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
For drugs elimination by kidney & liver, the effect of a bolus are eliminated by _________, multiple doses will result in ____________ with subsequent doses have a more _______ effect.
Redistribution
Accumulation
Prolonged
- Generally, elderly are ____ sensitive to anesthetic drugs.
- Factors: plasma protein binding, body content, drug metabolism & pharmacodynamics
- Main plasma binding protein: ____
- _↓↑_Albumin with age
- _↓↑_α1-acid glycoprotein levels
- _↓↑_lean body mass
- ↓↑ body fat (greater volume of distribution)
- _↓↑_total body water (smaller central compartment & ↑serum concentration after bolus of hydrophilic drug)
- Drug effect depends on which ____ drug is bound to
- In general, plasma binding protein levels not/is a predominant factor in how aging affects pharmacokinectics
- Generally, elderly are more sensitive to anesthetic drugs.
- Factors: plasma protein binding, body content, drug metabolism & pharmacodynamics
- Main plasma binding protein: albumin
- ↓ Albumin with age
- ↑ α1-acid glycoprotein levels
- ↓ lean body mass
- ↑ body fat (greater volume of distribution)
- ↓ total body water (smaller central compartment & ↑serum concentration after bolus of hydrophilic drug)
- Drug effect depends on which protein drug is bound to
- In general, plasma binding protein levels not a predominant factor in how aging affects pharmacokinectics
Hemodynamic response results of interactions with aging ______ and _________.
Hemodynamic response results of interactions with aging heart and vasculature.
Compensatory or reflex responses are blunted or absent T/F?
Compensatory or reflex responses are blunted or absent T/F?
Mac is decreased approx __% per ______.
MAC dec 6% per decade
Altered activity of neuronal ion channels are associated with what receptors.
Nicotinic
ACh
GABA
Glutamate
Thiopental changes seen
No change in brain sensitivity with
Most common 3 system complications
neuro
pulm
cardiac
Relative risk for 90 day mortality for any ADL and IADL impairment (instrumental ADL)
ADL - RR 1.9
IADL - RR 2.4
ADLs - 5 of them
bathing
dressing
toileting
transferring
eating
Instrumental ADLs - 7 of these
telephone
use public transportation
use shopping
meal prep
housekeeping
taking meds
properly managing finances
Multisystem loss of physiologic reserve; vulnerable to disability after stress
Frailty
prognostic factor for poor outcomes
Components of Frailty
mobility
muscle weakness
poor exercise tolerance
unstable balance
body composition factors
(weight loss, malnutrition, & muscle wasting)
Chronic inflammation & endocrine dysregulation “key drivers”
5 Criteria used to define
Frailty
(Which is a prognostic factor for poor outcomes - thought I’d throw that in there)
Weight loss
Exhaustion
Physical activity
Walk time
Grip strength
Quesioning weight loss criterion.
“In the last year, have you lost more than 10 lb unintentionally (i.e., not as a result of dieting or exercise)?” Patients answering “Yes” are categorized as frail by the weight loss criterion.
Questioning exhaustion criterion
The patient is read the following two statements: (1) I felt that everything I did was an effort; (2) I could not get going. The question is asked, “How often in the last week did you feel this way?” The patient’s response is rated as follows: 0 = rarely or none of the time (<1 day); 1 = some or little of the time (1 to 2 days); 2 = a moderate amount of the time (3 to 4 days); or 3 = most of the time. Patients answering “2” or “3” are categorized as frail by the exhaustion criterion.
Questioning about Physical activity criterion
The patient is asked about weekly physical activity.
Patients with low physical activity are categorized as frail by the physical activity criterion.
Questions about walk time criterion
The patient is asked to walk a short distance and timed.
Patients who are slow walkers are categorized as frail by the walk time criterion.
Questioning about strength criterion
The patient’s grip strength is measured.
Patients with decreased grip strength are categorized as frail by the grip strength criterion.
