Elderly Flashcards
What is the definition of elderly?
>65 years old
What are some issues the elderly have?
- chronic disease
- surgical intervention
- strength and coordination changes
- less able to compensate physiologically under stressful cirucumstances
- May be sedentary, difficult to assess exercise tolerance
What are the changes in body composition seen in the elderly
- Oxygen consumption decreases
- d/t decreased lean mass/muscle
- Basal resting metabolic rate decreases
- heat production decreases
- poor thermoregulation (elderly suffer heat stroke in the summer)
- decreased serum albumin production
- affects protein binding
- decreased ability to handle glucose load
What are specific body composition changes to women vs men?
- Women
- increase in body lipid reservoir
- store more fat
- decrease in bone mass
- decrease in intracellular water
- Men
- decrease in body mass (not as much increase in lipid reservoir/fat)
- decrease skeletal muscle
- decrease in other tissue mass (liver)
- decrease in intracellular water
What happens to CNS function in the elderly?
- brain size decreases- gray matter atrophies more than white
- neuronal shrinkage- 50,000 neurons lost per day
- cerebral and cerebellar cortices
- decrease in short term memory
- decrease in visual and auditory time
- More complex neurons are better maintained
- language, comprehension, long term memory
- Decrease stores of neurotransmitters (have be part of elderly depression)
- MAOs elevated
- No change to:
- autoregulation of cerebral blood flow
- vasoconstrictor response to hyperventilation
What hapens to PNS function in the elderly?
- Peripheral motor nerve conduction velocity decreases
- from decrease in nerve myelination
- lowed conduction of pain impulses
- leads to higher pain tolerance
- dynamic muscle strength, control, and steadiness of extremities declines 20-50% by the age of 80 years
How is autonomic function different in the elderly?
- Plasma levels of NE higher
- more sympathetic discharge than parasympathetic
- Beta-adrenergic agonist response of heart is blunted
- Endogenous beta blockade
- drugs that increase inotropy and chronotropy of heart will not have as much of an affect
- Little change to Alpha-adrenergic and muscarinic cholinergic response
- baroreceptor reflex response decreased
- Autonomic regulation less tightly regulated
- delay in re-stabilization (make position changes slowly)
- wider variation from homeostasis
- autonomic dysfunction
What are the anatomic and physiologic cardiovascular changes seen in the elderly?
- Anatomic
- increased ventricular wall thickness
- increased myocardial fibrosis
- increased calcification of valves
- physiologic changes
- decreased ventricular compliance
- decreased cardiac output hemodynamics
- systemic BP increases
- HR decreases
What CV changes would you expect in the elderly regarding:
Aorta
arteries
Atrial kick
- Aorta
- dilation, increase in thickness and stiff
- this causes increased pressure the LV has to pump against, decrasing LV function
- Arterials become less elastic
- pulse pressures increase with decreased compliance, diastolic pressures are reduced
- Atrial kick
- Elderly really need the squeeze of the atria to fill the ventricles
- As ventricle becomes stiffer, it becomes more difficult for the atria to pump against it, causing atrial stiffness, afib, CHF, etc
How do the elderly handle volume?
- The eldely are volume dependent yet volume intolerant
- the heart needs volume to maintain SV
- if overloaded, will not be able to mobilize fluid
What is increased in the elderly CV system?
- LV wall thickness and tension
- afterload
- cardiac workload
- systemic BP
- peripheral vascular resistance
- circulation time (longer)
- conduction system fibrosis
- incidence of dysrhythmias
- SA node cell loss
- symptoms of diastolic dysfunction
- vagal tone
What is decreased in the elderly cardiovascular system?
- Cardiac reserve
- CO and max CO
- resting and maximal HR
- LV compliance
- arterial compliance
- SV
- coronary blood flow
- perfusion to vital organs
- chronotropic and inotropic responses
- baroreceptor function
- adrenergic sensitivity decreases leading to decreases in HR
What are the structural changes seen in the lungs of the elderly?
- loss of elastic recoil- can cause small airway collapse and air trapping
- altered surfactant production
- increased lung/alveolar compliance
- loss of elastic elements associated with enlargement of respiratory bronchioles and alveolar ducts
- decreased chest wall compliance
- barrel chest appearance with diaphragmatic flattening
- signs of both obstructive and restrictive disease
- skeletal changes leading to kyphosis
How is gas exchange impaired in the elderly?
- Alveolar surface area reduction
- altered surfactant production
- alveolar-capillary membrane thickens
- anatomic deadspace increases
- decrease diffusing capacity
- pulmonary capillary blood volume declines
- Progressive V/Q mismatch
How is pulmonary function changed in the elderly?
- Increases:
- FRC
- closing capacity
- residual volume
- PVR and pulmonary artery pressure
- Decreases
- Vital capacity
- expiratory and inspiratory reserve volumes
- FEV1 (by 6-8% per decade)
- cross sectional area of pulmonary capillary bed
- hepoxic pulmonary vasoconstriction is blunted
- protective airway reflex
- Sleep apnea common
- more stimulation needed for vocal cord closure–increase risk of aspiration
Consideration for intubating the elderly
- mask ventilation may be more difficult in pts with no teeth
- will need oral airway
- temporomandibular joint mobility and cervical spine range of motion decreased
- may be difficult airways!
How can you prevent periop hypoxia?
