Apex- Geriatrics Flashcards
A 70kg patient can walk up two flights of stairs without stopping. How much oxygen is consumed per minute during this activity?
A. 250mls
B. 500mls
C. 1000mls
D. 1500mls
C. 1000mls
1 MET (metabolic equivalent) corresponds to o2 consumption of 3.5ml/kg/min
One metabolic equivalent (MET) corresponds to an oxygen consumption of what?
3.5ml/kg/min
Inability to achieve how many METs is associated with increased periop risk
4 METS
(climbing two flights of stairs without stopping)
Patients of what age and older are considered geriatric or elderly
65 and greater
Raking leaves = how many METS
4
T/F- getting older is the most significant risk factor for developing cancer
True
Light housework = how many mets
4
strenous sports ( running, swimming, basketball) = how many mets
10 +
For every MET a patient can achieve, mortality decreases by what %
11 %
Which factor increases in the elderly:
A. Dead space
B. lung elasticity
C. PaO2
D. Chest wall compliance
A. Dead space
(air, no blood)
Increased dead space necessitates increased minute ventilation to maintain a normal PaCO2
Aging is associated with a reduction in PaO2, lung elasticity, and chest wall compliance
Taken together, these changes reduce pulm reserve and increase risk of respiratory failure
T/F: reduced PaO2 is a normal change associated with aging
True
Increased or Decreased in the elderly:
Minute ventilation
increased
due to increased dead space
Increased or Decreased in the elderly:
lung compliance
increased
decreased elasticity - can fill the baloon up easier
Increased or Decreased in the elderly:
lung elasticity
decreased
Increased or Decreased in the elderly:
chest wall compliance
decreased
Increased or Decreased in the elderly:
response to hypercarbia and hypoxia
decreased
Increased or Decreased in the elderly:
protective airway reflexes
decreased
Increased or Decreased in the elderly:
upper airway tone
decreased
2 main lung paramters that are INCREASED in the elderly
- minute ventilation (to compensate for increased dead space)
- lung compliance
Why do the elderly have increased dead space?
loss of elastic recoil promotes small airway collapse
Increases/Decreases/no change with age:
upper airway tone
Decreases
decreased resp muscle strength
consider CPAP/BiPAP in at risk patients
Increases/Decreases/no change with age:
A-a gradient
Increased
decreased lung elasticity > increased small airway collapse >
increased dead space, vq mismatch and A-a gradient
Increases/Decreases/no change with age:
A:P diameter
increases
Which volumes and capacities are increased in the 70yo patient (select 3):
- Closing capacity
- Residual volume
- Total lung capacity
- Vital capacity
- Expiratory reserve volume
- Functional residual capacity
Closing capacity
Residual volume
FRC
geriatric lung volumes/capacities
IRV:
ERV:
RV:
IRC:
FRC:
VC:
TLC:
↓ IRV (due to increased RV)
↓ERV: (due to increased RV)
** ↑RV: (due to increased CC and gas trapping) **
↓ IRC: (due to increased FRC)
** ↑FRC: (due to increased RV)**
↓ VC: (due to increased chest wall stiffness, decreased recoil and strength)
* TLC: NO CHANGE (increased RV + decreased VC = net change for TLC) *
Closing capacity surpasses FRC at about what age in the supine position vs standing
45 yo supine
65 yo standing
i still dont know wtf this means
apparently it means that the small airways will collapse during tidal breathing, setting the stage for V/Q mismatch, increased anatomic dead space, and a reduction in PaO2
T/F: FEV and FEV1 are not affected by aging
False - they are both decreased
Why does the older patient have an increased FRC?
bc the aged lungs lose elastic recoil → lungs become overfilled with gas → increased RV (the volume that remains in the lungs after a full exhalation)
FRC = ERV + RV
why do the small airways in the old pt have a greater tendency to collapse during expiration?
bc of the reduction in elastic recoil
- small airways collapse before the lung can fully deflate
The following CV changes occur in response to aging EXCEPT:
A. diastolic dysfunction
B. loss of elastin in arterial wall
C. fibrosis of the cardiac conduction system
D. increased venous capacitance
D.
our veins become stiffer as we age and this reduces venous capacitance (the volume of blood the veins can hold)
in the OR this manifests as greater BP lability with anesthetic induction or during acute blood loss
Cardaic disease is the most common coexisisting disease in the elderly. What are the 4 most common coniditions
HTN, CAD, CHF, Myocardial ischemia
What are the 2 best indicators of cardiac reserve?
