Geriatrics

Question 1

By 2030, how much of the population will be older than 65?

Answer 1

20%

Question 2

Geriatric patients make up how many of the total hospitalizations? How much more likely to receive surgery than the non-elderly?

Answer 2

1/3 of hospitalizations
2-3x more surgery than non-elderly

Question 3

How common is memory decline?

Answer 3

40% of people > 60 years old

Question 4

What do CT/MRI’s show of the aging brain?

Answer 4

cerebral atrophy
reduced grey matter (d/t neuronal shrinkage)
decrease in white matter (causes progressive loss of memory, balance and mobility)
increased ventricular size

Question 5

What do animal studies show of the aging brain?

Answer 5

significant decrease in NT’s
No change in glutamate
EEG unchanged

Question 6

What are some changes we should account for with neuraxial anesthesia on geriatric patients?

Answer 6

decreased volume of LA required d/t decreased epidural space, increased permeability of dura, reduced CSF volume, and reduced number and size of myelinated fibers in the dorsal and ventral roots

Question 7

Why are the elderly more sensitive to neuraxial and peripheral blocks?

Answer 7

decreased inter-Schwann cell distance and decreased conduction velocity d/t reduced myelination across nerve fibers

Question 8

What are some cardiac changes in the elderly?

Answer 8

decreased myocytes
LV wall thickens and stiffens (higher filling pressure)
SA node cells decrease
conduction velocity decreases
decreased contractility
less Beta-adrenergic sensitivity
aortic valve becomes thickened and calcified

Question 9

Why do cardiac vessels stiffen in the elderly?

Answer 9

d/t the breakdown of collagen and elastin and reduced levels of endogenous NO
also d/t increased afterload and diastolic dysfunction

Question 10

What happens in the pulmonary system of the elderly?

Answer 10

loss of elastic recoil
loss of surfactant
enlarged bronchioles and alveolar ducts
early collapse of small airways during exhalation
increased anatomic dead space
impaired gas exchange

Question 11

What happens to the chest wall of the elderly?

Answer 11

osteoporosis leads to loss of vertebral height
vertebral column calcifies causing barrel chest
diaphragm flattens
chest wall stiffness leads to increased WOB

Question 12

What happens to the lung capacities of the elderly patient?

Answer 12

decreased VC
increased closing capacity and RV
TLC remains about the same d/t compensation
decreased FEV1 by 6-8% per decade

Question 13

What are some things that happen when we age that make our risk for aspiration higher?

Answer 13

weaker pharyngeal muscles decrease our ability to clear secretions
less efficient coughing
decreased esophageal motility
less protective upper airway reflexes

Question 14

What happens to the V/Q ratio in the elderly?

Answer 14

V/Q mismatch increases d/t increased FRC and increased CC (eventually CC exceeds FRC) which increases the alveolar-arterial oxygen gradient (shunting) and arterial oxygenation declines

Question 15

How is GFR impacted by advancing age?

Answer 15

it decreases 1 ml/min/m2

Question 16

What happens to the body’s response to aldosterone, vasopressin, and renin with aging?

Answer 16

response is blunted

Question 17

Which phase of liver metabolism is more impacted by aging?

Answer 17

Phase I (Redox and hydrolysis via CYP450)
Phase II (acetylation and conjugation not impacted as much)

Question 18

Which drugs should you avoid giving the elderly for PONV?

Answer 18

prochlorperazine, promethazine and metoclopramide

Question 19

What are some things that happen to the musculoskeletal system as the body ages?

Answer 19

muscle mass and strength decline
subcutaneous fat thins (making thermoregulation more difficult)
impaired wound healing
osteoartritis

Question 20

Older adults have decreased thermoregulation in part d/t less subcutaneous fat, but what else causes this?

Answer 20

lower vasoconstriction threshold (1 degree C less in persons aged 60-80)

Question 21

what are some predictors of 6 mo-1 yr mortality?

Answer 21

impaired cognition
recent fall
hypoalbuminemia
anemia
functional dependence
comorbidities

Question 22

Why are the elderly more at risk of long-term cognitive deficits post anesthesia?

Answer 22

anesthesia causes significant neuroinflammation and as the body ages the anti-inflammatory response is less robust

Question 23

What is the definition of Postoperative Cognitive Dysfunction (POCD)?

Answer 23

a measured decline in cognitive function that persists beyond the period expected as measured by mental examination

Question 24

What are the 4 factors thought to contribute to the pathogenesis of dementia?

