Gerontology Pathophysiology Flashcards
1
Q
What is life expectancy?
A
The average age that members of a population are expected to obtain when premature causes of death are taken out
2
Q
What is life span?
A
The average age of all those that die of natural causes , absence of disease or trauma
3
Q
What factors have increased longevity in the 20th century?
A
Advanced public health
Nutrition
Education
Social services
4
Q
What age group is said to be elderly?
A
Those older than 65 years old
5
Q
What is the fastest growing segment of the population?
A
Elderly people who are greater than 90 y/o
6
Q
What often complicates geriatric surgical procedures?
A
Infections, Organ system failure and prolonged hospitalization
7
Q
What is senescence?
A
Progressive deterioration of physiologic functions with aging
8
Q
What is longevity?
A
Summation of forces that avoid or retard senescence
9
Q
What is the formal definition for aging?
A
Progressive loss of physiologic research necessary to maintain homeostasis
10
Q
What is frailty?
A
Loss of physiologic reserve for a specific biologic system, especially in the presence of stressors
11
Q
Why shouldn’t a patients age be solely based on a number?
A
The elderly are neither a medically nor physically homogenous patient group such that rigid chronologic definition has little value other than administrative or epidemiological applications
12
Q
What does the term aging suggest about a patients body?
A
Degenerative changes in structure and functional reserve of organs and tissues
13
Q
When does functional decline begin to occur in the body?
A
Anatomic and physiologic changes begin in middle line in almost every system
14
Q
What are the three elements that contribute to damage to the elderly in the perioperative period?
A
Limited end organ reserve
Any underlying disease
Actual stress or the peri operative period
15
Q
What components make up frailty?
A
Disease
Dependency
Disability
16
Q
What are characteristics of frailty?
A
Wasting Loss of muscle mass/strength Decreased balance Slow performance/inactivity Decreased cognitive function
17
Q
What is multidimential geriatric syndrome?
A
Characterized by a loss of physiologic reserve that causes the patient to be vulnerable to adverse events
18
Q
What helps to identify populations at greatest risk of events in the elderly population?
A
Biologic markers of age and physiologic reserve
19
Q
What is the general rule of thumb for loss of organ system function per year?
A
Normally organ systems lose about 1% of function per year after 30 years of age
20
Q
What is the hallmark sign of aging?
A
The lack of functional reserve in response to stress
21
Q
What is the best indicator for biologic age?
A
Exercise tolerance, it is an important predictor of post op outcomes in the elderly
22
Q
How would one determine organ system functional reserve?
A
Maximum capacity - basal level of function
23
Q
What organ reserves can be tested prior to surgery?
A
Cardiopulmonary with stress test
24
Q
What organ systems functional reserves are assumed for surgery?
A
Renal, Hepatic, Immune and Nervous system
25
Why is it important to determine an organ systems functional reserve prior to surgery?
To determine safety margins
26
How does aging affect cerebral blood flow and brain mass?
Decreased cerebral blood flow and brain mass
27
Does age affect cerebral auto regulation?
No, cerebral auto regulation is preserved
28
What is thought to cause a decrease in brain weight with age?
6-7% decrease in brain mass thought to be due to neuronal shrinkage rather than neuronal loss
29
How is white and gray matter affected by age?
Gray and white matter both decrease and CSF increases
30
What is thought to contribute to parkinsons disease in the elderly?
Decrease in dopamine in the substantia nigra
31
What is thought to contribute to senile demential in the elderly?
Decreased Ach in the hypothalamus
32
What is thought to cause depression in the elderly?
Decrease in Norepinephrine and 5-hydroxytryptamine in the hypothalamus
33
What neurotransmitter levels seem unaffected by age?
Glutamate
34
What additional factor other than neurotransmitters are thought to contribute to depression and dementia in the elderly?
Sleep patterns altered, decreased REM sleep
35
How is memory affected by aging?
Impaired short term memory but long term memory may be preserved
36
What factors increase an elderly patients risk for post op delirium and cognitive dysfunction?
Mental confusion with difficulty in temporal and spatial orientation
37
Why are elderly patients prone to orthostatic HoTN?
