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Psychiatric emergencies 

Psychiatric emergencies
Psychiatric emergencies

Punit S. Ramrakha

, Kevin P. Moore

, and Amir H. Sam

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date: 20 January 2021

Acute confusion: assessment

Acute confusional states, or delirium, are relatively common. They are particularly common in care of the elderly and on orthopaedic wards. Risk factors include: age >65 years, prior cognitive impairment or dementia, multiple comorbidities, psychoactive drug use, polypharmacy, previous history of delirium/falls/CVA, and gait disorder. Acute confusion may occur on a background of chronic cognitive impairment (dementia) and may last for a prolonged period of days or even weeks. Acute confusion may occur as part of a mental illness or be secondary to organic disease (e.g. brain tumour or encephalitis).

Common features of acute confusion

  • Rapid onset.

  • Fluctuation.

  • Clouding of consciousness.

  • Impaired recent and immediate memory.

  • Disorientation.

  • Perceptual disturbance, especially in visual or tactile modalities.

  • Psychomotor disturbance (agitation or Psychiatric emergencies movements).

  • Altered sleep–wake cycle.

  • Evidence of underlying cause.

Common causes of acute confusion

  • Pain or discomfort (e.g. urinary retention, constipation).

  • Hypoxia.

  • Metabolic disorders (renal failure, liver failure, acidosis, hypercalcaemia, hypoglycaemia) or endocrine disease (thyrotoxicosis, Addison’s disease, DM).

  • Infection (systemic or localized).

  • Cardiac (MI, CCF, endocarditis).

  • Neurological (head injury, subdural haematoma, CNS infection, post-ictal states).

  • Drugs [prescribed: benzodiazepines, opiates, digoxin, cimetidine, steroids, anti-parkinsonian drugs, anticholinergics; or recreational: especially stimulants, alcohol, gamma-butyrolactone (GBL), ketamine].

  • Alcohol or drug withdrawal.

Detection of acute confusion

  • The presence or absence of cognitive impairment may help distinguish between organic and functional mental impairment.

  • The 10-point Abbreviated Mental Test Score, 30-point Mini Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), or the Confusion Assessment Method (short version) give a rapid estimate of key cognitive functions.

  • Take a clear history from friends or relatives, and try to determine whether delirium is superimposed upon dementia.

Acute confusion: management

  • Treat the cause. Always consider alcohol withdrawal. Ensure that common problems like dehydration, pain, and constipation are adequately treated.

  • It is often sufficient to manage the delirious patient’s behaviour conservatively (non-pharmacologically), while treating the underlying cause. Nurse in a well-lit, quiet room with familiar nursing staff or, better still, a familiar person such as a family member or carer. Ensure effective communication and reorientation, and provide reassurance to patients with delirium.

  • Occasionally, patients may refuse investigations or treatment. It may be important to go ahead with baseline investigations in order to rule out life-threatening causes for the confusion, and this may need to be done under the Mental Capacity Act 2005 or common law (Psychiatric emergencies The Mental Health Act, p. [link]; Psychiatric emergencies Common law, pp. [link][link]).

  • If sedation is required, use small amounts of sedatives, given orally if possible. Offer liquid preparations if tablets are refused. Parenteral medication may be indicated if patients refuse or are particularly disturbed. See Psychiatric emergencies Sedation for patients with delirium, pp. [link][link] for drugs and doses.

  • Patients with ongoing disturbance may require regular sedation.

Sedation for patients with delirium

(See Box 13.1.)

  • There are a few medication options here, so consider: the likely cause of delirium, concomitant medication, and any underlying comorbidities when choosing.

  • Start with low doses, and titrate upwards according to clinical response.

  • Antipsychotics are used, but not licensed for delirium, so this is off-label prescribing. However, some such as haloperidol have a licence for agitation in the elderly, and risperidone for short-term management of aggression in dementia. Haloperidol 0.5–1mg PO bd, with additional doses 4-hourly if needed. If using IM haloperidol 0.5–1mg, monitor for 1h and repeat if necessary. Remember it is recommended to have a pre-haloperidol ECG recorded due to risk of QT prolongation. Avoid haloperidol in neuroleptic malignant syndrome (NMS), anticholinergic toxicity, and hepatic failure. Olanzapine 2.5–5mg PO bd (max 20mg/24h) and risperidone 0.5mg bd (max 4mg/24h) can be used, but in the elderly with underlying dementia, there is an Psychiatric emergencies risk of CVA.

  • Lorazepam 0.25–1mg PO/IM every 2–4h, as needed (half doses in the elderly), but remember that benzodiazepines may exacerbate confusion.

  • Diazepam 5–10mg PO (2mg starting dose in the elderly).

  • In patients with Lewis body dementia or Parkinson’s disease, there is a high risk of severe extrapyramidal side effects, so best to avoid antipsychotics in these cases, and consider benzodiazepines.

  • Some patients who are neuroleptic-naïve are extremely sensitive to neuroleptics and may develop severe extrapyramidal side effects. Use low doses of antipsychotics if you are unsure. Dystonic reactions should be treated with anticholinergic drugs such as procyclidine.

