or in cardiac arrest. Take as detailed a pre-hospital history as you can, to find out what they were like before (RCEM). ABD can also be a distracting presentation: co-existing poisoning or injuries may not be immediately obvious.

The two commonest causes are substance intoxication and mental health conditions, and most cases are toxicological in origin (RCEM).

Causes include:

• Substance intoxication
• Mental health conditions
• Substance withdrawal
• Serotonin syndrome
• Hypoxia
• Hypoglycaemia
• Electrolyte disturbance
• Sepsis
• Head injury
• Anticholinergic syndrome
• Neuroleptic malignant syndrome
• Thyroid storm
• Heat stroke
• Seizures
• Metabolic disorders (new in 2026)

What’s new in 2026?

Metabolic disorders were added to the list in April 2026, following a coroner’s report. The patient had a previously undiagnosed urea cycle disorder, unmasked by giving birth 18 days earlier (RCEM’s response to the coroner).

Consider an ammonia level as part of the metabolic screen, from a free-flowing sample, kept on ice and taken straight to the lab (RCEM). Ammonia testing is difficult to do correctly, which is why it is a test to consider rather than a routine one (RCEM).

Keep it in proportion. Hyperammonaemia and other metabolic disturbances are very rare causes of ABD, and are far more likely to present with drowsiness and confusion than with agitation (RCEM).

What happens when the cause becomes clear?

Treating the cause matters, and it should be addressed as soon as possible. The difficulty is that a patient in acute behavioural disturbance is almost impossible to assess or treat safely until they’re calm and still. Observations and investigations happen at the earliest safe opportunity, which is often only after de-escalation or sedation, and the need for rapid tranquillisation is defined by being unable to give the patient a safe assessment or essential treatment (RCEM).

As more information comes in, a specific diagnosis may become clear, and managing the behaviour with that diagnosis’s own guidance may then be more appropriate (RCEM). Recognising ABD doesn’t stop other guidelines applying, and the ABD guidance can be used alongside them (Consensus on Acute Behavioural Disturbance in the UK, CABDUK).

If the agitation follows a seizure, the seizure needs its own work-up: our guide to status epilepticus covers the triggers and investigations. For serotonin syndrome, anticholinergic syndrome and the other toxidromes, see our guide to toxidromes and the unknown poisoning.

A senior emergency medicine clinician leads, and whoever gives rapid tranquillisation (RT) must be able to manage its complications. Consider early critical care support (RCEM).

Who else do you need?

• A safety person. If possible, assign someone who isn’t involved in the restraint or other interventions to watch the patient’s condition.
• Trained staff only. Staff without approved training shouldn’t be asked to restrain. Escalate early to on-site security, and don’t attempt restraint with too few staff.
• Police, in defined circumstances. They shouldn’t normally be called just to restrain a patient for a clinical intervention. Request them if staff have been injured, if healthcare support can’t arrive in time to keep everyone safe, or if there is a risk of serious injury or damage and safety is compromised.
• Friends and family may help with de-escalation, if it is safe. For a patient with a learning disability, check for a care plan, and have someone they know talk to them.

What should you ask the pre-hospital team?

The police and ambulance service are usually both involved, and police guidance is to bring the person to an ED rather than to custody. Ask the crew, if they don’t offer it (RCEM):

• the behaviour that made them suspect ABD
• the verbal or environmental de-escalation they tried
• any capacity assessment
• restraint: what, for how long, and why
• police or security involvement, including use of force, a Taser (controlled energy device) or PAVA spray
• sedation and any adverse events: some ambulance services and pre-hospital critical care teams give RT, and custody healthcare staff may have given oral benzodiazepines
• medications, drugs and alcohol, and the medical and psychiatric history

The Sedation Assessment Tool (SAT) scores agitation on responsiveness and speech (Calver, Stokes and Isbister, 2011). RCEM includes it as an example of a tool: using an agitation scale to guide the initial decision to give RT may be helpful where practicable.

Ketamine and droperidol are kept for severe agitation: SAT 2 or 3 (RCEM). An anxious, restless patient (SAT 1) doesn’t meet that threshold.

The scale runs down to −3, so the same tool describes how deeply sedated the patient is once the drug has worked.