Impaired postural control
38
Why do elderly patients often develop arrhythmias?
Impaired autonomic regulation of CV function
39
Why is it easier to achieve a higher level of anesthesia with a lower volume of LA in the elderly?
There is a decrease in area of the epidural space
40
What nervous system is affected more by age?
CNS is more effected than the peripheral nervous system
41
Why are reflexes slower in the elderly patient?
Loss of myelin in PNS and
| Decreased number of motor neuron in the spinal cord
42
What causes an increase in size of the heart in elderly patients?
Concentric ventricular hypertrophy (increase in wall thickness)
43
What causes concentric ventricular hypertrophy in the elderly?
Response to increase LV after load due to decrease in arterial distensibility
Cardiac myocytes hypertrophy but are less in number
44
How is cardiac connective tissue affected by age?
Increase in cardiac connective tissue leading to fragmented elastin replaced by collagen and increase wall stiffness and reduces diastolic compliance
45
What do the elderly depend on for preload?
Markedly dependent on atrial kick for preload
46
What is the most common supra ventricular rhythm in patients greater than 65y/o?
A-fib
47
What can precipitate congestive heart failure in the elderly?
Preoperative increase in blood volume or a decrease in contractility
48
How is heart rate altered with age?
No alterations of resting heart rate with age, maximum heart rate achievable decreases from 200-->160 b/m
49
What causes an increase in susceptibility to supraventricular arrhythmias and ventricular ectopy with age?
Fibrous infiltration of SA node with loss of pacemaker cells
50
Which parts of the heart are unchanged by age?
A-V node and bundle of his
51
Why is there a decreased responsiveness to cardiac beta adrenergic agonists with age?
Reduced receptor numbers or affinity and there is a decrease in generation of cyclic adenosine monophosphate after beta receptor activation
52
How are baroreceptors affected by age?
Response to decreased arterial pressure attenuated
May cause postural HoTN
HoTN with PPV, especially if patient is dehydrated
53
What vessel changes lead to an increased incidence of aortic aneurysms in the elderly?
Less distensible vessels from thickened intimate and media
54
What is thought to contribute to HTN in the elderly?
Large vessels become tortuous, elongated and dilated
55
What causes a change in pulse wave of an a-line on an elderly patient?
Normal cushioning effects is impaired, reflected back from peripheral circulation and augments systolic pressure
56
What is the importance of endothelium?
Important regulator od vasomotor response, coagulation, fibrinolysis, immunomodulation, vascular growth and proliferation
57
How does aging affect the endothelium?
Aging alters endothelial structure even in absence of disease
58
What accelerates endothelial function?
Smoking, DM, HTN and hyperlipidemia
59
What are characteristics of endothelial dysfunction?
Decreased ability to dilate blood vessels in response to physiologic or pharmacologic stimuli
Decrease NO in all vascular beds
Reduced vasodilating response
Diminished B2 and alpha responses
60
What mechanism is relied on in the elderly to increase SV?
Frank starling mechanism
61
What respiratory changes are seen in the elderly?
Decreased lung volumes and Reduced efficiency of gas exchange
62
Why do the elderly exhibit signs similar to that of emphysema?
Alveolar septa lost and decreased surface area
63
Why us lung recoil decreased with age?
Loss of lung elasticity
64
How is the residual volume affected by age?
Increased ratio of residual volume to total lung capacity
65
How are closing volumes affected by age?
Increased closing volume leading to small airway closure at larger lung volumes (tidal volume occurs below closing volume)
66
What is a common pulmonary problem when inducing the elderly with anesthesia?
V/Q mismatching from anesthetic induced depression of active hypoxia pulmonary casoconstriction
67
What is the primary cause of decreased lung volumes in the elderly?
Restrictive functional impairment, increased thoracic cage rigidity restricts chest expansion
68
What compensatory mechanisms are used when the chest wall becomes restrictive in the elderly?
Diaphragm and abdominal muscles compensate
69
What is the maximum breathing capacity of that of a 20y/o compared to an elderly patient?
20y/o = 100L/min
| Elderly: 30-40L/min
70
What is the only lung capacity unaffected by age?
TLC remains relatively constant
71
How is the VC affected by age?
