across the life span: geriatrics Flashcards
one metabolic equivalent (MET) corresponds with an oxygen consumption of
3.5mL/kg/min
walking up two flights of stairs without stopping is equal to
4 METS or 1000mL O2/min
activities equivalent to 1 met include
(poor functional capacity)
self care activities
working at a computer
walking 2 blocks slowly
activities equal to 4 mets include
Climbing up a flight of stairs without stopping
walking up a hill (>1-2 blocks)
light house work
raking leaves
gardening
activities equal to 10 mets or more
strenuous sports
for every met a patient can achieve, mortality decreases by
11%
frailty is characterized by what 2 things
decreased reserve and reduced resistance to stress (physiologic, physical, or psychosocial)
how does minute ventilation change in the elderly
increases. increased dead space = increased minute volume to maintain normal PaCO2
how does lung compliance change in the elderly
increases. easier to distend lungs. tired ole rubber band
how does lung elastane change in the elderly
decreases. rubber band is tired. she stretches better but doesn’t come back into place the same ever again. loss of elastic recoil. (increases dead space, decreases alveolar surface area, increases VQ mismatch and A-a gradient, decreases PaO2
how does chest wall compliance change in the elderly
decreases. stiffer, lesser tendency to expand.
how does response to hypoxia and hypercarbia change in the elderly
decreases because chemoreceptors are less sensitive to changes in pH, PaO2, and PaCO2
increased risk of hypoventilation, apnea, resp failure
(consider CPAP or BiPAP)
how do protective aw reflexes change in the elderly
decreased. reduced efficiency of cough and swallowing
greater stimulus to elicit cough reflex (better at bj’s when old????)
increased risk of aspiration (but die by the bj)
how does upper aw tone change in the elderly
decreases. decreased resp muscle strength. increased risk of resp failure and upper aw obstruction. consider CPAP or BiPAP in at risk patients.
which lung capacities increase as age increases
RV FRC and CC, minute ventilation
which lung capacities decrease as age increases
VC and ERV
which lung capacity doesn’t change as age increases
TLC
what happens to venous capacitance as we age
veins become stiffer which reduces venous capacitance
what happens to arterial compliance in the elderly and what is the pathophysiology
decreased, loss of elastin and increased collagen.
increased SVR and after load increases BP
increased PP
increased myocardial wall tension to overcome higher after load
increased LV thickness (concentric hypertrophy)
what happens to myocardial compliance in the elderly and what is the pathophysiology
impaired relaxation –> diastolic dysfunction
atrial kick is super important in non compliant ventricle.
what happens to cardiac conduction in the elderly
decreases due to fibrosis of concussion system, loss of SA node tissue
VTE increases in elderly because of virchows triad which is
venous stasis
hypercoagulability
endothelial dysfunction
what happens to pulse pressure in the elderly
widens because SBP increases to a much greater degree than DBP
what happens to lusitropy in the elderly
aged heart is slower to return Ca2+ to SR which decreases lusitropy
what happens to systolic function in the elderly
preserved!
what happens to SV and CO in elderly
both decrease r/t decreased cardiac reserve
what happens to HR in elderly
decrease because of decreased responsiveness to catecholamines
what happens to baroreceptor sensitivity in the elderly
decreases
what happens to sympathetic tone and plasma NE concentration in elderly
increases (but end organs are less responsive)
what happens to PSNS tone in elderly
decreased. may decrease anticholinergics ability to increase HR
what happens to autonomic sensitivity in the elderly
decreased. this means decreased response to baroreceptor reflex, thermoregulation, dehydration
MAC decreases by ____% for each decade of life over 40 years
6%
postoperative delirium versus postoperative cognitive dysfunction: onset
postop delirium: early postop period
postop cognitive dysfunction: weeks to months after surgery
postoperative delirium versus postoperative cognitive dysfunction: presentation
postop delirium: easy to ID: disordered behavior, perception, memory, psychomotor skills
postop cognitive dysfunction: subtle and difficult to pinpoint (impaired concentration, comprehension, psychomotor skills)
postoperative delirium versus postoperative cognitive dysfunction: risk factors
postoperative delirium (DELIRIUM pneumonic):
Drugs
Electrolyte imbalance
Lack of drug (withdrawal)
Infection (UTI and resp)
Reduced Sensory Input
Intracranial dysfunction
Urinary retention and fecal impaction
Myocardial event, male gender
cognitive dysfunction: advanced age, pre existing cognitive deficit, cardiac surgery, long duration of surgery, high ASA status, low level of education, anesthetic agents
postoperative delirium versus postoperative cognitive dysfunction: treatmetn
postop delirium: tx underlying cause, antipsychotics, minimize polypharmacy
cognitive dysfunction: no tx, most cases are mild and tend to resolve after 3 months
is there a higher or lower rate of false negative in elderly with epidural anesthesia
higher level of false negative related to reduced beta receptor sensitivity
how does sensitivity to nerve tissue and LA’s change in elderly
it increases due to a decrease in number and diameter of myelinated fibers as well as conduction velocity
how does sensitivity to spinal anesthesia change in the elderly
increased sensitivity due to greater spread (less CSF volume) and dura is more permeable to LA’s (reduce dose)
how does sensitivity to epidural anesthesia change in the elderly
increased due to decreased epidural space volume
how much does RBF decrease per decade
10%
how is first pass metabolism affected in the elderly
increased concentration of drugs with high first pass metabolism
decreased concentration of drugs that require liver for activation
what happens to total body fat as age increases
TBF increases as age increases. Vd of lipophilic drugs then increase
what happens to TBW and BV as age increases
TBW and BV decrease, decreased Vd of hydrophilic drugs
what happens to inhalation induction speed as age increases
decreased CO prolongs circulation time and actually increases speed of inhalation induction (but IV induction time is slower)
a change in what best explains the prolonged time of drug delivery for propofol?
circulation time
what happens to alveolar surface area in elderly patient
decreaed
most sensitive indicator of drug clearance in elderly?
creatinine clearance.
reduced as a function of lower RBF and fewer nephrons to clear creatinine
what does the x and y axis indicate on this illustration
x axis: age (horizontal)
y axis: total lung volume (which stays the same) (vertical)
reduction in elastic recoil over time causes overfill with gas and increase in RV
reduction in elastic recoil over time causes small aw’s to collapse during expiration, which increases CC as we age.
at what age does CC exceed FRC when laying supine
45y
does NE or decrease in the geriatric population
it increases but it causes a down regulation in adrenergic receptors and a decreased effect
