Neurobiology

Aggression is mediated by a circuit connecting the medial amygdala to the medial hypothalamus and the dorsal regions of the periaqueductal grey matter. This circuit is modulated by the orbital and prefrontal cortices which introduce the elements of associative learning which accompanies development. Disruption of any of these may contribute to inappropriately aggressive behaviour.

Noradrenaline, serotonin, gamma-amino butyric acid (GABA), vasopressin (AVP), testosterone, oestrogens, progestrogens, thy-roxine and cortisol have been implicated in the production and modulation of aggression. Among these, serotonin appears to carry a particularly important inhibiting effect, which can be enhanced by medications that promote the action of this transmitter.

Psychosocial elements

Personality development is critically important as this establishes the patterns of behaviour and internal experience which promote empathy, frustration tolerance and impulse control. The modulation of rage requires developmental experience which allows tolerance of emotional discomfort and learning of appropriate means for the expression of such anger. Social context and cultural practices further affect the expression of rage and goal-directed aggressive behaviour.

Prediction of violence

The prediction of violence is an inexact science, but certain factors are important clinical pointers. These are shown in Box 15.1. The reader is also referred to Chapter 18 for a broader discussion of risk in the psychiatric context.

Management

It is important to gather as much information as possible from nurses, family, friends and, where appropriate, other patients. Establish what led up to this event, and the immediate precipitant. Read past case notes and refer to any risk management plans for the patient. Remember that past violence is a good predictor of future violence and the modus operandi is often consistent.

Ensure your own safety. Remove any tie, scarf, necklace or similar item from around your neck, out of view of the patient, before approaching them. Remove any objects which might be used as weapons (e.g. mobile telephones and cutlery). Ensure a means of summoning help rapidly if required and agree upon signals in advance (e.g. ‘If I say I need Mr Black’s notes, it means I need help immediately’).

Avoid giving the patient the impression that they are trapped and allow yourself a route of escape, should it be needed. Unless the person is well known to you, address them formally and introduce yourself formally. If the patient has a weapon, suggest that they might put the weapon down, ‘so that no one will get hurt’. Never ask the patient to give you the weapon and do not accept it if offered. Optimally, the weapon should be placed away from everyone present.

Try to limit conversation to one professional person. Establish the precipitating event (if any) and try to work through this. Question slowly and allow time for responses: talk slow but think fast. Allow catharsis (release of emotion verbally). Maintain concerned attention, but avoid fixed or excessive eye contact. Perform a mental state examination as you can. Avoid writing notes until the situation is clarified and under control.

Time and the presence of trained staff are the best weapons of management. Try to have an agreed means of assistance and ensure everyone knows what their expected role is going to be.

If at all possible, offer the person oral medication to help them feel less distressed. In some circumstances, the patient may accept intramuscular medication and this has the advantage of rapid benefit.

Pharmacological management

The use of pharmacological agents in the management of the acutely aroused psychiatric patient should be judicious and carefully monitored (see Box 15.3 for important safety tips). Always check the patient’s physical status as far as is feasible, find out about any relevant medical conditions (e.g. cardiac conduction problems) and try to ascertain whether they have had any untoward reactions in the past to antipsychotics or benzodiazepines.

Offer oral medication first, unless the situation is too volatile to allow this. Intramuscular administration has the virtue of more rapid onset of action, though some agents (e.g. clonazepam) are rather erratically absorbed via this route. Intravenous administration should be considered only in extreme circumstances and the patient must be carefully monitored (notably for cardiopulmonary problems). The exact choice of agent should be predicated by the underlying problem (e.g. an antipsychotic in the patient with schizophrenia who has suffered an acute relapse), the acuity, the manifest symptoms and the prior experience of particular agents in the individual.

Oral medications

Oral medications include:

olanzapine (wafer or tablet) 5–10 mg

risperidone (rapidly dispersing or regular tablet) 1–2 mg

haloperidol (liquid or tablet) 5–10 mg

chlorpromazine (liquid or tablet) 50–100 mg

lorazepam 1–2.5 mg, and

clonazepam 0.5–2 mg.

Intramuscular preparations

Most common initial doses of intramuscular preparations include:

midazolam 5–10 mg (about 0.1 mg/kg body weight) for immediate and ultra-short-term sedation (30–60 minutes); larger doses may be required for stimulant intoxication; repeat at half-hourly intervals if needed; it is crucial to monitor respirations as these may be suppressed

lorazepam 1–2.5 mg for rapid sedation and short-term sedation (up to 4 hours); repeat at half-hourly intervals if needed

clonazepam 1–2 mg may be useful for continuing management, but be aware of the relatively long duration of action and frequency of ataxia

haloperidol 5–10 mg; higher doses may be needed for large males or intoxication states; monitor for extrapyramidal side effects

olanzapine 5–10 mg; it is usually well tolerated and can be repeated half-hourly if needed

ziprasidone 10–20 mg: 10 mg every 2 hours or 20 mg every 4 hours to a maximum of 40 mg in 24 hours, and

zuclopenthixol acetate 100 mg as starting dose (may repeat once after 24 hours if tolerated and needed; monitor for extrapyramidal side effects carefully as duration of action lasts about 48 hours); 100–150 mg if tolerance has been established and high dose needed; a third dose should be after a further 48 hours or more, if needed. Note: Onset of action will take about 2 hours and rapidly acting medications will be required simultaneously. Benzodiazepines are preferable because of the risk of extrapyramidal side effects of zuclopenthixol. Never use in a neuroleptic-naïve patient.

Intramuscular and oral medications are often usefully combined, such as the combination of a benzodiazepine plus antipsychotic. The combination of a benzodiazepine (for sedation) and antipsychotic (for reduction of aggression and gradual alleviation of psychosis) is frequently helpful. Beware, though, of the use of an intramuscular benzodiazepine and olanzapine, as there are potential dangerous interactions: a 2-hour gap should be left between such agents.

Intravenous administration

The most common initial doses of intravenous administration are as follows:

haloperidol 0.5–5 mg

lorazepam 1–5 mg, and

midazolam 1–5 mg.

Always give slowly with close monitoring of vital cardiopulmonary functions.

Clinician safety

The practice of psychiatry in any context carries a risk of injury to the clinician. The following principles are useful.

Recognise predictable risks and plan in advance the management strategies which could be employed to cope with aggression and violence. Duress alarms are frequently available in situations where violence is considered a likely occurrence and should be available at all times in such settings.

Engage other professionals in this process of planning and preparation. Teamwork is essential.

Avoid being alone with a potentially violent person wherever possible. This is critically important with home visits.

Remember that the object of the management of violence is for everyone involved to emerge unharmed. Taking unnecessary risks is not clever and bravado is foolish.

Do not approach a patient who is carrying a weapon. Call the police and summon professional help.

After dealing with a violent patient, give yourself time to debrief with other professionals. This is an opportunity to share experiences, and to feel supported and safe. Fear in a clinician is a natural emotion and not a weakness.