Geriatrics Flashcards
“Older adults” or “elderly” = ____.
persons 65 years or older
Aging is not synonymous with ____.
poor physiologic function.
Chronological age versus biological
Chronologic age (age in years since birth), is often used in clinical practice.
Biologic age also known as functional status
Chronologic age alone is no longer a reliable indicator of morbidity or of mortality.
MAP and PP calculations
MAP = SBP + 2 X DBP divided by 3
PP=SBP-DBP
The cardiovascular system is less _____ with advancing age.
Less Compliant CV system (heart/vessels/autonomic nervous system) less compliant- widen pulse pressure (higher sbp,lower dbp)
The decreased cardiac compliance increases ___ which ___.
Increases SBP which increases afterload—->LVH—->prolong LV ejection times—>late diastolic filling—>diastolic dysfunction.
The less compliant cardiovascular system results in increased dependence on ____.
atrial contraction “atrial kick” for optimal filling
Age related changes to autonomic nervous system
decrease responsiveness to adrenergic receptor stimuliation which decreases HR variability to respond to hypotension, hypovolemia, hypoxemia.
Age related changes to the conduction system
1.Calcification w/ fewer SA nodal cells
- predisposes the elderly to atrial fibrillation, sick sinus syndrome, first- and second-degree heart blocks, and arrhythmias.
- PPM/ICDs
- Calcification also w/ heart valves (primarily aortic and mitral).
* valvular stenosis or regurgitation. - Baroreceptors (aortic arch, carotid sinuses) are less sensitive in response to BP change which causes increased episodes of hypotension
Myocardium changes
less sensitive to b-adrenergic modulation results in lower HR, lower cardiac dilation at the end of diastole and systole).
Decreased CO & SV is related to _____.
decreased conduction velocity and reduction in venous blood flow.
What is the most common cardiac complication and the leading cause of death post op?
MI
Most common CV diseases in older adults
HTN, HLD, CAD, CHF
Mechanism and consequences of myocardial hypertrophy
Mechanism: Apoptotic cells are not replaced and there is compensatory hypertrophy of existing cells; reflected waves during late systole creates strain on myocardium leading to hypertrophy
Consequences: Increased ventricular stiffness, prolonged contraction and delayed relaxation
Anesthetic implications of myocardial hypertrophy
Failure to maintain preload leads to an exaggerated decrease in CO; excessive volume more easily increases filling pressures to congestive failure levels; dependence on sinus rhythm and low/normal HR
Mechanism and Consequences of myocardial stiffening
Mechanism: Increased interstitial fibrosis; amyloid deposition
Consequences: Ventricular filling dependent upon atrial pressure
Mechanism and Consequences of Reduced LV relaxation
Mechanism: Impaired calcium homeostasis; reduced B-receptor responsiveness; early reflected wave
Consequeces: Diastolic dysfunction
Mechanism and Consequences of Reduced beta receptor responsiveness
Mechanism: Diminished coupling of beta receptor to intracellular adenylate cyclase activity; decreased density of beta receptors
Consequence: Increased circulating catecholamines; limited increase in HR and contractility in response to endogenous and exogenous catecholamines; impaired baroreflex control of BP
Anesthetic implications of reduced beta receptor responsiveness
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
Mechanism & Consequences of Conduction system abnormalities
Mechanism: Apoptosis; fibrosis; fatty infiltration; and calcification of pacemaker and His-Bundle cells
Consequences: Conduction block; sick sinus syndrome; AF; decreased contribution of atrial contraction to diastolic volume
Anesthetic Implication of Conduction System Abnormalities
Severe bradycardia with potent opioids; decreased CO from decrease in end-diastolic volume
Mechanism and Consequence of stiff arteries
Mechanism: Loss of elastin, increased collagen, glycosylation cross-linking of collagen
Consequences:
1) Systolic hypertension
2) Arrival of reflected pressure wave during end-ejection leads to myocardial hypertrophy and impaired disatolic relaxation
Mechanism & Consequences of Stiff Veins
Mechanism: Loss of elastin; increased collagen; glycosylation cross-linking of collagen
Consequence: Decreased buffering of changes in blood volume impairs ability to maintain atrial pressure
Anesthetic implications for stiff arteries
Labile BP; diatolic dysfunction; sensitive to volume status
Anesthetic implications for stiff veins
Changes in blood volume cause exaggerated changes in cardiac filling
Name the 7 major age-related changes to the cardiovascular system
- myocardial hypertrophy
- myocardial stiffening
- reduced LV relaxation
- reduced beta receptor responsiveness
- conduction system abnormalities
- stiff arteries
- stiff veins
What are the top 5 comorbidities in the elderly patient population from most common to least common?
