Dr Greg Rogers explains how the NICE guideline on management of transient loss of consciousness will help guide appropriate cardiovascular and neurological referrals
  • At the initial assessment ask the person who has experienced a suspected TLoC episode, and any witnesses, to describe what happened before, during, and after the event. Try to contact any witnesses who are not present at the consultation
  • Record a 12-lead ECG using automated interpretation
  • Record the information obtained from all accounts of the TLoC, including paramedic records. Give copies of the ECG record and the patient report form to the receiving clinician when care is transferred, and to the person who had the TLoC
  • Within 24 hours refer anyone with TLoC who also has any of the following for specialist cardiovascular assessment:
    • an ECG abnormality
    • heart failure (history or physical signs)
    • TLoC during exertion
    • family history of sudden cardiac death in people aged younger than 40 years and/or an inherited cardiac condition
    • new or unexplained breathlessness
    • a heart murmur

(NB Anyone aged over 65 years who has experienced TLoC without prodromal symptoms should be considered for referral for specialist cardiovascular assessment within 24 hours)

  • Following the initial assessment, an uncomplicated faint should be diagnosed when there are no features that suggest an alternative diagnosis and there are features suggestive of an uncomplicated faint (the 3 Ps):
    • Posture—prolonged standing, or similar episodes that have been prevented by lying down
    • Provoking factors (such as pain or a medical procedure)
    • Prodromal symptoms (such as sweating or feeling warm/hot before TLoC)

(Note that brief seizure activity can occur during uncomplicated faints and is not necessarily diagnostic of epilepsy)

  • Refer people who present with one or more of the following features (i.e. features that are strongly suggestive of epileptic seizures) for an assessment by an epilepsy specialist within 2 weeks:
    • a bitten tongue
    • head-turning to one side during TLoC
    • no memory of abnormal behaviour that was witnessed before, during, or after TLoC by someone else
    • unusual posturing
    • prolonged limb-jerking (note that brief seizure-like activity can often occur during uncomplicated faints)
    • confusion following the event
    • prodromal déjà vu or jamais vu
  • Consider that the episode may not be related to epilepsy if any of the following features are present:
    • prodromal symptoms that on other occasions have been abolished by sitting or lying down
    • sweating before the episode
    • prolonged standing that appeared to precipitate the TLoC
    • pallor during the episode
  • Do not routinely use EEG in the investigation of TLoC.

TLoC=transient loss of consciousness; ECG=electrocardiogram; EEG=electroencephalogram


Earlier this year, NICE published its guideline on Management of transient loss of consciousness in adults and young people.1 Transient loss of consciousness (TLoC) is a spontaneous loss of consciousness with complete recovery without any residual neurological deficit. An episode of TLoC is often referred to as a ‘blackout,’ or a ‘collapse’; however, some people collapse without TLoC and this new guideline does not cover that situation. Transient loss of consciousness is very common—it affects up to half the UK population at some point in their lives.1

There are various causes of TLoC including faints, cardiovascular disorders (which are the most common, such as bradyarrhythmic or tachyarrhythmic syncope), neurological conditions (such as epilepsy), and psychogenic attacks. When a patient presents, the GP needs to differentiate which category the blackout may fall into so that the appropriate treatment can then be given. To determine the mechanism for TLoC correctly, each piece of evidence must be collected (detailed history, clinical assessment, appropriate investigations) and interpreted in the overall clinical context.1

Why did we need this guideline?

The diagnosis of the underlying cause of TLoC is often inaccurate, inefficient, and delayed. There is huge variation in how this symptom is managed and treated. A substantial proportion of people initially diagnosed with, and treated for, epilepsy, have a cardiovascular cause for their TLoC. Some people have expensive and inappropriate tests, or are inappropriately referred to specialists, while others who have potentially life-threatening conditions may not be given appropriate attention when they first present as they are dismissed as having experienced an uncomplicated faint (vasovagal syncope).1

Although guidance has already been published on the conditions that may contribute to TLoC,2,3 this is the first time that NICE has published a clinical guideline outlining the most effective ways that healthcare professionals can assess, diagnose, and manage this serious symptom in adults and young people.1

People experiencing TLoC may come under the care of a range of clinical teams and the previous lack of a clear treatment pathway may have contributed to misdiagnosis and inappropriate treatment. The NICE guideline provides a structured approach for dealing with this symptom and identifying the likely cause from the multiple aetiologies.1 It also suggests when further investigation from specialist teams is required.1

Implementing the NICE guideline may relieve the anxiety associated with missing the serious, and potentially life-threatening, causes of TLoC.

