Geriatrics
what is the FRAIL scale
1 MET = amt of O2 consumption of a 70 kg male (3-3.5 ml/kg/min) at rest 2 flights of stairs without stopping = 4 MET Inability to achieve 4 METs indicates increased periop risk
how much does one MET correspond to oxygen consumption
1 met is equal to oxygen consumption of 3.5 ml/kg/min
What is 1 MET equal to?
3.5 ml/kg/min at rest this is for a 70 Kg male
what are the CV effect of volatile anesthetics in the elderly
6% reduction in MAC per decade over 40 for isoflurane, desflurane, and sevo. So giving sevo to a 70 year old = .06 (%) x 3 (decades)= .18 2 (mac of sevo) - .18 = 1.82 - this is the mac you should give the 70 year old
A change in which factor BEST explains why the onset of Propofol is prolonged in the geriatric population A circulation time B Volume of distribution C Lipid solubility D Plasma protein binding
A circ time
what are the definite physiologic changes associated with aging
A decrease in CNS capabilities A decrease in bone compliance A decrease in alveolar surface area A loss of muscle mass
how does Afib affect ventricular filling
A-fib decreases ventricular filling by approximately 25% (no A kick)
what are the geriatric consideration for General Anesthesia
Adequate preoxygenation appropriative dose reduction for all drugs shorter acting drugs recommended prolonged recovery with non depolarizing muscle relaxants that undergo organ based clearance cautiously titrate fluids; euvolemic critical maintain normothermia provide satisfactory post op analgesia
aging produces what in the brain
Aging produces a form of low pressure hydrocephalus Because as there are 3 things in the brain. So when the brain matters starts to shrink there is a compensatory increase in ICF
what is the most common valve disease in the Elderly what are the Anesthetic considerations for these pts with AS
Aortic Stenosis Anesthetic considerations for the elderly patient with AS: Prevent systemic hypotension! (SVR) Maintain SR Adequate hydration
what happens at about age 55 to the lungs
At about age 55, respiratory muscles begin to weaken, and the chest wall gradually becomes stiffer. Age-associated kyphoscoliosis, calcification of intercostal cartilage, and arthritis of the costovertebral joints. so this is Decreasing compliance
what is the BIS number you want in the elderly
BIS 50-60 better than BIS 30-40 studies show lower death rate with higher BIS in elderly
what is the brain circulation time in adults what is it in the elderly what dose this mean for the elderly
Brain Circulation time = One arm brain circulation = 20 seconds you need 3-4 circs for maximum effect Elderly circ time is about 90 seconds. So it takes much longer to see the effects of drugs
what happens the elastin in the lungs after age 30
Changes in lung and chest wall compliance are primarily responsible for age-related decreases in ventilation. At age 30 - a decrease in the number and elasticity of parenchymal elastic fibers, which causes gradual loss of elastic recoil of the lungs this leads to an INCREASE in compliance since there is less elastin. Lungs become loose and floppy (they do not recoil very well when they exhale), only a small pressure difference is needed to maintain a large volume Loss of elastic recoil - the primary anatomic mechanism by which aging exerts deleterious effects on pulmonary gas exchange The increased outward pull of the stiffer chest wall combined with the reduced ability of the lung to pull inward result in a small increase in functional residual capacity (FRC) and residual volume (RV). There
what is the most sensitive indicator of elderly renal function
Creatinine Clearance is the most sensitive indicator of elderly renal function.
what is the induction dose of Propofol in pts under 65 and those over 65
DOSE: 2 mg/kg LBW < 65 yrs, 1 mg/kg LBW ≥ 65 yrs They say 1/10 to 1/2 the dose depending on the age and their condition
What is Pradaxa? what type of drug is it when should it be stopped when should you not use it?
Dabigatran (Pradaxa). it is used to Prevent stroke from A-fib Its is a Direct thrombin inhibitor No way to reverse · They are coming up with direct thrombin inhbitors · However pts on Pradaxa are usually told to stop 5 days before but then this puts them at risk for a thrombotic event It makes then a Higher risk of MI Contraindicated in renal impairment, Creatinine clearance < 30
what is deadspace
Dead space is no gas exchange occurring Dead Space- the space in the trachea, bronchi, and other air passages which contains air that does not reach the alveoli during respiration, the amount of air being about 140 milliliters. Also known as anatomical dead space.