How do you de-escalate?

Attempt verbal de-escalation, even if it feels futile. It is an important step in showing that restraint and RT were justified, and a clear record of it reassures the family and the public if an adverse outcome leads to a review. It is continuous: try again at any point (RCEM). The model is familiar: one person talking, out of arm’s reach, short sentences, clear limits set matter-of-factly rather than as a threat, and choices offered.

• Offer oral sedation as part of de-escalation: it is the least restrictive option in a patient who lacks capacity. RCEM’s example protocol uses oral lorazepam 1 to 2 mg (maximum 4 mg a day).
• No food or drink if sedation or general anaesthesia is likely.
• The room. The de-escalation area, often the mental health room, can help control the situation while you plan, but it may not be suitable for parenteral RT. Ideally it is quiet, not too warm and constantly observable, with doors that open outwards, exits staff can’t be trapped from, and nothing that could be used as a weapon or a barricade.

What are the dangers of restraint?

No method of restraint is risk-free in an undifferentiated, potentially unwell patient with ABD. Continued exertion against restraint can contribute to poor outcomes, likely by increasing catecholamine levels and worsening hyperthermia and metabolic acidosis (RCEM). Use the least restrictive intervention for the shortest time, and remove ongoing restraint at the earliest opportunity.

Positional asphyxia. The theory that prone restraint contributed to deaths hasn’t been supported by recent research, but make sure nothing obstructs ventilation and minimise the risk of asphyxia (RCEM). The specific rules come from mental health guidance:

• No pressure on the neck, rib cage or abdomen, and nothing over the mouth or nose (National Institute for Health and Care Excellence, NICE, guideline NG10; Mental Health Act Code of Practice)
• Avoid taking the patient to the floor. If you have to, use the supine position if possible, and if prone is necessary, keep it as short as possible (NICE NG10)
• No planned or intentional prone restraint, on any surface, unless there are cogent reasons (Mental Health Act Code of Practice)

Arriving restrained. Patients may arrive still restrained by the police, or after a Taser or PAVA spray. Check the airway and breathing, and remove the restraint at the earliest opportunity: only trained staff should restrain in the department (RCEM).

Restrained and fighting? Cannulating a patient under active restraint risks injuring staff. It may be safer to give IM sedation first, then cannulate (RCEM).

How long is too long?

RCEM sets no minute limit. Prolonged restraint should prompt consideration of RT, and early sedation should be considered in severe ABD, including where there has been prolonged activity or restraint.

The 10-minute figure is from NICE NG10, which was written mainly for mental health settings: don’t routinely use manual restraint for more than 10 minutes, and consider rapid tranquillisation instead.

In practice, with a patient in ABD, even two minutes of restraint feels like a long time. Every minute of struggling adds to the catecholamine surge, the heat and the acidosis, so in severe ABD (a Sedation Assessment Tool score of 2 or 3), plan the sedation early rather than watching the clock (RCEM).

The need for RT is defined by the inability to provide the patient with a safe assessment or essential treatment (RCEM). Parenteral RT is more likely to be needed if the patient:

• lacks capacity to refuse treatment and is non-compliant, and
• is a danger to themselves or others, or clearly needs further treatment or investigation.

Check how agitated they are too: RCEM keeps ketamine and droperidol for severe agitation, a Sedation Assessment Tool (SAT) score of 2 or 3.

Use a standard IM protocol. In a severely agitated patient, such as one needing continuous restraint, IV drugs, full monitoring and pre-oxygenation are rarely achievable first. A standardised IM protocol gives faster control, fewer adverse reactions and fewer injuries to staff (RCEM). This isn’t procedural sedation: there is no chance to optimise the patient first, and more potent drugs or higher doses than usual may be needed.

Where should you give it?

• Resus, if at all practicable, with staff who can manage the complications.
• If that isn’t achievable, have resuscitation equipment immediately available where you give it, and move the patient to resus once sedated.
• Once sedated, monitor in a high-dependency area (the resus room).
• Step down from resus to the department’s best environment for managing ABD at the earliest opportunity.

How do you prepare?

A short safety brief, if practicable: roles, the plan, anticipated problems, restraint, the IV access plan, the plan for moving to resus, and who decides when to relax the restraint.

