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111 Cards in this Set
- Front
- Back
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What proportion of people > 65 yrs have at least 1 fall per year
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1 in 3
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Consequences of a fall is the reason for presentation of what percentage of >65yo in emergency departments in Aus?
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20-25%
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T/F: Falls occur in older people who are PREDISPOSED because of accumulated effects of multiple diseases and impairment which limits their ability to compensate when exposed to PRECIPITATING insult
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True
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How do changes in
a) vision b) gait c) proprioception d) reaction times predispose the elderly to falls? |
a) reduced depth perception and contrast sensitivity
b) decr. stride length, speed. No tandem gait nor arm swing. Harder to one-leg stand. c) Reduced vibration sense d) Decr. reaction times |
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What are some precipitating factors for falls in the elderly?
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Acute illness
Medications Postural Hypotension Urinary incontinence Hospitalisation Post-hospitalisation Displacing activity eg carrying Environment |
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What types of medication usage can precipitate falls in the elderly?
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Psychoactive medications
Use of 4+ medications at once ?Anti-hypertensives |
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What symptoms and signs would you look for after an elderly patient has fallen?
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1. SYNCOPE
Amnesia? could be vasovagal, arrythmia, stroke, hypoglycaemia 2. DIZZINESS/UNSTEADY what type? vertigo? lose balance? light headed? 3. ORTHOSTATIC HYPOTENSION test lying/standing BP, medications, etc 4. GAIT |
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What are some causes of neurally-mediated syncope?
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Neurocardiogenic syndrome (vasovagal)
Orthostatic hypotension Situation syncope Carotid body sinus hypersensitivity |
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What is carotid body sinus hypersensitivity?
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Carotid sinus oversensitive to manual stimulation causing large changes in HR/BP. Pt may fall with amnesia to syncope
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What is the multifactorial treatment model for the elderly at risk of falls?
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1. MEDICAL
ID/treat precipitating factors 2. REHABILITATION physio, compensate for impairment 3. ENVIRONMENT OT, decr. impact impairment 4. SUPPORT AT HOME social worker |
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What interventions have shown benefit to reduce risk of falling in the elderly?
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Exercise that focuses on STRENGTH and BALANCE
(gait training, balance exercises, exercise against resistance) Decr. medications Occupational therapy Not wearing bifocal lenses |
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T/F: Blood Ca2+ is in equilibrium with ECF Ca2+
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True
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T/F: Blood Ca2+ is almost all protein bound
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FALSE
half ionised, about half protein bound |
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What are some short term consequences of decreased extracellular Ca2+
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INCREASES NA+ PERMEABILITY (partial depol)
-->muscle spasm, tetany -->pins and needles -->seizures |
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What are some short term consequences of increased extracellular Ca2+
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DECREASES NA+ PERMEABILITY (hyperpol)
-->dehydration (less water reabs, plus Pt anorexic) -->impair cognitive function -->constipation/ anorexia/ nausea (depend on sm. m. pushing content toward colon) |
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T/F: Exact regulation of phosphate is more important than that of calcium
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FALSE. less important than exact regulation of calcium
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What are some consequences of increased phosphate?
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Long term get soft tissue mineral deposition
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What are some consequences of decreased phosphate?
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Long term get inadequate bone mineralisation
Disorganisation of the growth plate |
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Which 4 substances regulate mineral metabolism?
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PTH
Calcitriol (Vit D hormone) FGF-23 Calcitonin |
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Release of PTH does what to blood Ca2+ concentration?
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High PTH --> INCREASED BLOOD CONCN OF Ca2+
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What stimulates release of PTH? via which mechanism?
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Low Ca2+
[via calcium sensing receptor – GPCR on surface of parathyroid gland cells] |
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What suppresses release of PTH?
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Calcitriol
High Ca2+ |
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Serum inorganic phosphate [PO43-] is normally ___ mmol/L
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normally 0.8-1.4 mmol/L
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Outline vitamin D metabolism to calcitriol
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1. Vitamin D produced in skin
(UV converts 7- dehydrocholesterol to vitamin D) 2. Liver converts vitamin D to 25(OH) vitamin D 3. Conversion to calcitriol [stimulated by PTH, low phosphate, growth and pregnancy] |
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How do you assess vitamin D status?
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Meaure levels of 25(OH)vitamin D.