  • If parenteral medications are required, use lorazepam and/or haloperidol (doses as listed earlier).

  • Reassess the degree of sedation after 15–20min.

  • Patients with heavy sedation require vital signs monitoring every 5–10min for the first hour, then half-hourly until they are ambulatory.

Prognosis in acute confusion

Delirium and dementia both carry adverse prognosis. In particular, delirium increases the length of hospital stay and is associated with significant mortality and may lead to residual cognitive impairment. It is important to ensure that cognitive assessment is repeated after the episode prior to discharge, as residual deficits may go undetected otherwise.

Rapid tranquillization for acutely disturbed or violent patients

Unfortunately, violent or dangerous situations do occur in medical settings. If a patient needs rapid sedation in order to keep them or others safe, consider this pathway.1

A stepped approach: always try to use the least invasive option; however, go ‘up’ the steps, as required by the situation.

  1. 1 Attempt verbal and situational de-escalation.

  2. 2 Offer oral treatment: consider what medication the patient is already on. If on a regular antipsychotic, offer lorazepam 1–2mg, or buccal midazolam 10–20mg. Can be repeated after 45–60min. If not already on regular antipsychotics, then consider olanzapine 10mg, risperidone 1–2mg, or haloperidol 5mg. Note that for haloperidol use, it is now recommended to have a pre-haloperidol ECG due to risks of QT prolongation. Avoid combining two or more different antipsychotics.

  3. 3 If oral medication is refused or ineffective and the patient is placing themselves or others at significant risk, consider IM treatment—lorazepam 1–2mg, promethazine 50mg, olanzapine 10mg, aripiprazole 9.75mg, or haloperidol 5mg are all options. Whichever option is chosen, it can be repeated after 30–60min if insufficient effect.

Remember to have flumazenil to hand if using benzodiazepines in case of respiratory depression. IM olanzapine should not be combined with IM benzodiazepine. IM promethazine is useful in patients with benzodiazepine tolerance. Haloperidol should be the last choice due to higher rates of dystonic reactions and risks of QT prolongation (pre-treatment ECG formally recommended).

  1. 4 Consider IV treatment. Diazepam 10mg over at least 5min. Repeat after 5–10min if insufficient effect, up to three times. Remember to have flumazenil to hand.

  2. 5 If all the above have failed, seek expert advice from the consultant on-call or senior clinical pharmacist on-call.

Monitor for potential problems: acute dystonic reactions, respiratory depression, arrhythmias, bradycardia, hypotension, and Psychiatric emergencies temperature (withhold further antipsychotics, risk of NMS, check plasma creatinine kinase).

Monitoring after rapid tranquillization: monitor temperature, pulse rate, BP, and RR every 5–10min for the first hour, then every 30min until the patient is ambulatory. If the patient is unconscious, consider continuous pulse oximetry; ensure the airway is maintained; a nurse should be present until the patient is ambulatory.

Haematological monitoring and ECG monitoring are recommended if parenteral antipsychotics are given, especially if high doses are administered. Hypokalaemia, stress, and agitation can increase the risk of cardiac arrhythmia. All patients given haloperidol should have ECG monitoring.


1. Taylor D et al., (2015). The Maudsley Prescribing Guidelines in Psychiatry, 12th edn. South London and Maudsley NHS Foundation Trust and Oxleas NHS Foundation Trust, Wiley–Blackwell.Find this resource:

Acute alcohol withdrawal

(Also see Psychiatric emergencies Acute alcohol withdrawal, pp. [link][link].)

It is estimated that there are between 1 and 2 million people in England who are alcohol-dependent. There is a spectrum of dependence, from mild to severe, and withdrawal symptoms occur also on a spectrum, often commensurate with the severity of dependence. Untreated, this carries a risk of seizures, permanent neurological complications, and death. Severe cases of dependence, cases complicated by other risks such as physical comorbidities and mental health problems, or when signs of delirium tremens (DT) or Wernicke–Korsakoff syndrome are present should be treated as a medical emergency.

Detection of alcohol withdrawal

Early clinical features include anxiety, restlessness, tremor, insomnia, sweating, tachycardia, ataxia, and pyrexia. Consider using the Clinical Institute Withdrawal Assessment of Alcohol (CIWA-Ar) scale to measure the degree of withdrawal. Withdrawal may be complicated by seizures, especially in those with known epilepsy and those with a prior history of withdrawal seizures. DT can develop and is characterized by confusion and disorientation, labile mood and irritability, hallucinations (auditory and visual), and fleeting delusions, often very frightening. Untreated, this condition carries a significant risk of death.

Do not forget to screen for Wernicke–Korsakoff syndrome, a complication of acute thiamine deficiency which occurs in chronic alcoholism. WE presents with acute confusion, ataxia, nystagmus, and ophthalmoplegia ± peripheral neuropathy. Not all of these symptoms need be present. Untreated, a large number of these patients will develop long-term memory problems from Korsakoff syndrome.