- exercise tolerance
- the ability to perform ADLs
Aging effects on CV: (increased/decreased/no change)
Arterial compliance
Venous compliance
Myocardial compliance
Conduction
Myocardial mass
ALL DECREASED EXCEPT MYOCARDIAL MASS (INCREASED)
T/F: in the postop period, MI is the most common cause of death in the elderly population
True!
T/F: filling pressures will underestimate chamber volume
False - overestimate
often have impaired relaxation -> diastolic dysfunction
diastolic dysfunction = chambers require a greater pressure to fill a given volume
so a certain filling pressure that normally would indicate a normal volume would be over-estimatimating this volume
why is tachycardia bad in the elderly population?
diastolic dysfunction = inability to relax
tachycardia = reduced filling time
reduced filling time = less blood able to get through -> backs up (CHF)
Why is afib usually not well tolerated in the older adults
bc they usually have some degree of diastolic dysfunction - chambers cant relax and require a higher pressure to fill (provided by the atria) - loss of that extra pressure → hypotension
If you have an old patient and notice they have a 1st or 2nd degree block - why would that be?
as you age, the cardiac system gets fibrosed and puts you at risk for dysrhythmias as you get older (afib, SSS, 1st and 2nd degree blocks)
The risk of venous thromboembolism (increases/decreases) with age
why or why not
increases exponentially
bc all 3 components of virchows triad affect the elderly
when you think venous thromboembolism risk –> think virchows triad:
1. venous stasis
2. hypercoagulability
3. endotheilal dysfunction
Virchow’s triad describes and consists of what
risk of venous thromboembolism
1. venous staasis
2. hypercoagulability
3. endothelial dysfunction
Is pulse pressure increased or decreased with age
increased due to loss of elastin (stiffer arteries, reduced compliance, increased SVR and SBP much greater than DBP )
SVR increased or decreased with age
increased - loss of elastin = stiffer, less compliant arteries
Which factor remains unchanged in the healthy geriatric patient?
A. Pulse pressure
B. Systolic heart function
C. SVR
D. Lusitropy
B. Systolic heart function
*SBP INCREASES , systolic function = unchanged
Increased/decreased/ no change in the geriatric patient:
Lusitropy
decreased
the aged heart is slower to return calcium into the sarcoplasmic reticulum during diastole, slowing the rate of myocardial relaxation
Increased/decreased or no change:
Heart rate
decreased
fibrosis of conduction system
*decreased responsiveness to catecholamines
*decreased ability to respond to hypotension, hypovolemia, and hypoxia
Increased/decreased/no change:
cardiac output
decreased
decreased SV and HR
T/F: older patients have no change in systolic function
TRUE
(increased SBP though)
im assuming bc of the adaptive mechanisms of the heart and this is at the cost of reduced diastolic function
How is stroke volume affected by age?
decreased due to diminished ability to increase stroke volume (stiff arteries/veins/decreased venous capitance)
*results and reduced exercise tolerance and cardiac reserve
Which factor decreases as a result of hte aging proces?
