Geriatric Anesthesia Flashcards
The geriatric demographic is typically defined as
chronological age > 65
By 2040, geriatrics are estimated to make up what % of the population
24%
What % of the population do geriatrics make up now
~12% (fastest growing age group)
Geriatrics account for what percent of healthcare expenditures
50%
% of geriatrics that require surgery before they die
50%
Currently, what % of all procedures are performed on elderly
35%
Risk of preoperative death in elderly
3x more likely
Geriatric effect on arteries
stiffen with age (naturally)
What does stiffening of arteries do to afterload?
Increase
What does stiffening of arteries do to systolic blood pressure?
increases
What does stiffening of arteries do to left ventricular hypertrophy
increases
Geriatric/aging effect on cardiovascular function
- stiff arteries
- myocardial fibrosis, valve calcification
- Increase vagal tone
- increased risk of dysrhythmias
- higher incidence of diastolic dysfunction
- decreased cardiac reserve
Geriatric/aging effect on vagal tone
increases (decreasing HR, decreasing sensitivity to adrenergic drugs; decreased natural response to hypovolemia)
Main dysrhythmias associated with geriatric cardiac function
A-fib/flutter
Geriatric effect on cardiac reserve
Decreases (predisposes pt to labile bp, longer circulation time for meds)
Cardiac disease states most common in elderly (5)
HTN CAD CHF PVD (peripheral vascular disease) anemia
Things you should do to assess cardiac function in elderly before surgery
- ECG indicated most of the time
- current medications related to heart (bb? warfarin? Ca channel blockers?)
- review/ask about cardiac testing (ECG, echo, stress)
- auscultate each valve
What are some drugs you should ask an elderly patient if they take if you’re concerned about the heart?
beta blockers
warfarin
Ca channel blocker
What are some tests you should review/interrogate about if you’re concerned with cardiac function?
ECG, echo, stress tests
Geriatric effect on pulmonary function
- decreased elasticity in lung tissue
- age-associated kyphoscoliosis
- anatomic/physiological dead space increase
- blunted response to hypercapnia and hypoxia
Geriatric effect on lung tissue elasticity
decreased
- alveolar collapse/distension common (atelectasis)
% reduction in alveolar surface area by 70
15%
Aging effect on spine
can get kyphoscoliosis leading to decreased chest height, altering respiratory mechanics
Aging effect on anatomic/physiologic deadspace
increase
- due to increase in central airway size
- small airways decrease in diameter from connective tissue loss
- airway resistance remains unchanged
Aging effect on the response to hypercapnia or hypoxia
blunted
Aging effect on central airway size? Small airway size?
increases central airway size
decreases small airways (connective tissue loss)
- increasing deadspace
Aging effect on total airway resistance
unchanged
What should you ask an elderly patient about when assessing pulmonary function?
- breathing issues, recent coughs/fevers, etc
- auscultate both apex and base of each lung (fluid will be at bottom)
- PFTs helpful if dz present (consider FiO2, Vt, PIP, PEEP)
GOLD acronym
global initiative for chronic obstructive lung disease
GOLD 1 classification of COPD
Mild
FEV1 >/= 80% predicted
FEV1/FVC <0.7
GOLD 2 classification of COPD
Moderate
50% = FEV1 < 80% predicted
FEV1/FVC < 0.7
GOLD 3 classification of COPD
severe
30% = FEV1 < 50% predicted
FEV1/FVC < 0.7
GOLD 4 classification of COPD
Very severe
FEV1 < 30% predicted
FEV1/FVC <0.7
Metabolic and endocrine effect from aging
- basal/max oxygen consumption decrease
- weight loss
- heat production decrease, loss increase
- insulin resistance increase
- stress response preserved
- renin and aldosterone decline
Aging effect on basal/max oxygen consumption
decreases; metabolic decreases creates hypothermia risk
Weight loss begins after what age
60
Heat production/loss effect from aging (why might this be?)
heat production decreases, loss increases
- hypothalamus function decreases
Aging effect on insulin resistance? Why does this matter?
increases; diabetes is more likely to occur
Aging effect on stress response
fairly preserved
Aging effect on hormones
Renin and aldosterone decline others unchanged (ACH, cortisol, TSH, thyroxine)
Drug to avoid with diabetics
decadron (GC steroid)
What should you assess for endocrine function?
Diabetes (glucose tests)
TSH/thyroxine levels if thyroid disease present
What drug will patients be on for hypothyroidism?
levothyroxine
A1C (percent) for non-diabetic patient
about 5
A1C (percent) for prediabetic patient
5.7 to 6.4
A1C (percent) for diabetic patient
6.5 or above
Fasting plasma glucose concentration for non-diabetic patient
99 or below
Fasting plasma glucose concentration for pre-diabetic patient
100-125 mg/dL
Fasting plasma glucose concentration for diabetic patient
126 or above
Oral glucose tolerance test for non-diabetic patient
139 or below
Oral glucose tolerance test for pre-diabetic patient
140-199 mg/dL
Oral glucose tolerance test for diabetic patient
200 or above
Aging effect on kidney mass
decreases
What percent of function glomeruli do kidneys lose by age 80? GFR?
50% for both
blood flow decreases as well
Aging effect on ability to dilute/concentrate urine and conserve sodium
decreases
Aging effect on renal function
- kidney mass decrease
- increase risk of ARF
- prone to electrolyte imbalance
- creatinine unchanged
Why are geriatric patients more prone to electrolyte imbalances
side effects from medications especially if on a diuretic for HTN
- more predisposed to dehydration or fluid overload
Why is creatinine unchanged in geriatric patients?
loss in muscle; but BUN increases (blood urea nitrogen)
What tests should you do to assess renal function?
