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