Atypical Presentation of Disease
Primarily linked to presence of
Dementia
NOT a characteristic feature of aging process
(Topic: malnutrition, immobility and dehydration)
Which is associated with
↑ morbidity, mortality & length of stay
Malnourishment
(Topic: malnutrition, immobility and dehydration)
Which is associated with loss of skeletal muscle, ventricular atrophy, hypovolemia, & orthostatic intolerance
Bedrest
(Topic: malnutrition, immobility and dehydration)
Which is associated with hypernatremia & infection
Dehydration
Leading cause of unintential falls
Trauma
Primary goal: prevention
Anticoags: highest mortality in head injury
(Chronic pain) Most prevalent indication for analgesics
Arthritis
Consequence of persistent pain:
depression
sleep disturbance
impaired ambulation
Fill in blank
Fill in blank
No evidence that use of either regional vs general anesthesia can alter 30 day mortality in elderly T/F
True
No alateration in 30 day mortality in studies
Specific benefits of regional anesthesia
1) prevent postop inhibition of fibrinolysis
2) ↓ blood loss in pelvic & lower extremity surgery
3) no instrumentation of airway → patients maintain their own airway & level of pulmonary function
4) opiate-sparing effects
5) improved postop pain control
Regional anesthesia use
Ortho
prostate
gynecologic
LE vascular
Placement of needle for epidural or spinal block may be difficult
- Calcification of interspinous ligament & ligamentum flavum
- Narrowing of intervertebral foramina
- Reduction in flexibility → difficulty positioning
Spread of LA in epidural space is exaggerated T/F
True
goes to higher level
Spead in spinal is narrow
False
Wide
Should decrease dose in spinals
Most common hemodynamic event in regional anesthesia.
Hypotension
Exaggerated in pts with HTN
Pretx with crystalloid NOT consistent in prevention
Hypotension is most likely due to
Vasodilation
Sympathetic Blockade
Decreased SVR
Decreased CVP
Redistribution of blood volume to the extremities from central splanchnic & mesenteric vascular bed.
Hypotension is of particular concern in very elderly patients with limited _____ ________, and may be exaggerated in patients with baseline hypertension.
Hypotension is of particular concern in very elderly patients with limited cardiac reserve, and may be exaggerated in patients with baseline hypertension.
Pretreatment with crystalloid does not consistently offset the hypotension following a spinal block
This assessment associated with masking more difficult; laryngoscopy easier
Edentulous
Hx of this may limit head & neck manipulation with DL (think basic)
Arthritis
This disease may predispose to cerebral ischemia during neck manipulation
Vertebrobasilar disease
(can’t be rough on trying to get the axis all line up - cerebral ischemia!!)
Used to treat exaggerated response to laryngoscopy?
Lidocaine 50 mg IV or short-acting beta-blocker may attenuate
Risk of pulmonary aspiration is due to
Decreased pharyngeal responses
Prolonged periods of intraop hypotension → ↑ in postop morbidit maintain BP within ___% of baseline
Prolonged periods of intraop hypotension → ↑ in postop morbidit maintain BP within 10% of baseline
Propofol implications
- hemodynamic effects can be greatly exaggerated in elderly
- ↓ initial dose & time interval between repeated doses
- Rapid recovery with minimal delayed cognitive effects
- ↑ brain sensitivity
Etomidate implications
- 30-60% of patients develop myoclonus
- Minimal cardiovascular effects
- Excellent for emergencies
- Volume of distribution ↓ - 50% ↓ in dose recommended
The hemodynamic effects of propofol can be greatly exaggerated in elderly patients, especially if their intravascular volumes are depleted possibly leading to significant cardiac or cerebral ischemia. Propofol infusion probably provides a more stable hemodynamic course.
no thinking required here just enjoy the paragraph
The hemodynamic effects of propofol can be greatly exaggerated in elderly patients, especially if their intravascular volumes are depleted possibly leading to significant cardiac or cerebral ischemia. Propofol infusion probably provides a more stable hemodynamic course.
