Extreme Final Flashcards
Cold Injuries
NFCI and FCI
NFCI
Chilbaiin + Pernio -
Trenchfoot
Both damage local vasculature
but trenchfoot can be life altering and Cibain and pernio cause lesions
FCI
Frost Nip - cell death of epidermis
Frost bite - crystallization of the cells within our vasculature
Forst bite can lead to free radicals on the influx of O2 during reprofusion
States of Hypothermia
Mild 34-32 - increase blood pressure and max shivering
Moderate 32-29 - no more shivering - arythmiaas and unconsciousness
Severe <29 - decrease cardiac function and brain activity
Cardiovascular Effects of Hyporthermia
Initially we get tachycardia then progresses to brady cardia @ 34ºC (505 reduced HR)
<30 = afib
<25 = asystole
Increase in cold = vasocantriction , blood goes central, increase blood pressure- BRADYcardia slows the HR to combat this
Asytole - Not dead until Warm and Dead
As we get cold we decrease the amount of activation energy it takes for the enzymes to work. This means the metabolism is less while we are cold so the demands that it requires are also less. Therfore we can function with less blood supplying less nutrients.
1 degree drop in temp = 2% drop in hematocrit
Increasing our Hemoconcentration Why
This is due to decrease in coagulation enzyme function of up to 40%
Caused by
Cold Induced Spleenic Contraction - increase is contraction of the spleen to put out RBC. we do this to hold onto as much oxygen as possible but this increases the thickness of the blood
Cold Induced Diueris - loose less than hlaf plasma volume due to this.
Oxyhemoglobin Curve Respiratory in Cold
Decrease in temp makes hemoglobin hold onto oxygen more tightly, giving off less oxygen at the saem partial pressure.
We hold onto it to use it when it matters.
WE ARE STORING MORE OXYGEN .
Less oxygen giving to tissues + vasoconstriction ad low HR = ischemia - no oxygen
Cold and Brain
decreased nueral transmission
paradoxical undressing (cold inuced vasodialation) + dimnished mental capacity makes them take off their clothes
stiffness/lack of reflexes
<32 = amnesia
loss of consciousness
Terminal burriowing behaviour - trying to tuck under something
Cold deaths more than heat deaths
Steps to combat hypothermia
- prevent further heat loss by getting them out
- insulate ( space blanket0
- sweet drink - glucose is anti freeze and
Alcohol is a diuretic (COLD)
make us piss - lose heat - loose radiatiing fluid
passive v active rewarming
passive is immediate
active - wait until they get back up to 34 degrees - dont want to lose more heat if they are still too cold
DOnt exercise to warm up hypothermics why
exercise increases blood flow to periphery - loose heat to tissue and to enviroment and return cold blood
swewating - loose heat to evaporation
depletes energy - need energy to stay more
DONT do these for hypothermics
- dont rub
- dont thaw
all increase risk of reprofusion injuries
therapeutic hypothermia
droppinghte temperature for those with TBI or heart attacks -
reduce the metabolism = reduce the amount of blood needed in those areas
- cranial vasoconstiction to stop swelling and pressure
- supresses the inflamattory cascade and reprosuion radicals
is it ever too cold too exercise ?
No, not if you can get back to warmth.
Risk of Exercising in the cold
FCI - increased heat loss thorugh the elements but our body generates enough heat to combat this
Airway Damage - cold dry air irriatae alveoli inducing imflammaotyr cells (eicosanoid) - and when we exercise we increrase the rate of breathing so even riskier.
EIB
Cardiovascular Strain just from the cold - increase blood pressure and increase hearate then you add exercise casuing more strain
Slipping and not getting back home
EIB
exercise induced bronchospasms
restriction of airflow formt he contration of bronchiotubes
less airflow means less oxyegn for exhcnage = less co2 removal
sympotoms - tight chest, dyspnea, wheezing, coughing
26% of non asthmatic people get this
EIB goes away when we stop running because we decrease the ventilation and can catch up to the amount of oxygen uptake.
