AGE RELATED CHANGES Flashcards
Post operative delirium vs Post Operative Cognitive Dysfunction : What is the difference?
Unlike POD, the onset of POCD is subtle and neurocognitive deficits may not present themselves
until weeks to months after surgery.
How to help POCD?
Establishing baseline cognitive function is critical because preoperative cognitive impairment may be
present prior to surgery.
By what age-related physiologic functions
in humans have peaked and gradually decline thereafter.
age of 30 years,
Heart and vascular system compliance in the elderly
the heart and vascular system is less compliant,
Afterload + Systolic BP , in the elderly leading to
increase
in afterload, and an increase in systolic blood pressure,
What is the change that occurs in the elderly patients ventricles? what about ejection times?
ventricular thickening (hypertrophy) and prolonged ejection times
Diastolic function in the elderly?
ventricular hypertrophy and slower myocardial relaxation
often results in late diastolic filling and diastolic dysfunction.
What is the screening tool for Cognitive Ability Capacity
Mini-Cog 3 Item Recall and clock draw
What is the screening tool for Alcohol and Substance abuse?
Modified CAGE
When assessing for Slowness, Weight loss, Grip weakness, Exhaustion, Decrease in physical activity: What are you assessing for
Frailty.
Levels of catecholamines is _______In the elderly?
higher amounts of circulating catecholamines, they
Adrenergic responsiveness in the elderly?
exhibit decreased end-organ adrenergic responsiveness.
Therefore the older adult has a reduced capacity to increase heart rate in response to
hypotension, hypovolemia, and hypoxia.
Causes a faster induction time with inhalation agents but
Prolonged circulation time
In the elderly what delays the onset of intravenous drugs.
Prolonged circulation time
Prolonged circulation time effect on elderly 2
Faster induction with inhalation agents
Slower induction with IV agents
Elderly patients are at risk for which cardiac arrhythmias and why?
loss of sinoatrial node cells, which predisposes the elderly to atrial fibrillation, sick sinus syndrome, first- and second-degree heart blocks, and arrhythmias
Loss of _____node cells predisposes elderly to afib, sick sinus syndrome, 1st and 2nd HB and arrhythmias.
Sinoatrial node cells
Calcification of these valves primarily in the elderly
valves (primarily aortic and mitral),
Pulse pressure in the elderly? and why?
With aging the pulse pressure widens because of a greater proportionate increase in systolic blood pressure
compared with diastolic blood pressure.
Baroreceptors in the elderly? which results in?
decreased sensitivity of baroreceptors in the aortic arch and carotid sinuses in response to blood pressure changes, which results in increased episodes of hypotension.
Ejection phase in the elderly is
prolonged.
Elderly and heart’s regulation of calcium?
include changes in the heart’s regulation of calcium, which causes the myocardium to generate force over a longer period after excitation, and prolongs the systolic phase of the cardiac cycle.
Phase of the cardiac cycle that is prolonged?
Systolic phase of the cardiac cycle.
Older adults have a higher blood pressure because of ______Vascular resistance
Increased Peripheral vascular resistance. decreased arterial elasticity.
What is the cause of stiff veins and arteries in elderly
Loss of elastin; increased collagen; glycosylation cross-linking of collagen
Elastin is ____ in elderly while collagen is _____
Loss of elastin, increased collagen
What is the effects of stiff veins in elder and consequences on anesthesia?
Changes in blood volume cause exaggerated
changes in cardiac fillin
Stiff arteries lead to impaired
Diastolic relaxation in the elderly
Stiff arteries in the elderly leads to impaired diastolic relaxation which leads to
Labile BP; diastolic dysfunction; sensitive to volume
status
Effect of myocardial hypertrophy in the elderly
Increased ventricular stiffness; prolonged
contraction; and delayed relaxation
Age related change: Reduced β-receptor
responsiveness: Anesthetic implications
Hypotension from anesthetic blunting of sympathetic tone;
altered reactivity to vasoactive drugs; increased dependence on
Frank-Starling mechanism to maintain CO; labile
BP, more hypotension
Altered reactivity to vasoactive drugs in the elderly is due to
Age related Reduced β-receptor responsiveness:
Elderly have increase dependence on ______to maintain CO
increased dependence on
Frank-Starling mechanism to maintain CO
Age related change: Reduced β-receptor
responsiveness: Consequences: comment on catecholamines, HR and contractility, baroreceptor control of BP
Increased circulating catecholamines; limited increase in HR and contractility in response to endogenous and exogenous catecholamines; impaired baroreflex control of BP
In Elderly; density of β-receptors
decreased density of β-receptors
Why is Ventricular filling dependent on atrial pressure in the elderly?
