Syncope
Common problem in Emergency Medicine, often initially labelled as "collapse ?cause."
Definition of Syncope
- Transient self-limited loss of consciousness.
- The onset is usually rapid and the recovery is spontaneous, complete and usually (but not always) prompt
Patients who are still unconscious when they are brought into the ED have not had a syncopal episode since their recovery doesn't fit the criteria. They should be evaluated for coma.
Role of the ED in the assessment of syncopal patients
- Full diagnostic assessment
- Risk stratification and appropriate disposition. Note that patients with syncope of a cardiac origin are at risk of sudden death and must be assessed in detail.
- Exclusion of significant injury.
- Consideration the patient's occupation and driving status to guide immediate discharge advice
Principal causes of syncope
Cardiac syncope
- Arrhythmias
- Structural cardiac or cardiopulmonary disease:
- includes valvular heart disease, LV outflow obstruction (aortic stenosis is particularly important), cardiac tamponade, pulmonary embolism
Reflex-mediated
- Simple faint
- Situational syncope: micturition, cough, defecation, pain, swallowing
- Carotid sinus syndrome
Severe orthostatic hypotension
Epilepsy
Assessment (and risk assessment )
History
- Circumstances prior to the episode (position, activity, predisposing factors or precipitating events)
- Symptoms at onset of episode (nausea, aura, visual, cardiac symptoms etc.)
- Details of the episode (you will need a witness, or collateral history from the ambulance crew): skin colour, duration of loss of consciousness, breathing pattern, movements, tongue biting etc.
- End of the episode: confusion, muscle aches, colour, injury, incontinence
- Previous presyncopal or syncopal episodes, previous cardiac and medical history, family history (sudden cardiac death, epilepsy etc
- Medications
- Occupation and driving status
Physical examination and investigations
- Focus particularly on the cardiovascular and neurological systems.
- Note the resting heart rate, BP, and SpO2 on air
- Check for injury
- Diagnostic carotid sinus massage should only be performed by an experienced operator, who is familiar with both the contraindications and interpretation of any effect
- 12 lead ECG in all patients. Look for arrhythmias and conduction defects (i.e. AV block, BBB, prolonged QTc etc ). If patient has symptoms whilst in the department obtain a contemporaneous ECG (ideally 12 lead but rhythm strip also very useful)
- Blood tests are useful only if clinically indicated.
- You should do a blood glucose
- Consider a pregnancy test in women of childbearing age
Orthostatic hypotension (OH) is an unusual primary cause of syncope. It might be worth looking for in patients who have syncope immediately related to assuming an upright posture. Because the test (using standard BP equipment) has a low sensitivity in detecting OH, it is important to document whether symptoms occur in the absence of BP change.
Management
The majority of patients with syncope will have normal findings on examination and be fully recovered when assessed. However risk stratification,
particularly seeking cardiac causes, is crucial to disposition. The patient should fit into one of the categories in the
disposal grid below. If in doubt, please seek advice.
Patients may warrant referral to a Syncope Clinic for diagnostic work-up (EEG, CT, tilt test etc.). Even if you suspect the patient is suffering from simple faints remember there are other proven interventions for those with recurrent vasovagal syncope.
The incidence of 'simple faints' can be reduced (without referral to a clinic) by advising the patient about avoidance of precipitating situations, maintaining hydration, not getting overheated, and taking avoiding action if warning symptoms appear. Many patients do not realise that lying down can be effective if they feel dizzy.
Adjusting cardiovascular medications may be helpful, especially in elderly patients who are having giddy spells with postural change and occasional syncope. By reducing the dose of a cardioinhibitory medication, or omitting a vasodilator (depending on whether you think they have symptomatic bradycardia or resting hypotension ), symptom frequency can be reduced. Advise both the patient and GP of any adjustments. If reducing a diuretic or antianginal ensure the patient/carer understands that breathlessness or angina are indications for restarting their 'culprit' medications, and to see their GP.
Disposition
If you have identified an underlying cause, disposition should be guided by the
disposal grid below.
If the patient is not admitted they should either be referred back to GP, or they can be referred directly toa neurology clinic. The latter option is best for patients in Group 2 below, or those with recurrent symptoms.