Etomidate, carboxylated imidazole ring, produces some ________ effects leading to development of myoclonus, in about 30-60% of patients
Etomidate, carboxylated imidazole ring, produces some disinhibitory effects leading to development of myoclonus, in about 30-60% of patients
What do you know about Midazolam for elderly?
- short duration, absence of active metabolites & CV effects
- Pharmacokinetic changes prolong elimination, but ↑ sensitivity due to pharmacodynamic change in benzodiazepine GABA receptor
- ↓dose 50-75%; repeat doses 0.5 mg or less
- Susceptible to midazolam-induced apnea
- Unwanted effects reversed with flumazenil
- Long-acting benzodiazepines associated with delirium in elderly due to prolonged clearance & active metabolites
Inhaled anesthetics implications
- MAC ↓ 6% every decade after age 20 years
- MAC at 90 yo ↓ by 30% compared to 40 yo
- Due to cerebral atrophy & alterations in neurotransmitter balance
Aging does ↑ sensitivity to muscle relaxants at NMJ
T/F
False
Aging does not ↑ sensitivity to muscle relaxants at NMJ
Muscle relaxant implications
- Other age-related changes may ↑ sensitivity or ↓ elimination (Thurman said in her experience, MR do not last as long actually)
- Avoid pancuronium because 85% eliminated by kidneys
- Vecuronium & rocuronium less dependent on renal excretion, yet elim t 1/2 is proloned
- Cisatracurium/atracurium not impacted by hepatic/renal function
Opioid pharmacodynamic changes account for ↑ sensitivity of brain T/F
True
- Sufentanil, alfentanil, fentanyl, remi 2 x as potent in older adult
- ↑ in brain sensitivity (not altered pharmacokinetics)
- ↑ brain sensitivity (½ bolus dose)
- Vol of central compartment, Vl & clearance ↓ (1/3 infusion rate)
General opioid implications
- Pharmacodynamic changes account for ↑ sensitivity of brain
- Pharmacokinetics changes on elimination/distribution less significant
- ↓ dose by 50%
- Variability of response common among elderly; titrate to effect
Fentanyl implications
Short-acting lipid-soluble
large VD
↓ dose by 50%
Remi implications
- ultrashort-acting Mu receptor agonist
- Metabolized by plasma esterases
- Bolus & infusion dose reduced & tritrated
Morphine implications
- ↓ VD
- metabolites morphine 3-glucuronide & morphine 6-glucuronide eliminated by kidneys →potential accumulation
Meperidine implications
Not recommended
except for shivering with smaller doses
12.5-25 mg
can cause delirium
MAC Concept: ______ dose or infusion but _____ interval
MAC Concept: reduce dose or infusion but increase interval
Monitored anesthesia care
Patients are susceptible to what 2 things per Thurman’s slides
Monitored anesthesia care
Patients are susceptible to hypoventilation & apnea
Tx/Drugs to use for MAC
- Supplemental O2 & monitoring of ETCO2 recommended
- Drugs used include benzodiazepines (midazolam), fentanyl, remifentanil
- I include propofol
- Ketamine 10-30 mg IV useful
- Dexmedetomidine (centrally acting α2-agonist) – no adverse respiratory effects; provides analgesia & sedation
- Side effects of Dex: prolonged sedation, bradycardia, hypotension
How to dilute precedex
Precedex
Dilute with sterile saline to a concentration of
4 mcg/mL
(2 ml of precedex added to 48 mL of saline)
Precedex dosing
loading
mainenance infusion
adjustment for elderly
Precedex dose:
- 1 mcg/kg IV over 10 minutes for loading dose
- maintenance infusion of 0.2-0.7 mcg/kg/hr up to 24 hours.
- Rate of maintenance is titrated to desired level of sedation.
- Decrease dose for elderly.