A. Baroreceptor sensitivity
B. Incidence of orthostatic hypotension
C. Plasma norepinephrine concentration
D. Sympathetic tone
A. Decreased baroreceptor sensitivity
Would you expect an old person to have a more or less exaggerated sympathectomy - why
more exaggerated
-aging is associated with decreased baroreceptor sensitivity and theyll be unable to compensate for the reduction BP with HR
aging is associated with an increased/decreased sympathetic tone
increased
aging is associated with an increased/decreased plasma norepinephrine concentration
increased
think heart doesnt respond as much to catecholamines so the body is gonna produce more to try and stimulate it more
PNS tone: increased/ decreased/ unchanged
decreased
T/F: the ability to thermoregulate is decreased in the elderly population
True
T/F: the elderly have higher norepinephrine concentration in the plasma
True –> increased SNS tone
higher, lower, unchanged:
SNS tone
higher –> higher levels of NE concentration in the plasma
higher/lower/unchanged:
PNS tone
decreased
-may affect the ability of anticholinergics to increased hr
(increased SNS tone, decreased PNS tone)
Do elderly have an increased or decreased response to catecholamines
decreased
- decreased adrenergic receptor density
- impaired B-receptor and adenylate cyclase coupling
- increased circulating catecholamines as partial compensation
- decreased ability to increase HR during hypotension or times of stress (decreased baroreceptor function)
T/F: elderly have decreased baroreceptor function
true
-reduced ability to increase HR during hypotension or times of stress
-increased risk of orthorstaitic hypotension, syncope, and greater degree of hemodynamic compromise following sympathectomy
T/F: elderly are at increased risk of hypothermia
True
due to impared thermoregulation
shivering increases VO2
vasoconstriction increases afterload and MVO2
risk of wound infection
increased blood floss
coaguloapthy
impaired drug metagolism
6 adverse effects of hypothermia
- shivering - increases VO2 400%
- vasoconstriction increases afterload and myocardial o2 consumption
- risk of infection
- increased blood loss
- coagulopathy
- impaired drug metabolism (all metabolic processes slow down)
MAC decreases what % each decade of life after how many years of age?
in the 80yo patient- how much is MAC reduced by?
6% every decade after 40yo
~25% (6x4=24)
increased/decreased/unchanged:
neurotransmitter activity in the brain
decreased
increased/decreased/unchanged:
brain mass
decreased
increased/decreased/unchanged:
peripheral nerve quantity and function
decreased
what is the most common perioperative CNS complication in the elderly?
postop delirium
timing of postop delirium vs postop cognitive dysfunction (POCD)
delerium - early in postop period
POCD - weeks to months after surgery
T/F- most cases of postop cognitive dysfunction are mild and tend to resolve after 3 months
treatment?
True!
none
dose of IV induction agent should be reduced what % in the elderly?
30-40%
Alzheimers vs PD
Alzhemiers = ↓ACH
Parkinsons = ↓Dopamine in the basal ganglia
T/F: decreased brain mass that’s associated with aging affects mental capaacity
false
what atrophies at a faster rate- gray or white matter
gray
Risk factors for postop delirium mneumonic
DELIRIUMM
Drugs (anesthetic agents? - use rapidly metabolized drugs)
Electrolyte imbalance
Lack of drugs (withdrawal)
Infection (UTI/Resp)
Reduced sensory input
Intracranial dysfunction
Urinary retention and fecal impaction
Myocardial event, male gender
T/F: postop delirium can be caused by a myocardial event
True
what is the most significant risk factor for postop cognitive dysfunction?
advanced age
t/f: myelinated nerves decreased with age
true - myelinated nerves and function
t/f: acetylcholine activity increases with age
false- decreases
How is dopamine activity affected by age?
decreasd dopamine activity
Is a long surgery more likely to produce postop delirium or postop cognititive dysfunction?