Treatment of alcohol withdrawal

  • Uncomplicated and mild-to-moderate alcohol withdrawal patients can often be treated as outpatients by community drug and alcohol services.

  • Consider inpatient or residential assisted withdrawal if a patient meets one or more of the following criteria. They:

    • Drink over 30U of alcohol per day.

    • Have a score of >30 on the Severity of Alcohol Dependence Questionnaire (SADQ).

    • Have a history of epilepsy or of withdrawal-related seizures or DT during previous assisted withdrawal programmes.

    • Need concurrent withdrawal from alcohol and benzodiazepines.

    • Regularly drink between 15 and 20U of alcohol per day and have:

    • significant psychiatric or physical comorbidities (e.g. chronic severe depression, psychosis, malnutrition, CCF, UA, chronic liver disease), or

    • a significant learning disability or cognitive impairment.

  • Consider a lower threshold for inpatient or residential assisted withdrawal in vulnerable groups, e.g. homeless and older people.

  • Any patient in withdrawal with signs of DT or Wernicke–Korsakoff syndrome needs to be admitted for urgent treatment.

  • Alcohol withdrawal should be treated with chlordiazepoxide or diazepam (consider lorazepam or oxazepam if elderly or significant liver disease) or carbamazepine. If an IV agent is needed, use diazepam. B-complex vitamins are required to prevent WE. Prophylaxis for Wernicke’s consists of parenteral therapy as Pabrinex® (one pair of ampoules od for 3–5 days IM or IV), and thereafter oral vitamin supplements should be given. In cases where evidence of Wernicke’s is already present, give Pabrinex® two pairs of ampoules thrice daily IV for a minimum of 2 days, followed by 5 days of one pair of ampoules daily; continue as long as symptoms improve.

  • Other useful drugs may include:

    • Atenolol or propranolol for hypertension.

    • Lorazepam for seizures.

    • Antipsychotics for hallucinations: not usually required. Use small doses and limit the duration. Haloperidol which has been previously used must be used with caution, as it may increase the risk of seizures, as well as having cardiovascular risks. Olanzapine may be an alternative.

Withdrawal regime

See Psychiatric emergencies Acute alcohol withdrawal, pp. [link][link].


  • Maintenance thiamine or multivitamin therapy should be given initially.

  • Screen for residual cognitive impairment.

  • Mobility and occupational therapy assessments before discharge may help if there are problems with the home environment.

  • Identify the patient’s local drug and alcohol service, and encourage the patient to self-refer.

  • Some hospitals have alcohol liaison nurses who may be able to assist with counselling or follow-up. Non-National Health Service (NHS) organizations include the Alcoholics Anonymous (AA).

Neuroleptic malignant syndrome

  • Essence: a rare, life-threatening, idiosyncratic reaction to antipsychotic (and other) medication (see Box 13.2), characterized by fever, muscular rigidity, altered mental status, and autonomic dysfunction. NB If diagnosed in a psychiatric setting, transfer the patient to acute medical services where intensive monitoring and treatment are available.

  • Pathophysiology: theories: secondary to dopamine (DA) activity in the CNS, i.e. striatum (rigidity), hypothalamus (thermoregulation—by blockade of D2-receptors or Psychiatric emergencies DA availability); impaired Ca2+ mobilization in muscle cells leads to rigidity (like malignant hyperthermia); sympathetic nervous system activation or dysfunction.

  • Epidemiology: incidence 0.07–0.2% (pooled data); ♀:♂ = 2:1.

  • Mortality: 5–20%—death usually due to respiratory failure, cardiovascular collapse, myoglobinuric renal failure, arrhythmias, or DIC.

  • Morbidity: rhabdomyolysis, aspiration pneumonia, renal failure, seizures, arrhythmias, DIC, respiratory failure, worsening of a primary psychiatric disorder (due to withdrawal of antipsychotics).

  • Symptoms/signs: hyperthermia (>38°C), muscular rigidity, confusion/agitation/altered level of consciousness, tachycardia, tachypnoea, hyper-/hypotension, diaphoresis/sialorrhoea, tremor, incontinence/retention/obstruction, creatinine kinase (CK)/urinary myoglobin, leucocytosis, metabolic acidosis.

  • Risk factors: Psychiatric emergencies ambient temperature; dehydration; patient agitation or catatonia; rapid antipsychotic initiation/dose escalation; withdrawal of anti-parkinsonian medication; use of high-potency agents/depot IM preparations; history of organic brain disease (e.g. dementia, alcoholism), affective disorder, previous NMS; predisposing drugs (e.g. lithium, anticholinergic agents).

  • Differential diagnosis: catatonia; malignant hyperthermia; encephalitis/meningitis; heat exhaustion; parkinsonism/acute dystonia; serotonergic syndrome; toxicity due to other drugs (e.g. amphetamine, MDMA, cocaine, antidepressants, antihistamines, sympathomimetics, salicylates); DT; rhabdomyolysis; septic shock; haemorrhagic stroke; tetanus ; phaeochromocytoma; strychnine poisoning.