Management of transient loss of consciousness

The guideline contains an algorithm that covers the assessment and diagnosis of TLoC (see Figure 1 below).4

By separating out the various possible causes of TLoC, the GP should be better equipped to undertake an accurate initial assessment of the patient. The GP, or other attending healthcare professional, must gather the evidence: from taking a detailed history, to ascertaining the circumstances that happened before, during, and after the suspected event, and whether there were any witnesses present.1

The guideline advises healthcare professionals to record details, such as:1

  • circumstances of the event
  • person’s posture immediately before the loss of consciousness
  • prodromal symptoms (e.g. sweating or feeling warm/hot)
  • appearance (e.g. whether eyes were open or shut) and colour of the person during the event
  • presence or absence of movement during the event (e.g. limb-jerking and its duration)
  • any tongue-biting (record whether the side or the tip of the tongue was bitten)
  • injury occurring during the event (record site and severity)
  • duration of the event (from onset to regaining consciousness)
  • presence or absence of confusion during the recovery period
  • weakness down one side during the recovery period.

Many patients can be reassured that they have experienced an uncomplicated faint; however some will require specialist assessment and treatment. NICE advises that healthcare professionals should assume that the person has experienced TLoC until proven otherwise.1 This is so that urgent cases can be referred appropriately and in a timely manner, and that the risks of misdiagnosis can be minimised.

Figure 1: Assessment and diagnosis of TLoC4

Click here to download a PDF of the assessment and diagnosis of TLoC algorithm

National Institute for Health and Care Excellence (NICE) (2010) CG 109 Transient loss consciousness (‘blackouts’) management in adults and young people. Quick reference guide. London: NICE. Reproduced with permission. Available from www.nice.org.uk

Promoting best practice and improving patient care

Getting the diagnosis right is vital in the management of TLoC, and in the majority of cases a simple faint will be correctly diagnosed. For this group of people, offering reassurance and advice on how to avoid possible triggers, and strategies to avoid TLoC episodes, is recommended.1,5 It is also helpful to suggest they keep a record of their symptoms when they occur and note what they were doing at the time to help understand trigger events.1 As a further safety net, the GP can also advise the patient to contact them if they experience future episodes, especially if these differ from their recent episode.

An uncomplicated faint may be diagnosed by identifying the following characteristics during the initial assessment:1

  • Absence of features that suggest an alternative diagnosis (note that brief seizure activity can occur during uncomplicated faints and is not necessarily diagnostic of epilepsy) and
  • Their features are suggestive of an uncomplicated faint (the 3 Ps):
    • Posture—prolonged standing, or similar episodes that have been prevented by lying down
    • Provoking factors (such as pain or a medical procedure)
    • Prodromal symptoms (such as sweating or feeling warm/hot before TLoC).

Recording a 12-lead electrocardiogram

The NICE guideline recommends that everyone who experiences a TLoC episode should be offered a 12-lead electrocardiogram (ECG) as part of their initial assessment;1 this test can be performed in primary care.

If this ECG shows any conduction abnormality (e.g. complete right or left bundle branch block, or any degree of heart block), evidence of long or short QT interval, or any ST segment or T wave abnormalities, then it should be treated as a red flag and the person should be referred for urgent cardiological advice within 24 hours.1

If the ECG is not automated then it is important that the output is interpreted by a clinician who has enough experience to identify inappropriate persistent bradycardia, ventricular arrhythmias including ventricular ectopic beats, long or short QT interval, brugada syndrome, ventricular pre-excitation, abnormal T wave inversion, pathological Q waves, sustained atrial arrhythmia, paced rhythm, and left or right ventricular hypertrophy. This is important as cardiac causes of syncope, such as arrhythmias, are associated with a two-fold or higher increase in mortality. Early identification of high-risk groups is critical in reducing mortality. If any of the above conditions are identified, urgent referral for a specialist cardiological assessment is advised within 24 hours.1

Specialist cardiovascular assessment

In addition to patients who have an ECG abnormality as described above, any person with TLoC who has any of the following should receive an urgent cardiological assessment within 24 hours:1

  • Heart failure
  • TLoC on exertion
  • Family history of sudden cardiac death in people aged younger than 40 years
  • New or unexplained breathlessness
  • A heart murmur.

Healthcare professionals should also consider referring within 24 hours anyone aged over 65 years who does not have prodromal symptoms.1

Specialist neurological referral

The guideline advises that, following TLoC, people who present with one or more of the following features (that is, features that are strongly suggestive of epileptic seizures) should be seen by an epilepsy specialist within 2 weeks:1,6

  • A bitten tongue
  • Head-turning to one side during TLoC
  • No memory of abnormal behaviour that was witnessed by someone else
  • Unusual posturing
  • Prolonged limb-jerking (although it is important to note that brief seizure-like activity can often occur during uncomplicated faints)
  • Confusion following the event
  • Prodromal déjà vu or jamais vu.

One should consider that the episode may not be related to epilepsy if any of the following features are present:1

  • Prodromal symptoms that on other occasions have been abolished by sitting or lying down
  • Sweating before the episode
  • Prolonged standing that appeared to precipitate the TLoC
  • Pallor during the episode.