POCD
T/F: low level of education is a risk factor for postop cognitive dysfunction
True
Identify the statements that MOST accurately describe neuraxial anesthesia in the elderly patient (select 2):
-spinal anesthesia is associated with a lesser spread of local anesthetic
- CSF volume is increased
- Epi test dose ahs a higher rate of a false-negative result
- Epidural anesthesia is asssociated wit ha greater spread of local anesthetic
- Epi test dose ahs a higher rate of a false-negative result
- Epidural anesthesia is asssociated wit ha greater spread of local anesthetic
- decreased beta-receptor sensitivity in the myocardium reduces the efficacy of an epi test dose
- epidural = greater spread of LA because of a reduction in epidural space volume
-spinal anesthesia is associated wtih a greater spread of LA because of a reduction in CSF volume
why would you want to reduce the dose of spinal vs epidural anesthetics in the elderly population
they have decreased CSF volume which results in a greater spread of LA in the spinal space
and decreased epidural space volume –> greater spread of LA in the epidural space
+
dura is more permeable to local anesthetics
is the dura more or less permeable to local anesthetics as we age
more permeable (reduce dose)
increased or decreased myocardial sensitivty to catecholamines
decreased
(but increased concentration of catecholamines in the plasma)
Which factor is unchanged in the geriatric patient:
A. creatinine clearance
B. Serum creatinine
C. GFR
D. Aldosterone
B. Serum creatinine
↓ muscle mass (body produces less creatinine) + ↓, GFR (less creat excreted) = no change
GFR decreases how many mL/min/year after age 40
1mL/min/year
how is aldosterone affected by aging
decreased aldosterone sensitivity → impaired ability to conserve sodium
why might hyponatremia not be unusual in the older person
decreased aldosterone sensitivity → impared ability to conserve sodium
T/F: perioperative renal failure is associated with very high mortality
True
T/F: serum creatinine is a poor indicator of renal function in the elderly
True
How much does renal blood flow decrease per decade?
10%
How is renal mass affected by aging?
decreased renal mass = loss of functioning glomeruli
what is the most sensitive indicator of renal function and drug clearance in the elderly?
creatinine clearance
T/F: creatinine clearance is not affected by the aging process
false -it’s reduced
decreased renal blood flow brings less creatinine to the nephron per unit of time + there are less nephrons (loss of renal mass) to clear the creatinine
Is GFR affected by aging?
normal rate in the adult male
yes decreases 1ml/min/year after age 40
125ml/min
3 consequences of decreased GFR in the elderly
at what age should you consider dose adjustments?
- risk of fluid overload (less plasma delivered to nephrons per unit of time)
*decreased renal blood flow - decreased elimination of hydrophilic drugs
- decreased hydrophilic metabolites of lipophilic drugs
> 60 yo
Why are the elderly at risk of dehydration?
- decreased aldosterone = decreased ability to conserve sodium (and water)
The following decrease as a normal response to aging EXCEPT:
A. Albumin
B. Pseudocholinesterase
C. alpha 1-acid glycoprotein
D. hepatic blood flow
C. alpha 1-acid glycoprotein
*binds basic drugs- production is increased
increased/decreased/nochange:
alpha 1-acid glycoprotein
increased
binds basic drugs
increased/decreased/nochange:
Albumin
decreased
binds aciditc drugs
increased/decreased/nochange:
pseudocholinesterase
decreased
*can prolong the durtion of sux
increased/decreased/nochange:
hepatic blood flow
decreased
*consequently, less drug is delivered to the liver per unit of time
*this can prolong the elmination of drugs with a high hepatic extraction ratio
Opioids, Induction agents, Locals, Betablockers, CCBs
High ER = > 0.7
low ER = <0.3 (PTT and MLD scores)
phenytoin, theophylline, thiopental, methadone, lorazepam, diazepam
intermidiate = MMVA - methohexital, midaz, vec, alfentanyl
T/F: there is no change in hepatocellular function with aging
true!
