What is the loss of consciousness of the body called?
National Clinical Guideline Centre for Acute and Chronic Conditions, Royal College of Physicians, London Show
Author information Article notes Copyright and License information Disclaimer Address for correspondence Dr Norma O'Flynn, National Clinical Guideline Centre for Acute and Chronic Conditions, Royal College of Physicians, 11 St Andrews Place, Regents Park, London NW1 4LE. E-mail: [email protected] Received 2010 Sep 3; Accepted 2010 Sep 7. Copyright © British Journal of General Practice, 2011 INTRODUCTIONTransient loss of consciousness (TLoC) is loss of consciousness with complete recovery. It is commonly described by the patient as a blackout. TLoC is very common and people who experience it may present to GPs during surgery hours or out of hours, or they may be referred from the ambulance services or the emergency department. There are a number of potential causes of TLoC:
The diagnosis of the underlying cause is often inaccurate, inefficient, and delayed, and misdiagnosis is common. NICE guideline CG1091 aims to define the appropriate pathways for the assessment of patients who experience TLoC, in order to obtain the correct underlying diagnosis quickly, efficiently, and cost-effectively, and to tailor a management plan to suit their true diagnosis. The guideline includes advice on the management of uncomplicated faint/situational syncope and orthostatic hypotension, as well as on detailed testing and assessment of those people considered to have a cardiovascular cause for their TLoC. GUIDANCEInitial assessmentThe guidance most relevant to GPs is likely to concern those areas related to initial assessment in order to determine whether the person has had TLoC, the possible causes of it, and the appropriate next steps. HistoryAsk the person who has had the suspected TLoC, as well as any witnesses, to describe what happened before, during, and after the event. Try to contact, by telephone, any witnesses who are not present at the consultation. Record details about:
Ask also about details of any previous TLoC, including number of episodes and frequency, as well as the person's medical history and any family history of cardiac disease (for example, personal history of heart disease and family history of sudden cardiac death). ExaminationPerform examination as clinically indicated. For example:
ElectrocardiogramIt is recommended that everyone has a 12-lead electrocardiogram (ECG) recorded using automated interpretation. If any of the following abnormalities are present, referral within 24 hours for specialist cardiovascular assessment is recommended:
If an automated ECG is not available, an ECG needs to be taken and interpreted by a trained and competent health professional who can identify the ‘red flags’ listed in Box 1. Box 1 Electrocardiogram ‘red flags’ that should prompt specialist cardiovascular assessment within 24 hours
a An inherited ion channel disorder, characterised by abnormal ST segment elevation in leads V1 to V3 on electrocardiogram. This predisposes the individual to ventricular arrhythmia and sudden cardiac death and may present with syncope. The possibility of underlying problems that are either causing or contributing to TLoC should not be forgotten; relevant examinations and investigations may be required (for example, into blood glucose or haemoglobin levels). Differential diagnosis and managementCardiological causesTLoC can occur due to an underlying cardiological problem. Referral for cardiovascular assessment within 24 hours is recommended if any of the following apply:
TLoC occurring during exercise indicates that a cardiac arrhythmic cause is probable; it should be distinguished from TLoC that occurs shortly after stopping exercise, when a vasovagal cause is more likely. EpilepsyPeople who present with features that are strongly suggestive of epileptic seizures will require referral to a specialist in epilepsy. Features to note are:
The episode may not be related to epilepsy if any of the following features are present:
Uncomplicated faint, situational syncope, and orthostatic hypotensionUncomplicated faint (uncomplicated vasovagal syncope) should be diagnosed when there are no features that suggest an alternative diagnosis (note that brief seizure activity can occur during uncomplicated faints and is not necessarily diagnostic of epilepsy). Features suggestive of uncomplicated faint include:
These are known as ‘the three Ps’. Situational syncope should be diagnosed when there are no features from the initial assessment that suggest an alternative diagnosis and syncope is clearly and consistently provoked by straining during micturition (usually while standing) or by coughing or swallowing. If a diagnosis of uncomplicated faint or situational syncope is made, no further immediate management is required. The mechanism of the syncope, possible triggers, and avoidance strategies should be discussed and patients reassured. The guideline recommends that if the presentation is not to the GP, a copy of the patient report form and the ECG record should be taken to the GP or sent to the GP. If an ECG has not been recorded, the GP should arrange one within 3 days. Orthostatic hypotension should be suspected on the basis of the initial assessment when there are no features suggesting an alternative diagnosis and the history is typical. If these criteria are met, measure the patient's lying and standing blood pressure (with repeated measurements while standing for 3 minutes). If clinical measurements do not confirm orthostatic hypotension despite a suggestive history, refer the person for further specialist cardiovascular assessment. If orthostatic hypotension is confirmed, likely causes or contributing factors, such as diuretics, should be considered. Further assessment and referralThe outcome from the initial assessment will be that all people with TLoC who do not have a firm diagnosis of uncomplicated faint, situational syncope, orthostatic hypotension, or symptoms suggestive of epilepsy should have a specialist cardiovascular assessment by the most appropriate local service. The aim is to categorise the TLoC as either caused by suspected structural heart disease, suspected cardiac arrhythmia, suspected neurally mediated, or unexplained. Specific guidance is given as to appropriate further investigation, depending on the suspected cause. The following tests are likely during specialist assessment:
Appropriate advice for people who experience TLoC is also included in the guidance. This involves advising them that they must not drive while waiting for a specialist assessment and explaining the fact that they will need to report to the Driver and Vehicle Licensing Agency following diagnosis. Consideration of safety at work may also be required. In addition, patients should be told what to do if they have another event before assessment is completed. CONCLUSIONFrom a general practice perspective, the recommendation that all people who have a TLoC episode should have an ECG is likely to be the biggest change from current practice. The recommendation that an automated ECG should be carried out is based on evidence assessing automated interpretation versus clinician-read ECGs, and evidence that clinicians who were not regularly interpreting ECG traces were likely to be less accurate than those who were experienced in this interpretation. Details of the evidence, together with discussions of the guideline development group, can be found in the full guideline. NotesFunding bodyThis work was undertaken by the National Clinical Guideline Centre for Acute and Chronic Conditions, which received funding from the National Institute for Health and Clinical Excellence (NICE). The views expressed in this publication are those of the authors and not necessarily those of NICE. Competing interestsGreg Rogers is a GP and was a member of the guideline development group that formulated the guidance. Norma O'Flynn is clinical director at the National Clinical Guideline Centre (NCGC) where the guideline was developed. The NCGC is funded by NICE. Discuss this articleContribute and read comments about this article on the Discussion Forum: http://www.rcgp.org.uk/bjgp-discuss What is it called when you faint without losing consciousness?If you have symptoms of dizziness or lightheadedness without loss of consciousness, this is often called presyncope (or near-syncope); however, dizziness and lightheadedness are nonspecific symptoms that can also be caused by conditions that are unrelated to syncope (such as inner ear disorders).
What are the main causes of loss of consciousness?The common causes include:. Hyperventilation.. Dehydration.. Sudden force or straining.. Abnormal heart rhythm.. Low blood pressure.. Low blood sugar.. Lack of blood flow in the brain.. Seizure, stroke or transient ischemic attack.. |