what are the common age related renal anatomic and Physiologic changes
Decreased renal blood flow decreased urine concentrating ability decreased ability to conserve water decreased elimination of drugs decreased GFR
what are the elderly more dependent on (cardiac wise)
Decreased responsiveness of β receptors (Not down regulated), less dependent on HR, they depend more on end diastolic volume to, CO. They are More prone to CHF if given lg volumes. whose law or relationship? So this is starlings law You need to stretch more to get the snap of the ventricles. They have Progressively stiff, fibrotic cardiac tissue.
how is the ANS affected in the elderly
Diminished peripheral and central chemoreceptor responses and CNS pathways These reductions increase the risks of developing hypoxia and hypercapnia if elderly people acquire disorders that produce low O2 levels (eg, pneumonia, COPD, obstructive sleep apnea). May require post op ventilation
What is a durable power of attorney?
Durable power of attorney is a legal method for a competent person to designate a medical decision maker in the event they later become incapacitated.
What is the most common physical feature of inadequate ventilation in the post-operative geriatric patient
Dyspnea Remember there are usually both restrictive and obstructive lung disease in the elderly. Treat accordingly!
what cardiac arrhythmia are the elderly predisposed to. when can it occur
Elderly are Predisposed to afib Afib -can cause emboli and stroke Afib may take up to 3 days after surgery to develop
when will the elderly start to shiver
Elderly patients (over 80) will not shiver until core temperatures reach 35.2°C. it is easier to maintain their temp then it is to increase it Also the ability of the elderly to vasoconstrict in reduced temperatures is impaired.
are elderly able to regulate their body temp as well as a younger pts. why
Elderly patients are unable to regulate body temperatures as effectively as younger patients. autonomic responses to a decrease in core body temperatures include vasoconstriction and shivering. Of these two shunt vasoconstriction is the more effective in maintaining temperature in the elderly. The relationship between age and impairment in thermoregulation is not linear.
why is Euvolemia critical in the elderly
Elderly patients compensate poorly for hypovolemia or hypervolemia EUVOLEMIA is critical - increased reliance on Frank Starling mechanism for CO And they rely Heavily dependent on atrial kick
what do geriatrics have trouble with maintain homeostasis or restoring it
Geriatric - may be able to maintain homeostasis but have trouble restoring it (trauma, disease drugs) They don't have the reserve
What is HPV? how is is affected in the elderly
HPV is a local response to hypoxia by small muscular pulmonary arteries in response to alveolar hypoxia. HPV allows redirection of blood flow to alveolar with higher O2 tension thereby reducing the V/Q mismatch. This is when Blood flow to hypoxic, hypercarbic, or atelectatic alveoli is actively diverted at a precapillary site. The decrease in blood flow to focal diseased areas of the lung improves the V/Q matching. So this will be blunted in the early and because we are using inhalation gas so their HPV mechanism may not be working adequately.
how to the elderly respond to hypoxia and hyper capnia
Heart rate and ventilatory responses to hypoxia and hypercapnia diminish.
how is hepatic blood flow affected by age how is liver mass affected
Hepatic blood flow decreases 10% per decade (40% by 80) Liver volume/mass decreases approx 20% to 40% with aging
what is the ratio to surface area and body mass in elderly
High body surface to body mass ratio - same as neonate
What are the implications for the elderly and hypothermia? what are the adverse consequences of hypothermia
Hypothermia lasts longer in the elderly and is more difficult to recover from than in younger patients Vasoconstriction and skin blood flow are reduced in the elderly Hypothermia causes increased incidence of myocardial ischemia in the geriatric patient decreased wound healing and risk of infection Adverse consequences: Alteration in immune response An effect on bleeding - plt tend to clump An effect on wound closure in the OR
what is blunted in the elderly
Hypoxic Pulmonary Vasoconstriction (HPV) reflex is blunted in the elderly.
how does the prolonged circulation time in elderly affect IV drugs How does the prolonged circulation time affect inhalational agents
IV = Prolonged circulation time in the elderly is reflected by a delay in the onset of intravenous drugs. Inhalational = prolonged circulation speeds the induction time of inhalation agents Decreased Cardiac Output increases the speed of inhalational induction and decreases the onset of IV induction Increased Cardiac Output (fever, increased metabolic conditions) decrease inhalational induction and increase IV induction
Opioid have a high lipid solubility How does this effect Volume of Distribution of opioids? what about meperidine in the elderly
In general doses should be decreased by approx 50%, titrate to effect Use opioids with short half-lives in the elderly. Do not use meperidine in the elderly, unless benefits outweigh risks. Why? Decreased protein binding with age, more unbound Metabolite of meperidine called normiperidine is toxic in the face of renal insufficiency. Meperidine's half-life is 3-5 hours, half-life of normeperidine is 15-20 hours
what is the glomerular filtration rate of the elderly
In the elderly glomerular filtration rate (GFR) is about 60% that of younger patients. This means a reduction in the ability of the elderly to excrete drugs.
