Aging Flashcards
Peak age of increased organ function (functional reserve).
Around 30
Age of gradual/rapid decline organ function (functional reserve).
80
Age process is highly variable. T/F
True
What further diminishes functional organ reserve.
Disease interaction
Sensory changes with age.
DECREASED
Salivation
Taste buds for sweat & salty
Visual acuity
Sensitivity to sound
Response to pain
Thirst sensation
Motor skills
General - changes in dentition
Renal changes with aging.
DECREASED
Renal capacity
Renal blood flow
Glomerulofiltration
Renal drug clearance and metabolism
CNS changes with aging
DECREASED
Neuronal density
Reflexes
Sympathetic response
Proprioception
Baroreceptor response (postural hypotension)
GI changes with aging
DECREASED
GI absorption
Gastric emptying
Hepatic BF / Drug clearance
Drug absorption
Motility
Transit time
Cardiovascular changes with aging (increases)
INCREASED
Myocardial irritability
Dysrhythmia
(PVC, PAC, inc AV Block, dec max HR, dec sinus rate) Systolic BP
Circulation time
Conduction changes
Defective ischemic preconditioning
Endocrine chaos gets with aging
High or low thyroid function
Dec insulin sensitivity
Ortho changer with aging
Osteopenia
High fracture risk
Dec ROM
Dec ligamentous stiffness
Immune changes in aging
- Dec neurohormonal response
- Dec WBC reserve (secondary to bone marrow splenic stenosis)
- Sluggish T-cell response
Aging: response to beta receptor stimulation
Reduced capacity to inc HR in response to low BP, hypovolemia, and hypoxia
Myocardium, arteries and veins become soft or stiffer?
Stiffer
Cariovascular
Aging changes in ANS
Cardiovascular
Increased SNS
decreased PNS
Rhythm disturbances
Fibrosis of conduction system (blocks)
Sick sinus syndrome
A fib prevalence
Calcification in valves
Ischemic preconditioning: brief periods of myocardial ischemia will LESSEN or INCREASE effects of subsequent, more prolonged ischemic event
Ischemic preconditioning: brief periods of myocardial ischemia will LESSEN effects of subsequent, more prolonged ischemic event
Diminished or eliminated with age
Manifestation of arterial stiffening due to
Widened pulse pressure
Pulse pressure > _________ mmHg is associated with 3 things
80
- All cause mortality
- Cardio mortality
- Variety of comorbidities
HTN risk for periop complications. Risk ____ for every ____mmHg in sbp and ___ mmHg in dbp
Doubles
20sbp
10 dbp
HTN caused by
Increased PVR, dec arterial elasticity and cardiac workload
Most common complication and leading cause of death
Myocardial infarction
Most prominent pulmonary changes with aging
Inc chest wall stiffness
Dec stiffness of lung parenchyma
Chest wall stiffening does what in aging
Increases work of breathing
More barrel shaped
Flattened diaphragm
What makes elderly more prone to fatigue when challenged by inc minute ventilation?
Stiff chest wall
Flattened diaphragm
Loss muscle mass make
What causes decreased lung stiffness
Loss of elastin
Easier to inflate (more compliance)
Dr. Thurman clarified there is decreased in CHEST WALL compliance and increase in LUNG compliance.
Adverse effects of increased LUNG compliance
- Need further lung inflation to prevent small airway collapse
- Inc VQ mismatch
- Greater limitation during forced exhalation
- Predisposition to upper AW Obstruction
Closing capacity is ______
CC is > or < FRC in erect position in 65 or older
Increased
CC > FRC at 65
VQ change with inc compliance
Increased VQ
___% decrease in response to hypercapnea and hypoxia
50 %
Best indicator of drug clearance
Creatinine clearance
What is the Cockcroft formula?
Can overestimate or underestimate?
(140 – age) x (LBW weight in kg) (x 0.85 if female)
72 x (serum creatinine)
May overestimate
Elderly with impaired renal at risk for
Fluid overload
Metabolite and renal excreted drug accumulation
Decrease drug elimination
Electrolyte imbalances
Aging on liver function
Increased fibrosis
Inc oxidants
Dec mass and integrity
Dec BF 20-40% ↓
Dec insulin sensitivity
Modest reduction in phase I metabolism ( oxidation, reduction, & hydrolysis); mediated by cytochrome P450 system
Modest ↓ in bile production
Metabolism of most anesthetic agents as well as nondepolarizers affected by age-related changes
Age not a factor in Phase II (conjugation, sulfonic acid, acetylation)
Brain/neuron changes: list 3
Most prominent where?