Answer 24

1. amyloid beta
2. Tau proteins
3. calcium
4. Neuroinflammation (TNF, IL1)

Question 25

What causes amyloid beta plaques?

Answer 25

when synapses are broken amyloid beta is formed and it accumulates extracellularly to form amyloid plaques that disrupt cell membranes over time

Question 26

Describe the pathology of tau proteins...

Answer 26

When they are phosphorylated they aggregate into plaques and cause neurofibrillary tangles which can destabilize microtubules

Question 27

What two things in the OR can increase Tau protein phosphorylation?

Answer 27

decreased temperatures (by 2-3 decrees C) and repeated exposure to halothane, isoflurane and sevoflurane

Question 28

How is calcium related to neurotoxicity?

Answer 28

some patients may have a genetic mutation of the ryr1 receptor causing less dramatic Ca2+ release, leading to neurotoxicity. Volatiles and Succ exaggerate Ca2+ release from the endoplasmic reticulum

Question 29

Can you use Dantrolene to combat VA and Succ induced neurotoxicity?

Answer 29

No because it cannot cross the BBB

Question 30

Which inflammatory factors contribute to neuroinflammation?

Answer 30

Cytokines IL-6 TNF-alpha

Question 31

Are there any anti-inflammatory anesthesia drugs one can provide to modulate anesthesia induced inflammation?

Answer 31

dexamethasone, lidocaine and Toradol (not well studied)

Question 32

Which general anesthetics last the shortest period of time post-Op?

Answer 32

Propofol (TIVA) is the shortest then Desflurane followed by Isoflurane

Question 33

According to the Bedford study, how many patients (older than 50) experienced long-term or permanent mental deterioration post-anesthesia?

Answer 33

10 %

Question 34

According to the International study of Postoperative Cognitive Dysfunction what proportion of non-cardiac patients older than 59 experienced cognitive dysfunction at 1 week? After 3 months post-Op?

Answer 34

1 week: 22% 3 months: 7%

Question 35

What are some identified risk factors for increased cognitive dysfunction post-anesthesia in the elderly?

Answer 35

increased age duration of anesthesia lesser education second operation postoperative infection respiratory complications

Question 36

What are some anesthesia recommendations with regards to patients of advanced age?

Answer 36

1. use neuraxial/regional when possible 2. avoid long acting NMBD and reverse adequately 3. opioid sparing 4. neutralization of stomach acid 5. consider using EEG based titration 6. avoid hypotension 7. pad skin (and nerves) well 8. maintain normothermia

Question 37

drugs are slower to onset and have slower clearance in the elderly why?

Answer 37

Onset: decreased CO (longer time to get to effector organ) Clearance: kidneys and liver take longer to metabolize

Question 38

What are some drug challenges associated with the neuromuscular junction?

Answer 38

1. increased distance between axon and motor end plate 2. decreased concentration of ACh-R 3. decreased amount of ACh in the presynaptic vesicle 4. decreased release of ACh

Question 39

Which anesthesia drugs are not liver/ kidney dependent?

Answer 39

Succ Cisatricurium Remifentanil

Question 40

Pulmonary resection surgery has significant respiratory and cardiac complications in the elderly population. What tool can you use to evaluate odds of recovery?

Answer 40

via predicted postoperative FEV1

Question 41

How do you calculate the predicted postoperative FEV1 (ppoFEV1)?

Answer 41

Preop FEV1 % x (1 - % of lung tissue removed/ 100)

Question 42

There are 42 segments of the lung... how many are in each lobe?

Answer 42

RUL = 6 RML = 4 RLL = 12 LUL = 10 LLL = 10

Question 43

If your patient is to have a RLL lobectomy, what is their predicted postop FEV1 if their preop FEV1 is 70%?

Answer 43

RLL = 12/42 segments = 29% 70 x ((1 - 0.29)/100) = 50%

Question 44

What is the triad of preoperative assessment for thoracotomy surgery?

Answer 44

respiratory mechanics (as measured by the ppoFEV1) cardiopulmonary reserve (can patient climb two flights of stairs with < 4% decrease in SpO2) Lung parenchymal function (DLCO defined as PaO2 > 60, PaCO2 < 45)

Question 45

Based on ppoFEV1, what are the post-thoracotomy anesthetic considerations regarding emergence and extubation?

Answer 45

ppoFEV1 > 40% : extubate in OR if patient is alert, warm and comfortable ppoFEV1 > 30% : consider extubation if exercise tolerance and DLCO are good ppoFEV1 < 30%: staged weaning, consider extubation if > 20% with thoracic epidural analgesia