Kit and people (RCEM’s example protocol):

• A senior doctor with critical care experience
• Drugs drawn up and prepared correctly, with antidotes available
• Oxygen with a high-flow reservoir mask, on the patient or ready
• ECG, pulse oximetry, blood pressure and end-tidal CO₂ (ETCO₂) monitoring
• Airways, suction and a bag-valve mask
• Enough staff

Why ketamine?

• Shorter time to adequate sedation than benzodiazepines or antipsychotics.
• In severe ABD, its dissociative effects appear to reduce the adrenergic features, and its sympathomimetic effects are unlikely to cause significant harm.
• Fast onset, cardiovascular stability, and preserved respiratory drive and airway reflexes.
• The high intubation rates after ketamine are mainly seen pre-hospital, where they are likely to reflect the need for safe transport to hospital.

Why droperidol?

• Fewer adverse events than lorazepam or midazolam, and less need for additional sedatives than haloperidol or midazolam.
• The historic concerns about QT prolongation haven’t been replicated in later studies.

What if neither is available?

• Midazolam 5–10 mg IM: more adverse events than droperidol, and benzodiazepines cause more respiratory adverse events than antipsychotics.
• Lorazepam 4 mg IM: slower to work than midazolam.
• Haloperidol 5 mg IM, with or without lorazepam 2 mg IM: the combination sedates better than either drug alone, with no increase in adverse effects. Haloperidol alone has fewer adverse events but succeeds less often, and apnoea after haloperidol has been documented.

Which dose details matter?

• The doses are for an average-sized adult. Halve them over 65, and adjust for body habitus and any medication recently taken.
• Higher concentrations than usually stocked may be needed for IM injection, and large volumes may need giving at more than one site.
• IV is easier to titrate but may not be practicable, and IV doses may need reducing after an IM dose.
• When choosing, weigh the speed of onset, side effects, the IM volume and your own experience: in an emergency, the safest drug may be the one you know best (RCEM).

Strongly consider critical care support if the full first doses haven’t worked (RCEM). The guideline sets no interval for repeating the first dose.

What if the patient has Parkinson’s disease or Lewy body dementia?

Haloperidol and droperidol are both contraindicated (RCEM), and both drugs’ product licences list Parkinson’s disease. That removes one first-line drug and one fallback, and leaves ketamine.

What if the patient takes antipsychotics?

Droperidol may be a less suitable option if the patient is known to take antipsychotics, or if the presentation may be linked to antipsychotic use, such as anticholinergic syndrome or akathisia (RCEM). Ketamine is the other first-line option.

What about ischaemic heart disease or cocaine?

Midazolam could be considered when the history suggests a risk from sympathomimetic features, where a transient rise in heart rate or blood pressure may be particularly relevant: ischaemic heart disease, or possible cocaine-induced psychosis (RCEM). It has more adverse events than droperidol, and benzodiazepines cause more respiratory adverse events than antipsychotics, so be ready to support the airway.

What about older and frail patients?

Halve the doses over 65, and start low and go slow in frail patients. The differential in this group is less likely to feature stimulant drugs and more likely to be hyperactive delirium, for which delirium guidance is likely to be more appropriate. Benzodiazepines may worsen delirium and cause prolonged, excessive sedation in older patients (RCEM).

What about a head injury or co-ingestion?

Ketamine and droperidol are supported as first line in ABD even where there may be co-existing drug ingestion or a head injury. This can look contrary to BNF advice, for example in hypertension, hypovolaemia or hallucinations, but the evidence for both drugs in ABD is now extensive (RCEM). Once the patient is sedated, look for the injury or the ingestion: ABD can hide both.

What if tachycardia or hypertension worsens after ketamine?

If tachycardia or hypertension gets worse after ketamine, the synergistic sympathomimetic effects may increase the cardiac risk. Consider adding a benzodiazepine (RCEM).

What about benzodiazepines and flumazenil?

If you give parenteral benzodiazepines, have flumazenil available as a precaution: initial dose 200 micrograms, given slowly. It can be hazardous, particularly in mixed overdoses involving tricyclic antidepressants, and in patients dependent on benzodiazepines (RCEM).

Which drugs carry an airway risk?