  • Investigations: FBC, blood cultures, LFTs, U&Es, Ca2+ and PO43– levels, serum CK, urine myoglobin, AST and ALT (be aware that ALT increases in muscle injury), ABGs, coagulation studies, serum/urine toxicology, CXR (if aspiration suspected), ECG; consider head CT (intracranial cause) and LP (to exclude meningitis).

  • Management: benzodiazepines for acute behavioural disturbance (NB use of restraint and IM injection may complicate the interpretation of serum CK). Stop any agents thought to be causative (especially antipsychotics), or restart anti-parkinsonian agents. Supportive measures: O2, correct volume depletion/hypotension with IV fluids, reduce the temperature (e.g. cooling blankets, antipyretics, cooled IV fluids, ice packs, evaporative cooling, ice-water enema). Rhabdomyolysis—vigorous hydration and alkalinization of the urine using IV sodium bicarbonate to prevent renal failure. Pharmacotherapy to reduce rigidity: dantrolene (IV 0.8–2.5mg/kg qds; PO 50–100mg bd), lorazepam (up to 5mg); second line: bromocriptine (PO 2.5–10mg tds, increase to max 60mg/day), amantadine (PO 100–200mg bd); third line: nifedipine; consider ECT (NB Psychiatric emergencies risk of fatal arrhythmias).

  • Course: may last 7–10 days after stopping oral antipsychotics and up to 21 days after depot antipsychotics (e.g. fluphenazine).

  • Prognosis: in the absence of rhabdomyolysis, renal failure, or aspiration pneumonia, and with good supportive care, prognosis is good.

  • Follow-up: monitor closely for residual symptoms. Once symptoms have settled, allow 2+ weeks (if possible) before restarting medication (use low-dose, low-potency, or atypical agents). Consider prophylaxis (bromocriptine). Inform the patient about the risk of recurrence if given antipsychotic medication. Ensure this is recorded prominently in their medical notes.*

Dealing with violent patients

Occasionally, you may encounter violent patients in medical settings, and assaults on doctors and nurses do happen from time to time. Violence may be a symptom of a disorder (e.g. psychosis, post-ictal, acute confusion), or patients may be violent because of frustration, criminality, etc. Diagnosis is key because management is very different.

Predisposing factors

  • Delirium.

  • Dementia.

  • Epilepsy.

  • Brain damage (especially temporal or frontal lobes).

  • Alcohol intoxication or withdrawal.

  • Drugs (cocaine, crack, amphetamine, opiate, or sedative withdrawal).

  • Acute psychotic episode.

  • Personality disorder.

  • Previous violent behaviour in patients with such conditions may give an indication of the future risk.


Risks posed by violent patients may be minimized by following some simple rules.

  • Do not see patients who may be violent in an isolated room, and do not see them on your own—ask a nurse or other professional to join you.

  • Keep yourself between the patient and the door.

  • If you are uncomfortable or afraid, end the interview and leave.

  • It is usually sufficient to calm the patient down verbally and avoid confrontation.

  • On occasion, it is necessary to sedate violent patients. See Psychiatric emergencies Rapid tranquillization for acutely disturbed or violent patients, p. [link], Psychiatric emergencies The Mental Health Act, p. [link], and Psychiatric emergencies Common law, pp. [link][link] for what legal frameworks and circumstances under which this can be done.

  • Restraint may be required, particularly if sedation is needed; security and nursing staff may do this ± the police if necessary.

  • If violence is part of an underlying psychiatric disorder, liaise with the psychiatric team about current and ongoing management.

Deliberate self-harm

Deliberate self-harm (DSH) is a common presenting complaint to A&E and reason for admission. The severity and sequelae of DSH vary greatly, from superficial cuts to serious ODs requiring prolonged spells in hospital. Suicide is uncommon, but DSH increases the risk of subsequent suicide (1% of those who commit acts of DSH kill themselves in the next year—100 times the general population risk), and 40–60% of suicides have a history of DSH. Assessment of patients who have harmed themselves is important in order to:

  • Detect those at risk of subsequent DSH or suicide (see Box 13.3).

  • Identify patients with significant mental health problems requiring treatment.

  • Plan aftercare in hospital or in the community.

Assessment by general medical staff

Assessment of DSH is normally done by a psychiatrist, specialist nurse, or social worker experienced in the field. However, it is important for all staff to be able to make a basic assessment of these patients, because patients may refuse to see a mental health worker or may attempt to leave the ward or department before a detailed assessment can be carried out.

What if a patient wants to leave before they are assessed by a mental health professional?

  • You have a duty of care to the patient that includes protecting them as best you can from ongoing risk.

  • Try to persuade the patient to stay for an assessment. If they agree, refer to the psychiatric team and ask the nursing staff to monitor the patient.

  • If the patient refuses, then you will need to ask them to stay while you make your own assessment of risk.

