Lecture 2: Diseases of Aging and Anesthetic Considerations AL Flashcards by William Leake

Aging Trends
• Elderly is defined as those older than X years
• people are living much longer
• high-risk surgeries 20 years ago are now being ________ performed in the elderly.
• about X% of all surgery & inpatient procedures are performed on elderly patients.

Elderly is defined as those older than 65 years
people are living much longer
high-risk surgeries 20 years ago are now being routinely performed in the elderly.
about 40% of all surgery & inpatient procedures are performed on elderly patients.

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Contributors to Aging:

*genes contribute 25% to longevity
nutrition
lifestyle
environment
chance

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Aging Trends
The elderly can develop the same illnesses as the rest of the population, but their:
1. ?
2. ?, and
3. ?
warrant a focused discussion of anesthetic management.

**diminished physiologic reserve
long-term persistence of ds, and
comorbid conditions

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Physiology of Aging
• ______________—the body’s ability to respond to additional stress, such as surgery or infection. A reduced ability is often termed frailty.
• Seemingly minor issues→ produce significant impacts on persons with dec _____________
• Attention to detail is rarely as important as when taking care of pts w/extremes of age.

Functional reserve

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Risk factors for perioperative M/M
• >X years of age 
• male or female? 
• inc or dec albumin levels? 
• inability to perform ? 
• ASA X or greater 
• \_\_\_\_\_\_\_\_\_\_ surgery 
*these risks are most often associated with age-related physiologic changes.

• >80 years of age 
• male 
• dec albumin levels 
• inability to perform ADLs 
• ASA 3 or greater 
• emergency surgery 
*these risks are most often associated with age-related physiologic changes.

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Nervous system changesTEXT PG 330
Normal aging process:
• brain mass decreases by X%
• _____ matter shrinkage
• compensatory increase/decrease CSF production?
• decreased CBF d/t reduction in CMR→ susceptible to ____________ stress

brain mass decreases by 15%
gray matter shrinkage
compensatory increase CSF production
decreased CBF d/t reduction in CMR→ susceptible to metabolic stress

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Nervous system changesTEXT PG 330
Neurodegenerative effects: cellular signaling
• increased/decreased dopamine?
• increased/decreased NE levels?
• increased/decreased (GABA)A binding sites?
• pathologic processes r/t amyloid plaques = ?

decreased dopamine
increased NE levels
decreased (GABA)A binding sites
pathologic processes r/t amyloid plaques = alzheimer’s

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Atherosclerosis
• __________ is the hallmark of atherosclerosis—damage to vascular endothelium
• Atherosclerosis causes ________ (occlusion, dilatation) of arteries?
• Age-related changes cause______ (occlusion, dilatation) of arteries?
• aortic lumen ________ (increases, decreases) in diameter ?
• arteries become ________ (more, less) responsive to vasodilators/constrictors ?

So what are concerns about administering ephedrine, neo, NE?

Inflammation
occlusion
dilatation
increases
less

We will see LESS response from these meds in these pts!

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Cardiovascular changes
Stiff arteries cause PROBLEMS
• Inc SVR→ Inc SBP →LVH → inc LV end-diastolic press→ ?
• vent hypertrophy and increased workload predisposes the myocardium to_______.
• systolic BP _________
• diastolic BP _________
• pulse pressure_______

HF
ischemia
SBP increase
DBP stays same
PP increase

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Cardiovascular changes

Increased incidence of ?

Inc SVR→ Inc SBP →LVH → Inc LV end-diastolic press→ ?

Inc need for ___________ to maintain CO (which is usually ~ 20% of ?)

? alters the ratio of B1 to B2 adrenergic receptors:
without ?—the left ventricle has 80% B1 and 20% B2 receptors
with ?—the ratio changes to 60% B1 and 40% B2
*in/dec response to B receptor stimulation?

Increased incidence of heart failure

Inc SVR→ Inc SBP →LVH → Inc LV end-diastolic press→ HF

Atrial Kick

Heart failure alters the ratio of B1 to B2 adrenergic receptors:
without HF—the left ventricle has 80% B1 and 20% B2 receptors
with HF—the ratio changes to 60% B1 and 40% B2
*decreased response to B receptor stimulation

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Cardiovascular Changes
The electrical system declines with age:
• # of pacemaker cells is reduced by X% by age X 
• resting HR is increased/decreased ?
• peak HR is increased/decreased ?
• peak CO is increased/decreased ?

So what about the elderly’s response to atropine?
So how is CO restored in the elderly?