Progressive loss of VC
72
How is RV and FRC affected by age?
Progressive increase
73
What is considered to be a normal PO2 in elderly patients greater than 60y/o?
81 mean, 71-90mmHg
74
Why do the elderly experience a markedly attenuated increase in HR and minute ventilation in response to increases in PaCO2 or decrease in PaO2?
Decreased peripheral chemoreceptor sensitivity
Reduced respiratory muscle activity
Decreased respiratory mechanical efficiency
General respiratory deconditioning
75
What anesthetic agents further attenuate the response to hypercarbia and hypoxia in the elderly?
Opioids, sedatives and volatile agents
76
Why do the elderly have a reduced cough effectiveness?
Desensitization of airway epithelial cough receptors and impaired muscle function
77
When is the highest prevalence of snoring in the elderly?
Highest in the 7th decade, associated with increased risk of stroke
78
How are the kidneys affected by age?
Renal blood flow and GFR decline
79
What is thought to cause a decrease in renal mass with age?
Decreased number of functional renal glomeruli, disproportionate loss of cortical nephrons and medullary nephrons relatively preserved
80
How does the decrease in tubular excretion affect the elderly?
Impaired sodium handeling
Decreased ability to concentrate
Decreased drug excretion and
Impaired fluid handeling
81
Why does Creatinine remain normal in elderly patients even if pathology is present?
Decline in skeletal muscle mass
82
Why do elderly patients have a decreased volume of distribution?
They have an increase percent of body fat and decrease intracellular water content
83
What sex has less synthesis of plasma cholinesterase in the elderly population?
Males
84
How are enzyme activities of the liver affected by age?
Appears to be preserved
85
Why is there an increased incidence in glucose intolerance and DM in patients older than 70?
Due to decreased pancreatic function
86
What changes occur with decreased renin production in the elderly?
May lead to decreased plasma aldosterone production
87
Why is thermoregulation impaired in the elderly?
Thermal stress poorly tolerated
Age related decrease in muscle mass
Unable to efficiently conserve heat
88
What an appropriate focus in the pre operative period for the geriatric patient?
Evaluation of physical status and identification of age related disease rather than aging itself
89
What are the components of Friedman's model and how many places a patient at risk?
```
Weight loss
Exhaustion
Weak grip strength
Slow walking speed
Low physical activity
Three or more of these place a patient at risk and are considered frail
```
90
Why do minor insults in the elderly population often result in large changes?
When a complex system fails, it fails with higher order functions first
91
What is the primary determinants of hospital mortality?
Age
Pre operative disease
The site of surgery
92
What should be thoroughly assess prior to airway manipulation in the elderly patient?
Extension and rotation of the head: mental status changes could reflect vertebrobasiliar arterial insufficiency or the patient could have cervical arthritis
Cervical arthritis may be present
93
Why is HoTN often seen in the elderly during induction?
Diuretic use
Decreased thirst
Age related decrease in renal capacity to conserve water and sodium
94
Why are the elderly sensitive to fluid overload?
Decreased left ventricle compliance
95
How is pharmacokinetics affected by age?
Overall reduced drug clearance from decreased renal and hepatic function
96
Why does Reglan in the elderly prolong the effects of succyncholine and remifentanyl?
Interferes with the action of plasma cholinesterase
97
How is the dose of hypnotics altered with age?
Decrease with age
98
How should opioid doses be altered in the elderly?
Decreased the initial dose by 25-50% to achieve desirable serum levels and compensate for reduced rate of clearance
99
Which non depolarizers are unaffected by age?
Atracurium and Cisatracurium (Hofmann elimination)
100
How should the anesthetic provider dose reversal for the elderly?
Reversal agent dosages are not modified in the elderly
101
How much does the MAC change with age?
MAC decreases 6.7% per decade of life
102
What types of surgeries are associated with post op delirium in the elderly?
Ophthalmologic, cardiac and hip surgeries
103
When does interval delirium occur in the elderly?
POD 1 or 2
104
What are the four factors of surgical risk and outcome in the elderly?
Age
Patient physiologic status and coexisting disease
Surgery elective or urgent
Type of procedure