what lung volumes are Increased Decreased no change in elderly RV, TLC, ERV, CC, VC, FRC
Increased = RV, FRC, and CC decreed = VC, and ERV Unchanged = TLC
what should you do in elderly who have DM
Increased insulin resistance Assume CAD - so give β-blocker ± statin Stop oral hypoglycemics and switch to Insulin infusion Timely antibiotics Avoid Pancuronium - It is a vagolytic and will cause tachycardia
What is life expectancy?
Life expectancy - typical longevity under prevailing conditions it has changed dramatically during short periods in history So during pandemics it less
What is life span?
Life span it is species specific biological parameter that quantifies maximum attainable individual age under optimal conditions. For Humans = 120 years Life span is often confused with life expectancy ·
how much of your brain do you lose by age 80
Loss of 20 to 30 percent brain matter by 80 y.o.
how is MAC affected by age? how do we calculate this
MAC for inhalationals is Reduced 4 - 6% per decade of age over 40 Ex. Sevo in a 80 yr old 2.0 (MAC) - (2.0 X .06 (5) X 4 (Decades)) 2.0 - .48 = 1.52 Mac for this pt for their age MAC approx. = 1.52
what is the most common post op cardiac complication and the leading cause of death in elderly pts
MI is the most common post-op cardiac complication and the leading cause of death in elderly patients
when is the maximum physiologic function
Maximum physiologic function occurs between the late twenties to early thirties!
what drugs should you avoid in the elderly
Meperidine Pentazocine Butorphanol Methadone Transdermal Fentanyl
what are water soluble drugs
Muscle relaxants Glycopyrrolate Midazolam these have covalent bonds
how should you position elderly pts
Optimal body alignment = keep them in alignment Move geriatric patients slowly using proper body mechanics and ROM principles. For lateral position - Use the log roll method. Be careful not to overstretch limbs, ligaments and tendons For placing patient in lithotomy position, flex both of the patients legs at the same time SLOWLY to prevent lumbosacral strain. Remove the patients legs one at a time to prevent hemodynamic instability when done with procedure Check extremities and pressure points frequently and PAD, PAD, PAD boney prominences. Chart what you are doing
what is the organ system functional reserve
Organ system functional reserve - difference between maximal organ system capacity and basal function
do elderly have more of less plasma protein which protein is unchanged in levels how does this affect out anesthetic agents
Overall, plasma protein binding is decreased. So you have Decrease in circulating albumin levels So if you have a decrease in circulating albumin so you have less drug bound to the protein and more free floating drug. therefor anesthetic agents produce an exaggerated effect Alpha -1 acid glycoprotein levels are unchanged Geriatric patients have altered nutritional status = decreased albumin
should we use a PCA and epidurals in the elderly
PCA Make sure pt. understands concept of the machinery. Patient must be physically able to push delivery button. Instruct family/significant others in use. Use base rate with CAUTION. Epidurals Decrease dose of opioids in the elderly epidural Decrease parenteral opioid use Monitor patient for over sedation, respiratory depression
how do you calculate the Pa02 in the elderly what is the equation
Pa02 = 100- (0.4 * age)
What is pharmacodynamics?
Pharmocodynamics - the relationship between the concentration of the drug at the site of action and the intensity of the effect produced (How the drug affects the Body)
What is pharmacokinetics?
