MT Flashcards
two main types of studies
descriptive (PO)
-survey and qualitative
analytic (PICO and PECO)
-experimental or observational anaytic
what does PICO stand for?
patient/problem
intervention
comparison
outcome
how to determine study design
Q1: descriptive (PO) or quantifying a relationship (PICO)?
Q2: random allocation? if yes, RCT, if not observational analytic
Q3: observational:
if outcomes determined after intervention: cohort/perspective
if at the same time, cross sectional/survey
if before exposure, case-control/retrospective
randomised control trial
comparison study where participants are randomly assigned to treatment/intervention group or control/placebo group advantages: -unbiased distribution of confounders -blinding more likely -randomization facilitates statistical analysis disadvantages: -expensive (time and money) -volunteer bias -can be ethically problematic
crossover design
controlled trial where each participant has both therapies (randomized order)
advantages:
-subjects are their own controls and error variance is reduced (smaller sample size needed)
-all subjects receive treatment
-blinding, statistical test assuming randomization
disadvantages
-all subjects receive alternative treatment or placebo at some point
-cannot be used for treatments w/permanent effects
cross-sectional survey
-examines relationship b/t diseases and other variables in a population at one particular time
advantages: cheap and simple, ethical
disadvantages
-establishes association at most, not causality
-recall bias susceptibility
-confounders unequally distributed
-group sizes unequal
case-control study
compares patient w/a disease to controls and determines which people have been exposed to the factor under investigation
advantages
-quick and cheap
-the only feasible method for rare disorders or long lag time b/t exposure and outcome
disadvantages
-reliance on recall or records to determine exposure
-confounders
-control group selection is difficult
cohort
data from groups who have been exposed or not exxposed to new factor (from databases), no allocation of exposure made by experimenter
advantages
-ethically safe
-subjects can be matched
-can establish timing and directional of events
-standardized eligibility and outcome assesment
disadvantages
-controls may be difficult to identify
-exposure may be linked to a hidden confounder
-blinding difficult
-no randmization
-large sample size needed
selection bias
error in choosing individuals or groups taking part
measurement bias
poorly measuring outcome (calibration)
interviewer bias
opinion or predudice or influence of the interviewer, affecting behavior
response bias
respondents answer in the way they think the investigator wants them to answer
referral bias
- preferences or local practices influencing recruitment
- eg more severe cases sent to academic centers
reporting bias
selective reporting or suppression of information (eg publication bias against negative studies)
sensitivity
of all individuals with the condition, the percentage that will test positive (true positives/all cases)
-highly sensitive tests good for ruling things OUT
specificity
off all individuals who DO NOT have he condition, the percentage that will test negative
eg true neg/true neg + false pos
-highly specific good for ruling things IN
three symptoms that could contribute to upper respiratory symptoms
anemia, anxiety, asthma
what does anemia not effect?
saturation %: it’s number of Hb, not number occupied
wheeze
strained breathing out
stridor
strained breathing in
crackling sound
what’s the difference b/t asthma and exercise induced asthma
- asthma is chronic and brought on by many triggers
- eg smoke, allergies, exercise could be a trigger, cold air, dry air, cats, mold
- exercised induced bronchospasm=reaction brought on by exercise
asthma
chronic inflammatory disease of airways
-variable and recurring symptoms: reversible airflow obstruction and bronchospasm
EIAB
intermittent narrowing of airways + decrease in airflow
-wheezing, chest tightness, coughing, dyspnoea triggered by exercise
in 50-90% of asthmatics
how does transient airway narrowing occur?
thickened bronchi lining–>narrower airway
- expiration relies more on elasticity of chest wall and pressure leads to smaller airway collapse
- higher Ve leads to more water loss
- changes in airway –> inflammatory cascade and sm contraction
what is often the first symptom of EIB?
poor performance for given level of conditioning
-season and climate related
EIB signs and symptoms
wheeze, cough, dyspnoea, chest tightness
for 1-2 hrs after exercise
-chlorine and exhaust are aggravators
EIB test
field test: make symptoms occur, then measure lung function
also chemical ways to trigger attack (insensitive)
and osmotic challenge, which causes drying of lungs and mimics exercise
eucapnic voluntary hyperpnea
mimic exercise breathing
-breathe in some CO2 so they can breathe at the same rate as heavy level
exercise
-sensitive and specific
treatment for EIB
- ideal activities in warm, humid environment
- extend warm-up, low to moderate intensity
- use refractory period (less risk of attack after 1 attack)
- increase intensity in steps
asthma treatment
stabalize w/bronchodilators, corticosteroids
-salbutabol b/f exercise and as rescue medication
what should be considered when EIB treatment fails?
vocal chord dysfunction
pulmonary embolism
vocal chord dysfunction
paradoxical vocal chord adduction obstructing inspiration
-females and younger patients more common
vocal chord dysfunction signs and symptoms
throat tightness, stridor, chest tightness, air hunger, coughing/hoarseness
-often at very high exercise intensity
how is VCD treated?
treatment of aggravating factors (eg gerd, post nasal drip) may be enough
-vocal chord resynchronization w/coughing or panting, RMT?
-postural techniques and stress
management
pulmonary embolism
rare cause of exertional dyspnoea
axillary vein thrombosis common (more so in elite athletes and throwers) is possible
-clot goes from R side of heart through hole (20% of ppl have it)
thromboembolism risk factors
use of elicit substances
ritual dehydration (lightweight, boxers)
effort-induced thrombosis (trauma to vessel wall?)
symptoms of pulmonary embolism
- pain, swelling, numbness in distal limb
- poor exercise performance
- profound arterial desaturation during exercise
distinguishing factors of pulmonary embolism
no wheeze, stridor, or abnormal spirometry
-affects blood, not lungs
possible adverse effects of pollution
cancer, heart disease, stroke
pollution componenets
gaseous: ozone, CO, oxides of N
particulate: eg diesel
does increased exercise intensity add to effects of pollution?
no, increases in Ve and O2 consumption at low but not high as a result of exposure
no effect on norepinephrine, endothelial function, heart rate variability
concussion considerations
short term impact
post concussion syndrome
dementia, parkinsons, depression/suicide
cost to professional sports teams
concussion
functional head injury w/symptoms that usually last a short period of time.
acute clinical symptoms reflect functional disturbance, not structural injury
may not involve loss of consciousness
mechanisms of concussion
direct blow to head
coup contrecoup
-whiplash motion of head results in axonal shearing and damage to neurons/release of chemicals
-acceleration/decceleration of brain w/in skull
final determination regarding concussion diagnosis
based on clinical judgement
- there are no grades
1. can’t prove someone has it so certainly can’t prove how severe
2. initial injury doesn’t correlate to symptoms so grading is even more useless
SCAT assessment
- LOC
- balance/coordination
- disorientation or confusion
- loss of memory
- blank or vacant look
Maddocks score
for sideline assessment
-questions about game + game last week
SCAT 3
for further assessment
-involves orientation questions (month/year/time)
concentration task (count digits or months backward)
-memory task (repeat words)
-balance test
when to refer to emergency
- worsening headache
- very drowsy
- can’t recognize ppl or places
- significant nausea/vomitting
- confusion/irritability
- seizures
- weakness in limbs
- slurred speech or unsteadiness
- pupils would be UNCHANGED (no swelling or bleeding)
reasons for not returning to sports the same day
- brain may be in state of neurometabolic crisis, increased energy demand slowing healing
- window of vulnerability for second worse injury
how long does concussion recovery take?
about 10 days
symptom free w/daily activity before sports
gradual return
-go back one step if symptoms return
how many canadians have pre or type II diabetes
9 mil