Myocardial stiffening
Increased interstitial fibrosis; amyloid deposition
What happens to the myocardium of the elderly ?
Myocardial stiffening
Increased interstitial fibrosis; amyloid deposition
2 combined adversely affects the compensatory mechanisms of the older adult under the stress of anesthesia and surgery
decreased cardiac reserve and decreased maximum heart rate
In the elderly, what is the most common cardiac complication and the leading cause of death in the postoperative period.
Myocardial infarction
The most frequently associated cardiovascular coexisting diseases in the older adult are
HTN
HLD
CAD
CHF
Elderly patients and chest wall
calcifications of the chest wall,
Elderly chest wall compliance
decreased intercostal muscle mass, contributes to a decrease in chest wall compliance
Intercostal muscle mass in the elderly is
Decreased
Change in the spine affected chest wall compliance in the elderly
changes in spinal lordosis, which may further diminish
chest wall compliance.
Lung parenchyma changes in the elderly,
loss of elastic tissue recoil of the lung.
Gas exchange and ALVEOLAR surface area in the elderly
Reduced functional alveolar surface area available for
gas exchange
In elderly patients, even in the absence of disease, Lung compliance________ which impairs what ______? Physiologic shunt is __________ and results in the ________of oxygen exchange at the alveolar level.
increase in lung compliance impairs the matching of ventilation and perfusion, increases physiologic shunt, and results in the reduction of oxygen exchange at the alveolar level
Closing volume in the elderly is
Increased
Why does closing volume increase in the elderly?
It loses lung elastic recoil. Lung elastic recoil is necessary for maintaining small airway caliber, an increased lung compliance causes small airway diameter to narrow, and eventually increases the closing volume
The closing volume exceeds functional residual capacity (FRC) at approximately (E before S)
65 years of age in the erect (sitting) position and at age 45 years in the supine position
In the supine position The closing volume exceeds functional residual capacity (FRC) at approximately ___years of age
45
In the sitting position, The closing volume exceeds functional residual capacity (FRC) at approximately ___years of age
65
Vital capacity in the elderly is_____ with ______in inspiratory reserve volume and expiratory reserve volume.
decrease; decreases
Residual volume in elderly
INCREASE
FRC in elderly is
INCREASE
Inspiratory and Expiratory volume in the elderly
DECREASE
Total Lung capacity in the elder
Total lung capacity remains UNCHANGED or may slightly decrease
The forced vital capacity (FVC) and the forced
expiratory volume in 1 second (FEV1) are both decreased in the elderly why?
decreased as a result of the loss of lung elastic recoil, decrease in small airway diameter, and
subsequent airway collapse with forced expiration
Small airway diameter in the elderly is
decreased
Overall the elderly have______ efficiency of gas exchange.
impaired
Why is there impaired oxygenation ?
Impaired oxygenation is reflected by a decline in resting arterial oxygen tension (PaO2),
PaO2 is what level after 75
83 mm Hg, after 75 years of age.
PaO2 is 83 mmHg after
75 years of age
The decline in PaO2 in the elderly is due to
premature closing of small airways and the reduction in the alveolar surface area.
What predisposes the elderly to apnea
ventilatory response to hypoxemia and hypercarbia is decreased, predisposing them to increased episodes of apnea.
Elderly airway changes (laryngeal) include
decrease in laryngeal and pharyngeal support that accompanies aging, which can result in airway obstruction
Protective airway reflexes in the elderly?
protective airway reflexes (i.e., coughing and swallowing) are decreased
What put the elderly patients at increased risk of aspiration
In addition, protective airway reflexes (i.e., coughing and swallowing) are decreased
Age related changed : Increased lung compliance Consequences and anesthetic implications?
Consequences –> Increased V ̇/Q̇ mismatch
Anesthetic Implications–> Avoid high pressure/large TV
Increased small airway closure consequences on dead space, alveolar surface area, PCBF and PaO2
Increased anatomic dead space (leading to an increased in MV to maintain a normal PaCO2)
Decreased alveolar surface area
Decreased PCBF (Pulmonary capillary blood flow)
Decreased PaO2
Increase small airway closure in the elderly, what are your anesthetic considerations?