  • If they will not stay, and you are concerned, you may need to detain them under common law, pending a formal psychiatric assessment.

  • If they agree to stay, make your assessment. Do not forget to enquire about past episodes of self-harm and ongoing psychiatric problems, and drug or alcohol problems, as well as the questions already detailed.

  • If, after your assessment, you have concerns that require the patient to see a mental health professional, try to persuade them to stay. If they refuse, consider their capacity to decide to leave under the MCA framework and whether you can use this to keep them from leaving, or consider detaining them under common law, pending an urgent psychiatric assessment.

  • If you are satisfied that the ongoing risk is not of a magnitude that requires them to be detained, then allow them to be discharged, but ensure that the GP is informed.

  • For detaining patients who will not stay in hospital, see Psychiatric emergencies Patients who do not wish to stay in hospital, p. [link].

  • For guidelines on treatment for patients who are refusing treatment, see Psychiatric emergencies Mental Capacity Act 2005 (England and Wales), p. [link] and Psychiatric emergencies Common law, pp. [link][link].

Points to remember about DSH

  • Risk assessment in older adults or children and adolescents requires specialist input. Always obtain advice in these cases.

  • Staff attitudes towards patients who self-harm, especially if they do so frequently, can be very negative. Patients usually notice this. Try and maintain an empathic attitude and to understand what may motivate the behaviour, however difficult this may be.

  • Some patients present repeatedly with DSH. These patients may have personality disorders, with or without substance misuse, and may be very difficult to manage. Most A&E departments know their frequent attendees well and have strategies in place for particular individuals—always ask.

The Mental Health Act

There is frequent confusion about the ability of patients with mental health problems to consent to, or refuse, medical treatment and what to do if a patient is acting in a way that will lead to self-harm or harm to others.

The Mental Health Act 1983 (revised 2007)

Different rules apply in Scotland, although the principles are the same—seek local advice.

This Act allows for the compulsory detention and/or treatment of patients with a mental disorder (defined as: any disorder or disability of the mind) of a nature and/or degree that requires inpatient treatment against their wishes. Thus, patients who need to be in hospital because of a risk to their health and safety or that of others may be detained or brought into hospital if the appropriate people agree that this is necessary.

  • Section 2 allows a period of assessment and/or treatment for up to 28 days and is usually applied to patients presenting for the first time or known patients with a new problem.

  • Section 3 (which may also follow Section 2) allows detention for treatment for up to 6 months.

  • Patients have the right to appeal against both Sections 2 and 3. Both Sections require opinions from two appropriately qualified doctors and an approved mental health professional (AMHP).

  • Section 4 allows patients to be brought to hospital with only one medical and one AMHP’s opinion, and is only used in emergencies.

  • Sections 5(2) and 5(4) apply to hospital inpatients (Psychiatric emergencies Detaining a patient in an emergency, p. [link]).

  • Section 136 allows the police to detain people (in public places) with a suspected mental disorder and associated risks and bring them to a ‘designated place of safety’ (often a dedicated suite within a psychiatric hospital, but in some localities, this may be A&E or a police station) to be assessed by a doctor and an AMHP who may make them informal or arrange for a Section 2 or 3.

People may be detained under a Section either in the community or in hospital.

Remember: the Mental Health Act only allows treatment for mental health disorders against the wishes of patients, and not physical health problems.

Patients detained under the Mental Health Act often have capacity to decide whether to accept or refuse medical treatment, but if this is in doubt, then the Mental Capacity Act should be used to assess their capacity. If, according to the tests set out in the Mental Capacity Act, they do not have capacity, then treatment for physical health problems may be given against their wishes in accordance with the stipulations of the Mental Capacity Act (Psychiatric emergencies Treating patients without their consent, p. [link]).

Treating patients without their consent

The issue of whether and how to treat patients without their consent arises surprisingly often. It is frequently presumed that this is due to mental illness, although often this is not so.

What to do in this situation

The key to whether or not a patient is able to refuse treatment is whether or not they have capacity to do so. Every qualified medical doctor should be able to assess capacity; however, psychiatrists are frequently asked to do so or provide a second opinion in complex cases. In an emergency, it may not be possible to obtain specialist psychiatric advice, so you may need to act based on your assessment.

For a patient to have capacity to make a specific decision, they must be able to understand the information relevant to the decision; understand the alternative courses of action—and be able to weigh up the pros and cons of each; retain memory of decisions and the reasons for them; and communicate their intent (Psychiatric emergencies Mental Capacity Act 2005 (England and Wales), p. [link]).


  • You are only assessing capacity for a specific decision (e.g. does the patient have capacity to refuse NAC treatment for paracetamol OD?); there is no overall/global capacity which a patient has or lacks.

  • Patients may have the capacity to make some decisions and not others.

  • Capacity in the same patient may fluctuate over time.

Mental illness or cognitive impairment may impair capacity but need not do so—there are legal precedents where patients who are mentally unwell have been wrongfully treated against their will. Disagreeing with medical advice does not automatically constitute incapacity.

