Presentation of disease in older people Flashcards
Who does delirium most commonly affect?
Commonly affects up to 30% of all elderly medical patients
What is delirium?
Disturbance of consciousness with reduced ability to focus, sustain or shift attention.
A change in cognition or the development of a perceptual disturbance that is not better accounted for by a pre-existing or evolving dementia.
What is the onset of disturbance due to delirium?
Develops over a short period of time (hours to days)
Tends to fluctuate during the course of the day
How is delirium normally caused?
Evidence from the history, physical examination, or laboratory findings suggests it is caused by the direct physiological consequences of a general medical condition, substance intoxication or substance withdrawal
What are the long term effects of delirium?
Patients who develop delirium have high mortality, institutionalisation and complication rates, and have longer lengths of stay than non-delirious patients
Delirium is often not recognised by clinicians and is often poorly managed
What are the clinical features of delirium?
Consciousness (Impaired-rapid onset, fluctuating)
Disorientation (Place, time , not always person)
Behaviour (Quiet and withdrawn, Hyperactive and irritable)
Thinking (Slow, often delusional-staff plotting against them)
Perception (Visual hallucinations, compare with schizophrenia)
Mood ( Anxiety, fear, agitation, depression)
Memory (impaired short term memory, may forget episode)
How would you manage the symptoms related to delirium?
Nurse them in moderately lit room
Minimise distractions
Same Nursing staff if possible
Familiar people very helpful
Repeated orientation in time and place
Identify and treat underlying cause
Sedate if a danger to themselves or others
How are absorption of drugs changed with age?
Achlorydria (affects certain drugs)
Decreased first metabolism - due to reduced hepatic blood flow (affects beta blockers, and Ca+ channel blockers)
How are the distribution of drugs changed with age?
Affected by body composition and protein binding
Body fat increases, muscle mass declines
=>
Increased distribution of lipophilic drugs
Decreased distribution of hydrophilic drugs
How can illness affect the distribution of drugs?
Illness can cause changes in levels of albumin and alpha-1 acid glycoprotein
Reduced plasma binding can dramatocally increase bioavailability
What can affect the half life of a drug?
The volume of distribution
half life = (0.693 x Vol of dist.)/ clearance
Which phase of hepatic drug metabolism is most affected by age?
Phase 1
- oxidation, reduction, hydrolysis)
- mediated through cytochrome p450
Why may a normal serum creatinine level hide renal impairment?
In the elderly creatinine production becomes less due to less muscle
Therefore low production may hide the fact that creatinine is not being cleared properly
Formula for creatinine clearance?
Creatinine clearance =
((140 - age) x (weight) x gender factor ) / Serum creatinine
What affect can a change in pharmacodynamics have?
Adverse drug reactions