Most sedatives used in ABD have been associated with apnoea, airway obstruction or the need for subsequent intubation, haloperidol included (RCEM). Prepare for it with oxygen, ETCO₂ monitoring, suction and a bag-valve mask.

Why can some options look wrong?

If you look them up in the BNF or their product licences, ketamine and droperidol can look like the wrong answer. Droperidol is licensed in the UK for IV use in postoperative nausea and vomiting, so IM droperidol for agitation is off-label, and its licence lists a prolonged QTc as a contraindication. Ketamine is licensed for anaesthesia, and its licence lists cerebral trauma.

But RCEM recommends both as first line for ABD. It acknowledges that this can look contrary to the BNF, and says there is now extensive evidence supporting them, including where the patient may have taken other drugs or has a head injury. RCEM doesn’t require an ECG before droperidol (RCEM).

How should you monitor them?

Establish and secure IV access, and monitor in a high-dependency area (the resus room). Use routine ED sedation monitoring, as for procedural sedation, including ETCO₂ (RCEM). Our guide to procedural sedation covers the monitoring standards.

Which investigations do you need?

• Blood gas, including glucose
• FBC, U&E, LFT, troponin, CK and coagulation
• As indicated: blood cultures, trauma bloods, overdose bloods, a toxicology screen, and a metabolic screen (consider ammonia)
• ECG
• Imaging if clinically indicated

Get a collateral history at the earliest opportunity.

What needs correcting?

• Rehydrate: these patients are likely to be dehydrated
• Correct glucose, electrolyte and acid–base abnormalities
• Correct hyperthermia if needed
• Prevent or manage rhabdomyolysis and disseminated intravascular coagulation (DIC)

For a toxicological cause, TOXBASE gives the agent-specific treatment.

How do you keep the patient settled?

Agree ongoing sedation with the admitting specialty, and maintain it with IV boluses until a definitive plan is in place. Options outside critical care, without anaesthetic support (RCEM):

• Diazepam 0.3 mg/kg, titrated IV (or oral), repeated as needed
• Lorazepam 0.03 mg/kg, titrated IV (or oral), repeated as needed
• Haloperidol 2.5 mg IM (1.25 mg in older patients) or 2 mg oral (1 mg), repeated as needed
• Olanzapine 5–10 mg IM or oral (2.5–5 mg in older patients), repeated up to twice in 24 hours
• Suspected serotonin toxicity with severe psychosis or hyperthermia: chlorpromazine 25–50 mg IV or IM, in addition to a benzodiazepine

Haloperidol and olanzapine may prolong the QT interval or cause arrhythmias, and the Parkinson’s and Lewy body contraindication applies to haloperidol here too. Benzodiazepines treat withdrawal from alcohol or sedative drugs; in gamma-hydroxybutyrate (GHB) or gamma-butyrolactone (GBL) withdrawal, add baclofen, guided by TOXBASE. Patients who have taken large amounts of stimulant or serotonergic drugs may need sedation for long periods, and at higher doses than you expect (RCEM).

Don’t give IM olanzapine at the same time as a parenteral benzodiazepine: wait at least an hour after the olanzapine (olanzapine product licence).

Where do they go next?

• Suspected mental health cause: if repeat IM sedation is needed, ideally agree it with mental health services, pending their review.
• Non-psychiatric cause, with sedation needs beyond ward-level care: critical care input is required. Consider advice from the National Poisons Information Service (NPIS), via TOXBASE.
• Liaise with the specialty taking over: further treatment depends on the cause.

Refer to critical care early if intubation looks likely. The indications (RCEM):

• The airway needs securing
• Spontaneous ventilation can’t maintain oxygenation and prevent hypercapnia
• Severe agitation despite maximal safe sedative doses
• Persistent metabolic derangement
• Hyperthermia that needs managing
• Other interventions or investigations that need it

How should you anaesthetise them?

From the RCEM guideline (2026).

From the RCEM guideline (2026).

What if they arrest?

Most cases of ABD are toxicological in origin, so give consideration to prolonged resuscitation efforts (RCEM). The typical features may be missing in a patient who arrives peri-arrest or in arrest, so the pre-hospital history matters.