If a patient does not have capacity and requires emergency treatment, then this may be given against their will under the Mental Capacity Act 2005 or under common law, depending on which is more appropriate.

Mental Capacity Act 2005 (England and Wales)

When considering treatment without a patient’s consent, you need to assess their capacity to refuse the proposed treatment under the Mental Capacity Act framework. This has more safeguards for patients and doctors from a legal standpoint than the common law approach.

Five principles

  1. 1 A person must be assumed to have capacity, unless it is established that he lacks capacity.

  2. 2 A person is not to be treated as unable to make a decision, unless all practicable steps to help him to do so have been taken without success.

  3. 3 A person is not to be treated as unable to make a decision merely because he makes an unwise decision.

  4. 4 An act done, or decision made, under this Act for, or on behalf of, a person who lacks capacity must be done, or made, in his best interests.

  5. 5 Before the act is done, or the decision is made, regard must be had to whether the purpose for which it is needed can be as effectively achieved in a way that is less restrictive of the person's rights and freedom of action.2

Assessment of incapacity

Sections 2 and 3 of the Act set out a two-stage test for assessing incapacity.

  1. 1 A person lacks capacity if he is unable to make a decision for himself in relation to any matter because of a permanent or temporary impairment in the functioning of the mind.

  2. 2 A person is unable to make a decision for himself if he is unable to: understand the information relevant to the decision; retain that information for a sufficient period to make a decision; use or weigh that information as part of the process of making the decision; and communicate his decision.

Judgements about incapacity are to be made on the balance of probabilities. Lack of capacity is not to be presumed based on a person’s age or appearance, on any aspect of his behaviour, or on any condition or disorder from which he suffers. The Act specifies certain decisions that cannot be made by one person on behalf of another. These are: agreeing to marriage, civil partnership or divorce, consent to a sexual relationship, and casting a ballot in an election.3

NB Section 6 of Mental Capacity Act allows the restraint of a patient who lacks capacity to make a particular decision, provided restraint is necessary to prevent harm to self and that the restraint is proportionate to the likelihood of the patient suffering harm and to the seriousness of the potential harm and that it does not constitute a deprivation of liberty.

If you assess someone as lacking capacity with regard to refusing urgent treatment and act under the best interests principle of the Mental Capacity Act and treat someone without their consent, make sure you document your capacity assessment and the rationale for your actions in the notes.


2. Mental Capacity Act 2005. Psychiatric emergencies

3. Semple D, Smyth R (2013). Oxford Handbook of Psychiatry, 3rd edn. Oxford University Press, Oxford.Find this resource:

Common law

  • This allows medical practitioners to act in the patient’s best interests in emergency situations where they are unable to give consent (e.g. if they are unconscious, or conscious but lack capacity—although if time permits, in cases where patients lack capacity, then the Mental Capacity Act framework should be used over common law).

  • If in an emergency, it is deemed necessary to detain a patient pending assessment, it may be done under common law.

  • Treatment under common law is given in the best interests of the patient if it is carried out to save life or to ensure improvement or prevent deterioration of physical or mental health.

Always document in the notes that you are giving treatment in the patient’s best interests under common law.

Common law principles for medical treatment decisions

  • Act in accordance with the patient’s wishes: a fundamental principle of the doctor–patient relationship. Doctors should, in general, respect the patient’s autonomy in decision-making, only acting against the patient’s wishes in very limited circumstances.

  • Presume capacity in adults: a patient over the age of 16 is presumed to have capacity to make treatment decisions, unless there is evidence to the contrary (assessed on the balance of probabilities).

  • Apply the ‘reasonableness’ test: a frequently used consideration in law is the test of what a hypothetical ‘reasonable man’ would do in the circumstances. For medical treatment decisions, the test is what the ‘reasonable doctor’ would have done in those circumstances.

  • Act in the patient’s ‘best interests’: in emergency situations, it may not be possible to obtain consent (e.g. in an unconscious RTA victim requiring drainage of an extradural haematoma); here, it is accepted that the doctor’s overriding duty is to preserve life.

  • Doctrine of necessity: ‘necessity’ provides a defence against a potential criminal charge that you have assaulted a patient by giving non-consensual treatment. A doctor may therefore give emergency treatment to preserve life and prevent significant deterioration in health.

  • Act in accordance with a recognized body of opinion: it is accepted in law that medicine is not an exact science—that, in any situation, multiple courses of action may be potentially reasonable. However, there is an expectation that any treatment decision is considered suitable by a body of professional opinion (the ‘Bolam test’).

  • Act in logically defensible manner: the Bolitho case added a consideration to the Bolam test by stating that medical decisions made must, in addition to being in accordance with a recognized body of opinion, be logically defensible in the circumstances.

  • Consider use of applicable law: the treating doctor should consider whether the provisions of any statute law provide guidance and additional protections for the patient. However, they should not delay urgent treatment to enact the provisions of statute law.

