Assessment of Cause

« Previous | Next »

History

Important Note

Be aware of the limitations of history in guiding your assessment decisions; seek other informants and witnesses.

Many people who fall are NOT able to give a good history of the fall events. Especially if:

It was preceded by syncope or
It was followed by a loss of consciousness or
It involves a blow to the head or
There is any baseline cognitive impairment.

Medications

Drugs particularly associated with falls are:

Benzodiazepines

Even long-standing prescriptions can decrease alertness to the environment and blunt reaction to falling; Benzodiazepines (BNZ) are the single highest relative risk for falls.

Hypo-glycemics

These drugs, particularly the sulfonylureas can cause precipitous drops in blood sugar with attendant weakness or decreased awareness.

Anti-hypertensives

Diuretics can cause a volume contraction which impairs cardiac filling; beta-blockers can impair chronotropic response to postural changes; calcium channel blockers decrease peripheral resistance.

Alcohol

A commonly used “drug” in all populations – it causes significant issues with cerebellar function, judgement, blood pressure and heart rate. Assessment of acute and chronic use should be a part of each history.

Visit the module on Medication Management to explore this topic further.

Syncope

The following are common causes of syncope among older patient in the ED. Click on the cause below to learn more.

Normal Age-Related Changes

Cerebral perfusion decreases by about 25% with age so even a slight decrease in cardiac output can significantly impair adequate brain oxygenation and produce symptoms
“Stiff pump; Stiff pipes”:
- Vascular compliance decreases with loss of elastin and increase in calcium in vessel walls
- Cardiac muscle hypertrophies and becomes less distensible
- Net effect is poor diastolic function – the ventricles fill poorly so any condition that further decreases preload and filling (medication, dehydration, a fib) can cause syncope
Blunting of beta-adrenergic response leads to impaired cardiac acceleration and impaired contractility; unopposed alpha-mediated vasoconstriction causes increased peripheral resistance and decreased cardiac output
Impaired thirst mechanism leads to chronic dehydration

Cardiac syncope

The single largest cause of geriatric syncope: tachyarrhythmias, bradyarrhythmias, AV blocks. Older patients are often NOT aware of or able to describe “palpitations.”
Maintain a high index of suspicion in the situation of unexplained falls. Advise or arrange follow up with Holter monitoring. If there has been a significant increase in falls, admission may be the safest alternative.

Orthostatic hypotension

Defined as a drop in systolic BP of >20 mm Hg on standing. The normal response is for carotid aortic and cardiac baroreceptors to increase sympathetic response and increase heart rate. However in older people baroreceptor function is impaired, and adrenergic sensitivity is significantly decreased. Medication effects (beta-blockade, calcium channel blockers) and chronic vascular contraction (dehydration, diuretics) further impair the response.

Carotid sinus hypersensitivity

Induces a bradycardia which both reduces preload and reduces heart rate (by Vagal stimulus)
Ask about neck ties, scarves, and tight-fitting shirts.

Micturition/defecation/cough syncope

Syncope is induced by a Valsalva maneuver which both impairs pre-load (by increasing intra-thoracic pressure) and causes vagal bradycardia.

Weakness

The fall may be caused by the onset of a new illness – a febrile condition, cardiac ischemia, TIA, acute anemia (from UGIB or LGIB).
A new fall or increased number/frequency of falls needs to be interpreted as a symptom of other medical problems. (To learn more, visit the Atypical Presentations module.)