# of pacemaker cells is reduced by 90% by age 70
resting HR is decreased
peak HR is decreased
peak CO is decreased

So what about the elderly’s response to atropine?
- low peak HR so less effective?
So how is CO restored in the elderly?
- SV

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Respiratory Changes***
Decreased elastin also affects the respiratory system
• the chest wall becomes stiffer
• lung tissue loses its elastic recoil, thus
chest wall compliance________
lung compliance ________

decreases

increases

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Respiratory changes***
• Total lung capacity?
• Residual volume ________ (increases, decreases)
• Vital capacity _________ (increases, decreases)
• PaO2 _________ (increases, decreases)
• Closing volume _______ (increases, decreases)
• protective reflexes, ie coughing is decreased
-> susceptible to _______.
• Work of breathing ________ (increased, decreased)
-> resp failure
• FEV1_______(increased, decreased)

**See also Fig. 16.6 slide 21

Total lung capacity remains the same
increases
decreases
decreases
increases
asp
increased
decreased

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Renal System
• renal tissue atrophy→ X% dec of functioning nephrons by age 80 & 1-1.5% decline in ?
• GRF _____
• creatinine clearance _______
• serum creatinine _________
Renal vascular dysautonomy ~ risk f insult
• Maintain UOP (>X)—crucial for preventing postop renal dysfunction

50%, GFR
decline
decrease
remains WNL

> 0.5 mL/kg/hr

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Pharmacodynamic/pharmacokinetic alterations
• **inc/dec body fat → inc/dec Vd for lipid-sol drugs→ ___________ of drugs? **
• in/dec plasm vol →larger/smaller Vd for hydrophilic drugs → higher/lower plasma conc?
• inc/dec protein binding?
• faster/slower hepatic conjugation?
• inc/dec renal elimination?
Influence anesthetic planning!

**inc body fat → inc Vd for lipid-sol drugs→ prolongation of drugs **
**reduced plasm vol →smaller Vd for hydrophilic drugs → higher plasma conc. **
reduced protein binding
slower hepatic conjugation
dec renal elimination

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Renal, GI, Immune, and Endocrine changes?????
• liver size, perfusion, and hepatic blood flow inc/dec?
• Are these significant? ???????????

decreases

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Renal, GI, Immune, and Endocrine changes
• bactericidal substances (macrophages, natural killer T-cells, etc) are inc/dec?
• cytokines and chemokines (consistent with inflammation) are inc/dec?
• consistent with a low-grade chronic_________process
These changes impact the ability to fight infection and control cancer

bactericidal substances (macrophages, natural killer T-cells, etc) are decreased
cytokines and chemokines (consistent with inflammation) are increased
consistent with a low-grade chronic inflammatory process

These changes impact the ability to fight infection and control cancer

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Renal, GI, Immune, and Endocrine changes
• endocrine glands atrophy
• impaired glucose homeostasis→ diabetes
• decreased thyroxine, growth hormone, testosterone
• metabolism decreases- 1%/yr after age 30
In terms of energy expenditure, what about those w/multiple comorbidities?

Use more energy quicker / fatigue quicker!

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Body composition
• Total body _____ (intracellular) declines by 10-15%
• weight declines
• lean body mass inc/dec?
• total fat inc/dec?
• % of fat per total body weight inc/dec?

Total body water (intracellular) declines by 10-15%
weight declines
lean body mass decreases, but…..
total fat decreases
% of fat per total body weight increases

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Osteoarthritis???????????

Increased susceptibility
• ? and ? ancestry
• >X years of age

Risk factors (review)
▪ estrogen deficiency  
• male hypogonadism  
• smoking  
• alcohol consumption 
• calcium def 
• cancer
• immobilization
• long-term corticosteroid usage
• obesity

Anesthetic significance?

Increased susceptibility
• Caucasian and Asian ancestry
• >70 years of age

Risk factors
▪ estrogen deficiency  
• male hypogonadism  
• smoking  
• alcohol consumption 
• calcium def 
• cancer
• immobilization
• long-term corticosteroid usage
• obesity

Positioning and padding!

cervical spine (Xray, awake intubation, etc)
consider positioning prior to asleep, etc…..

Parkinson’s disease
• most significant risk factor is age
• cause:\_\_\_\_\_\_\_\_\_\_\_\_\_\_
• What is the classic triad?
• What leads to classic triad?

decreased dopamine (inhibitory)
trimmer, bradykinesia, rigidity
decreased dopamine = unopposed Acetylcholine

Parkinson’s disease
• mainstay treatment = dopamine agonists
(Should levodopa be continued the morning of surgery?)
• drugs that precipitate/exacerbate Parkinson’s ds = ?
• drug(s) that might treat EPS?
• choice of muscle relaxant?

dopamine agonists

YES! Short 1/2 life

Phenothiazines, butyrphenones (droperidol), metoclopramide

benadryl (anticholinergic properties)

does not impact choice of muscle relaxant

Postop Delirium and Cognitive Dysfunction

Delirium affects X% of older patients

FYI….Hypothesis: surgical stress and associated inflammation → leukocyte migration into CNS where leukocytes play an important role in the pathophysiology of postop delirium.