Pharmocokinetics - the relationship of the drug administered and the concentration delivered to the site of action In other words how the body affects the drugs
what is the definition of physiological age
Physiological age -A person's age as estimated by his or her body's health and probable life expectancy. So it is Age in terms of function.
what is the greatest determinate of post op complications
Preop comorbid disease is a greater determinant of postoperative complications than anesthetic management
What are anesthetic risks with the elderly
Pulmonary complications with surgery increase depending on the length of surgery. Patients age (over 70 = have a greater risk) Degree of obesity. Females have a higher mortality than males over 65. Co-morbid disease rates increase anesthetic risks. Examples of co-morbid diseases include - DM, Hypertension,
what happens to renal flow as you age (renal blood flow and mass) what happens to GFR as you age
Renal Blood Flow (RBF) decreases approximately 10% per decade after age 30. The kidney decreases in mass by 20% between the ages of 40 to 80. Glomerular Filtration Rate (GFR) decreases about 1ml/min/year by age 40. The decline in GFR is usually not associated with an increases in serum creatinine. Most of the decline in blood flow occurs in the cortex.
what is the most common perioperative complication
Renal dysfunction is a common perioperative complication. Acute tubular necrosis accounts for about 90% of perioperative renal failure. Acute renal failure is responsible for 20% of all perioperative deaths in the elderly.
what happens to renal mass as you age
Renal mass decreases 30% by age 80 - the loss of mass most prominent in renal cortex Results in decreased # of functioning glomeruli Impairment of sodium handling, concentrating ability and diluting capacity - so they are predisposed to dehydration/fluid overload The elderly release large amounts of ADH in response to hypertonic fluids. The elderly have a diminished response to ADH and aldosterone.
What are the signs of Aortic stenosis what is the tx
Senile aortic stenosis is characterized by heavy calcification of an apparently three-leafed aortic valve causing it to be immobile and restricting its orifice. S & S - Fainting, weakness, breathlessness, palpitations, chest pain Almost always hear a heart murmur Treatment in the elderly generally is aimed at controlling heart failure. Diuretics, digoxin
what factor is unchanged in the geriatric pt A creatinine clearance B serum creatinine C GFR D Aldosterone
Serum Creatinine
what is the spread of LA in a regional anesthetic with the elderly
Spread of local anesthetics is greater because of Spine - age related changes, disc degeneration, fibrosis of intervertebral foramina, reduction in fat in epidural space More enhanced spread of local injection in epidural Subarachnoid block they will have a variable and higher level of analgesia Local anesthetic metabolism and clearance is delayed Hypotension
Which fibers does a spinal affect?
Sympathetic block - sympathetic efferent nerves Even in a modest spinal blockade there may be a profound hypotension in the geriatric Even if you don't give a lot you have to be careful with them.
how is the pressure flow loop changed in the elderly pt what happens the the EDV and EDV
The EDV and ESV is increased in the older pt. Then they have increased intracavitary pressures throughout the cardiac cycle due to increased myocardial stiffness and delayed active relaxation during diastole. you have a higher peak in the elderly due to the increased pressures Reduced arterial compliance results in increased afterload. So you have increased afterload but decreased preload. Elevated systolic blood pressure. eft ventricular hypertrophy In the absence of coexisting disease, diastolic blood pressure remains unchanged or decreases .
How does FEV1 change with age? what are the numbers for a male and female
The FEV1 decreases with aging about 27 ml/yr in the male and 22ml/yr in the female. (8 - 10% per decade) d/t reduced pulmonary compliance and muscle strength
how do the lung volumes change in the elderly what will have to increase if the another volume decreases think about the Apex chart
The FRC will increase the closing capacity increases no change in total lung volume Vital causticity decreases. if the VC decreases then the residual volume must increase reciprocally decrease in FEV & FEV1, expiratory reverse and inspiratory reserve
which type of opioids should you use in elderly if need must use option
The Fentanyl elimination half-life in the elderly is dramatically longer (945 minutes vs. 265 minutes in younger patients). So the short acting ones are better for the elderly Alfentanil is very rapid, short acting, low pKa, small Vd and is a good choice in the elderly.
what does the aging kidney not able to do was well
The aging kidney has a decreased ability to dilute and concentrate urine. This problem is compounded by a decreased thirst perception. The aging kidney also has decreased ability to conserve sodium. Ability to reabsorb glucose is decreased Decreased capacity to handle fluid and electrolytes = hypokalemia and hyperkalemia. decreased kidney function that may interfere with drug metabolism and excretion. may also lead to fluid and electrolyte imbalances in the elderly.
What is the most important complication that may arise from this transfer of fluids (like blood loss)?
The most important is heart failure! Which could also be pulmonary edema which is what she said in the slide And then she said hypotension Acute blood loss will result in fluid being taken from the extravascular space into the intravascular space
What physiologic change occurs in the large airways of the elderly?
The trachea and the large bronchi increase about 10% in diameter from childhood to senior hood Airway structures undergo anatomical changes which may lead to a decrease in protective airway reflexes.