Guidelines for disposition from the ED
Disposition |
Driving restrictions as per UK DVLA guidelines ** |
|
1. Simple FaintDefinite provocational factors with associated prodromal symptoms and which are unlikely to occur whilst sitting or lying. Benign in nature. If recurrent, will need to check the 3 "Ps" apply on each occasion (provocation / prodrome / postural). |
Discharge, if social circumstances favourable |
Group
I No driving restrictions Group
II No driving restrictions |
2. Loss of consciousness / loss or altered awareness likely to be unexplained syncope . low risk of re-occurrenceThese patients have no relevant abnormality on CVS and neurological examination, and have a normal ECG. |
Refer to GP for follow-up. However, if you feel investigations are warranted refer the patient to Syncope Clinic. See referral form in ED |
Group
I Can drive 4 weeks after event. Group
II Can drive 3 months after event |
3. Loss of consciousness / loss or altered awareness likely to be unexplained syncope . high risk of re-occurrenceFactors indicating high risk: (a) associated chest pain (b) abnormal ECG (c) clinical evidence of structural heart disease ( be particularly aware of aortic stenosis ) (d) sudden syncope occurring whilst driving, or whilst sitting / lying, or on exertion. (e) more than one episode in previous six months. |
Admit overnight to the obs unit or under the medical team Arrange review by the Cardiology team on their post take ward round |
Group I Can drive 4 weeks after the event if the cause has been identified and treated. If no cause identified, then require 6 months off. Group II Can drive after 3 months if cause has been identified and treated. If no cause found then licence refused/revoked for one year. |
4. Unwitnessed (presumed) loss of consciousness / loss or altered awareness with seizure markersThe category is for those where there is a strong clinical suspicion of epilepsy but no definite evidence. The seizure markers act as indicators and are not absolutes
|
Admit medically if suspect new-onset epilepsy, or focal neurology present. The latter group will need urgent neuroimaging ( see the CT guidelines ) If relapse in known epileptic then admission not always indicated, provided the seizure activity represents their normal pattern |
Group I I year refusal/revocation Group II 5 year refusal/revocation |
**Group I; cars, motorcycles, Group II; LGV, HGV etc.
Driving assessment
For patients requesting a formal assessment specifically checking for driving ability, Mr. Sean O' Callaghan (Southern Mobility Assessments 087 9304335) is available for an initial fee of circa €100.
Conditions that can easily be mislabelled as syncope
Disorders with impairment or loss of consciousness
- Metabolic disorders (hypoglycaemia, hypoxia)
- Intoxication
- TIAs of vertebrobasilar origin
Disorders resembling syncope without LOC
- Cataplexy
- Drop attacks (although these can be syncopal in origin. If they are recurrent consider referral to syncope clinic)
- Pseudosyncope, somatisation disorders
- TIAs of carotid origin
Points to note
- Brief symptoms / signs such as nausea, and diaphoresis are common and non-specific in syncope
- Brief myoclonic jerking is common in syncope. Syncope may also present as a true seizure, due to the cerebral hypoperfusion.
- Presyncope should be evaluated as being an identical entity to true syncope
Syncope / neurology clinic
To refer a patient write a standard referral letter, preferably typed by the ED secretaries. Include information such as the circumstances of the episode, and ED assessment. A copy of the patient's ECG and any rhythm strips should be enclosed. If relevant request a 24 hour ECG tape prior to the appointment.
Useful reading
- European Task Force report; Guidelines on management of Syncope. Brignole et al. European Heart Journal 2001; 22: 1256-1306.
- 'At a glance' Guide to the current medical standards for fitness to drive.Drivers medical group, DVLA, Swansea. Jan 2003.
- Risk stratification of patients with syncope in an accident and emergency department. Crane S. EMJ 19(1): 23-7.
- Potential drug-drug interactions in elderly patients presenting with syncope.Gaeta et al. J Emerg Med '02; 159-62.
- Strategy for the management of vasovagal syncope. Bloomfield et al. Drugs Aging 2002; 19(3): 179-202.
- Diagnosing syncope in clinical practice. Implementation of a simplified diagnostic algorithm in a multicentre prospective trial- the Oesil trial. Ammirati et al. European Heart Journal 2000; 21: 935-40.
- Diagnosing syncope Part I; Clinical guidelines. American College of Physicians. Linzer et al. Ann Intern Med 1997; 126(12): 989-96.
- Diagnosing syncope Part II; Clinical guidelines. American College of Physicians. Linzer et al. Ann Intern Med 1997; 127(1): 76-86.
Links
DVLA site - await link