4 phases of cold water immersion
- Cold shock - 0-2min
- Muscle/ Swimming Failure (2-15min)
- Hypothermia15-30
- Post rescue collapse
co,d water defined as
less than 25 degrees, worse effects at less than 15 degrees
Cold Shock
when first immersed in the cold, we gasp
we increasse - vent rate and inspiratory volume
and we increase our heartrate form vasoconstriction
cold core and sucking in water to lungs are not good.
Gradual immersion can shorten the effects of cold shock once habituating , and increaseing our breath hold times
Diving response
head first submersion triggers the trigeminal nerve in our face closing the epiglottis to protect against influx of water and cold air nto lungs
lessens the immediate cold shock and reduces our hr more than regualr cold shock
People who will survie a boat sinking
fat people - more insulation and more buoynat save energy
women - more fat insulating
- Insulation jacket floating thing
Help position - Huddle
- PDF
4 Treading water
survival tactic in water
if more than 800m assume huddle
if less than self rescue
Post Rescue Collapse
Afterdrop causing loss of more heat even after out of the water
due to
blood flow and thermodynamics
lose heat in blood and recool the core
thermo - lose heat through migration through the tissues
hihg altitude basics
less air particles
less pressure exerted
colder becasue less particles to warm up
less pressrue in air casues less of a driving force of oxygen into us
why decreased water vapour pressure in high altidue
cold climates hold lesss water and their are less particles in the air = less water vapour pressure
respiratory response at altitude
increase tidal volume and breathing frequecy trying to increase the pressure of oxygen
tidal volume - alwasy breath the saem amount but becasue less o2 we get less drive - low hypoxic drive
breathing frequency - breathing faster expels co2 quicker to make rooom for oxygen
respiratory alkalosis
at altitide the increased tidal volume and breathinf frequency makes us expel c02 much more, this takes hydrogen ions away nad makes our body become more basic
oxyhemoglobin at altitude
because of low c02 in our blood
we try to add mroe co2 with bicarbonate equation.
when we have less c02 our body begins to hold onto oxygen more tightly (hemoglobin) allwoing us to store more 02 for later
up and to the left
Loss of blood volume at altitude why
- breathe out water
- cold and altiitude induced diuresis
loose blod volume we decrease edv and SV so we increase hr to maintain cariac output but we also see the blood more viscous because of increased hematocrit (good when its near the alveoli, more o2 carrying capacity)
Altitidue iduced diuresis
- increase pressure in thorax cuases increase BP making us lower HR and piss more
- also casue due to respiratory alkaloissi
- getting too much bicarbonate so we reomve it thorugh urine
V02 at altitude
hr x sv x a-v02
hr increases as we increase blood pressure
sv decreases as we los volume of blood
a-v o2 decreases as we old oxygen more tightly as we are becoming more cold and basic(harder to extract)
enduracne sports in altitude
v02 is down
in altidue becasue we have less oxygen supply/drive we begin to rely less on aerobic and more on anaerobic
even thought aanaerobic doesnt use oxygen we still need to repay the systems that were used.
lactate paradox
we increase reliance on our anaerobic metabolism during altitude.