- higher O2 concentrations
- small increments of PEEP
- aggressive pulmonary toileting
- IS
Elderly have ________ response to hypoxia and hypercapnia
depressed
Elderly have potential for ________ sensitivity to _______ _________ from opioids as well as non-narcotics like versed
increased
respiratory depression
What happens to renal function in the elderly?
- decreased RBF and renal mass
- function declines with age
- decreased ability to respond to changes in water/electrolyte balance
- impaired ability to concentrate and dilute urine
- at risk for hypo/hyperkalemia
- less responsive to ADH and Aldosterone
- frequent use of diuretics
- *lower TBW
- thirst desire is blunted
If the surgery is longer than ____ hrs, an elderly pt should have a foley.
Give fluid ________.
- >2 hours
- Give fluid slowly, do not get behind.
What changes to the hepatic system would you expect to see in the elderly?
- liver mass decreases by 40% by age 80
- Hepatic blood flow is proportionally reduced
- loss of perfused hepatic mass is the reason why they have decreased rates of plasma clearance and prolonged clinical effects of narcotics
- Decreased plasma cholinesterase- seen more in men than women
What changes to the hematologic system would you expect to see in the elderly?
- decreased B and T cell activity
- decreased IgE
- decreased response to allergens and impaired hypersensitivity
- Sepsis is 2nd only to respiratory failure as cause of M/M in elderly trauma patients
What are some endocrine changes you would expect to see in an elderly patient?
- diabetes- increased insulin resistance
- thyroid dysfunction
What changes to the GI system would you see in elderly patients?
- prolonged gastric emptying time
- increased gastric PH
- higher risk of aspiration due to decrease in laryngeal reflexes
What is the perioperative risk of the elderly ?
- major morbidity and mortality
- concomitant diseases such as DM, HTN, RA, osteoarthritis and other major risk factors increase mortality rate
How is plasma binding changed in the elderly?
- decreased albumin- binds to acidic drugs
- increased alpha1-acid glycoprotein- binds to basic drugs
- i.e. LAs
- increased body fat, therefore increased volume distribution of lipid soluble drugs
- decreased volume distribution of water soluble drugs
- **will need to decrease dosing of barbs, opioids, and benzos
What is alpha 1 acid glycoprotein?
- a carrier of basic and neurtally charged lipophilic compounds
- produced in hepatocytes
- slightly increases with age
How would you expect to adjust doses of induction agents for elderly patients?
for thiopental?
for etomidate?
for propofol?
- typically decrease induction agents
- Thiopental- less than 1/2 compared to a 20 y.o.
- most likely due to slower redistribution and prolonged plasma concentration
- Etomidate- decrease dose due to decreased clearance and initial volume of distribution
- if pt is severely compromised (hypovolemic), will probably still see unstable hemodynamics after induction
- propofol- typically decrease dose by 1/2
- increased brain sensitivity and decreased clearance
How would you expect elderly patients to respond to opioids?
VD
E1/2 life
pharmacodynamics
- smaller initial distribution/delayed intercompartmental transfer of drug
- prolonged E1/2 life
- increased brain sensitivity
How would you adjust doses of benzos for elderly patients?
Which benzo is not a good choice?
- Diazepam
- not a good choice
- accujlates in fat stores
- VD is larger, elimination slowed
- 1/2 life is more than 36 hours, pt can be confused for days
- Midazolam
- aging increases pharmacodynamic sensitivity
- Lorazepam
- less lipid soluble
- E1/2 life remains relatively unchanged
How would you expect elderly to respond to neuromuscular blockers?
- doses of succ and NDMR are virtually unchanged
- delayed onset b/c of decreased CO
- prolonged effect b/c of decreased renal and/or hepatic function
- elderly men may have prolonged effect for succ due to decreased plasma cholinesterase
How would you expect elderly to respond to Inhalational agents?
- Decreased MAC requirements by 6% per decade after age 40
- Myocardial depressant effect is more pronounced
- Attenuated tachycardia for desflurane and isoflurane
- b/c they are naturally beta blocked
- Isoflurane decreases CO for elderly patients more than younger population
What changes would you expect regarding local anesthetics for elderly patients?
- Elderly have in increased threshold for all sensory modalities (touch, temp, proprioception, hearing, vision)
- Regional has a more extensive cephalad spread
- time of onset is decreased
- Decrease LA doses (typically)
- Increased DOA d/t decreased clearance of LAs
- esp. important if using an infusion
- placing epidurals can be difficult in the elderly d/t bone changes
General anesthetic management for elderly:
Which is best?
Would you use local without sedation?
- No one plan is better than another
- Local without sedation may be good option if the pt is fragile
When may you see mental status changes in the elderly?
Elderly will sometimes have mental status changes weeks after a procedure. Mechanism is unknown, but it is seen with both GA and regional.
Do you need to reverse a muscle relaxant on an elderly patient?
Yes! always
What are some other anesthetic concerns for an elderly patient?
- prone to peripheral ischemic injury
- friable tissue and thin skin
- be careful with padding
- weaker airway reflexes
- decreased thermoregulation- keep them warm
- give supplemental O2
What are the 4 key things to keep in mind with elderly
- Elderly at greater risk of M&M
- require adequate diagnosis and treatment of disease and meticulous attention to detail
- adequate pre-op, positioning and monitoring is vital
- stay out of harms way
