Bonita Flashcards
What factors influence the Bohr effect (directly) curve to move right i.e. easier to offload O2 from Hb?
- Decreased pH (acidosis)
- Inc body temp
- Inc 2,3 DPG
- Inc CO2
What factors shift the Bohr effect to the left i.e. allows increased Hb saturation at the same PaO2?
- Presence of HbF (F = foetus)
- CO
Name four factors that influence oedema?
- Low blood albumin
- Inflammation (makes leaky capillaries)
- Obstruction of LNs (no drainage = fluid build up)
- Increased pressure within vessels (osmotic or hypertension)
Why shouldn’t you climb Everest if you have respiratory issues?
- PaO2 is lower therefore resting RR is already higher
- Breathing frequency increases as a result of increased physical exertion
- Increased mucous production to help humidify the air = narrower airways
- More fluid in airway = greater distance for O2/CO2 to diffuse = less likely for appropriate saturation to occur
Why shouldn’t you climb Everest with a heart condition?
- Increased resp rate = increased HR too
- This + SNS input puts more stress on the heart which may trigger an event
Why should you drink lots more water at altitude?
- Air is drier so you are using more water to humidify the air for diffusion to occur
- Chances are you are probably doing physical activity so you’re sweating a lot anyway
What might happen if you become dehydrated at altitude?
- Confusion/dizziness
- Osmoreceptors trigger thirst response via RAAS
- Low bp (low blood volume) –> SNS activn triggers RAAS response
- Increased SNS = decreased appetite
Why couldn’t Bonita feel the blisters and frostbite she had on her toes?
Decreased PaO2 = decreased oxygen perfusion to her extremeties = less sensation to blisters/frostbite
What can the body do to ADAPT to high altitude?
- Upregulate 2,3-DPG to help offloading of O2 from Hb to tissues
What happens when someone has acclimatised to high altitude?
- Increase EPO production to make more hematocrit (RBCs)
Our bodies compensate to a low oxygen environment by increasing resp rate. What are some consequences of this?
- Inc RR = blowing off lots of CO2 = inc pH = alkalosis
- Body tries to get rid of HCO3- (bicarbonate) in urine to compensate for alkalosis
- Now there is less ability to buffer acid which will result in pH fluctuations (especially when exercising)
Why do people’s ears pop on planes?
- Decreased partial pressure of O2 in the air = expansion of air within ear canals = ouch
Why do most people find it hard to sleep on planes?
- In response to decreased PO2 in air, body increases HR and RR
- SNS activation is also occurring = more alert
What happens if someone on beta blockers jumps on a plane?
- They’ll be super tired afterwards
- This is because beta-blockers (pacemakers too) reduce the body’s ability to compensate for the decreased oxygen environment
Why do you have to poop on the plane but sometimes you can’t?
- GI discomfort occurs because the air has expanded in your GIT
- SNS activation suppresses this :(