- GFR, creatinine, BUN
- electrolyte imbalances (could cancel case like if hypokalemic)
Normal GFR
60-120
Kidney disease GFR
59-15
Kidney failure GFR
14-0
Elderly effect on GI function
- liver mass decrease
- Gastric pH rise
- prolonged gastric emptying but lower volumes
- swallowing/esophageal motility maintained if healthy (but more prone to developing dz state)
How much does liver mass decrease by age 80?
40%
Elderly effect on hepatic blood flow? Why is this important?
decreases, this is important because of metabolism of certain drugs
Aging effect on liver function tests and liver enzymes?
normal
How should you assess GI function in a geriatric patient?
Liver function tests
EGD/colonoscopy charts (Esophagogastroduodenoscopy)
Where produced: Alanine transaminase
What does it measure?
liver
Measures level of ALT in blood; can be sign of liver damage
Where produced: Aspartate transaminase
What does it measure?
large amount in liver and other parts of body; measures AST in blood and high levels can be sign of liver damage
Where produced: alkaline phosphatase
What does it measure?
large amounts found in liver, bile ducts, and other parts
ALP test measures ALP in your blood; high levels can be sign of liver or bile duct damage
Where produced: gamma-glutamyl transpeptidase
What does it measure?
large amount found in liver, bile ducts, and pancreas. GGT test measure GGT in blood and high levels can be sign of liver or bile duct damage
What does total protein tests measure?
protein in blood; mainly globulins and albumin
Where produced: albumin
What does it measure?
Made in liver; albumin tests measure how well your liver makes proteins your body needs. Low levels can be sign of liver damage
Where produced: prothrombin
What does it measure?
made in liver and helps with clotting blood. PTT (prothrombin time) tests how long it takes your blood to clot. High prothrombin can mean liver damage
Where produced: bilirubin
What does it measure?
yellow fluid made when RBCs break down. Measure bilirubin in blood. If liver is damaged, bilirubin will leak out into blood and cause jaundice and make your urine look dark
Liver protein tests
total protein, albumin, prothrombin
What does globulin do? Where is it made? What happens if it is low?
made in liver; helps immune system fight infections
low levels can be sign of liver failure or other
Normal creatinine range
80-132
Normal total protein range
64-82
Normal albumin range
35-50
Normal globulin range
23-35
Normal bilirubin range
3-17
Normal alkaline phosphatase range
50-136
Normal Alanine transaminase (ALT) range
12-78
Normal Aspartate transaminase (AST) range
15-37
Normal gamma-glutamyl transpeptidase range
15-85
What percent does brain mass decrease by age 80? From what?
30% from neuronal loss/shrinking in cerebral cortex
What percent does cerebral blood flow decrease in elderly?
10-20%
Aging effect on cerebral auto regulation
still functional
Aging effect on neurotransmitter (and associated receptor) production
decrease
Aging effect on peripheral nerves; what does this cause?
degenerates
- causes muscle atrophy and increased sense threshold (so less narcotics because less pain felt)
Aging effect on cognitive function
mostly normal if no disease but pt still at higher risk for post-op delirium
Neurological assessment on elderly patient
interviewing patient helps a lot
- alzheimers, parkinsons, dementia
family members also help with how advanced disease is
If your patient has Alzheimer’s, Parkinson’s, Dementia what drugs should you consider holding?
benzodiazepines because they can interfere with levodopa treatment that must be maintained. Also consider minimum required amnestic agents
Aging effect on musculoskeletal
- overall less muscle mass
- skin atrophies and prone to trauma
- arthritic joints can make positioning, intubation, regional/neuraxial anesthesia difficult
- weak respiratory muscles
Considerations if your elderly patient has skin atrophies and is prone to trauma?
Cautious with tape, Bovie pads, ECD pads
- try to use paper tape
- be careful with IVs (veins prone to rupture)
Aging effect on laryngeal reflexes
decreased; aspiration pneumonia much more common
How should you assess musculoskeletal function in an elderly patient?
- take a good look at them and how frail they look
- ask pt about exercise tolerance
- ask about arthritis and osteoporosis
Pharmacological effects of water-soluble drugs on an elderly patient
since they overall have less body water there is a reduces distribution volume. leads to high plasma concentration
Pharmacological effects of fat-soluble drugs on an elderly patient
increased distribution volume because adipose tissue is more prominent and muscle less so; causing lower plasma concentration
What happens to elimination half life if distribution volume increases?
elimination half life with also increase unless clearance rate also increases BUT renal and hepatic function decreases as well
MAC requirements per decade past 40
decreases by 4% (so decreases 8% by 60)
Myocardial depression effects effect on elderly and how this might effect inhalation agent onset
exacerbated, and may lead to decreased CO causing faster onset time
Why high emergence/recovery time be prolonged in elderly?
fat; weak respiratory efforts
IV medications for elderly
use lower doses for propofol, etomidate, barbiturates, opioids, benzodiazepines
Propofol dose for elderly versus 20 year old
elderly may require half the induction dose of propofol
How come you don’t need to decrease ketamine for elderly patients?
it’s water and fat soluble
Reduction of fentanyl for elderly patient
up to 50%
Reduction of versed for elderly patient
up to 50%
Onset of a non-depolarizing NMBD in an elderly patient? Recovery?
2X longer onset with delayed recovery due to decreased liver and renal function
Onset of a depolarizing NMBD for an elderly patient
unchanged since sux uses something else but elderly mean may have lower plasma cholinesterase levels, slightly prolonging sux
Degradation of organ system is dependent on
genetics, environment and diet
What types of medications should you lean towards with an elderly patient?
short acting and avoiding renal/hepatic elimination drugs
Elderly recovery from GA
they take longer and are more likely to experience post-op delirium
Intraoperative awareness in elderly
more likely because of lower medications