The law here is for England and Wales. In Scotland and Northern Ireland, the Adults with Incapacity (Scotland) Act 2000 and the Mental Capacity Act (Northern Ireland) 2016 apply, with similar principles.

Do they have capacity?

Patients with severe ABD are likely to lack capacity to make treatment decisions, but assess it formally and document it (RCEM). Treatment is then given in their best interests, using the least restrictive option that will achieve the purpose (Mental Capacity Act 2005, MCA, section 1).

What allows you to restrain them?

• To prevent harm to the patient: MCA section 6. Restraint, meaning force or restricting their liberty of movement whether or not they resist, is covered only if you reasonably believe it is necessary to prevent harm to the patient, and it is a proportionate response to the likelihood and seriousness of that harm. Restraint just to make a task easier isn’t covered (MCA Code of Practice).
• To prevent harm to others: common law. Staff may take appropriate and necessary action to restrain or remove a person to prevent harm to them and to anyone else (MCA Code of Practice). Reasonable force to prevent crime is also covered by section 3 of the Criminal Law Act 1967. The common law power lasts only until the crisis subsides (RCEM, 2017).
• A Deprivation of Liberty Safeguards (DoLS) authorisation in the ED is inappropriate: manage any restrictions under the MCA, least restrictive and for the shortest time, and arrange urgent transfer (RCEM, 2026).

What are the Mental Health Act traps?

• Section 5(2) can’t be used in the ED. The doctor’s holding power is for hospital inpatients, including those on a general ward for a physical illness. It can’t be used for an outpatient attending the ED, and a patient shouldn’t be admitted informally just to use it (Mental Health Act Code of Practice). It gives no power to treat either.
• Section 136 gives no power to treat. A patient detained under section 136 is in the same position on consent to treatment as one who isn’t detained (Mental Health Act Code of Practice). Treatment, including RT, needs their consent, the MCA if they lack capacity, or common law.
• The section 136 clock starts on arrival in the ED. If the police bring the patient to the ED first for treatment, the 24-hour detention period starts on arrival, because a hospital is a place of safety. The doctor responsible for the assessment can extend it by up to 12 hours, but only if the patient’s condition makes assessment within 24 hours impracticable, for example severe intoxication. A delay in the approved mental health professional (AMHP) attending isn’t a valid reason (Department of Health and Home Office guidance, 2017).
• A patient under section 136 who tries to leave may be restrained and prevented from leaving by the police or by trained security staff (RCEM, 2017).

If a mental health problem is diminishing the patient’s capacity, assess them under the Mental Health Act (MHA). Emergency treatment such as sedation can still be given to a patient with a mental disorder who lacks capacity, in their best interests, before or after any formal detention (RCEM, 2017).

What should you document?

• Why RT was needed, and the de-escalation tried
• The capacity assessment
• The features supporting ABD, and the collateral history
• Restraint: what was applied, for how long, and why
• Police or security involvement, including use of force and any Taser use
• The sedative strategy and any adverse events
• Other specialties involved

They are written for different settings. Mental health guidance is written mainly for psychiatric wards; the RCEM guideline is for patients at risk of physiological collapse, in a department with resuscitation facilities. The psychiatric consensus guideline, from the British Association for Psychopharmacology and the National Association of Psychiatric Intensive Care and Low Secure Units (BAP/NAPICU), itself accepts that the ED can safely use a wider range of drugs, because resuscitation equipment and ventilation are to hand.

What do psychiatric guidelines say?

RCPsych has no RT drug guidance of its own. Its position statement on ABD (PS02/22, 2022) is about terminology and gives no clinical guidance. Psychiatrists very rarely describe anyone as having ABD, and RCPsych is concerned that ABD guidance could be applied to people whose needs would be better met by de-escalation and a specialist mental health response. It accepts transfer to an ED and RT for patients who don’t respond to sustained de-escalation and in whom there is a serious concern of physiological collapse, with red flags of a high temperature, rapid breathing, a rapid pulse, and extreme, sustained agitation.

Mental health wards follow NG10, the BAP/NAPICU guideline and their own trust policies, and those policies vary widely.

Which guidance applies in the ED?

