research assessment Flashcards
4 main necessities of a good research assessment
- correlative (risk, something related to something else)
- causative ( need something to cause something to happen)
- necessitive ( if we dont have a key part, won’t get the same outcome)
- descriptive (to measure something, it is what it is)
what is needed for research
- tools and assessments that are highly specialized
- highly standardized assessments
- validity and reliability
what does craig study
- integrative human physiology
- sympathetic nervous system control of cardiovascular function
- adaptation and plasticity related to physiological stressors
- specifically environmental stressors (decreased O2)
a decrease in O2 availability
- hypoxia
- less o2
- in environment or level of tissue
a decrease in O2 in blood
- hypoxaemia
- unable to maintain O2 in the blood
categories (static) and caused of deviations (dynamic) from normoxia
- ambient environment (hypoxia or hyperoxia)
- biological compartment (hypoxia or hyperoxia)
- control of respiration (hypoxia or hyperoxia)
what effects our O2 uptake
- our health, impaired ability to take up and circulate O2 (asthma, COPD, heart failure)
- our activities , use > availability
- our environment , reduction in environmental availability
reduction in environmental availability
- amount of environmental O2 is decreased
- barometric pressure of O2 changes
- molecules are further apart at higher altitudes
- each volume has less molecules of O2 in it
- O2 everywhere is constant (21%), doesn’t change but molecules do
- less O2 in every breath
measuring hypoxia/hypoxaemia at places around the world
- measures partial pressure
- 700mmHg in edmonton
- 760mmHg is sea level
- 250mmHg is Mt.Everest
how to measure hypoxia/hypoxaemia
- gas analyzer
- mass spectrometer
- pulse oximetery
- near-Infrared spectroscopy
- tissue microscopy
gas analyzer
- sees 21% of O2
- can change the O2 in the air (can change it to nitrogen)
- looks at gas present
- infared light
- O2 absorbs light to measure O2
- relatively cheap
mass spectrometer
- ionizes gas molecules
- very expensive
- gold standard
- can measure many substances
- challenges because some molecules weight the same / are similar
pulse oximetery
- light projected through tissues
- worn on finger and connected to watch
- amount of O2 bound to hemoglobin reflects certain light + and some that doesn’t bounces different light
- there’s different lights to determine between what you look for
- CO can bind to hemoglobin which if counted for can be dangerous
near-InfraRed Spectroscopy
- makes sure the brain is receiving O2
- more sensors to detect O2 in tissues + venous compartment
- is attached to the forehead
- penetrates deep in to tissue
tissue microscopy
- not for humans (rats)
- red cells circulation + desaturation
arterial oxygen saturation
- depending on the amount, is presented differently in thermal charts
- represents amount of O2 going to actual tissue
- uses computer modeling
fight-or-flight response
- regulation, plasticity, and adaptation along the sympathetic neurovascular cascade
- brain - signal - do
neurovascular health lab
- takes blood samples and direct neural recordings like microneurography
sympathetic nervous system activity
- burst frequency
- burst amplitude
- burst probability/occurrence
defining altitude ranges
- 8000m is the death zone: little O2 concentration, cells cannot build new cells
- over 5000m is extreme: unconsciousness and dizziness
- 3000m - 5000m is very high : tingling sensations and headaches
- 1500 - 3000m is high : where AMS can begin to be seen
- lowest is sea level.
exercise capacity at altitude
- is harder above the altitude you are used to
- O2 uptake is less
performance at altitude
- not necessarily dangerous, but performance decreases
- air resistance decreases which can also equal better performance
acute mountain sickness
- shows up at or above 2500m
- happens in 25% of people
- headaches, GI issues, Fatigue, dizziness
- underlying causes are not known
- can’t predict who will get it
lake Louise score
- diagnoses acute mountain sickness
- must have headache 1+
- in only headache 3+
- 3-5 Mild AMS
- 6-9 moderate AMS
- ## 10-12 Severe AMS
guidelines for appropriate acclimatization
- take appropriate prophylactic drugs (Diamox)
- no more than 300-500m in elevation gain per day (sleeping elevation)
- incorporate a rest day for every 1000m gained
- avoid respiratory depressants (alcohol)
- if you are unwell do not ascend higher
- go down if symptoms persist or get worse
failure to acclimatize
- can get really sick and have to climb down the mountain
- O2 amount around 50%
how we respond to decreases in oxygen
- correction: mechanisms designed to counter the drop in O2 availability, breathing more
- compensation: mechanisms designed to preserve function of critical organs , more O2 to where it is needed
- short term
ventilation
- increases at higher altitudes
- more O2 over time
- tidal volume 1000ml
- 850ml enters the alveoli
- 150ml enters the “dead space”
- alveoli are increased with higher altitude
- short term
adaptation of HR
- compensation for increased altitude
- increased HR and increased CO and SV
- short term
redistribution of blood flow
- fight + flight
- more O2 to where needed
- mostly to the brain as it is an important organ
- short term
changes in O2 delivery and consumption
- brain is good at conserving O2
- redistributes correctly
- redistributes blood and O2 to the brain as well as lowering the metabolism/o2 utilization
- short term
long term acclimatization blood volumes
- what is in the blood actually matters
- if you only had plasma and you had to dissolve o2, it would take 180l of blood per minute to transport enough O2 to meet basal demands
- plasma is 55% of total blood
- buffy coat of leukocytes and platelets is <1%
- erythrocytes is 45% of total blood
- plasma volume DECREASE in altitude
erythrocytes
- red blood cells
- hold the carrying capacity of O2
- how much is there matters
oxygen transport at sea level
- hematocrit is 40-50% (red blood cells)
- Hb concentration = 13-17 g/dl
- how much hemo is on a red blood cell x total number of cells = more carrying capacity
oxygen transport at altitude
- hematocrit = 50+%, has more carrying capacity
- Hb concentration = 20+ g/dl
- fluid (plasma) volume decreases
- artificially increases hematocrit
- every beat moves more red cells
renal function during acclimatization
- decreased plasma volume due to urine output and fluid volume shifts
- shifts whole body’s blood volume
- artificially increases hematocrit
- blood volume measurement (co rebreathe)
- CO into system to bind to hemo, how much you measure = how much binded = blood binding
- excitation of bicarbonate to buffer increase in pH
- blood gas analysis
long - term adaptation
- become more acclimatized the longer you live somewhere
- genetic adaptations
- sherpa-people resided at altitude for ~25,000 yrs
Andean populations
- most studied high altitude population because they are easily accessible
- rely upon increased hemoglobin to sustain O2 delivery
- prone to chronic mountain sickness which is characterized by excessive red blood cell production
quechua people
- resided at altitude ~11,000 years
- 80% hematocrit , very sludgy , cannot move O2
- hypoxic tissue level conditions
chronic mountain sickness assessment
- Quinghai score for CMS
- > 5 is a diagnosis of CMS
- must have increased hemoglobin mass
- (+3 added if Hb is >21 g/dl on men or >19 in women)
- breathlessness, sleep disturbance, cyanosis, dilation of veins, paresthesia, headache, tinnitus, high hemoglobin concentration