Anesthesia Implications for Geriatrics - Exam 2 Flashcards
1
Q
Nervous System
Memory decline is r/t ________, ________, and the aging brain.
A
- dementia
- alzheimer’s
elderly more active & read = less cog. decline
2
Q
Nervous System
What are the 3 neuro structural changes in the elderly?
A
- Cerebral atrophy
- decreased gray matter (neuronal shrinkage)
- decreased white matter (increase ventricle size)
progressive loss of memory, imbalance, mobility
3
Q
Nervous System
What are 4 reasons why elderly need less doses of LA in neuraxial?
A
- decreased epidural space
- increased permeability of dura
- decreased CSF volume
- decreased diameter/# of myelinated fibers in dorsal & ventral nerve roots
4
Q
Nervous System
Peripheral nervous system
________ - ________ cell distance is decreased.
Why is conduction velocity decreased?
What does this make elderly more sensitive to?
A
- inter-schwann cell
- decreased myelination across nerve fibers
- Neuraxial & PNB
5
Q
Cardiac
What 2 types of cells decrease in #?
A
- Myocytes
- SA node cells - susceptible to tachy & brady
6
Q
Cardiac
Why do the elderly have LV wall thickness?
A
- increased afterload from years of HTN
more pressure the heart has to pump against = L heart strain
7
Q
Cardiac
What happens to SVR and vascular compliance w/ aging?
A
- increased SVR (afterload)
- decreased vascular compliance
8
Q
Cardiac
What happens w/ the aortic valve and aging?
A
- becomes thick & calcified = aortic stenosis
9
Q
Cardiac
What does LV hypertrophy cause contractility to do? (increase/decrease)
What does the increased LV stiffness lead to?
A
- contractility decreases
- higher LV filling pressures (LVEDP) ventricle does not stretch w/ more volume
10
Q
Cardiac
What happens w/ beta-adrenergic sensitivity and the elderly?
A
- pts have a decreased response to beta stimulation
- they can’t increase HR and EF in stress
- more prone to decompensation - neuraxial esp.
11
Q
Cardiac
Why do the elderly have increased vascular stiffness?
A
- b/c of breakdown of collagen & elastin
12
Q
Cardiac
What does a reduction in the levels of endogenous NO lead to?
A
- less NO related vasodilation
- coronaries can’t dilate optimally in times of stress
13
Q
Cardiac
Increased vasc. stiffness leads to an early ________ ____ ________.
What does this mean?
A
- pressure wave deflection
- pressure travels through stiff vessels faster - returns to heart in systole instead of diastole
14
Q
Cardiac
What effects does an early pressure wave deflection have on afterload and diastolic function?
A
- increased afterload
- less diastolic blood flow - less support for DBP - less coronary perfusion
15
Q
Pulmonary
What are the 3 main structural changes that happen w/ aging?
A
- loss of elastic recoil & surfactant
- enlarged bronchioles and alveolar ducts
- loss of vertebral height, calcification of vertebrae and intercostal cartilage
16
Q
Pulmonary
The loss of elastic recoil causes lung compliance to do what?
A
- increase
- easier to get air in lungs/harder to get air out b/c collapse of small airways
17
Q
Pulmonary
Enlarged bronchioles and alveolar ducts happen as a result of what?
This leads to an increased ________ ________, and impaired ____ ________.
A
- early collapse of small airways in exhalation
- increased closing capacity
- impaired gas exchange
increased physiological DS (alveolar)
18
Q
Pulmonary
What changes does loss of vertebral height & calcification of vetebrae/intercostal cartilage cause?
A
- barrel chest
- diaphragm flattening
- CW stiffness
- SOB on exertion
- increased WOB
19
Q
Pulmonary
What are the 5 main functional changes that happen w/ the pulmonary system and aging?
A
- decreased VC
- increased CC
- increased RV
- decreased muscle mass
- weaker pharyngeal muscles
20
Q
Pulmonary
VC =
A
IRV + Vt + ERV
amount of air that can be moved in and out of the lungs
21
Q
Pulmonary
CC =
What happens w/ FEV1 in response to decreased muscle mass & increased closing capacity?