Most patients experience a full recovery, however this disorder is far from benign!

Delirium affects 15-55% of older patients

Comparison of CNS disorders (review SLIDE 35!!!)
Takeaways:
Slow onset =
Acute =
Subtle (weeks to months) =
Single or recurrent episode; may be chronic (dont enjoy things anymore) =

Dementia
Delirium
Postop Cognitive Disorder
Depression

``` The Confusion Assessment Method (just review) Diagnostic Algorithm 1. ? 2. ? 3. ? 4. ? ``` • Diagnosing delirium requires features 1 and 2 and either 3 or 4

Algorithm 1. Acute change in mental status and fluctuating course • Is there evidence of an acute change in cognition from baseline? • Does the abnormal behavior fluctuate during the day? 2. Inattention • Does the patient have difficulty focusing attention 3. Disorganized thinking • Does the patient have rambling or irrelevant conversations, unclear or illogical flow of ideas, or unpredictable switching from subject to subject? 4. Abnormal level of consciousness • Is the patient anything besides alert-hyperalert, lethargic, stuporous? • Diagnosing delirium requires features 1 and 2 and either 3 or 4

The Mini-Cog = ? Results: 0-2 points indicates a positive screening for dementia

The Mini-Cog 3-item recall + clock drawing Scoring: 1 point for ea item recalled 2 points for a normal appearing clock Results: 0-2 points indicates a positive screening for dementia

Management of anesthesia **Increased sensitivity to anesthesia: ** MORE or LESS anesthesia?

* loss of neuronal tissue | * changes in receptor function

Anesthetic Strategies • ***Reduction of TBW→ inc/dec central compartment vol→inc plasma conc with __ administration? • ***Inc body fat + dec muscle mass →large/small VOD (lipid soluble)→________ drug actions? • Changes in serum proteins: - plasma albumin inc/dec ? - a1-acid glycoprotein inc/dec ?

* ***Reduction of TBW→ dec central compartment vol→inc plasma conc with IV administration. * ***Inc body fat + dec muscle mass →large VOD (lipid soluble)→prolonged drug actions. * Changes is serum proteins: * plasma albumin dec * a1-acid glycoprotein inc “these protein changes do not appear to have a significant impact on geriatric anesthesia pharmacology. A greater concern is dose adjustments based on smaller lean body mass and weight in elderly”, Akhtar, p. 335

Anesthetic Strategies • Metabolism of drugs dependent upon ________ may be affected. - *these changes may reduce _________ 30-40%* • As renal function declines, drugs met. by kidneys should be carefully administered, *ie ?*

• Metabolism of drugs dependent upon CYP450 may be affected. - *these changes may reduce clearance 30-40%* • As renal function declines, drugs met. by kidneys should be carefully administered, *ie neuromuscular blockers*

Inhalational Agents*** ? decreases by ~6% per decade after age 40 for volatile anesthetics

MAC decreases by ~6% per decade after age 40 for volatile anesthetics

``` Age differences in T1/2 B (elimination half-life) ~concept only Drug: fentanyl Young adults: Elderly adults: ```

Drug: fentanyl Young adults: 250 min Elderly adults: 925 min

``` Age differences in T1/2 B (elimination half-life) ~concept only Drug: midazolam Young adults: Elderly adults: ```

Drug: midazolam Young adults: 2.8 hr Elderly adults: 4.3 hr

``` Age differences in T1/2 B (elimination half-life) ~concept only Drug: vecuronium Young adults: Elderly adults: ```

Drug: vecuronium Young adults: 16 min Elderly adults: 45 min

Propofol • current lit→ at least ~X% reduction in the induction dose. - dose according to LBW (very old ~ 1mg/kg) - do NOT underdose induction! • Age-related changes in the elderly: - _________ levels of anesthesia - *inc/dec time to reach deeper stages of anesthesia*? - prolonged ___________ time

Propofol • current lit→ at least ~20% reduction in the induction dose. • Age-related changes in the elderly: - deeper levels of anesthesia - *increased time to reach deeper stages of anesthesia* - ----decreased circulation time - prolonged recovery time

Etomidate • Is/is not an anesthetic and amnestic, but is/is not an analgesic • *Often considered an _____ drug for the elderly d/t ?* • As with propofol, a much higher/lower induction dose is recommended?