This is the reactive metabolite Do NOT measure calcitriol |
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What is the molecular structure of calcitriol?
What stimulates its production? |
1,25(OH)2D
PTH, low phosphate, growth and pregnancy |
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Severe vitamin D deficiency can result in what?
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Rickets or osteomalacia because can't mineralise bone
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Where is FGF-23 predominantly produced?
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In bone by osteocytes
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Where does FGF-23 predominantly act?
What are the physiological consequences? |
Acts in KIDNEY to:
incr. phosphate wasting decr. calcitriol production incr. calcitriol degredation |
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Excessive FGF-23 can have what consequences?
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Osteomalacia or Rickets due to low phosphate, low calcitriol
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What stimulates production of FGF-23?
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Calcitriol
PTH ?High phosphate |
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From where is calcitonin released?
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parafollicular cells (“C cells”) of the thyroid gland
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Calcitonin is released in response to what?
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Incr Ca2+
Pentagastrin Gastric hormones |
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What is the action of calcitonin?
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Switches off resorption of bone because calcium is coming in through the gut
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T/F: Active absorption of Ca2+ in the gut is stimulated by calcitonin?
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False - stimulated by calcitriol
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T/F: Absorption of calcium in the gut is inefficient
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true
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What actions does calcitriol have in the gut?
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Enhances active Ca2+ absorption.
Also increases phosphate absorption. |
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What actions does calcitriol have in the kidney?
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increasing renal tubular reabsorption of calcium
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How do PTH and calcitriol differ in terms of the way they increase blood Ca2+?
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Both stimulate osteoclasts to release Ca2+ from bone
BUT, calcitriol aims to incr. DIETARY Ca2+ absorption and renal reabsorption PTH on the other hand aims to increase phosphate dumping in urine, so that more will come out of bone (bringing Ca2+ along with it) NB: PTH also incr. renal reabsoption of Ca2+ |
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How does calcitriol stimulate release of Ca2+ from bone?
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acts on OSTEOBLASTS, causing them to release RANKL, which in turn activates osteoclasts
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T/F: need some vitamin D for PTH to be able to resorb bone properly
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TRUE
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T/F: in the kidney, phosphate is reabsorbed to a transport maximum
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true
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T/F: in the kidney, filtration of Ca2+ depends on blood Ca2+ concentration
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TRUE
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What sunlight exposure is recommended to prevent vitamin D deficiency?
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Casual exposure of 15% body surface to 1/3 minimal erythemal dose most days
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what is 1 minimal erythemal dose?
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dose of UV that causes faint redness of skin
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What are the bone mass determinants?
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Genetics
Age Mechanical loading Mineral balance Vitamin D status PTH Sex steroids Gender |
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What are the bone density determinants?
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Genetics
Exercise Calcium intake Vitamin D status Sex steroids |
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What components of "bone quality" can contribute to fracture risk?
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1. DEAD CELLS
Glucocorticoids can kill osteocytes so they are less able to respond to changing loads 2. UNREPAIRED MICROFRACTURES 3. CONNECTIVITY how well the bone compartments connect 4. RATES OF BONE TURNOVER high rates - higher risk 5. DEGREE OF MINERALISATION |
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What type of exercise is needed to decrease fracture risk of bone?
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Gravity/weight bearing exercise
Need to LOAD BONE and have a degree of bone deformity |
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What is the recommended daily intake of calcium?
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800-1200mg
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What happens to the growth plate in Rickets?
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Growth plate becomes THICKER and DISORGANISED
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A mild vitamin D deficiency has what consequences?
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Impaired gut calcium absorption.
Incr PTH --> incr bone turnover --> decr. bone density (impaired muscle function and increased risk of fracture) |
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What type of PTH is given to stimulate bone formation?
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Intermittant doses
[Give injection so levels spike and come back down] |
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What is the main effect of intermittent PTH?
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Intermittent PTH stimulates OSTEOBLASTS
-->anabolic effect on bone |
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How many hours can PTH levels be high before you lose anabolic effect?
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Lose anabolic effect if PTH levels are high for longer than a couple of hours
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T/F: Wnt signalling pathway one of the major catabolic pathways in bone forming cells
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FALSE
it's ANABOLIC! |
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Outline the Wnt signalling pathway.
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Wnt = extracellular proteins that bind to complex receptors on cell.
