(19) Clinical Correlate Flashcards
1
Q
(Hypoxia vs. Hypoxemia)
- What is hypoxemia?
- What is hypoxia?
A
- decreased O2 in blood (specifically arterial blood)
- Low O2 in tissues
2
Q
What are the five causes of hypoxemia?
A
- decreased inspired O2 (altitude)
- Diffusion impairment
- hypoventilation
- Shunt
- V/Q mismatch
3
Q
(Body’s Natural Mechanisms)
- What are thebesian veins? How do they work?
- Hypoxemic Vasoconstriction - what is it? What of the five is this an example of?
- What is V/Q mismatch to the extreme?
A
- veins that create a natual shunt in the body; send blood from the oxygenated blood to the bronchiole tree to the heart itself - they are the veins that pull the blood back - blood that doesn’t get reoxygenated - a natural shunt in the body
Basically blood that doesn’t get oxygenated at alveoli bt goes to left side of heart to get sent throughout the body anyway
- In most circumstances when tissues are not getting the oxygen they need - there is vascular dilation… The lungs use this when there is a part of the lung not getting oxygen - use this to send blood to regions that are -
- V(ventilation)/Q(flow) mismatch (because respiration is fine, but blood flow is not - or vice versa) - shunt
4
Q
(Causes of Hypoxia)
- There are four… what are they?
A
- Hypoxic
- Low FiO2, diffusion - Anemic (hypemic)
- Anemia, CO, MetHgb (acetaminophen - tylenol toxicity), ZINC TOXICITY - DESTROYS RBC - Stagnant (ischemic) - oxygen gets into blood but doesn’t get there
- heart failure, emboli (blood, other) - Histiotoxic (cytotoxic) - oxygen gets to tissue - but cyanide inhibits oxidative phosphorylation at level of tissue itself
- cyanide (CN), sepsis
5
Q
(Delivery of oxygen to tissues - DO2)
- Name the clinical sydrome that is a result of decreased DO2
- What are the signs (5 of them)
A
- shock (nutrients not getting what they need to)
- pallor (pale mm), cool extremities, dull mentation, pulse quality/heart rate, prolonged refill time (CRT)
6
Q
What is the importance of DO2?
What is the biproduct of anaerobic metabolsim? Is it used to measure if oxygen is getting to tissues?
A
- you get aerobic rather than anaerobic oxidation (2 ATP vs 34 ATP)
- lactic acid, yes
7
Q
What is the simple definition of shock?
A
- not gtting oxygen to your tissues
8
Q
(DO2 equation - clinical significance)
- look at this - maybe watch the thing again when studying too
1. Which form of oxygen is more important for delivery?
2. What does a patient that doesn’t have enough hgb need?
3. what form of oxygen goes across the tissues? What does this mean?
4. How do we measure saturated O2?
5. How do we measure hgb level?
6. How do we measure PaO2?
A
- (this is the equation)
1. hemoglobin
2. blood transfusion
3. the dissolved form; once we get to the level of the tissue the dissolved oxygen becomes more important
4. pulsoctemer
5. PCV, centrifuge, hematocrit
6. Measure arterial blood gas
9
Q
How to treat if…
- deficient in hemoglobin
- if hemoglobin isn’t working
- how to increase PaO2?
A
- transfusion
- glutathione
- increase oxygen they are getting
10
Q
(Cardiac Output)
- Cardiac output is related to what?
- What three things affect the stroke volume?
A
- rate/rhythm and stroke volume
- preload, afterload, contractility
11
Q
(Stroke volume)
- How much we are delivering into the heart? How can we improve this?
- What is the stuff that the blood needs to push against (resistance of the blood vessels)? How can we manipulate afterload?
- What can we do to help with contractility?
A
- preload; iv fluids
- the afterload; giving pressors or vasodilators
- dopamine, dopudamine, beta-1-receptors - increase our contractility
12
Q
(Rate/Rhtym)
- What happens when our heart rate is too high?
- What can you give to raise contractility?
A
- our stroke volume goes way down
- atropine
13
Q
WATCH at 42:24 so you know what you acutally need to know about that gigantic grapsh
A
14
Q
Just start watching at 42:24 - she is a pain in the ass to follow and I can’t do it right now
A
