Send the link below via email or IMCopy
Present to your audienceStart remote presentation
- Invited audience members will follow you as you navigate and present
- People invited to a presentation do not need a Prezi account
- This link expires 10 minutes after you close the presentation
- A maximum of 30 users can follow your presentation
- Learn more about this feature in our knowledge base article
Do you really want to delete this prezi?
Neither you, nor the coeditors you shared it with will be able to recover it again.
Make your likes visible on Facebook?
Connect your Facebook account to Prezi and let your likes appear on your timeline.
You can change this under Settings & Account at any time.
Transcript of 10 equations
PAO2 = (760-47)FiO2 - PaCO2 (1.2)
therefore, at sea level on room air:
PAO2 = 150 - PaCO2(1.2)
Delivery O2 = Cardiac output (Hgb x SaO2)
Mean arterial pressure = cardiac output x systemic vascular resistance
Metabolic need = Cardiac output x (SaO2 - SvO2)
Flow = K[P(in)-P(out)] - [Onc(in)-Onc(out)]
Wall tension = [Pressure x radius^4]/wall thickness
The 10 Equations
AKA: everything you really need to know about internal medicine
Alveolar gas equation: air to the alveoli
Diffusion = [pressure gradient x area] / wall thickness
Fick's Law of Diffusion: alveoli to blood
blood to tissues
How much is enough?
Spigots & Drains
Fluid across a membrane
How does the body handle
fluid in its chambers?
Assuming a normal PaCO2, what would the PAO2 be?
PAO2 = 150 - 40(1.2)
PAO2 = 150 - 48
PAO2 = 102
What's the A-a gradient?
ABG (room air) @ sea level: pH 7.40, PaCO2 40, PaO2 90
Adapted from: Wiese J. "Teaching in the Hospital"
Adapted from: Wiese J (ed.). "Teaching in the Hospital"
Adapted from: Wiese J (ed.) "Teaching in the Hospital" ACP Press, American College of Physicians, Philadelphia 2010
PAO2 = [(760-47)(0.21)] - [(40)(1.2)] = 102
PaO2 on ABG = 90
A-a gradient = PAO2 - PaO2
Normal ~ (1/3 pt's age, minimum of 10)
A-a gradient = 12
CaO2 = (SaO2 x Hb (g) x 1.34 (mL/g)) + .003(PaO2)
Cardiac output =
stroke volume x heart rate
Why do I get more short of breath running in humid weather?
PAO2 = (760 - Vapor Pressure H2O)(0.21) - (PaCO2)(1.2)
Why do I get more short of breath running at altitude?
PAO2 = (Barometric pressure - Vapor Pressure H2O)(FiO2) - (PaCO2)(1.2)
As humidity increases, vapor pressure increases
As altitude increases, barometric pressure decreases
FiO2 does NOT change
Stroke volume = preload x contractility
% metabolic need being met
Delivery of O2 = CO x Hb x SaO2
Insult 1 -
Insult 2 -
Insult 3 -
Metabolism = the facuet
Minute ventilation = the drain
Ventilation and perfusion are not equal across the lung
Illness or exertion drive up metabolism
PaCO2 = CO2 production - minute ventilation
Minute ventilation = (respiratory rate)(tidal volume)(1-deadspace %)