1) HTN
2) High cholesterol
3) Ischemic heart disease
4) Arthritis
5) Diabetes
What are two major age-related changes to the respiratory system?
1) Decreased chest wall compliance from calcified intercostal/intervertebral joints & flattened diaphragm.
2) Loss of elastic recoil of lung increases lung compliance.
Increased lung compliance causes _____.
small airway diameter to narrow, increases the closing volume & elastic recoil is need to keep small airways open.
What is closing volume?
lung volume at which small airways in the dependent parts of the lung begin to close
(volume in which the smallest airways collapse)
What is the FRC?
volume in lungs at end of passive exhalation-
point of the breathing cycle where the lung tissue elastic recoil and chest wall outward expansion are balanced and equal.
FRC=ER+RV
The age-related changes to the respiratory system reduce ____.
the number of functional alveoli.
The closing volume exceeds the ____ at ___ years old.
The closing volume exceeds functional residual capacity (FRC) at approximately 65 years of age in the erect position and at age 45 years in the supine position.
Patient-related risk factors for postoperative pulmonary complications
- Age > 60, COPD, OSA, ASA class II or greater
- Functional dependence
- Congestive heart failure
- Pulmonary HTN, current cigarette use
- Impaired sensorium, Preoperative sepsis
- weight loss >10% in the past 6 mos
- serum albumin level < 3.5 mg/dL
- Blood Urea Nitrogen level >/= 7.5 mmol/L
- Serum Creatinine level > 133mmol/L
Surgery-related risk factors for postoperative pulmonary complications
- prolonged operation (> 3 hours)
- surgical site
- emergency operation
- general anesthesia
- perioperative transfusion
- residual neuromuscular blockade after an operation
What are some interventions to reduce the risk of pulm complications?
- Smoking cessation at least 8 weeks prior to surgery.
- Implementing inspiratory muscle training and lung expansion maneuvers via incentive spirometry.
- Medically optimize patients with COPD and/or asthma.
Changes in the chest wall causes ___ and has what anesthetic implication?
Impaired gas exchange
Anesthesia implication = risk for respiratory failure
Stiffness/decreased compliance causes ___ and has what anesthesia implication?
Increased WOB
Anesthesia Implication = Careful use of NMDRs (non-depolarizing muscle relaxants?), opioids, and benzodiazepines
What structural change occurs in the diaphragm?
It flattens
Changes to lung parenchyma cause ___ and have what anesthetic implications?
Impaired gas exchange
Anesthesia Implications: risk for respiratory failure
Increased lung compliance causes ___ and has what anesthesia considerations?
Increased V/Q mismatch
Anesthetic consideration: Avoid high pressures/large tidal volumes
Increased small airway closure causes ___ .
- Increased anatomic dead space
- decreased alveolar surface area
- Decreased PCBF (pulm capillary bloodflow)
- Decreased PaO2
Increased small airway closure has what anesthetic considerations?
- consider alveolar recruitment maneuvers (PEEP)
- Limit high inspired O2 (because you risk absorption atelectasis)
- Maintain PaCO2 near normal preoperative value
- Consider regional/local with sedation
Decreased pulmonary muscle strength causes ___. What are the anesthetic considerations?
Increased WOB and decreased protective airway reflexes
Anesthetic considerations = Adequate hydration, consider RSI with GA, Ensure fully reversed before extubation, consider postop CPAP or BiPAP, vigilant monitoring, encourage cough/deep breathing postoperatively
Decreased central/peripheral chemoreceptor sensitivity causes ____. What are the aesthetic considerations?
Increased hypoventilation, increased apnea, decreased ventilator responses
Anesthetic considerations: Risk for respiratory failure, consider postoperative CPAP or BiPAP, vigilant monitoring, encourage cough/deep breathing postoperatively, supplemental oxygen postoperatively
For an aging adult, what is the best indicator of drug clearance?
Creatinine clearance
Renal function in older adults
- Renal atrophy, decrease blood flow, deterioration of vascular structures.
- 25-50% decline in renal blood flow from age 20 years to age 90 years.
