Lecture 2: Diseases of Aging and Anesthetic Considerations AL Flashcards
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.
Contributors to Aging:
- *genes contribute 25% to longevity
- nutrition
- lifestyle
- environment
- chance
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
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
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.
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
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
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!
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
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
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
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
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
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
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
Renal, GI, Immune, and Endocrine changes?????
• liver size, perfusion, and hepatic blood flow inc/dec?
• Are these significant? ???????????
decreases
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
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!
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
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
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?
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?