so we should see more lactate being produced inthose who are those who are native to the area but we dont
metabolic changes at altitude
increased basal metabolic rate
due to thyroid oroducing catachollmines and thyroid hormone from non shivering thrermogenies
increased reliance on carbs since we rely more on anaerobic meatbaolism
decreased appetite acutely casue we cant get food
altitude response chornically to low oxygen
becuase of the decrease oxygen carrying capacity and and low 02 in blood, over time our body begins to increase epo (RBC) to tim more rbc fromt he liver to help increase 02 carrying capacity (increasing the a in a-v02 diff)
AAS/AMS diagnosis
acute altitdue sickness
- changed altitdues within the past 4 days
- have a headeache
- have one or moer of thease syptoms
- loss of coordination
- insomnia
-GI distress etc
starts at around 2500m 15-40% of people get it
LAke Lois Questionaire
50A% of people get it at 4000m
can avoid it if we ascend gradually 9 acclimate then climb )
combat with oxygen or descent
HACE
swellling (liquid) in cranial cavity
recognizing low 02 in the bloood so the body increases blood flow to the brain. increasees pressure in capillaries that can leak out fuid . increases blood into the brian
and increases permeability of blood brain barrier whihc causes more blood allowed into brian swelling
if not displaced with cerbro spinal fluid then we can get the full affects of HACE
HACE SYMPTOMS
ataxia,lethargy, confusion
can progress to death becasue of the other sympotms of AAS and occurs around 4300 m
HAPE
liquid in the lungs
low 02 in the blood our body tells us to maximmizze the contat that it makes with the well aerated regions of the lungs, this vasoconstricts the poorly aerated regions of the lungs increasing the pressure ofblood their whihc can leak into to the lungs
symptoms includ cchest tightness, coughing, confuison, blu elip s
if there is pressrue on the capillaries it can casue endothelial damge which causes endothelyial dysfucntion which causes increased blood presssure and it will cycle or cause infection
respiratory adaptations ot altitude
- inrease resting ventilattion at rest by 40
- iubmaximal vet will platuea at 50% higher
blood adaptations to altitude
increase red blood cells
increase plasma volmue - due to increasesing the hormine to conserve water when we stay there linger
increase hemoglobin -oxygen carrying capacity
muscle adaptations to altitude
- decrease muscle csa
- decrease glycolyti and mitochondirial c enzymes (casue lsot muscle mass)
- angiogenisis - to increase more 02
cardiovascular adaptations to altitude
decrease v02
work capacity increased
hard to tell if sea level or altidue traingn is benefical why
casue we increase all this stuff when you jsut train and becasue intensity and volume of trainng is reduced at altitidue
and hard ot bring up equipmetn
Increased perfomrance on gorund from Hypoxic envirometn
- increase HIF-1 (allows for more genes that increase epo and angiogeneissi and glucose transport to the cells) an idividual difference
- increased epo
- increase hyperventilatory response which causeses increase in looading of oxygen on the oxyhemoglobin curve
- increased economy of movemtn since less particels in the air
take into account when moving ot altitude
a;titude is calssified at 2000m or above
have to deal withthe negative psychological and psyhiological effects of altitude
12-16 hr a day of traiing adn w can lose adaptations in 2 weeks
takes long to see the adaptations
live low train high
acute syptoms will occur in trianing casuing less of a traing stimulus buyt symptoms may be reduced
live high train high
goes either way-
cant accoutn for periodization
live high train low
increased hypoxic effects when we are resting at altitiude
and better trainng stimulus when we are trianing at low altitdue
increased v02, epo, hemoglobin , perfomrance
this is the best
Hyper baric basics
air is compressable , water is not
eery 10 m belwo sea levels is 1 atmoisphere of pressrue
boyle law - increase in pressure is a result of decrease in volum eand decreease in volume increases pressure
how do we combat the pressure compressing the air in us
we inspire dense air in order to push back against the pressurefrom the water until it is equal
respiratory challeng to hyperbaric
increased dead space not participating in gas exchange so we need a respirator
hihg dednsity of gases form the respoirator as pressure increases will dissolve reater into our tissue
air temp we inhale is low os its hard to thermoregualte when we continuously are cooling
henrys law
more pressure = more dissolved a gas into our tissue
helium then nitrogen then oxygen
lung colllapse/ squeeze
imncreasaeing outside pressrue as we descend increases pressure on the lungs which have lower relative pressure indie them, this will force the ari out of the lungsand close the lung to resiudual volume which can damge the alveoli at this spot