  • Consider a request for court judgement: in difficult situations, consult more experienced colleagues; where appropriate, seek legal advice on whether it is appropriate to apply to the court for a ruling.4


4. Semple D, Smyth R (2013). Oxford Handbook of Psychiatry, 3rd edn. Oxford University Press, Oxford.Find this resource:

The law on consent and capacity

  • There is no such thing as proxy consent for adults in the UK; a third party cannot make a decision on a patient’s behalf, though it is good practice to take their views into consideration, both under common law and the Mental Capacity Act best interests principle.

  • The Mental Health Act 1983 (revised 2007) does not allow doctors to treat mentally impaired patients against their will for physical problems. The Scottish Act allows a broader view of allowable treatments and may well include treatment of self-poisoning (implied in the code of practice) and certainly does include treatment of delirium and starvation syndrome in anorexia, for example.

  • Different rules apply to children and individuals with advance directives—you must always obtain specialist advice in such cases.

  • Treating a patient who has capacity to refuse against their will can constitute a criminal offence. However, you are unlikely to be criticized for taking a decision to give lifesaving treatment against a patient’s will if you are unsure about capacity. Most people would acknowledge that it is better to treat than not to treat in such situations.

  • In any situation where you are unsure what to do, obtain senior advice at an early stage. Some of the medical defence organizations offer legal advice on a 24h basis.

Patients who do not wish to stay in hospital

Sometimes patients do not wish to stay in hospital. Usually the problem can be discussed, and an agreement can be reached between the patient and the medical team. From time to time, this is impossible. If a patient is acutely confused, they may not be willing to stay and require physical restraint in order to keep them there. In the case of patients who have harmed themselves, teams may be concerned about the possible risks to the patient if they leave the ward.

What to do in this situation

  • Assess the patient. What are the medical issues that require them to stay? Is their wish to leave a symptom or part of an organic illness that needs to be treated? What are the potential risks to self or others if the patient leaves?

  • Is it possible to reason with the patient and persuade them to stay?

  • If not, assess whether they have capacity to decide to leave. If you are unsure or it is a complex case or one involving a psychiatric patient, ask for a psychiatric second opinion.

  • If the patient tries to leave before a psychiatric assessment, they may be detained under common law.

  • If the wait for a psychiatric opinion is likely to take a long time (e.g. no psychiatric team on site), it may be necessary for them to be detained. Hospital inpatients may be detained by a nurse under Section 5(4) of the Mental Health Act or by a single doctor under Section 5(2). Patients in A&E departments must be detained under common law or the Mental Capacity Act if appropriate.

  • If the patient leaves (e.g. they ran past security guards before they could stop them) and you have significant concerns over their safety or that of the public (i.e. you can breach confidentiality), inform your seniors and consider informing the police. If you contact the police, ensure you can provide as much detail as possible (name, age, physical appearance, clothing, last known movements, address, etc.), as well as specific concerns (e.g. he said he wanted to jump off London Bridge), to assist in finding the patient. Inform the psychiatric team involved if the concerns are over mental health or if the patient is already under psychiatric community care so that they may follow up on the attendance to A&E/premature self-discharge.

  • If the patient has capacity to refuse ongoing treatment and is not detainable under the Mental Health Act, then they may be allowed to leave against medical advice. It is often possible to get them to sign a form to that effect; if not, it should be documented that their self-discharge was against medical advice.

Detaining a patient in an emergency

Common law

If you believe it is in the interests of the patient not to be allowed to leave, and you are unsure about their capacity and therefore not able to use the Mental Capacity Act framework, the security staff may be asked to prevent them from doing so. Document that you are doing this under common law. This should take place until a psychiatric opinion may be obtained.

Section 5(2)

  • This section allows an inpatient on any ward to be prevented from leaving. It lasts a maximum of 72h and is only a holding measure, pending a full Mental Health Act assessment by appropriate doctor(s) (usually two doctors) and an AMHP.

  • Any registered medical practitioner may use Section 5(2), not only a psychiatrist. It must be applied by the consultant under whose care the patient currently is or their ‘nominated deputy’, i.e. a member of their team or whoever is covering their patients out of hours. It is actioned by filling in Form H1 (these should be available on the ward) which should be delivered to the local Mental Health Act administration office as soon as it is practicable.

  • If a patient has been placed under Section 5(2), the duty psychiatric team should be informed, as should the AMHP, to ensure that the patient is reassessed appropriately and quickly. Section 5(2) expires once the patient has been seen by an appropriately qualified doctor approved under Section 12 of the Mental Health Act and rescinded, or converted to Section 2 or 3 following a Mental Health Act assessment.

  • Section 5(2) does not allow you to enforce medical treatment of any kind. This would need to be given under common law or the Mental Capacity Act if the patient is not consenting.

Section 5(4)

  • This Section entitles a suitably qualified nurse to hold a patient for up to 6h, pending the arrival of a doctor to assess the patient for Section 5(2). It is only used in situations where a doctor cannot arrive quickly, e.g. if they are off site.