- Cumulative effect is decreased GFR
- Kidneys do not respond to nonrenal loss of water and sodium which leads to dehydration.
- Cr is often unchanged RT decreased muscle mass w/aging.
Aging adult liver decreases in mass by approximately ___.
20% to 40 % (RT decreased blood flow).
What affects the liver MORE than physiological aging?
Comorbid diseases (i.e., hepatitis, drug-induced liver injury, cirrhosis) and lifestyle habits (i.e., smoking, alcohol consumption, poor nutrition)
The liver produces ____.
key proteins such as albumin and α1-acid glycoprotein(AAG).
Albumin primarily binds acidic drugs (benzodiazepines, opioids)
AAG binds basic drugs (local anesthetics).
Protein binding changes with aging do not routinely require ___.
alterations in drug dosing as the protein binding on free plasma concentration is rapidly counteracted by clearance.
What are the aging related changes within the endocrine system?
- Decreased insulin secretion due to fewer pancreatic islet beta cells and decreased islet function.
- Insulin resistance occurs peripherally which leads to hepatic production of glucose and impaired breakdown of fats and proteins making the elderly glucose tolerant or diabetic
- Check Hem A1C
What are the changes in body composition/thermoregulation?
- Decrease in basal metabolic rate (BMR).
- 50% of skeletal mass being lost by the age of 80 years (sarcopenia).
- Body fat increases (viscera, subcutaneous abdominal area, intramuscular and intrahepatic areas).
- Decreased total body water.
- Thermoregulation impaired (lower BMR, high ratio of surface to body area mass).
- Decrease in dermal and epidermal thickness of the skin (less collagen, elastin) increases in skin tears and nerve injuries.
- Anesthesia consideration: Maintain normothermia!! Warm fluids, thermal blanket, warm room.
Blood volume decreases _____.
20% to 30 % by age 75 years (hypotension/postural hypotension).
Inhalation Agents inhibit ____.
the temperature regulating centers in the hypothalamus; thus, the aging adult has this added insult to an already inhibited hypothalamus.
Age related physiological changes to the CNS = ___.
progressive neuronal loss, brain volume loss-(esp. frontal lobes/cerebral cortex), BBB more permeable, change in NTS (less ACH).
How do the age related changes to the CNS impact anesthesia considerations?
- increase sensitive to inhalational agents, hypnotics, benzos, opiods).
- Anesthetics-decrease dose of induction agents 50%,avoid benzos.
- Local Anesthetics-fewer myelinated neurons, narrowed intervertebral/foramina, dura more permeable (postulated) decrease dose of local anesthetic (LA), enhanced spread of LA.
How might an older adult respond differently to local anesthetics?
impaired baroresponse may cause severe hypotension from sympathectomy.
Epinephrine in test dose may be less reliable-less increase HR w/adrenergic response.
What types of postoperative complications occur most in the elderly?
What are the factors that influence periop outcomes?
- Most postoperative complications in the elderly are cardiac, pulmonary, and neurologic complications.
- Factors that influence perioperative outcomes in older adults include emergency surgery, the number of comorbidities, and the type of surgical procedure.
- Risk assessment tools for elderly: operative risk and overall physical status in relationship to type of surgery and organ specific indices (i.e., cardiac, neurocognitive).
Why do we see more pronounced CNS effects from medications in the older adult?
- Decreased cholinergic neurons or receptors in the brain
- reduced hepatic and renal function
- increased blood-brain permeability
Why should we avoid using first generation antihistamines? Which ones specifically?
- Benadryl (diphenhydramine) is most common and Phenergan (promethazine)
- Low receptor specificity and can interact with both peripheral and central histamine receptors and readily cross the blood-brain barrier.
- They are also muscarinic antagonists and may have anticholinergic side effect (sinus tach., urinary retention, agitated delirium, dilated pupils)
- Central nervous system side effects- excessive sedation, dizziness or hypotension, somnolence, next day sedation, cognitive decline, psychomotor effects, and loss of coordination.
Describe the older adult and protein levels/drug metabolism
They have a decreased plasma protein binding (low albumin) which means they’ll have an increase in the free plasma concentration for drugs that are highly protein bound.
A decrease in renal function leads to ___. (drug metabolism)
leads to increased serum concentration and prolonged effects of drugs dependent on renal elimination.