mask squueze
putting a mask on outside of the water traps the atmospher air, this is lower than the pressure of water at certain levels and pressrue exerted onto the mask can ccasue rupturing of blood vessels in the eyes,
to prevent this we canput the mask on outside of the water or breathe dense air from our nose inot the mask to equal pressure
pneumo thorax
when the plural sack ruptures
as we decreas the pressure exerted from the water onto our lungs but happen to have too much high dense gases in our lungs at the wrong time, we can have pressrue from the lungs expand outwrds (greater than that of the water around us) and burst the like a ballon, this will get rid of the suction from the plural sack to the lung and influx ocygen here,
oxygen here cancreate air embolisms which are bubbbles which may be move to ither areas of the blood in the body
to reduce this we breath out whil ewe are ascending to reduce pressrue in the lungs
hood squuze
increase pressrue durig descent from the outside into or low pressrue ear canals can rupture tympanic membranes
this can affect heearing, balance and orientation which are senses that are needed to get out of riskyy enviorments
get rid of this will the valsva manuever or, swallowing
aerotitis
hihg pressrue outside onto low pressrue ear inflammes the middle ear
aerosinitus
during ascnet, ikf we get air trapped in our sinuses from the high pressrue enviroment/ gases due to cloggred onose or something, we can iexert pressrue from the sinus on the mucous lined walls of the causing immflamaition or capillary ruptrue in the sinus
On gassing
increasing the pressure in our lungs throuhg high desnity gasses, casues the gases in the lungs to absorb into the blood/tissues
ON Gassing Problems
Inert Gas Narcosis and Oxygen toxicicyt
Inerert gas narcosis
when too much nitrogen absorbs into our blood, cna be reversed, vcausng euphoroia, imparired judgement, loss of consciousness
noticed @ 100 ft with compressed air
ffeeling mildly intoxicated
high pressrue more absorbs (henry)
HPNS
HiHg Pressure Nervous Syndrome occurs in descent
greater than 400 ft
dizziness trauma cause vomiting muscle twitching stomach cramps
ususally we want to take out nitrgogen because of the narcosis effect but in the case of HPNS we add 5-10% nitrogen back into the mix in order to combat the effects of Narcotic
COmbat On Gassing
decreasey of the gas in order to allow for less dissolving into our tissues to elimiante narcosis
notriox shallow
heliox deep
trimix very deeps
dont need c02 casue we produced the co2 into the tank
Oxygen toxicity
too much oxygen can suck up electron create super oxicdce anion which leads to the creating of freee radical swhich abosorb electrons from other tissues /decreaing cellular function
Off Gassing
reducing hte pressure reduces the gases that are dissolved in the tissue
low pressure in the lungs will have the gas in the tissue move to the lungs
decreaseing ambient presssrue so high pressure has to go somewhere
Off Gassing Problems
the bends
pneumonia thorax
aerosinitus
fst and slow tissues
take on and left off gasses quicker or slower
if its slow tissue then we need to stay their longer for the gases to absorb
the bends (decompression sickness)
when we increase ascent too wuickly the gases in our blood and tissues need to go somehwere as they will now be high pressure and the enviroment will be low, gases from the tissues push into the apillaries and can create bubbles that block block from going downstream (ischemic tissues) the bubblecan also irritate the tissues insode the capillary and casue leakage and imflammation (wbc cause clottign = blockage)
determinants of the bends
depth - deep mor on gassing
time - time more the time
ascent rate - too fast
multiple dives - residual gasses no fully gone
How would treat decompression sickness?
Recompress them in a hyperbaric chamber @ 60 ft of sea water fsw. and can use pure oxygen without the risk of oxygen toxicicity since the pressure (60 ft ) is much less than deep dives so lower risk of oxygen toxicicity ( less drive of oxygen dissolving into blood)
G- Forces
force of gravity or acceleration on the body
high gravity.
Gx - anteroposterior
Gy - horizontal
Gz - vertical
Positive G z responses
- head to foot
blood rushing from head to foot, we increase our heart rate and force in order to get cirulated blood around the body
- increase vascular tone in head to keep blood there
without being able to get blood back to the head, we can loose vision and begin to go unconscious (GLOC)
slwly narrow tunnel vission to the point of GLOC greyout then blackout
negative Gz forces
foot to head
too much blood goes to the head, less blood out of the head and we can get red out where the capillaries fill with blood and we cant see then we can also go unconscious becasue the blood that there is pooling but not doing gas exchange
neurovestibular responses to microgravity
have fluid in our canals in the ear.