A
CC = CV + RV
* the point at which the small airways close
* FEV1 decreases 6-8% per decade
22
Q
Pulmonary
What happens w/ TLC?
A
- stays the same d/t compensation over time
23
Q
Pulmonary
What does weaker pharyngeal muscles cause w/ aging?
A
- decreased clearance of secretions
- less efficient coughing
- aspiration risk d/t decreased esophageal motility
- less protective upper airway reflexes
24
Q
Pulmonary
What causes a VQ mismatch w/ aging?
A
- FRC increases, BUT CC increases more
- airways can close in normal Vt
- shunt increases = less arterial oxygenation
25
# Renal
How much does GFR decrease by?
What conditions exacerbate a decline in renal function?
* GFR decreases by 1mL/min/m2/yr or 10mL/min/m2/decade **after 30y/o**
* DM, HTN, drugs, IVP contrast, dehydration
26
# Renal
Elderly pts have a decreased response to what 3 hormones?
1. aldosterone = hyponatremia
2. vasopressin (ADH) increased = dilutional hyponatremia
3. renin
**trouble balancing F/E**
27
# GI & Hepatic
What phase of liver drug metabolism is affected more by aging?
* phase 1 (oxidation, reduction, hydrolysis) - **CYP450**
* phase II - not affected (acetylation, conjugation)
28
# GI & Hepatic
What drugs that we commonly give are metabolized w/ phase I?
* narcotics & anesthetics
* **prolonged effects in elderly**
29
# GI & Hepatic
Do elderly have less or more PONV?
What drugs should we avoid?
* less
* avoid Prochlorperazine (Compazine), Phenergan, Reglan **b/c SE**
30
# Musculoskeletal
What are the 4 main changes that happen w/ the MS system and aging?
1. muscle mass & strength decline
2. subQ fat thins - less ability to thermoregulate
3. impaired wound healing
4. OA
31
# Thermoregulation
Why are the elderly more prone to hypothermia?
* **Vasoconstriction threshold lowers**
* they won't vasoconstrict until they get to a lower temp
* ***1 degree C less for adults 60-80***
32
What 3 things can we do to optimize surgical healing in elderly?
1. ensure adequate hydration
2. maintain normothermia
3. ensure good tissue oxygenation
33
What are the significant predictors of 6 month - 1 yr mortality in elderly?
1. impaired cognition
2. recent fall
3. hypoalbuminemia - compromised healing
4. anemia - tissue oxygenation
5. functional dep. to do ADLs
6. comorbidities
34
# Neurotoxicity
What are the 4 substances involved in the pathogenesis of dementia?
1. amyloid B
2. Tau
3. Calcium
4. Neuroinflammation (TNF, IL)
35
# Neurotoxicity
What is amyloid B?
What is its relationship w/ neurotoxicity/dementia?
* protein fragment - develops when synapse breaks down
* accumulates extracellularly in amyloid plaques
* may disrupt cell membranes
* **does not build up permanently**
36
# Neurotoxicity
How is amyloid B neurotoxic?
* interferes w/ synaptic fx
* impairs neurotransmission
* cog decline
37
# Neurotoxicity
What is Tau?
* protein that normally stabilizes microtubules (neurons)
38
# Neurotoxicity
How does Tau contribute to neurotoxicity/dementia?
* it is hyperphosphorylated and aggreated into Tau chunks
* disrupts the internal structure of neurons - cell death
39
# Neurotoxicity
What is the relationship b/w temp and Tau?
* decrease in temp 2-3 deg. C = increased Tau
* **Tau is not cleared w/ severe hypothermia**
40
# Neurotoxicity
What are the anesthesia precautions w/ Tau?
* repeated exposure to Halothane, Iso, & Sevo = increased phosphorylation of Tau
41
# Neurotoxicity
How does Calcium release cause neurotoxicity?
