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