Consider alveolar recruitment maneuvers (PEEP)
Limit High inspired O2
Maintain PaCo2 near normal value
Limit this as far as O2 for elderly
Limit High inspired O2
Decreased airway reflexes , anesthetic considerations
Consider RSI with GA
Ensure fully reversed prior to extubation
Consider postoperative CPAP or BiPAP
WOB in elderly be careful with
Careful use of NDMRs, opioids, and benzodiazepines
3 main respiratory parameters DECREASE In elderly
IRV
ERV
VC
2 main respiratory parameters INCREASE There is a corresponding increase in
residual volume (RV’) and functional residual capacity (FRC’) such that the total lung capacity remains approximately the same
Why does the TLC remains the same
IRV , ERV, VC decrease
FRC and RV increases
Increase risk of this post-op for elderly patients
Increase risk of post op pulmonary complications
Top Patient risk factors for Postoperative pulmonary complications
Age greater than 60 years
• Chronic obstructive pulmonary disease
• ASA class II or greater
• Functional dependence
Top surgery related risk factors for postop pulmonary complications
Surgery-Related Factors • Prolonged operation (> 3 hours) • Surgical site • Emergency operation • General anesthesia
For example, smoking cessation at
least
8 weeks prior to surgery, implementing inspiratory muscle training and lung expansion maneuvers via incentive spirometry, and medically optimizing patients with COPD and/or asthma
4 main renal changes in the elderly
atrophy of kidney parenchymal tissues
Deterioration of renal vascular structures
Decreased renal blood flow
Decrease in renal mass
Renal mass is
Decreased
Renal blood flow in the elderly
decreased
Decrease in renal blood flow and renal mass leads to what changes in the GFR?
Decrease glomerular filtration rate (GFR) resulting in decreased renal drug clearance and decreased renal blood flow from age 20 years to age 90 years
GFR decline %
(approximately a 25%–50% decline).
Decrease GFR effect on drugs
diminished renal clearance of hydrophilic agents
and hydrophilic metabolites of lipophilic agents
If overzealous administration of fluid
decrease in GFR and impairment of the diluting segment of the nephron can easily predispose the patient to fluid overload if overzealous intravenous fluid is administered.
Segment of the kidney that is impaired in the elderly
Diluting segment of the nephron
Sodium conservation in the elderly
The production of renin and aldosterone is decreased with age, causing impairment of sodium conservation
Renin production in elderly is
Decreased
Aldosterone production in elderly
decreased
Sodium conservation in the elderly is
decreased
Hydrogen ion excretion in elderly
Decreased
Impaired ability of the kidneys to respond to
changes in electrolyte concentrations, intravascular volume, and free water
Why does the serum creatinine remains unchanged with aging?
The serum creatinine is often unchanged if there is no renal failure because of decreased creatinine production from the overall declining skeletal muscle mass associated with aging.
Skeletal muscle mass is
Decreased
Why is Creatinine production decreased in the elderly
from the overall declining skeletal muscle mass associated with aging.
Best indicator of drug clearance?
Creatinine clearance
What is a common formula for estimating creatinine clearance, which in turn estimates GFR (eGFR) in the healthy older adult
The Cockroft–Gault equation
Formula of Cockroft–Gault equation for GFR?
eGFR mL/min = (140-age) X weight (kg) / 72 x serum creatinine (mg/dL)
the whole thing x 0.85 for female patients.
Renal changes put the patient at risk for 4 things
1/ fluid overload;
(2) accumulation of metabolites and drugs that are excreted by the kidneys;
(3) decreased drug elimination, which can prolong the
effects of a wide range of anesthetic drugs and adjuncts;
(4) electrolyte imbalances, which can lead to arrhythmias by affecting cardiac conduction
The aging adult liver decreases in mass by approximately
20% to 40 % and may be attributed to the decrease in its blood flow.
As far as liver changes what affects liver more than the age related changes?
it is the combination of coexisting diseases (i.e., hepatitis, drug-induced liver injury, cirrhosis) and lifestyle habits (i.e., smoking, alcohol consumption, poor nutrition) that affect liver function more so than the physiologic aging
liver.
Phase 2 drug metabolism involves
conjugation reactions, sulfonic acid, or acetylation.
The liver produces key proteins such as
albumin and α1-acid glycoprotein (AAG).
In the elderly, serum albumin and AAG
decreases ; increases
Low albumin, Theoretically this may result in adverse drug effects especially when?
when malnutrition is present.
However, protein binding changes with aging do not routinely require alterations in drug dosing why? as
the protein binding on free plasma concentration is rapidly counteracted by clearance
The most notable endocrine organ to impact the aging adult patient and postoperative morbidity is the
pancreas.