* exaggerated release (ryanodine or IP3 receptors)
* MH - genetic predisposition w/ volatiles or succ
* causes - mitochondrial damage, cell death, neuronal dysfunction & death
42
# Neurotoxicity
How does neuroinflammation contribute to cog. decline?
* release of inflammatory factors
* cytokines
* IL-6
* TNfa
43
# Neurotoxicity
What are possible drugs for anti-inflammatory prophylaxis?
* dexamethasone
* lidocaine
* toradol
44
# Anesthesia & Brain
What anesthetic agents are most associated w/ cog decline?
* Iso > Des > Prop
**TIVA maintenance of choice**
45
Risk Factors for the development of POCD: (6)
1. increasing age
2. duration of anesthesia
3. lower SES
4. 2nd surgery
5. post op infection
6. resp. complications
46
What are 7 anesthetic implications we can do for the elderly?
1. neuraxial/regional anesthesia
2. avoid long-acting NMBD & reverse adequately
3. opioid sparing strategies
4. Neutralize stomach acid w/ non-particulates (Bicitra)
5. EEG based titration
6. avoid HoTN - can't compensate
7. pad skin & nerves
47
# Drug Challenges
What are the drug challenges r/t **decreased CO?**
* slower distribution to site of action
* slower redistribution
* slower distribution to metabolic organs
**slower onset & clearance**
## Footnote
*less redose of meds needed*
48
# Drug Challenges
What are the 4 drug challenges r/t the NMJ?
1. increased distance b/w axon & motor end plate
2. decreased concentration of Ach
3. decreased amount of Ach in presynaptic vesicle
4. decreased release of Ach
**less efficient NMJ - less NMBD required**
49
# Drug Challenges
What happens to drugs that depend on kidney/liver metabolism?
* prolonged effect & DOA
* decreased re-dose needed in maintenance
* **delayed recovery for non-depolarizers**
50
What is the pre-op assessment for thoracic non-cardiac surgery?
1. TTE - r/o pulm. HTN
2. poor exercise tolerance, DM, CAD, or CHF
3. perfusion imaging w/ dobutamine stress test or persantine thallium scan
4. coronary angio
5. surgical revascularization
6. case by case management
**if no to any of the above = candidate for lung resection surgery**
51
What is the formula for ppoFEV1?
ppoFEV1 = pre-op FEV1% **x** (1- % lung tissue removed/100)
52
What do we want a ppoFEV1 to be before we extubate our pts?
at least 40%
53
What 3 things are a part of the "three-legged" stool of pre-thoracotomy resp. assessment?
1. Respiratory mechanics
2. cardiopulmonary reserve
3. lung parenchymal function
54
# Pre-thoracotomy resp. assessment
How do we assess Resp. Mechanics?
1. FEV1 ppo >40%
2. MVV
3. RV/TLC
4. FVC
55
# Pre-thoracotomy resp. assessment
How do we assess cardiopulm. reserve?
1. VO2 max (>15mL/kg/min)
2. stair climb > 2 flights
3. 6 min walk
4. exercise SpO2 <4%
56
# pre-thoracotomy resp. assessment
How do we assess lung parenchymal function?
1. DLCO (ppo > 40%)
2. PaO2 > 60
3. PaCO2 < 45
57
# Post-thoracotomy anesthetic management
What do we do if ppoFEV1 is > 40%?
**extubate in operating room if:**
* pt is AWaC
* (alert, warm, and comfortable)
58
# Post-thoracotomy anesthetic managment
What do we do if the ppoFEV1 is **30-40%?**
**consider extubation based on:**
* exercise tolerance
* DLCO >40%
* V/Q scan
* associated diseases
59
# Post-thoracotomy anesthetic management
What do we do when the ppoFEV1 is **< 30%?**
* Staged weaning from mechanical ventilation
* consider extubation if > 20% plus: thoracic epidural analgesia
60
How many subsegments are in the R lung?
RUL: 6
RML: 4
RLL: 12
61
How many subsegments are in the L lung?
LUL: 10
LLL: 10
