Short presentation on Blackouts

1. DR. RAJESH T EAPEN
SPECIALIST – ANESTHESIA
ATLAS HOSPITAL
RUWI

2. What is Syncope?
• Common clinical problem and a primary
goal of evaluation is to determine
whether the patient is at increased risk of
death.

3. Definition
• Sudden, self-limited loss of
consciousness in postural tone caused by
transient global cerebral hypoperfusion
& followed by spontaneous complete
and prompt recovery

5. History
• It is vital to establish exactly what
patients mean by 'blackout'
• Do they mean loss of consciousness
(LOC)?
• A fall to the ground without loss of
conscious-ness?
• A clouding of vision, diplopia, or vertigo?
• Take a detailed history from the patient
and a witness

6. Epidemiology
• Common in the general population
- 6% of medical admissions
- 3% of Emergency room visits
• Incidence: Male = Female

8. Risk Factors
• Cardiovascular disease, h/o stroke or TIA
& HTN
• Low BMI, ↑alcohol intake & diabetes or
elevated blood glucose concentration

9. Vasovagal (neuro-cardiogenic)
syncope
• Due to reflex bradycardia ± peripheral
vasodilatation provoked by emotion,
pain, fear or standing too long
• Onset is over seconds (not
instantaneous), and is often preceded
by nausea, pallor, sweating and closing
in of visual fields (pre-syncope)
• It cannot occur if lying down

10. Vasovagal (neuro-cardiogenic)
syncope …..contd.
• The patient falls to the ground, being
unconscious for ~2 min
• Brief clonic jerking of the limbs may occur
(reflex anoxic convulsion due to cerebral
hypo-perfusion), but there is no stiffening
or tonic → clonic sequence
• Urinary incontinence is uncommon (but
can occur), and there is no tongue-biting.
• Post-ictal recovery is rapid

11. Situation syncope
• Syncopal symptoms are as described for
vasovagal syncope
• Cough syncope: Syncope after a paroxysm
of coughing
• Effort syncope: Syncope on exercise;
cardiac origin, e.g. aortic stenosis, HOCM
• Micturition syncope: Syncope during or
after micturition. Mostly men, at night
• Even during swallowing & defecation!

12. Carotid sinus syncope
• Hypersensitive baroreceptors cause
excessive reflex brady-cardia ±
vasodilatation on minimal stimulation
(e.g. head-turning, shaving)

13. Epilepsy
• Attacks vary with the type of seizure,
• Certain features are more suggestive of
epilepsy:
 attacks when asleep or lying down
 aura
 identifiable triggers. e.g. TV
 altered breathing
 cyanosis
 typical tonic-clonic movements
 incontinence of urine
 tongue-biting (ask about a sore tongue after the fit)
 prolonged post-ictal drowsiness, confusion, amnesia and
transient focal paralysis (Todd's palsy)

14. Stokes-Adams attacks
• Transient arrhythmias (e.g. bradycardia
due to complete heart block) causing
↓ cardiac output and LOC
• The patient falls to the ground (often
with no warning except palpitations),
pale, with a slow or absent pulse
• Recovery is in seconds, the patient
flushes, the pulse speeds up, and
consciousness is regained

15. Stokes-Adams attacks …contd.
• Injury is typical of these intermittent
arrhythmias
• As with vasovagal syncope, a few clonic
jerks may occur if an attack is
prolonged, due to cerebral hvpo-
perfusion (reflex anoxic convulsion).
• Attacks may happen several times a day
and in any posture

16. Drop attacks
• Sudden weakness of the legs causes the
patient, usually an older woman, to fall to
the ground
• There is no warning, no LOC and no
confusion after-wards
• The condition is benign, resolving
spontaneously after a number of attacks.
• Other causes: hydrocephalus (these
patients, however. may not be able to get up
for hours); cataplexy-triggered by emotion
(associated with narcolepsy)

17. Other causes
• Hypoglycaemia: Tremor, hunger, and
perspiration herald light-headedness or LOC;
rare in non-diabetics
• Orthostatic hypotension: Unsteadiness or LOC
on standing from lying in those with
inadequate vasomotor reflexes: the elderly;
autonomic neuropathy; antihypertensive
medication; over-diuresis; multi-system
atrophy (MSA)
• Anxiety: Hyperventilation. tremor, sweating.
tachycardia, paraesthesias, light-headedness,
and no LOC suggest a panic attack.

18. Other causes ……….contd.
• Factitious blackouts: pseudo-seizures,
Munchausen's
• Choking: If a large piece of food blocks
the larynx, the patient may collapse,
become cyanotic, and be unable to
speak. Do the Heimlich manoeuvre
immediately to eject the food

19. Examination
• Cardiovascular
• Neurological
• BP lying and standing

20. Investigations
• ECG ± 24h ECG (arrhythmia, long QT, e.g. Romano-
Ward)
• U&E, FBC. glucose
• Tilt-table tests
• EEG, sleep EEG
• Echocardiogram
• CT/MRI brain
• HUT (Head Up Tilt test)
• PaCO2 ↓ in attacks suggest hyperventilation as the
cause
• While the cause is being elucidated, advise against
driving

21. Treatment – Neurocardiogenic Syncope
• Counsel patients to take precautionary steps to
avoid injury by being aware of prodromal
symptoms & maintaining a horizontal position at
those times
• Avoid known precipitants & maintain adequate
hydration
• Employ isometric muscle contractions during
prodrome to abort episode
• Midodrine (start at 5mg PO Tid & can be increased
to 15mg Tid) probably helpful in the treatment
• Cardiac pacing for carotid sinus hypersensitivity is
appropriate in syncopal patients

22. Treatment – Orthostatic hypotension
• Adequate hydration & elimination of
offending drugs
• Salt supplementation, compressive stocking
& counselling on standing slowly
• Midodrine & fludrocortisone can help by
increasing systolic BP & expanding plasma
volume respectively

23. Treatment – Cardiovascular (arrhythmia or
mechanical):
• Treatment of underlying cause(valve replacement,
antiarrhythmic agent, coronary re-vascularisation
etc.)
• Cardiac pacing for sinus node dysfunction or high-
degree AV block
• Discontinuation of QT prolonging drugs
• Catheter ablation procedure in select patients with
syncope associated with SVT
• ICD for documented VT without correctable cause
and for syncope with EF < 35% even in absence of
documented arrhythmia