B-catenin is small protein, normally degraded Stimulate Wnt pathway --> Wnt receptors come together, change shape, release B-catenin from degradation B-catenin goes to the nucleus, get transcription of bone formation genes |
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What inhibits Wnt pathway?
What stimulates it? |
SCLEROSTIN (from osteocytes) inhibits.
Intermittant PTH stimulates |
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What effect on bones to androgens have?
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Bigger, more mechanically strong bones
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What are the actions of ESTROGEN on bone?
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ANTI-RESORPTIVE!
Reduces rate of turnover Promotes coupling May incr. formation Incr. lifespan of osteoblasts and osteocytes |
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What are the consequences of low sex steroid?
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Impaired coupling
(more rounds of bone remodelling, each of which results in less bone formed) Increased osteoclast lifespan |
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When can estrogen be low?
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Anorexia
Congenital deficiency Alcoholism (high levels) Post-menopause Old age |
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Why is bone geometry important?
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For resistance to bending
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How do androgens make bones mechanically stronger?
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1. PERIOSTEAL ACQUISITION
-->bone increases at periosteum 2. RELATIVE RESORPTION AT ENDOSTIUM |
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What are the effects of glucocorticoids at pharmacological doses?
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CATABOLIC.
Decr. gut Ca2+ absorption Incr. Ca2+ losses in kidney Reduced no. replacement osteocytes Decr. IGF-1 in bone Reduced osteoblast viability |
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What are the outcomes after 12 months post-hip fracture
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21% dead
18% institution 61% in communitiy |
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What is SF-36 scoring used for?
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estimate physical function and emotion (i.e. quality of life)
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What does total hip replacement cost per QALY?
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$2,500 per QALY
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What are the categories of the International Classification of Functioning, Disability and Health?
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1. HEALTH CONDITION
2. BODY FUNCTION/STRUCTURE 3. ACTIVITIES 4. PARTICIPATION 5. ENVIRONMENTAL FACTORS 6. PERSONAL FACTORS |
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What is the Barthol index?
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Most commonly used assessment of ADL (activities of daily living)
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Define the followingin the context of a health condition:
A) Impairment B) Activity C) Participation D) Environmental factors E) Personal factors |
A) Impairment = loss or abnormality of body structure or psychologica/physiological function
B) Activity = execution of task by individual C) Participation = involvement in life situation D) Environmental factors = phsyical, social, attitudinal. can be barriers or facilitators E) Personal factors = identifying details about person |
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T/F: Mobilisation is extremely important after hip fracture
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TRUE
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Approximately what percentage of Australians have low health literacy?
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60%
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T/F: informed consent involves communicating what the patient needs
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TRUE
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In NSW, children are presumed incompetant until what age?
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14.
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What is the Gillick test?
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aka "mature minor doctrine"
--> test for competance using series of questions |
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T/F: parents have power over children in NSW until they are presumed competent at 14
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FALSE. have power until child turns 18
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T/F: Withdrawal of treatment has to be approved by a court (e.g. letting baby die)
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False. Doesn't need to be court approved
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In what situations would court approval be required to perform 'special medical treatments' on a child?
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- if causes permanent infertility
- contraception - menstrual regulation - vasectomy - experimental - occlusion - drug of addiction for > 10 out of 30 days |
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T/F: You can forcibly treat an under 18 yo if it is a life-saving treatment
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TRUE.
U18s do not have right to refuse life saving treatment |
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T/F: ultimately, medical decisions can be made by supreme court
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TRUE. known as "parens patriae"
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What are the 2 main layers of skin?
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Epidermis
Dermis |
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Where is thick skin found?
Where is thin skin found? How many distinct layers are in the epidermis of each? |
Thick skin = palms of hands and soles of feet [5 layers]
Thin skin = skin over rest of body [4 layers] |
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Which epidermal layer is ONLY found in thick skin?
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Stratum lucidum.
[a subdivision of stratum corneum] |
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What are the 4 layers of the epidermis of THIN skin, starting with the deepest.
How are they characterised? |
1. STRATUM BASALE
[single layer cuboidal epithelial cells on basement membrane] 2. STRATUM SPINOSUM [several cell layers thick, lots of short cytoplasmic processes extend from cells and attach to others via desmosomes] 3. STRATUM GRANULOSUM [cells containing numerous darkly staining granules] 4. STRATUM CORNEUM [flattened, disiccated, anucleate cells filled with keratin.] |
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What forms the major component of the water barrier in the epidermis?