Describe hepatic drug metabolism in the older adult
Elimination of hepatic-dependent drugs varies.
- Phase I metabolism oxidation may be reduced (oxidation (via cytochrome P450), reduction, and hydrolysis reactions)
- phase II are not affected (convert a parent drug to more polar (water soluble) inactive metabolites for renal excretion)
A decreased blood volume results in a ____.
decrease in initial volume of distribution (higher drug concentration of IV bolus).
How does decreased lean body mass and total body water impact the volume of distribution of drugs?
- increased Volume distribution for lipophilic drugs
- decreases Volume distribution hydrophilic drugs
How do drug-induced changes manifest in the older adult?
Drug-induced changes tend to be longer lasting with greater length of time for recovery to preanesthetic steady state.
How is neuromuscular blockade impacted in the older adult?
NMB drugs have prolonged onset, if renal/liver disease prolonged effect. Consider cisatracurium (Hoffman elimination).
How does MAC change with age?
The minimal alveolar concentration (MAC) of inhalational agents decreases roughly 6.7% per decade from the MAC value of 40-year-old adults.
Do any medication guidelines exist for geriatric anesthesia care?
Overmedication and potential overdosing most common. Currently there are no specific medication dosing guidelines for anesthesia medications for the older adult patient.
American Geriatric Society suggests we avoid which drugs perioperatively and why?
- Avoid meperidine-Meperidine is converted to an anticholinergic metabolite (normeperidine) that has longer half life, renally excreted, that can cross the blood-brain barrier and lead to delirium.
- Avoid scopolamine-tertiary amine that crosses BBB-muscarinic blocker-anticholinergic (structurally similar to atropine)-Unlike glycopyrrolate (quaternary amine)that does not cross BBB.
- Avoid starting new benzodiazepines and reducing the dose prescribed to patients at risk for POD.
- Adjust dosing of medications that undergo renal excretion based on estimated GFR
Recommendations for Propofol
Anesthetic considerations: Hypotension, prolonged recovery, increased brain senitivity
Dose: Decrease bolus and induction dosing by 50%
1-1.5 mg/kg on induction
Recommendations for Etomidate
Anesthetic considerations: Increased brain sensitivity, greater hemodynamic instability
Dose: Decrease bolus by 50%
Recommendations for Opioids
Anesthetic considerations: Increased brain sensitivty, profound physiological effects, slower onset and delayed recovery, consider route of metabolism and metabolites, avoid meperidine
Dose: Decrease bolus dose by 50%
Recommendations for Midazolam
Anesthesia Considerations: AVOID. Increased brain sensitivity.
Dosing: Decrease dose by 75% or avoid
Recommendations for nondepolarizing muscle relaxants
Anesthesia considerations: slower onset and delayed recovery, consider route of metabolism and metabolites, avoid long-acting NDMRs
Dosing: No change
Recommendations for depolarizing muscle relaxants
Anesthesia considerations: Slower onest and delayed recovery
Dosing: No change
Comorbidity in the Older Adult
Nagelhout text says Comorbid=multimorbid (two or more chronic medical conditions within one person)
- Is associated with advanced age
- 65 to 74 years=62%
- 75 to 84 years=75%
- 85 years of age and older=81%
- Most common-HTN, HLD, DM, and ischemic HD
- Elderly 30% higher risk for postoperative complications and mortality with emergency surgery.
- Multimorbity associated with frailty, which in turn is associated with poor postoperativeoutcomes
What is frailty?
•Biologic state of increased vulnerability to adverse outcomes and decreased resistance to stressors as a result of deterioration in multiple physiologic systems.
Primary frailty-part of the intrinsic process of aging.
Secondary frailty-related to the end-stage of chronic illnesses, caused by inflammation & wasting (CHF, COPD, inflammation, and wasting associated with cancer).
Fried et al. created an operational frailty score based on ___.
the physiologic parameters of grip strength, weight loss, walking speed, as well as energy level and physical activity.
What is the Mini-cog tool?
- neurocognitive assessment for dementia.
- 3 item recall-if unable to repeat 3 words have them complete clock drawing (face, numbers, with stated time).
Severe Nutritional Risk = ?
- a BMI less than 18.5 kg/m
- serum albumin less than 3.0 g/dL without evidence of renal or hepatic dysfunction
- unintentional weight loss within the past 6 months of greater than 10% to 15%.
