Geriatric

Question 1

What year will 20% of the population be greater than 65 years old.

Answer 1

2030

Question 2

What percentage of people older than 60yo will experience memory decline? How can we prevent it?

Answer 2

40%

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Question 3

What structural changes occur in the brain as a part of aging?

Answer 3

Cerebral atrophy, decreased gray matter (neuronal shrinkage not loss), and decreased white matter (increased in ventricular size and progressive loss of memory, balance, and mobility).

Question 4

Animal studies have shown a decrease in which neurotransmitters as age progresses?

Which NT stays the same?

Answer 4

Dopamine, ACh, norepi, serotonin

No change in glutamate.

Question 5

What 4 reasons do elderly patients require less neuraxial anesthesia?

Answer 5

• Decreased epidural space
• increased permeability of dura
• decreased volume of CSF
• decreased diameter/number of myelinated fibers in dorsal and ventral nerve roots

Question 6

How does the peripheral nervous system change as we age?

Answer 6

• Inter-schwann cell distance (node of ranvier) distance decreases.
• conduction velocity decreases

Question 7

What cardiac (heart only) changes occur as we age?

Answer 7

• Myocyte # decreases
• left ventricle wall thickens.
• SA node cells decrease
• conduction velocity decreases
• aortic valve thickens and calcifies.
• decreased contractility
• increased ventricular stiffness
• higher filling pressures
• less beta adrenergic sensitivity

Question 8

What usually causes age related left ventricular wall thickness to increase?

Answer 8

Hypertension over time

Question 9

What happens when we lose SA node cells?

Answer 9

We are more susceptible to tachy and brady arrhythmias

Question 10

What does less beta-adrenergic sensitivity cause?

Answer 10

Decreased maximal heart rate and EF during stress

Basically the SNS can’t kick Off the fight or flight response to maintain CO through tachycardia when things like aesthetics drop their blood pressure.

Question 11

Why do blood vessels get stiff as they age?

Answer 11

Breakdown of collagen & elastin
Less endogenous NO release
Early wave deflection (increased afterload, diastolic dysfunction)

Question 12

What structural changes occur in the lungs as we age?

Answer 12

• Loss of elastic recoil and loss of surfactant
• increased lung compliance
• Enlarged bronchioles and alveolar ducts
• loss of vertebral height and calcification of vertebra

Question 13

What changes in lung capacities/volume/breathing when we have enlarged bronchioles and alveolar ducts?

Answer 13

Early collapse of small airways during exhalation.

We have increased anatomic dead space, increased closing capacity, and impaired gas exchange

Question 14

What is closing capacity?

Answer 14

The amount of air left in the lungs when the small airways start to close off.

Question 15

What physiologic changes occur with loss of vertebral height and calcification of vertebra?

Answer 15

• Barrel chest
• Diaphragmatic flattening
• Chest wall stiffness leading to increased work of breathing.

Question 16

What lung volumes/capacities change as we age? Which stay the same?

Answer 16

Change:
- decreased vital capacity
- increased closing capacity
- increased residual volume

Same: total lung capacity

Question 17

How much does your FEV1 change as you age?

Answer 17

Decreases by 6-8% per decade

Question 18

What effects does weaker pharyngeal muscles have?

Answer 18

• Decreased clearance of secretions
• less efficient coughing
• decreased esophageal motility
• less protective upper airway reflexes

Question 19

How does V/Q mismatch change with age?

Answer 19

FRC increases slightly while closing capacity increases a lot. This causes increased shunting leading to decline in arterial oxygenation.

This is the most important MOA for alveolar-arterial oxygen gradient.

Question 20

How much does GFR decrease as we age?

Answer 20

1 ml/min/m2 per year after the age of 30

Question 21

What renal changes occur as we age?

Answer 21

Decreased GFR, blunted response to aldosterone, vasopressin, and renin leading to trouble adjusting fluid and electrolytes

Also retention and UTI’s are more common.

Question 22

What types of hepatic metabolism decline as we age?

Answer 22

Phase 1 metabolism: oxidation, reduction, hydrolysis via CYP450 enzymes.

Question 23

What types of hepatic metabolism do not change as we age?

Answer 23

Phase 2: acetylation and conjugation

Question 24

What PONV medications should we avoid in elderly patients?

Answer 24

Prochlorperazine, promethazine, metoclopramide

Question 25

What is the vasoconstriction threshold for thermoregulation for the elderly compared to adults < 60 yo?

Answer 25

1 degree Celsius less for adults 60 - 80 years old

Question 26

What are significant predictors for the elderly of 6-month to 1-year mortality?

Answer 26

• impaired cognition
• recent fall
• hypoalbuminemia
• anemia
• functional dependence
• comorbidities

Question 27

How does surgery cause long term POCD in the vulnerable brain?

Answer 27

Surgery and anesthesia cause peripheral inflammatory response and release neural afferent signals which both lead to neuroinflammation. In the vulnerable brain, this causes a dysfunctional anti-inflammatory response leading to exaggerated neuro-inflammation and acceleration of alzheimer’s/dementia pathology.

Question 28

What are the 6 neurotoxicity factors?

Answer 28

• Amyloid B
• tau
• calcium
• neuroinflammatory factors (cytokines, IL-6, TNFa)

Question 29

How does amyloid B develop and what does it lead to?

Answer 29

It is a fragment of the synapse when it breaks down and has an unknown function.

It builds up extracellularly to form plaques and may disrupt cell membranes over time.

Question 30

How is amyloid B affected by anesthesia?

Answer 30

Halothane showed to increase amyloid plaque leading to accelerated onset of Alzheimer’s / dementia in older mice.

Unclear translation to humans.