Geriatric considerations Flashcards
Elderly patients disproportionately utilize
more medical care
40% of surgery/procedures performed on elderly
Describe oxidative damage*
free radicals (reactive oxygen species) that are byproducts of oxygen use/metabolism that can damage chromosomal DNA–> impair gene function, damage mitochondrial DNA & damage telomeres
Describe DNA damage & repair**
age related increases in somatic mutations & other DNA damage occur–> permanent alterations in DNA sequences & function
- centenarians who have good health have higher levels of PARP-1
- telomere length related to mortality
Describe environmental factors in the biology of aging:
lower calorie diet leads to longer lifespan
Describe malfunction of proteins in the biology of aging:
damaged, misfolded or malfunctioning proteins accumulate over time; seen in Parkinson’s disease, Alzheimer’s disease, & senile cataracts
Describe mitochondrial senescence as it relates to the biology of aging
increased incidence of mutated mitochondrial DNA noted in aging brain tissue, muscle cells, and gut epithelium
Physiologic effects of aging affect the
CNS, CV, respiratory, renal system, fluids & electrolytes, GI, immune, endocrine, body composition, and frailty
___________ in the brain undergo structural changes
all major cell types*****
neuronal death, synaptic loss, glial cell reactivity
With aging, there is a _____ in neuronal regenerative capacity
reduction
Mass of brain ____ 15% with aging with ____ in CSF volume
decreases; increases
Neural plasticity
decreases
_______ in nerve conduction velocity
decrease
Elderly patients have an increased risk of
postoperative delirium or cognitive dysfunction
There is a ________number of myelinated fibers
decreased
In the CNS, there are decreased
alpha 2 agonist receptors
_____ signaling becomes impaired in the eldelry
Cholinergic & dopamine
In the CNS for elderly patients, there are decreased
neurotransmitter activity- decreased glutamate & GABA binding sites
decreased cerebral blood flow
decreased cerebral metabolic rate
Elderly patients have an increase in susceptibility to
metabolic stress
Intellectual functioning, attention, memory, & psychomotor function ______ with age
decline
Describe the anesthetic considerations for elderly patients:
increased sensitivity to drugs
- Decreased number of receptors
- BBB more permeable
- Exaggerated response to CNS-depressant drugs
- Decrease induction agents 50%**
With neuraxial anesthesia in the elderly:
decreased myelinated nerve fibers causes a risk for neural damage
volume of CSF decreases
Enhanced spread of LAs
DECREASE dose of LA’s for spinal/epidural block
difficulty with placement due to anatomic changes
Describe the two major structural effects in blood vessels in the elderly patient:
stiffening & atherosclerosis**
With the CV system in elderly patients, they will have
decreased tissue elasticity/less compliance
-increased stiffness in tissues
will see stiffening & atherosclerosis of blood vessels
INCREASED afterload due to stiffer arteries
Describe changes to the left ventricle with aging:
LVH develops*
myocardium prone to ischemia*
Describe how blood pressure changes in the elderly individual.
systolic blood pressure increases 5 mmHg per decade until age 60, & then increases 10 mmHg per decade
systolic function is abnormal
Elderly individuals have mismatch
between supply & demand
Describe increases you may see for CV in the elderly.
incidence of heart failure increases
increase in ventricular septal thickness
increase in LA size
increased incidence of aortic sclerosis & stenosis
Describe the electrical system of the heart in the elderly.
Electrical system of heart DECLINEs with age
-pacemaker cells reduced
prolongation of PR, QRS, & QT intervals
INCREASED incidence of dysrhythmias**
resting heart rate slows
increased incidence of pacemakers and/or AICD
increased heart rate variability
decrease in maximum heart rate in response to exercise
The most common complication and leading cause of death in the postoperative period for elderly patients is______
myocardial infarction****
Describe the anesthetic implications of the CV system.
decreased end-organ adrenergic responsiveness
prolonged circulation time
widened pulse pressure
decreased sensitivity to baroreceptors in aortic arch in response to BP changes
decreased CO & SV
decreased sensitivity to beta-adrenergic modulation**
Changes in cardiovascular physiology include:
decrease in peak heart rate & CO
slower resting heart rate
decreased ability to increase CO by change in HR
decreased ability to withstand stress
Describe chest wall compliance in the elderly.
decreased chest wall compliance due to calcifications
decreased intercostal muscle mass
further decreasing chest wall compliance due to flattening of diaphragm & loss of intervertebral disc height
Describe the relationship between FRC & closing volume.