In a 90 y/o brain, what happens ventrilce size?
Sulci?
Neuron changes
- Progressive loss of neurons and neuronal substance
- Dec in neurotransmitter activity
- Dec in brain size
Most prominent in
Cerebral cortex, especially frontal lobes
In a 90 y/o brain, ventrilce increase in size.
Sulci become deeper.
Result of progressive dec in brain mass and neuronal substances. List 4
- Dec CSF
- nerve conduction velocity
- Degeneration of peripheral nerve cells
- Number of myelinated nerve fibers
Effects of GA on regulation of brain
And induction dose changes needed
Inc sensitivity to anesthetics
Inc risk for delirium
Inc sensitivity bc of dec number of receptors
(dec dose of induction agent 30-40%)
Neuraxial implications
Neural damage with regional
Anatomic changes
Enhanced spread of LA
Epidural test dose less reliable
Anatomic neuraxial changes
- Intervertebral disc height
- Narrow intervertebral foramina
- Dec space btw spinous process
- Calcification
- Lordosis
Post Op Delirium:
Definition
Characrteristics
Onset
Pathogenesis/risk factors
Post Op Delirium: transient reversible state of cognitive alteration after surgery
Characrteristics: disruption of perception, thinking, memory, psychomotor behavior, sleep-wale cycle, consciousness, & attention
Onset: subtle
Pathogenesis: multifactorial; dec synthesis/release of ACh, older age, male gender, dementia, history of alcohol abuse, depression, duration of anesthesia, anesthesia stimulated vasodilation -> hypermetabolic state in brain, poor functional status, abnormal electrolytes & glucose, Parkinson’s disease, cardiovascular disease, dehydration, metabolic disease (diabetes, hyperthyroidism), anticholinergics, ICU, inadequate pain control & type of procedure (ortho! cardio!)
Changes in kinetics of medications
- Drug redistribution phase – blood concentrations level higher/lower:
- Mildly contracted blood volume
- ↓ muscle mass speeds/slows removal of drug from blood
- Induction gives moderate-to-severe hypotension
- ↓/↑ vol of distribution of water-soluble meds → ↑ plasma concentration
- ↓/↑ total body fat → fat-soluble meds have longer half-life. However, Thurman clarified, there is a decrease in subcutaneous fat/tissue.
- Target organ may be more sensitive/insensitive to drug level
- IV bolus takes longer/faster to take greater effect?
Changes in kinetics of medications
- Drug redistribution phase – blood concentrations level higher:
- Mildly contracted blood volume
- ↓ muscle mass slows removal of drug from blood
- Induction gives moderate-to-severe hypotension
- ↓ vol of distribution of water-soluble meds → ↑ plasma concentration
- ↑ total body fat → fat-soluble meds have longer half-life. However, Thurman clarified, there is a decrease in subcutaneous fat/tissue.
- Target organ may be more sensitive to drug level
- IV bolus takes longer to take greater effect?
Circulation time is ____.
Slower
Rate of transfer into organs
Slower
Drug effects are result of tissue/plasma concentration.
Drug effects are result of Tissue (not plasma) concentration.
BBB crossing is quicker or longer?
Longer
No explanation for this
Drugs distribute based on ______& ______.
Tissue mass and solubility
Most IV anesthetics are ___ soluble, end up in ____ after initial redistribution in vessel- _____group.
Most IV anesthetics are lipid soluble, end up in fat after initial redistribution in vessel-rich group.
Most prominent and consistent pharmacokinetics is decrease in drug ___________.
Drug metabolism
Dec in clearance
Inc Vd ss
(?Due to inc in body fat)
GFR is ____
Renal eliminating drug metabolism is _____ bc of this.
What effect on elim half life.
GFR is dec
Renal eliminating drug metabolism is dec bc of this.
Doubles effect on elim half life.
3 Drugs to avoid in elderly due to SE from central anticholinergics!!
- Scopalomime
- Phenergan
- Chlorpheniramine
Haldol (small anticholinergic properties - smaller doses for agitation and nausea usually okay)
*Time to dec effect site concentration is ____ by aging when a large % ____ in plasma level if necessary to dip below therapeutic threshold*
*Time to dec effect site concentration is increase by aging when a large % decrease in plasma level if necessary to dip below therapeutic threshold*
* astrics used on slides, who knows
Sensitivity of opioids is _____. Pharmacokinetics are ______ according to Barash.
More
Unaffected