Etomidate • Is an anesthetic and amnestic, but not an analgesic • *Often considered an IDEAL drug for the elderly d/t hemodynamic stability.* • As with propofol, a much lower induction dose is recommended (20-50% reduction in bolus doses

Thiopental • Central VOD is inc/dec? • X% reduction dose in an 80-year old compared to adult patient

Thiopental • Central VOD is decreased • 50-80% reduction dose in an 80-year old compared to adult patient

Midazolam*** • Elderly are MUCH more sensitive than younger individuals • Duration of action is ________ • Might contribute to ? • Midazolam→ _____________ (active metabolite)→excreted by ? • A X% reduction in dose from a 20 y/o to 90 y/o is recommended. (I do not give in patients over age 70)

prolonged postop delirium hydroxymidazolam, kidneys 75%

Opioids Pharmacodynamic changes are present within the opioid receptor. • inc/dec sensitivity to opioids? Pharmacokinetic changes, especially • opioid ___________ affect the choice of opioids used in the elderly • _______ metabolizes the opioids • _______ excrete metabolites • Metabolites of some opioids are ______ (codeine, morphine, demerol) and contribute to both analgesia and side effects!

Opioids • Pharmacodynamic changes are present within the opioid receptor. • increased sensitivity to opioids • Pharmacokinetic changes, especially • opioid metabolism affect the choice of opioids used in the elderly • Liver metabolizes the opioids • Kidneys excrete metabolites • Metabolites of some opioids are active (codeine, morphine, demerol) and contribute to both analgesia and side effects!

Fentanyl • a 50% inc/dec in the potency has been reported in the elderly, so 50% _________ in dose • inc/dec sensitivity

Fentanyl • a 50% increase in the potency has been reported in the elderly, so 50% reduction in dose • increased sensitivity

``` Remifentanil • *ultrashort-acting* • metabolized by _________ • perhaps *ideal*, but why? • dosage is X the bolus dosage of younger patients ```

Remifentanil • *ultrashort-acting* • metabolized by cholinesterase • perhaps *ideal*, no worries about kidney or liver issues • dosage is ½ the bolus dosage of younger patients

Demerol (meperidine) • _____ mu-agonist • metabolized to —>____________ (active met?)→ excreted by? ) • VERY long/short half-life—X hours • associated with postoperative ________ • is/is not recommended in the elderly?

Demerol (meperidine) • weak mu-agonist • metabolized to —normeperidine (active met)→ excreted by kidneys) • VERY long half-life—15-30 hours • associated with postoperative delirium • not recommended in the elderly (except maybe to tx shivering)

Neuromuscular blocking agents Pharmacodynamics are/are not significantly altered? Pharmacokinetics are/are not significantly altered?

Pharmacodynamics are not significantly altered • the ED95 is essentially the same for young and old patients • use lower end b/c of prolonged recovery time! Pharmacokinetics ARE significantly altered • onset to max block is delayed • metabolism and excretion prolonged in pts with hepatic &/or renal dysfunction • recovery time could be PROLONGED by as much as 50%

``` Perioperative outcomes (“Functional recovery after cardiac and noncardiac surgery is not the norm. Some studies report that fewer than X% of elderly patients are discharged back to their homes. Instead, many patients are discharged to long-term rehab facilities and nursing homes” (Akhtar, 2018, p. 337).( ```

50%

Preoperative assessment • review of geriatric syndromes • evaluation of frailty • *nutritional status (albumin

Preoperative assessment • review of geriatric syndromes • evaluation of frailty • *nutritional status (albumin <3, BMI <18.5, 10-15% wt loss over 6 mo) • assessment of functional status (hearing and vision impairments) • baseline cognitive status (Mini-Cog) and *document preop findings* • review of medications-polypharmacy • goals of care

Intraoperative monitoring | • Age alone is/is not an indication for invasive monitoring?

Intraoperative monitoring • Age alone is not an indication for invasive monitoring • Decision should be based on potential risks/benefits, the potential massive blood loss, patient’s ASA status, presence of comorbidities, and the planned surgery.

Choosing an anesthetic plan | Does one plan demonstrate improved outcomes?

NO!

IV anesthetics: review pronounced hemodynamic effects smaller doses required to achieve same anest depth doses of induction agents/opioids—dec ~25% benzodiazepines should be avoided, if possible meperidine should not be used in the elderly

Beer’s criteria: avoid these medications in the elderly (review?)

benzodiazepines transderm fentanyl agonists-antagonists methadone 1st generation antihistamines (diphenhydramine) anticholinergics (atropine, scopolamine) skeletal muscle relaxants (cyclobenzaprine)

``` Remember…(review) ❖Decreased skin elasticity *reduced skin and soft tissue perfusion *concerns? • Elderly patients are often dehydrated *assess intravasc vol status prior to induction *susceptible to hypovolemia→ severe hypotension overhydration→ CHF • Conservation of body heat • Concerns? Shivering? ```