What is closing volume?
The volume at which small airways start to close - Alveoli are then likely to collapse. which makes them prone to atelectasis closing c. the volume of gas in the lungs at the time the airways close during respiration; the closing volume added to the residual volume, usually expressed as a percentage of total lung capacity When closing capacity (CC) exceeds functional residual capacity (FRC), there will be airway closure even during normal breathing. CC exceeds FRC in a person with normal lungs beyond age 45 when supine and beyond age 65 when standing. CC exceeds FRC at approximate ages 45 when supine 65 when standing
what are the CV changes in the elderly Apex chart Arterial compliance Venous compliance Myocardial compliance Myocardial hypertrophy Cardiac conduction
There is Decreased vein compliance - so there is a decreased venous return, this means the right atrium will be UNDERFILLED due to the lack of venous return
how is the airway affected in the elderly
With aging the diameter of the small airways decreases dramatically. Despite this, airway resistance is not increased appreciably. structural changes lead to collapse of distal airways and less surface area for gas exchange. There is an increase in dead space in the elderly. Breakdown of alveolar septae reduce total alveolar surface area Increases both alveolar and anatomic deadspace Alveolar surface area available for gas exchange decreases by about 15% at age 70 Decrease in elasticity of lungs Physiologic shunt increased d/t VQ mismatch Hypoxic Pulmonary Vasoconstriction (HPV) reflex is blunted in the elderly. Air trapping occurs owing to decreased surface area for gas exchange. Stiffening of the chest wall, decreasing recoil of the lungs and a decrease in motor abilities lead to significant changes in lung capacities and volumes. So less elasticity for the lungs to close and at the same time the chest wall is stiffing which makes it even more difficult for the lungs to recoil with expiation
what is the effect of aging on the diaphragm.
With aging, the diaphragm weakens by up to 25%. not usually clinically relevant in healthy people, but in the presence of a disorder that requires sustained increases in ventilation (eg, pneumonia), it predisposes the elderly to hypoxemia and hypercapnia.
how do you determine creatine clearance
You would use 0.85 in the numerator for females 0.72 in the numerator if the patient is male
what are the surgical pts at risk for post operative delirium
age 70 or older history of delirium history of alcohol abuse preoperative use of narcotic analgesics preoperative depression
What is beneficence?
an obligation or responsibility to hep the pt basically to do good
what are the age related changed and pharmacokinetics nagelhout chart
contracted vascular volume - effect is high initial plasma concentration Decreased protein binding - increased availability of the free drug increased total body lipid storage sites = effect is prolonged action of lipid soluble drugs decreased renal and hepatic blood flow - effect is prolonged action of drugs dependent on kidney and liver elimination
what are the common age related CNS anatomic and physiologic changes
decreased activity decreased 02 consumption reduced number of functioning receptors reduced production of neurotransmitters neuron loss decreased cerebral blood flow
how does the neuromuscular junction change as we age is the sensitivity of the NMB affected by age?
distance between the junctional axon and motor end plate is increased in the elderly there are folds in the motor end plate become flattened with age. so Acetylcholine receptors at the motor end plate is decreased and amount of acetylcholine at the junctional vesicles is decreased so the amount of acetylcholine released is decreased In spite of all these factors sensitivity of the acetylcholine receptor to NMB is not affected by age.
What is nonmaleficence?
duty to do no harm to not intentionally harm the pt
How does aging affect the pharmacokinetics of anesthetic drugs pick 2 Faster induction with etomidate faster induction with sevo increased volume of distribution of Propofol Increased volume of distribution of Roc
faster induction with sevo increased volume of distribution of Propofol
how are Vec and Roc Metabolized
in the liver so in elderly this is prolonged. so if you have liver of kidney issues it is best to use Cisatracurium
what is increased in the resp for elderly
increase deadspace increased V/Q mismatch increased stiffness
What is frailty?
it is multidimensional syndrome characterized by the loss of physical and cognitive reserve that predisposes to the accumulation of deficits and increased vulnerability to adverse events
Where is Norepinephrine produced?
locus coeruleus in the pons
Where is dopamine produced?
neostriatum and substantia nigra
what happens to the glomeruli as you age
number of functionary glomeruli decrease (up to 50% by age 80) but the size and capacity of the remaining nephrons remain constant in compensation.