in space we cant sense orientation with no gravity but after a few days we can be unconfused as what are eyes sees catches up with what are brain is senseing
motion sicknesss is conflicting imformation of our senses
- crista - semicircular canals
- sense angular motion, not really effected in micro gravity
- Maccula in the Saccules
- sense linear motion and as our bodies accelerate in the linear direction otoliths embedded in the fluid of the ear canals get sent forward or backward triggeringthe hairs to sense this
70% of astronauts get the nausesa nd vomiting and disorientation but it onyl catches up with us in a few days so if the mission is shrot than we cant really do a lot of productive stuff
cardiovascular responses to micro gravity
in micro gravity fluid is not pulled down to the legs but floats throught the body dispersing around, this can fill sinuses which can cause a headache and will generally make our faces puffy
Micro gravity induced diuresis - the shifting of fluid causes the kidney to get rid of excess fluid so we piss so plasma volume decreases ,, kidney also reduces epo and wbc making most astronauts anemic as early as 4 days ( 15% plassma loss ion 3 months
exposure can cause 22% loss of blood volume
we dont get as thirsty
myocardial tissue resposne to micro gravity
since we are losing blood volume and we are also reducing the amount of work the heart has to do to fight gravity, we decrease the cost of moving which detrains the heart making it smaller and weaker
cardiovascular when we return to earth
orthostatic intolerance and presyncope
since we have a reduced cardiac work in space and reducesblood volume then we add gravity pulling pulling down the blood back to our legs
orthosttic intolerance- when we cant commabt the effects of gravity when we stand ( getting light headed when we stand up)
presyncope - reduced blood pressure casuing light headed ness dizziness feeling faint
addd on top of it the suits trying to cool us off so we lose mroe fluid
how to combat return to earth cardiac effects
Low body negative pressure- putting our legs in a vaccum to drive the pressrue out adn from the upper body down to the legs
orthostatic intolerance can be combatted with lots of fluid and salt because water follows salt in order to drive up blood volume or cool them down to vasoconstrict adn drive blood back up centrally / g suit - increases pressure int he legs to drive blood back up centrally
respiratory in space
space is a vaccum so we neeed to mek artificaila pressure in the space station
this can casue high pressrue inside and no pressure outside meaning decrompression sickness wehn we go outside
thats why we pressurize the suits or else the suits would be stiff, but if we can add pressure in them we can maintain mobility and
to combat the decompression sickness they use pure O2 because the pressure is low so no need for oxygen, any pressure will be enough to drive oxygen into the blood eliminating the risk of inert gas narcosis
thermoregulation in space
hot when facing the sun and freezign when not facing the sun
no atmosphere so increasesd heat transfer from thermal radition and fluid loss (hot in space suit for vasodialation adn fluid loss)
fromt he space suit it over cools
we are protected by the earths magnetic field low earth orbit
muscle in space
muscles atrophy because we arent using them 5% a week in atrophy
30% decrease in myotcytes
lose slow fibres
lose actin more than myosin
lose structural proteins
more relaince on muscle glycognen thatn fat metabolism
all lead to lack of endurance and fatigue
bone in space
wiehgt bearing bones lose much less
arms still used to fly around so we see only 1-2% loss a motnth 0.3% calcium
kidney stones may occur because as we lose the calcium in our ou rbone it has to go somwhere so it goes to the blood increasing blood ca concentration ultimatley leading to increase output to kidney and kidney sotne formation (also due chewed up bone by osteoclasts)
direct and indirect effects of radiation in space
direct effects - radiation changing dna and cellular componetns that we need for survival
indirect - hihg chance of breaking down water into hydroxylz that can create free radicals which can casue tissue damage
risk to radiation depends on
type of radiation, dose , energy , dose rate, absorbed dose
liver is low risk
eyes are high risk
kidneys spleen gall moderate risk
best defences is to limit duration adn amoun t of exposre
RADS and exposure to low dose radiation
radiation absorbed dose
space close to 200 rads
genetic - radiation changing ameetes and sex cell s
somatic - radiation carcinogenic effects
in utero. - mutation in fetus
