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48 Cards in this Set
- Front
- Back
Reduction in CI is from
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less requirement, not degeneration. Contractility not changed until 8th decade.
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does he heart atrophy with age?
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The heart does not atrophy with age.
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Aging reduces the _______ and _________ responses to adrenergic stimulation and beta=agonists.
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Aging reduces the inotropic and chronotropic responses to adrenergic stimulation and beta=agonists. Less EF enhancement under stress.
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The stiffer ventricle and atrium do not undergo complete relaxation until
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relatively late in diastole and passive ventricular filling, which occurs during early diastole, is significantly reduced.
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Progressive change in _______ function, dependent of synchronous function.
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distolic
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Small decreases in _______ (PPV, hemorrhage, vasodilators) may significantly compromise SV.
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venous return
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Systolic HTN with increased arterial pulse pressure is a major CV risk factor; caused by
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increased large artery stiffness d/t fibrotic replacement of elastic tissue. Reduces the ability of the aorta and large arteries to store hydraulic energy and increased vascular impedance to ejection of stroke volume. Leads to a prgressive and sustained rise in LV wall tension and workload that produces symmetric ventricular hypertriophy.
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"Ringing" charachteristic of radial artery waveform in geriatric partients from
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incresed vascular stiffness and loss of arterial cross-sectional area that cause increased reflection of radial artery waveform.
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Age related loss of elasticity occurs in the lungs and CV system; an increase in fibrous connective tissue in lung parenchyma and
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degeneration/cross-linking of lung elastin.
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All elderly patients eventually demonstrate some degree of emphysema-like increases in
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lung compliance, but calcification and stiffening of costrochondral joints reduce CW compliance so net pulmonary compliance is essentially unchanged. Nevertheless, loss of lung elastic recoil is the primary anatomic mechanism by which aging exerts deleterious effects on pulmonary gas exchange.
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Breakdown of alveolar septae also reduces total alveolar surface area, increasing both
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anatomic and alveolar dead space. This causes increased shunting and dead space.
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Closing capacity/volume
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increases. Small airways patency is compromised.
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VC is
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compromised because RV increases at the expense of IRV and ERV.
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Skeletal calcification and increased airway resistance
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increase work of breathing and predispose geriatric patients to postoperative ventilatory failure.
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CV and ventilatory response to hypoxia or hypercarbia is
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delayed in onset and is smaller.
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Opioid induced CW rigidity occurs more
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frequently.
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Hepatic enzyme function is
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unchanged but liver tissue mass declines 40% by 80 years and hepatic blood flow is proportionally reduced.
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Loss of hepatic tissue mass largely explains the reduced
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rates of plasma clearance and prolonged clinical effects of narcotics.
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1/3 of renal mass lost by 80 years. RBF decreases by
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10% per decade in early adulthood, especially in renal cortex, although the loss is masked by diffuse interstitial fibrosis and increase in intra-renal fat. 1/3 of glomeruli and tubular structures disappear and sclerosis impairs filtration by producing diverticula and impairing arteriole continuity.
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Serum creatinine remains normal because of
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loss of skeletal muscle mass
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Geriatric patients do not require a unique fluid replacement protocol, but do
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have a lower functional reserve.
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Diminished thirst, poor diet and diuretic agent use for tx of HYN predispose debilitated elderly to
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intracellular dehydration.
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Decreased immune responsiveness, decreased B and T-cell activity, immunoglobulin E. Elderly are predisposed to
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strep pneumonia, meningitis and septicemia. Sepsis is 2nd to respiratory failure in M/M with trauma.
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Changes in body composition reduce basal metabolic requirements
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by 10-15%. Impaired thermoregulatory vasoconstriction. 2x faster loss of heat.
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glucose
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Impaired of ability to handle glucose challenge, even though insulin release/timing is normal. Impairment of insulin function or tissue sensitivity.
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Men lose 10-15 of TBW from
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adipose gain and muscle loss..limited to intracellular compartment.
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Plasma volume, red cell mass and ECF volumes
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remain unchanged.
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Decreased circulating blood volume are typically only in
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bedridden or those with essential HTN.
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Brain mass decrease
The most active, specialized neurons suffer the most. |
20% by 80 years (mostly grey matter/neruons. glial unchanged) CSF volume increases to offset. (low-pressure hydrocephalus).
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Decreased CBF is a consequence of
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atrophy, not a cause. BBB remains intact.
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Aging does not impair autoregulation of
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cerebrovascular resistance and the vasoconstrictor response to hyperventilation remains intact.
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Crystallized intelligence (language, personality) d
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o not decline with increasing age.
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PNS threshold intensities for perceptions
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increase.
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Reduced peripheral motor nerve conduction velocity and impairment of efferent corticospinal transmission
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increases the latency between intention of onset of motor activity.
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Neurogenic skeletal muscle atrophy causes
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20-50% decreases in strength and steadiness.
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Adrenal tissues atrophy and cortisol secretion declines at least
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10% by age 80, although plasma %'s of nor-epi are 2-4x higher, this is offset by age-related depression of beta-adrenergic end organ responsiveness. (an endogenous beta-blockade)
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There is ______ change in alpha or muscarinic cholinergic activity.
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little
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The autonomic reflex responses that maintain CV and metabolic hemostasis are progressively
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impaired, evidenced by hypotension after induction.
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The autonomic nervous system is
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under-damped and is characterized by wider variation from baseline.
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IV Morphine requirements are
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inversely related to age and a higher block is achieved with the same LA dose. Segmental dose requirements are reduced.
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MAC values
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decline as much as 30% d/t increased sensitivity.
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inter-compartmental transfer of drugs.
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Delayed
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NMB ED50
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unchanged or increased. Duration prolonged.
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_____ largely determines M and M. Outcomes r/t prior functional level.
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Age-related disease, not aging itself
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"best' single anesthetic technique.
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none
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Use depth of anesthesia required to prevent awareness only, higher increases
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M/M.
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Full recovery of psychomotor function _____
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delayed.
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Psychometric disruption
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in 10-15% of patients remains after 3 months.
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