but there is less hepatic mass → less total enzyme produced
+ less hepatic blood flow→ less drug or toxin delivered to the liver per unit of time
*leading to decreased perioperative hepatic function
increased reservoir for basic drugs or aciditic drugs
basic drugs
- basic drugs bind to A1A GP (increased levels)
- acid drugs bind to albumin (decreased levels)
how is sux altered in the elderly
prlonged duration due to decreased pseudocholinesterate production
men > women
(also prolonged duration of ester LAs)
how are phase 1 vs phase 2 reactions altered in the elderly
decreased phase 1 (HOR)
no change in phase 2 (conjugation and acetylation)
t/f: older patients have a slowed first pass metabolism
true
due to reduced hepatic mass and liver blod flow
How does aging affect the pharmacokinetics of anesthetic drugs (select 2):
-Faster induction with etomidate
-Faster induction with sevoflurane
-increased volume of distribution of propofol
-increased volume of distribution of rocuronium
increased Vd of propofol → increase in total body fat = large Vd for lipophilic drugs
faster induction with sevo → decreased cardiac output = faster inh induction and slower Iv induction (prolonged circ time)
total body water and blood volume are decreased accounting for a smaller Vd for hydrophlic drugs (roc)
increased/decreased/unchanged:
Circulation time
increased
reduced CO prolongs the time of drug delivery from the side of administration to hte site of action :
slower IV induction
-faster inhalational induction
increased/decreased/unchanged:
Surface area to body mass ratio
significance?
increased
decreased lean body mass
increased/decreased/unchanged:
lean body mass
decreased
decreased surface area to body mass ratio
increased/decreased/unchanged:
total body fat
increased
*increased Vd of lipohilic drugs -may prolong their elmination
effects of reduced lean body mass in the elderly (4)
what kind of drugs are affected?
- decreased BMR
- decreased total body water
- decreased blood volume
- decreased plasma volume
smaller vD for hydrophilic drugs –> higher than expected plasma concentration of a given dose
how are hydrophilic drugs affected in the elderly?
smaller Vd (decreased total body water) –> increased plasma concentration for a given dose
*reduce dose!
T/F: age does not affect pharmacodynamic effects of neuomusuclar blockers
true
but increased DOA of steroidal NMDs if renal or hepatic clearence is reduced
In the elderly patient, consequences of decreased lung elasticity include an increased: (select 2):
-dead space
-alveolar surface area
-PaO2
-A-a gradient
Dead space & A-a gradient
the aged lung tissue has high compliance (easy to inflate) but low elasticity (harder to return to origina lshape). Loss of elastic recoil promotes small airway collapse, which ahs the following consequences:
-increased dead space
-increased VQ mismatch
-increased A-a gradient
-decreased alveolar surface area
-decreased PaO2
Age
TLC
The aged lug has a reduction in elastic recoil, causing it to become overfilled with gas.
this process: increases RV and increased RV explains why FRC is increased
the reduction in elastic recoil cause the small airways to collapse during expiration which is why closing capacity increases as we age: concenquences = VQ mismatch, decreased PaO2, and increased deadd space
vital capacity decreases as a result of decreased lung elastic recoil, increased chest wall stiffness, and weakness of respiratory musculature.
TLC stays about the same, respresented by the Y-axis
Mneumonic for things at increased closing volume
c
what is closing capacity?
CLOSE-P
COPD
LV failure
Obesity
Supine position
Extremes of age
Pregnancy
CC = CV + RV
In the PACU, a patient with parkinsons is experienceing an exacerbation of exgrapyramidal symptoms. What is hte MOST appropriate drug to administer at this time?
A. Droperidol
B. Diphenhydramine
C. Metoclopramide
D. Chlorpromazine
B. Diphenhydramine
PD = loss of dopaminergic neurons in the substantia niagria in the basal ganglia
DA inhibits the firing rate of extrapyramidal neurons
loss of DA fibers creates a realtive in crease in ACH activity in the extrapyramideal neurons
pts often exhibit motor excitation: resting tremor and rigidity
knowing hte pathophys makes the treatment obvious: There are 2 pharmacologic broad options:
1. reduce Ach with an anticholinergic such as benztropine or diphendyramine
2. increase DA with levodopa or selegiline
If hte patient experiences an exacerbation of parkinsonian signs during the periop period, the most approriate choice is a drug with anticholinergic properties