•Malnutrition and Protein Deficiency are associated with increased risk of postoperative complications (i.e., surgical site infection, pneumonia), increased length of hospital stay, and mortality.
Functional Status in the older adult
- Ability to perform self-care tasks, or activities of daily living (i.e., bathing, dressing, toileting), and instrumental activities of daily living (i.e., preparing meals, handling finances, driving or using public transportation).
- Impaired preoperative functional status is a predictor for longer postoperative recovery time with poor postoperative outcome, increased risk for POD, and increased length of hospitalization
Ethical Principals
Autonomy: Patient’s right to self-determination. Informed consent is the cornerstone for upholding the practice of autonomy.
- exercised through an advanced directive which enables a surrogate or agent to act on pt. behalf when unable.
- Living Will-provides instructions to physician desired medical treatment if pt. unable to make decision.
Beneficence: An obligation or responsibility to help the patient; “to do good”
Nonmaleficence: To not intentionally harm the patient; “do no harm”
Justice: To treat the patient fairly
The four legally–relevant criterion for decision making capacity are ____.
(1) Understanding his/her treatment options
(2) Appreciating and acknowledging his/her medical condition and likely outcomes
(3) Exhibiting reasoning and engaging in a rational discussion of his/her surgical treatment options
(4) Clearly choosing a preferred treatment option
DNR
- Informed consent must address DNR status during perioperative care
- DNR often suspended during perioperative period.
- Discuss with pt.-resuscitation orders (CPR, electricity, meds, airway).
(1) the full suspension of the DNR status
(2) acceptance or refusal of specific resuscitative interventions
(3) resuscitation will be determined by the anesthesia provider and the surgeon based on clinical judgment, while keeping in mind the patient’s values and wishes.
CLEARLY DOCUMENT 2 AND 3!!! VERY DIFFICULT IF ANOTHER PROVIDER GIVES ANESTHESIA AND WAS NOT INVOLVED IN DICUSSION
Age over 65 years is a predominant risk factor for both ___ and ____.
Postoperative Delirium(POD) & Postoperative Cognitive Dysfunction (POCD)
Postoperative Delirium
- POD-acute confusional state, marked by a disorder of attention and cognition that fluctuates throughout the day. It involves cortical dysfunction and the electroencephalogram (EEG) can show diffuse slowing.
- POD generally develops 24 to 72 hours postoperatively after a lucid interval.
- 2 motor subtypes-hypoactive, or hyperactive/agitated
- Unknown etiology-multifactorial
- Duration days to weeks
Risk Factors for Postoperative Delirium
Age >65, dementia, ETOH, depression, sensory impairment, poor functional status, severe illness, hip fracture, type of surgery (aortic/hip fracture #2), abnormal electrolytes (low sodium) anticholinergic drugs used intraoperatively, ICU (#1), inadequate pain control, ASA greater than or equal to 3, low serum albumin, and type of surgery.
Postoperative delirium is associated with __.
increased morbidity, mortality, duration of hospital stay, nursing home placement, and technical, consult, and nursing costs, fall risk, injury to clinicians.
May be risk factor accelerated cognitive decline and for the development of POCD.
Treatment of Postoperative delirium
PRIMARY TREATMENT IS PREVENTION!
Identify underlying cause (sepsis/UTI/Meds)
Multicomponent non-pharmacological interventions are treatment mainstay (sleep/nutrition/pain control/mobilization). Meds are secondary-Haldol, Ativan, dexmedetomidine (ICU setting).
Intra-op-use EEG to avoid burst suppression and titration of IA/hypnotics, avoid prolonged hypotension, severe anemia, hypoxemia. Regional anesthesia may provide superior pain control postop.
Postoperative Cognitive Dysfunction (POCD)
- POD and POCD both neurocognitive disorders, unlike POD onset of POCD subtle.
- characterized by an array of cognitive impairments: memory, concentration, impaired comprehension, and delayed psychomotor speed.
- Deficits often present weeks to months after surgery.
- No universally accepted diagnostic criteria or standard definition.
- Must have preoperative cognitive baseline to compare postop!
- Multifactorial etiology?? Inflammation, cerebral hypoperfusion, excess dopamine/Ach deficiency??
- Persons with POCD have decreased cognitive reserve.
- Risk factors: age, lower SES, educational level, postop infection, cognitive decline.
- Recommended to avoid hypoxemia, maintain CPP (no known effective prevention measures intraop).