• ABD in the ED: RCEM. A known psychiatric illness doesn’t take the patient out of it, because mental health conditions are one of the two commonest causes. It changes who you involve: repeat IM sedation for a suspected mental health presentation should ideally be agreed with mental health services.
• A specific diagnosis becomes clear: its own guidance may be more appropriate, and the ABD guidance can still be used alongside it (RCEM; CABDUK).
• Agitated, but not ABD: other guidance may be more appropriate if the patient can tell you what they are experiencing, responds to verbal de-escalation, holds a consistent conversation for more than 60 seconds or directs their aggression at one person, has no physiological disturbance on assessment, or has a known diagnosis that explains the presentation, such as schizophrenia (CABDUK). For a patient with a mental health problem, that is NICE NG10: don’t exclude them from the ED, don’t use seclusion, and refer urgently for a psychiatric assessment within 1 hour.
• Older and frail, with hyperactive delirium: delirium guidance is likely to be more appropriate (RCEM).
• Children: adolescents are likely to have a similar differential to adults, and in a potentially life-threatening situation, similar sedative strategies. In pre-adolescent children, brief restraint is more likely to succeed if de-escalation fails. RCEM gives no paediatric doses.

What if you revise from RCEM Learning?

The free RCEM Learning pages on ABD (2021, reviewed 2024) predate the current guideline, and some lines conflict with it: they describe haloperidol as best avoided and quote NICE’s IM lorazepam as first line. For the exam, follow the 2026 guideline.

The questions are about the next steps, the nuances of treatment and when to deviate from the standard approach. Work through the stem in this order:

• Where are you in the process? Has de-escalation been tried, oral sedation offered, and is the restraint safe? Choose the next step from where the stem picks up: oral, then IM, then critical care.
• How agitated is the patient? Turn the description into a SAT score. Ketamine and droperidol are for SAT 2–3.
• Who is the patient? Over 65: halve the dose. Parkinson’s disease or Lewy body dementia: no droperidol or haloperidol. On antipsychotics: droperidol is less suitable. Ischaemic heart disease or cocaine: consider midazolam. Head injury or co-ingestion: ketamine and droperidol are still supported.
• Where are they? Resus if practicable; if not, kit at the bedside and move once sedated.
• What happened after the drug? Worse tachycardia or hypertension after ketamine: consider a benzodiazepine. Full first doses failed: critical care. Intubating: ketamine induction, no suxamethonium, no opioids, keep ventilating. Cardiac arrest: consider prolonged resuscitation.
• What’s driving it? Check the glucose and the gas. Once a specific cause is clear, its own guidance may take over.
• Agitated, but not ABD? Talking, responding to de-escalation, none of the dangerous physiology: consider the mental health pathway and NICE NG10.
• What does the law allow? The MCA for harm to the patient, common law for harm to others, no section 5(2) in the ED, and no treatment under section 136.

Where can you read the guidance?

• The guideline — RCEM, Acute Behavioural Disturbance in Emergency Departments (version 4, April 2026). Read it in full; the Sedation Assessment Tool (Appendix 1) and the example rapid tranquillisation protocol (Appendix 2) are worth printing.
• Capacity and restraint in the ED — RCEM, The Mental Capacity Act in Emergency Medicine Practice (2017).
• DoLS in the ED — RCEM, Deprivation of Liberty Safeguards (DoLS) position statement (2026).
• The Mental Capacity Act — Mental Capacity Act 2005, section 6 (restraint), and the MCA Code of Practice.
• The Mental Health Act — Mental Health Act 1983, section 136, the MHA Code of Practice (2015), and the Department of Health and Home Office guidance on police powers and places of safety (2017).
• Where the wrong answers come from — NICE NG10, Violence and aggression: short-term management in mental health, health and community settings (2015), and BAP/NAPICU, Clinical management of acute disturbance: de-escalation and rapid tranquillisation (2018).
• The psychiatric view — RCPsych Position Statement PS02/22, ‘Acute behavioural disturbance’ and ‘excited delirium’ (2022; copy published by the Sheku Bayoh Inquiry), and the CABDUK consensus report (2023).
• RCEM Learning — Acute behavioural disturbance (2021, reviewed 2024): read it alongside the 2026 guideline.

Drug doses are for reference only — confirm against the BNF and the current RCEM guideline.