Blackouts: Remedial Measures and Restoration Practices – Asian
Atlas blackouts
-
Upload
hiranger -
Category
Health & Medicine
-
view
101 -
download
2
Transcript of Atlas blackouts
What is Syncope?
• Common clinical problem and a primary goal of evaluation is to determine whether the patient is at increased risk of death.
Definition
• Sudden, self-limited loss of consciousness in postural tone caused by transient global cerebral hypoperfusion & followed by spontaneous complete and prompt recovery
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 consciousness?
• A clouding of vision, diplopia, or vertigo?
• Take a detailed history from the patient and a witness
Epidemiology
• Common in the general population
- 6% of medical admissions
- 3% of Emergency room visits
• Incidence: Male = Female
Risk Factors
• Cardiovascular disease, h/o stroke or TIA & HTN
• Low BMI, ↑alcohol intake & diabetes or elevated blood glucose concentration
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
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
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!
Carotid sinus syncope
• Hypersensitive baroreceptors cause excessive reflex bradycardia ± vasodilatation on minimal stimulation (e.g. head-turning, shaving)
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)
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
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
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 afterwards
• 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)
Other causes • Hypoglycaemia: Tremor, hunger, and
perspiration herald lightheadedness 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.
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
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
• 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
Treatment – Neurocardiogenic Syncope
• 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
Treatment – Orthostatic hypotension
• 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
Treatment – Cardiovascular (arrhythmia or mechanical):