Author(s): Sandeep Hothi and David Sprigings
The causes of transient loss of consciousness (TLoC) (Box 9.1) can usually be differentiated by a detailed history taken from the patient and any eyewitnesses (Tables 9.1 and 9.2), supplemented by the examination findings and a careful review of the ECG (Table 9.3). Further investigation may be needed for definitive diagnosis.
Is transient loss of consciousness related to acute disease?
Consider those acute diseases which may be associated with TLoC:
These patients will typically have other symptoms (e.g. headache, chest pain, breathlessness) or abnormal physiological observations (e.g. hypotension). Further assessment and management of these diseases is given in the corresponding chapters.
Admit or discharge?
High-risk features warranting admission for inpatient management include:
Occupational issues
Suspected cardiovascular cause
Suspected epilepsy
See Chapter 16 for the advice you should give to patients after a generalized seizure.
The choice of ECG monitoring depends on the frequency of episodes and the presence or absence of heart disease. Patients with high-risk features (see above) should be admitted for investigation. For those without high-risk features, recommendations for ECG monitoring are:
National Institute for Health and Care Excellence (2010) Transient loss of consciousness (blackouts) in over 16s. Clinical guideline (CG109) Last updated: September 2014. https://www.nice.org.uk/guidance/cg109.
Wieling W, vanDijk N, deLange FJ, et al. (2015) History taking as a diagnostic test in patients with syncope: developing expertise in syncope. Eur Heart J . 36, 277280. http://dx.doi.org/10.1093/eurheartj/ehu478.