what is the most common health disorder in the elderly
o AORTIC STENOSIS - most common health disorder in the elderly § They will have, concentric hypertrophy - so a big thick ventricle wall
what are the clinical risk factors for surgery which is the greatest
o Age ≥ 70 yrs o CHF o Angina o Past MI o CRI (Chronic renal insuff) o DM o COPD o Past CVA
ageing dramatically affect what 2 lung volumes
o Aging dramatically effects the Closing Volume (CV) and Closing Capacity (CC).
what is post operative cognitive dysfunction
o Can be demonstrated up to 3 months after uncomplicated surgery o Different from delirium o 10 - 15% of pts 60 yrs and older who have had major surgery with hospital stay longer than 4 days
what are the advantages of regional with the elderly
o Decrease in sedative requirement o Continuous spontaneous ventilation o Potential decrease in post op thrombosis and blood loss o Improved post op pain control o No data to support reduction in M&M with regional versus general
what are the common age related anatomic and physiologic changes
o Decreased organ function o Increased body fat o Decreased blood volume o Loss of protective reflexes o Decreased ability to retain body heat o Decreased lean body mass o Decreased skin elasticity o Collagen loss o Decreased intracellular water
what volumes all increase in elderly
o Functional residual capacity o Reserve/residual volume o Closing volume and capacity · Total lung capacity (TLC - lung volume after maximal inspiration) remains fairly constant.
what preop questions should you ask about functional status
o Mental status § Coherent o Cardiac Status § Medications § Work up, EKG, TEE o Functional Capacity, METS § Can they walk stairs? o Pulmonary Disease § Dyspnea § Auscultate o Hypertension § DOCUMENT BASELINE BP o Anorexic, dehydrated § Assess skin turgor o Prior surgeries § How did the patient tolerate anesthesia, narcotics and the procedure
what is is post operative delirium how do you treat it
o Transient, fluctuating mental dysfunction o Usually between POD 1 and 3 o May resolve in hours or days o May persist from weeks to months o Hyperactive, hypoactive o Literature states incidence is 1-63% o May increase morbidity and mortality Impaired cognition, differing levels of cognition o Treat with Haldol o Benzos may worsen the agitation unless cause is alcohol withdrawal
elderly that have DM will also have an increase or decrease in theses Ischemic heart disease Pulmonary and wound infections Duration of muscle relaxants MAC with insulin infusions
o ↑ Ischemic heart disease o ↑ Pulmonary & wound infections o ↑ Duration of muscle relaxants o ↓ MAC with insulin infusions
what can lower MAC levels
opioids lower MAC spinals & epidurals lower MAC
Where is serotonin produced?
raphe nuclei of the brainstem
what is autonomy
right to self-determination
what ate the MET? this is the Apex chart
the Inability to achieve 4 METs indicates increased periop risk
How is onset of action of NDMR affected by aging?
the circulation time is decreased and decrease skeletal muscle blood flow So the Onset may be twice as long so it is belter to use Remifentanil, Cisatracurium, Sevo, Des
how do the compartments change in the elderly
they have a decreased blood volume they have a larger fat compartment When an anesthetic is administered into a geriatric patient it is being delivered into a decreased blood volume thereby producing a higher drug plasma concentration initially. That is the peak we were just talking about but since they have a larger fat compartment you will have a longer duration action especially of lipid soluble drugs
What is justice?
to treat the tp fairly
what are the surgical risk an outcomes for pts 65 years and older. there are 4 factors
§ Age § Physiologic status and coexisting disease (ASA status) § Surgery elective or urgent Type of procedure
What are some pharmacological agents used to treat hypotension in the elderly? what should you not use?
§ Phenylepherine, Ephedrine and epinepherine Studies have shown that there is little benefit to prehydrating these patients. Crystalloids alone are unable to mount an adequate defense against severe hypotension.
what is the definition for chronological age
· Chronological age - The number of years a person has lived
what is the definition of psychometrics
· Psychometrics - being concerned with the design and analysis of research and the measurement of human characteristics
how do the elderly respond to bolus injections
·The peak is higher in the elderly and it takes longer for the concentration to drop in the elderly and it drops less than that of a younger pt. Basically bolus injection leads to higher peaks and longer excretion The figure illustrates higher blood levels in the elderly, initially due to smaller volume of distribution and later due to a slower drug metabolism. Also the brain is more sensitive to the drug in the elderly. So these effects increase the length of time that the drug in active in the elderly.