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Cells in stratum corneum have thick plasma membranes, which are coated with extracellular lipid layer
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How is the dermis classified?
What does it contain? |
Classified as IRREGULAR, DENSE CONNECTIVE TISSUE
Contains: collagen fibres, elastic fibres, fibroblasts, glands, adipose tissue, blood vessels |
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How does the epidermis attach to the dermis?
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Epidermal ridges and dermal papillae interdigitate
[this is known as a fingerprint] |
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What and where is the hypodermis?
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Below the dermis.
Consists of ADIPOSE TISSUE, SMOOTH MUSCLE and LOOSE CONNECTIVE TISSUE |
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What are the different types of cell junctions?
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1. ZONULA OCCLUDENS
Tight junction 2. ZONULA ADHERENS Intermediate junction 3. MACULA ADHERENS Dermasome/spot junction 4. NEXUS Gap junction (communication) |
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What biochemical species cannot be synthesised?
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Vitamins (except vitamin D in skin)
Essential amino acids Essential fatty acids |
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T/F: in osteoporosis, bone is normally mineralised there is just less of it
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TRUE
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What happens to bone connectivity in osteoporosis?
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Lose connectivity - some 'struts' of bone are resorbed completely
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What happens in Paget's disease?
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Localised areas of markedly increased bone turnover.
Gross disorganisation of newly reformed bone (may be triggered by dysfunctional osteoclasts) Pain, deformity and increased fracture risk |
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What would someone with renal osteodystrophy's blood tests show?
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Decreased calcium and calcitriol
Increased phosphate and PTH |
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What proportion of men and women will suffer some type of osteoporosis related fracture in their lifetime?
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more than 1/2 woman and 1/3 men
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T/F: Highter rates of hip fractures in black Afrifcans and East Asian
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False - lower rates
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What hip fracture interventions have been shown to be effective?
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External hip protectors
combined vitamin D/Ca supplementation Bisphosphonates HRT no more than 5 yrs |
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Undernutrition can have what consequences
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Incr risk fractured NOF
Impaired immunity Recurrent infections Poor wound healing Pneumonia Pressure ulcers Incr. length hospital stay |
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T/F: salt, caffeine and other drugs can increase renal losses of calcium
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true
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What is the optimal BMI for over 65s
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24-29
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What biochemical markers are used to indicate undernutrition?
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Serum albumin < 35g/L
Total lymphocyte count <1.5 x 10^9 cells [other indicators = pre-albumin, transferrin, iron, vit B12, folate] |
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What are some clinical indicators of undernutrition?
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Difficulty chewing/swallowing
Angular stomatitis (irritation/fissuring in corners of lips) Glossitis Skin changes - dry, loose Oedema |
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T/F: Post-osteoporotic fracture, back braces should be used to treat kyphosis
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FALSE - they weaken the back extensor mm.
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What is the surgical management for fractured NOF?
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Undisplaced - multiple parallel lag screws/pins
Displaced - open reduction and internal fixation if young and active, hemi-arthroplasty for older and less active |
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What is the management for intertrochanteric fractures?
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Surgical stabilisation with sliding hip screw followed by early mobilisation for both displaced/undisplaced.
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What are the levels of prevention of a fall and how are they implicated?
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1. PRIMARY [to reduce disease incidence - maximise health and fitness of individual]
2. SECONDARY [reduce prevalence of injury by shortening duration - screening programs] 3. TERTIARY PREVENTION [reducing number or impact - reducing long term impairment, disability, suffering] |
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T/F: Half of accidental falls in over 65s occur in the home
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TRUE
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By 2051, what percentage of the Australian population will be over 65?
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24%
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How is Australian society responding to the impact of falls and ageing population?
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- National Falls Prevention for Older People Initiative
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List 3 main stages of bone healing and briefly describe events that happen in each.
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1. PRO-CALLUS
[approx first week, organisation of acute haematoma, cytokine release from inflammatory cells recruits osteoprogenitor cells] 2. BONY CALLUS [approx 3-4wks after fracture, deposition of woven bone throughout soft callus] 3. CALLUS REPOSITIONING/ REMODELLING [more than 4 wks after fracture, portions of callus not physically stressed are resorbed, outline of fractured bone reestablished] |