  • If the doctor decides that the patient needs to be held under Section 5(2), then the 72h duration of this latter Section begins at the time the nurse imposed Section 5(4). It ends once the patient has been assessed by appropriate mental health professionals regarding further detention or being made informal.

  • Sections 5(2) and 5(4) are only applicable to inpatients, not to patients in A&E or outpatients. Patients in these areas are detained under common law, pending psychiatric assessment.

Mentally ill patients in hospital

Patients with chronic mental illnesses, such as schizophrenia, are at Psychiatric emergencies risk of ill health, compared with the general population, and frequently require care from general physicians.

Guidelines for looking after patients with mental illness

  • Hospital is frightening for all patients. Mentally ill patients may require a lot of reassurance and explanation about what is happening to them.

  • If people are on regular psychotropic medications, then give them. They will usually be able to tell you what they take and when. Remember that sudden discontinuation of certain medications, such as lithium, clozapine, and SSRIs, can precipitate mental health crises.

  • Some patients are on depot injections, rather than tablets. Find when their next injection is due and, if this falls during their hospital stay, ensure that they receive it.

  • If there is a reason for stopping a drug used in psychiatry, you should ask advice. Ideally, this should be from the psychiatrist and prescriber.

  • It is good practice to communicate with the mental health team who know the patient, who will probably be based in the community. They will have a consultant and may have a social worker, community psychiatric nurse, or other keyworker who will appreciate knowing that their patient is in hospital.

  • Communicate discharge plans to the community team—it may help you to speed up the discharge, as community support may already be in place.

Remember, if you are ever unsure about a patient’s mental state, it is best to talk to a psychiatrist about it and ask for the patient to be reviewed, if necessary.

Sectioned patients on medical wards

Occasionally, patients who are in hospital under a Section of the Mental Health Act 1983 (revised 2007) become medically unwell. They may need to be transferred to, and cared for on, a medical, rather than a psychiatric, ward at these times. Please remember the following.

  • Patients who are detained are likely to be seriously mentally unwell and therefore prone to becoming disturbed.

  • It is acceptable for patients to be detained on a medical, rather than a psychiatric, ward under their Section if that is where they need to be, but you should expect ongoing input from the psychiatric team caring for the patient during their stay.

  • Patients who are under a Section should be nursed by a mental health nurse at all times, alongside the general ward nurses. If a patient presents particular risks or is very disturbed, >1 nurse may be required.

  • Ensure that the psychiatric team looking after the patient are kept informed of the patient’s progress, so that their transfer back to the psychiatric unit and their ongoing medical care may be coordinated smoothly.

  • Many psychiatric wards have neither the staff nor the equipment to perform even basic procedures (e.g. IV drips, monitoring). Patients going back to these wards need to be well stabilized medically before they return.

Further reading

Hughes R (2003). Neurological Emergencies, 4th edn. BMJ Books, London.Find this resource:

Lingford-Hughes AR, Welch S, Peters L, Nutt DJ; British Association for Psychopharmacology, Expert Reviewers Group. BAP updated guidelines: evidence-based guidelines for the pharmacological management of substance abuse, harmful use, addiction and comorbidity: recommendations from BAP. J Psychopharmacol 2012;26:899–952.Find this resource:

Mental Capacity Act 2005. Psychiatric emergencies

National Institute for Health and Care Excellence (2010, updated 2017). Alcohol-use disorders: diagnosis and management of physical complications. Clinical guideline [CG100]. Psychiatric emergencies this resource:

National Institute for Health and Care Excellence (2010). Delirium: prevention, diagnosis and management. Clinical guideline [CG103]. Psychiatric emergencies this resource:

National Institute for Health and Care Excellence (2011). Alcohol-use disorders: diagnosis, assessment and management of harmful drinking and alcohol dependence. Clinical guideline [CG115]. Psychiatric emergencies this resource:

Royal College of Psychiatrists and Royal College of Physicians (2003). The Psychological Care of Medical Patients, A Practical Guide, 2nd edn. Royal College of Psychiatrists and Royal College of Physicians, London.Find this resource:

Semple D, Smyth R (2013). Oxford Handbook of Psychiatry, 3rd edn. Oxford University Press, Oxford.Find this resource:

South London and Maudsley NHS Foundation Trust (2013). The Maze 2013: A Practical Guide to the Mental Health Act 1983 (amended 2007), 3rd edn. South London and Maudsley NHS Foundation Trust, Beckenham.Find this resource:

Taylor D, Barnes TRE, Young AH (2018). The Maudsley: Prescribing Guidelines in Psychiatry, 13th edn. South London and Maudsley NHS Foundation Trust and Oxleas NHS Foundation Trust, Wiley-Blackwell.Find this resource:

Wyatt JP, Illingworth RN, Graham CA, Clancy MJ, Robertson CE (2006). Oxford Handbook of Accident & Emergency Medicine, 3rd edn. Oxford University Press, Oxford.Find this resource:


* Reproduced from Semple D, et al. Oxford Handbook of Psychiatry, 2013, with permission from Oxford University Press.