Residual volume, closing volume and FRC increase** with age
TLC remains the same
Closing volume exceeds FRC in supine position at age 45 & exceeds FRC in upright position at 65
Describe mechanical changes of the respiratory system in the elderly.
progressive decrease in elasticity changes respiratory mechanics & alveolar architecture
- chest wall compliance & vital capacity decrease
- lung compliance, work of breathing, and residual volume increase
- decreased endurance of respiratory muscles
Elderly individuals are more prone to
respiratory failure**
Describe changes in gas exchange of the respiratory system of the elderly.
Reduced oxygen exchange at alveolar level*******
reduced functional alveolar surface area for gas exchange
reduction in arterial oxygen tension
reduced elastic tissue in lung
increased intrapulmonary shunting
increase in V/Q mismatch
PaO2 decreases at a rate of
0.35 mmHg per year
Elderly individuals have an increased tendency for airways
to close
closing volume exceeds FRC
More prone to atelectasis****
Decreased how residual volume & FVC & Fev1 change in gas exchange.
residual volume increases
FVC & FEV1 are decreased
Describe changes in the respiratory sensing mechanism of the elderly.
decreased ability to clear secretions
increased risk of aspiration**
reduced respiratory drive in response to hypoxia, hypercarbia, & resistive load
increased airway reactivity
Describe changes in the renal system of the elderly.
decreased function with normal aging
decreased renal blood flow
decreased renal mass
reduced clearance of hydrophilic agents & hydrophilic metabolites
The renal system is unable to
self-regulate due to renal vascular dysautonomy- attenuated autonomic renal vascular reflexes that protect from hypo/hypertensive events
The renal system in the elderly has
tubular dysfunction
medullary hypotonicity
tubular frailty
The aging kidney is more susceptible to
injury***
The renal system has a decreased ability to
accommodate hemodynamic changes
-decreased renin & aldosterone production
decreased GFR & decreased ability to excrete free water
Describe thirst response and volume sensitivity in the elderly.
diminished thirst response
decreased sensitivity to volume & osmoreceptors
The best indicator of drug clearance is
creatinine clearance
Patients with renal impairment, may be at increased risk for:
- fluid overload
- accumulation of metabolites & drugs
- decreased drug elimination
- prolonged effects of anesthetic drugs & adjuncts
- electrolyte imbalances
- arrhythmias
Describe the hepatic function of the elderly.
liver mass decreases decreased blood flow decreased functional hepatic reserve in elderly decreased drug metabolism prolonged half-life
Describe phase 1 & phase 2 drug metabolism in the elderly.
phase 1 drug metabolism is variable
phase 2 drug metabolism is not significantly altered
Describe serum albumin & alpha-1 acid in the elderly
serum albumin decreases
and alph-1 acid glycoprotein increases
Describe the GI system of the elderly.
decreased motility of upper esophageal
decreased colonic function
decreased GI immunity
decreased GI drug metabolism
Describe the immune system of the elderly.
reduced activity of immune cells
increased levels of cytokines & chemokines
decreased T & B cell function
reduced ability to fight infection & control cancers
Describe the endocrine system of the elderly.
reduce hormone production
impaired endocrine function
impaired glucose homeostasis
deficiencies of insulin, thyroxine, GH, renin, aldosterone & testosterone
Resting metabolic rate decreases
1%/year after 30
decreased lean body mass
_____ is a major risk factor for CV disease.
Diabetes****
Describe what happens to the pancreas in the elderly.
decline in number and function of pancreatic islet beta cells
-decreased insulin secretion
-increased hepatic production of glucose
-impaired production of fats/proteins
increased incidence of glucose tolerance or diabetes