Driving following TLoC

General practitioners should advise all people who have experienced TLoC that they must not drive while waiting for a specialist assessment.1 Following this assessment, the healthcare professional should advise the person of their obligations regarding reporting the TLoC event to the Driver and Vehicle Licensing Agency.1,7

Implementation in primary care

Primary care plays a crucial role in the initial assessment and management of TLoC. For some patients, symptomatic orthostatic hypotension is likely to be the diagnosis of their TLoC episode but the GP should consider other possible causes, including drug therapy, and manage appropriately (e.g. NICE Clinical Guideline 21 on management of falls).1,8

If a secondary pathology is suspected, the GP or other primary care healthcare professional should refer the patient to the most appropriate specialist. If a red-flag symptom is identified, it is important to obtain a specialist cardiology opinion within 24 hours; whereas if epilepsy is expected, the patient must see a neurologist within 2 weeks.1

If these services are not currently available, this new guideline from NICE explains why clinicians ought to petition to have these services commissioned by local healthcare providers. By following the steps in this pathway, it should be possible to provide guidance and either reassurance or referral onwards to an appropriate specialist.

Conclusion

One of the challenges for primary care is not knowing what symptoms the next patient will present with. If the person tells you that they have experienced a a blackout, the NICE guideline will provide you with the tools needed to obtain an informative history and from this determine the right clinical course of investigation and treatment.

Implementation tools

NICE has developed the following tools to support implementation of Clinical Guideline 109 on Transient loss of consciousness (‘blackouts’) management in adults and young people. The tools are now available to download from the NICE website: www.nice.org.uk

Audit support
Audit support has been developed to support the implementation of this guideline. The aim is to help NHS organisations with a baseline assessment and to assist with the audit process, thereby helping to ensure that practice is in line with the NICE recommendations. The audit support is based on the key recommendations of the guidance and includes criteria and data collection tools.

Baseline assessment tool
The baseline assessment tool is an Excel spreadsheet that can be used by organisations to identify if they are in line with practice recommended in NICE guidance and to help them plan activity that will help them meet the recommendations.

Costing tools
A costing statement and local cost templates for the guideline have been produced:

  • The costing statement provides an implementation tool to estimate the financial impact to the NHS of implementing this clinical guideline. The statement focuses on the financial impact of the recommendations that require most change in resources to implement in England
  • Costing templates are spreadsheets that allow individual NHS organisations and local health economies to estimate the costs of implementation taking into account local variation from the national estimates, and they quickly assess the impact the guideline may have on local budgets.

Slide set
The slides provide a framework for discussing the NICE guideline with a variety of audiences and can assist in local dissemination. This information does not supersede or replace the guidance itself.

Podcast for ambulance services
This tool focuses on the impact of the recommendations to the ambulance service.



  • The NICE guideline raises some specific challenges for commissioners
  • In particular there is a need for rapid access to specialist epilepsy services within 14 days and access to specialist cardiovascular assessment within 24 hours
  • Commissioners should also consider access to a remote specialist ECG interpretation service (e.g. by fax) as most primary care practitioners are not fully conversant with subtle ECG abnormalities (e.g. long QT syndrome)
  • Failure to commission specific rapid-access services is likely to lead to increased emergency medical admissions at a far greater cost
  • Commissioners should meet with local specialists to plan a response to this guidance, which should include contracts with primary and urgent care providers (including out-of-hour services)
  • Tariff prices:
    • epilepsy (general medical outpatient) = £222
    • cardiology outpatient (new) = £215
    • general medical admission (syncope with/without complications codes EB08I/EB08H) = £1082–£2208.

ECG=electrocardiogram

  1. National Institute for Health and Care Excellence. Transient loss consciousness (‘blackouts’) management in adults and young people. Clinical Guidelne 109. London: NICE, 2010. Available at: www.nice.org.uk/guidance/CG109 nhs accred
  2. Department of Health. National service framework for coronary heart disease: Modern standards and service models. London: DH, 2000. Available at: www.dh.gov.uk/
  3. Moya A, Sutton R, Ammirati F et al. European Society of Cardiology. Guidelines for the diagnosis and management of syncope. Eur Heart J 2009; 30: 2631–2671. Available at: www.escardio.org/
  4. National Institute for Health and Care Excellence. Transient loss consciousness (‘blackouts’) management in adults and young people. Quick reference guide. London: NICE, 2010. Available at: www.nice.org.uk/guidance/CG109/QuickRefGuide/pdf/English nhs accred
  5. STARS website. Managing your syncope. www.stars.org.uk/patient-info/treatment-options/managing-your-syncope (accessed 18 October 2010).
  6. National Collaborating Centre for Primary Care. The epilepsies: the diagnosis and management of the epilepsies in adults and children in primary and secondary care. London: RCGP, 2004. Available at: www.nice.org.uk/guidance/CG20/Guidance
  7. Drivers Medical Group, DVLA. For medical practitioners: At a glance guide to the current medical standards of fitness of drive. Swansea: DVLA, 2010. Available at: www.dft.gov.uk/dvla/medical/medical_professionals.aspx
  8. National Collaborating Centre for Nursing and Supportive Care. Clinical practice guideline for the assessment and prevention of falls in older people. London: RCN, 2004. Available at: www.nice.org.uk/CG021G