Geriatrics Flashcards
What are the two types of opioids?
Typical opiates = full Mu agonists
E.g codein, oxycodone, morphine, hydromorphone, fentanyl, methadone
Atypical opiates = partial Mu agonists
E.g. buprenorphine, tramadol, tapentadol
What type of receptor are opioid receptors?
G protein-coupled receptor
What is the mechanism of action of opioids?
Activate mu opioid receptors in midbrain which stimulate descending inhibitory pathways which act upon the periaqueductal gray and nucleus reticularis to reduce pain signalling
What is the goal of multimodal analgesia? What agents are used?
To reduce opioid-related adverse effects by reducing opioid requirement and to improve pain relief
NSAIDs, gabapentin, pregabalin, systemic lidocaine, ketamine
What factor should dictate changes to medication for acute pain?
Functional outcome
What medication class is the leading cause of accidental overdose?
Opioid medications (followed by benzodiazepines)
What are the harms of opioids?
Death
Respiratory depression
Immune suppression: infection, wound healing
Dental caries
Opioid induced hyperalgesia
HPA axis suppression: low testosterone, sexual dysfunction, fluid retention, osteoporosis
What is the definition of delirium?
Clinical manifestation of acute encephalopathy
DSMV:
Disturbance in attention, cognition and awareness developing over a short period of time representing an acute change from baseline and fluctuates over the course of the day that is due to a physiological consequence of another medical condition and not better explained by a pre-existing condition
What type of delirium is associated with highest mortality?
Hypoactive delirium
What features of an ageing brain contribute to the pathophysiology of delirium?
Loss of cholinergic and noradrenergic pathways
Microglia and astrocytes are primed to produce enhanced inflammatory response
Astrocytes less able to support neuronal metabolism
Vascular changes result in impaired cerebral perfusion, leaky blood brain barrier, impaired microcirculatory function
What are precipitants of delirium?
- Alterations in oxidative metabolism: hypoxia or hypoglycaemia/increased insulin resistance
- inflammation
- impaired neurotransmitter function from drugs or stress
How is polypharmacy defined?
The use of 5 or more medicines
What are common drugs and their ADRs that pose risk to older people?
- NSAIDs: GIB, renal impairment, HTN
-Benzos: falls
-AntiCh: urinary retention, cognitive impairment
-TCAs: postural hypotension, sedation
-Sulphonylureas: hypoglycaemia
-Prazosin: postural hypotension, dry mouth, urinary problems
What are the potential risks of the following drug-drug interactions in the elderly:
1. ACEi + diuretic
2. ACEi + potassium
3. Anti-arrhythmic + diuretic
4. Benzo + antidepressant, antipsychotic or benzo
5. CCB + diuretic or nitrate
6. Digoxin + antiarrhythmic
- hypotension, hyperkalaemia
- Hyperkalaemia
- Electrolyte imbalance, arrhythmia
- confusion, sedation, falls
- Hypotension
- bradycardia, arrhythmia
Where do the majority of falls in the elderly occur and what are the most common mechanisms?
Most common in home (53%), followed by aged care facility (21%)
At home most commonly fall outdoor (16.5%) or in the bathroom (12%)
Common mechanisms:
- trip from standing height
- fall from household object
What is the biggest risk factor for dementia?
Age
What proportional of people with dementia die of their dementia?
50%
What is the key difference between mild neurocognitive disorder and mild dementia?
In mild neurocognitive disorder the cognitive impairment should not impair ability to function
What are the 4 major pathological types of dementia and their frequencies?
- Alzheimer’s dementia neuropathological changes (ADNC) due to amyloid and Tau proteins 40%
- Vascular dementia 25%
- Lewy body (alpha-synuclein) 12%
- TDP-43 17%
What are the key characteristics of dementia as a diagnosis?
Decline in cognitive function with impairment in 2 or more domains that interferes with persons performance of ADLs
What are the key features of Alzheimer’s dementia?
Clinical diagnosis, may have postive genetic test or family history
Insidious onset of memory impairment (+other domains)
Often accompanied with low mood and apathy
May feature aggression, abnormal gait
What are key features of vascular dementia?
Cognitive deficit has to be temporally associated with vascular event (ischaemic, haemorrhagic)
Mostly affects speed of information processing, complex attention, frontal executive functioning
What is the second most common form of dementia in the elderly?
Lewy body dementia
(Note vascular dementia is second most common overall)
What are key features of lewy body dementia?
Insidious onset primarily affecting attention and executive function
Accompanied by visual hallucinations and REM sleep disorder
May be followed by Parkinson symptoms (often 1 year after cognitive symptoms)
What is the underlying aetiology of Lewy body dementia?
Alpha-synuclein protein folding and aggregation with Lewy body formation in cortex and brainstem
What are the 3 variants of fronto-temporal dementia?
Behavioural
Primary progressive aphasia
Motoric
What are the key features of behavioural variant of frontotemporal dementia?
-Personality change: apathy, innapropriate social behaviour
-Cognitive testing displays executive dysfunction with intact memory
What are the key features of primary progressive aphasia variant of frontotemporal dementia?
Impairment in language in the absence of other cognitive problems (memory in tact until late in disease)
- Logopenic = difficulties in single word retrieval, repetitive phrases
- semantic = loss of familiar objects, people, places
- agrammatic = poor grammar in written and spoken language
What are the key features of motoric variant of frontotemporal dementia?
Impairment in attention, executive functioning and visuspatial function with intact memory
May accompany supranuclear palsy, corticobasal degeneration, motor neurone disease
What is the role of biomarkers in Alzheimer’s disease?
For research only, no clinical significance due to low specificity (e.g. positive test does not mean positive diagnosis)
What medications can be used for dementia?
-Cholinesterase inhibitors approx 50% patients will derive benefit in symptoms but does not delay disease progression
- Memantine = NMDAR antagonist, improve cognitive function in moderate to severe AD
Cannot be used in conjunction
How should symptoms of dementia be managed?
Non-pharmacologically
What medications have evidence for symptom relief in dementia?
Analgesia for pain
SSRIs for agitation
Risperidone or olanzapine for severe distress