Look at this
Review
Review
The few with No increased brain sensitivity, BUT have dec initial Vd
Etomidate
Thiopental
N/A for brain sensitivity
Panc
Cisatra
Atra
Few without any decreased clearance issues
inhaled
sufe
alfe
fenta
atra
cisatra
Drugs with decreased clearance in elderly
etomidate
prop
midazolam
morphine
remi
panc
Postop mgmt/considerations: what are some key points?
- Pulmonary problems of particular importance
- Most important patient-related factors are age, ASA status
- Greater incidence of postop desaturation
- Higher risk for aspiration due to progressive ↓ laryngopharyngeal sensory discrimination & associated dysfunctional swallowing
- Urinary retention more common in older adults
Treatment of Acute Postoperative Pain
- Age-related ↓ pain perception (↓ nerve conductivity & receptors)
- Postop pain asso with what 4 things?
- Cognitively intact – recommend PCA
- Cognitively impaired report less pain
Treatment of Acute Postoperative Pain
- Age-related ↓ pain perception (↓ nerve conductivity & receptors)
- Postop pain asso with ↑ length of stay, ↑ morbidity, pulmonary complications, & delirium
- Cognitively intact – recommend PCA
- Cognitively impaired report less pain
3 Principles for Tx of acute post op pain:
3 Principles for Tx of acute post op pain:
1) mult modalities (acetaminophen, gabapentin)
2) use site-specific analgesia – regional blocks
3) caution with NSAIDS - risk for renal failure & GIB
Iatrogenic complications
Iatrogenic complications
Adverse drug events
dehydration
delirium
functional decline
Outcomes
Goal of surgical intervention to preserve or improve activity & _________ while avoiding _______.
Functional recovery may be challenging & require time
Outcomes
Goal of surgical intervention to preserve or improve activity & independence while avoiding disability
Functional recovery may be challenging & require time
Age has no effect on duration of motor blockade with bupivacaine T/F
Age has no effect on duration of motor blockade with bupivacaine T/F
Neuraxial Anesthesia & Peripheral Nerve Blocks
- Age has ____ effect on duration of motor blockade with bupivacaine
- Time of onset increased/decreased.
- Spread is more diminished/extensive with hyperbaric bupivacaine
- Effect on duration of epidural with bupivacaine not known
- Ropivacaine ____% for PNB: ____ a major factor in determining duration of motor & sensory block
Neuraxial Anesthesia & Peripheral Nerve Blocks
- Age has no effect on duration of motor blockade with bupivacaine
- Time of onset ↓
- Spread is more extensive with hyperbaric bupivacaine
- Effect on duration of epidural with bupivacaine not known
- Ropivacaine 0.75% for PNB: age a major factor in determining duration of motor & sensory block
Consider shorter acting anesthetics
- Shorter-acting opioid, such as ______.
- Shorter- acting muscle relaxants
- No significant difference in recovery profile of cognitive function with ______ ______.
- ______ inhalation agent is associated with the most rapid emergence
Consider shorter acting anesthetics
- Shorter-acting opioid, such as remifentanil
- Shorter- acting muscle relaxants
- No significant difference in recovery profile of cognitive function with inhaled anesthetics
- Desflurane associated with the most rapid emergence
Most 5 important risk factors for periop complications (elderly)
- Age
- Physiologic status
- Coexisting disease (ASA)
- Elective or urgent surgery
- Type of procedure
Chronologic age is less/more important than sum of cormorbidities
Chronologic age is < important than sum of cormorbidities
Independent predictor of adverse events
Emergency
(poor preop and prep)
NH considers elderly age at
65 or older
POCD
- characterized by:
- Onset:
- Dx:
- Pathogenesis:
POCD
- characterized by: cognitive imprairments
- Onset: subtle & may not present for weeks to months postop
- Dx: no universal criteria
- Pathogenesis: multifactorial
Incidence of POCD is similar with regional vs general.
T/F
True dat
