Pharm
Card Set Information
Author:
shirljoa
ID:
214727
Filename:
Pharm
Updated:
2013-04-20 23:37:54
Tags:
Inhalationals
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Description:
Inhalationals
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Ficks law of diffusion
diffusion= (P1-P2)(Area)(solubility)
----------------------------
(membrane thickness)(sq.root of MW)
Graham's law of diffusion
rate of diffusion = 1/sq root of density = 1/sq root of molar mass3.
Henry's Law
amt of gas that will dissolve in a liquid is proportional to the partial press of the gas in the gas phase
- allows determination of amts of gases (O2 and CO2) that will dissolve in blood
Amt of O2 tha dissolves in blood
0.003 ml/100 ml blood/mmHg partial press
-so, if PaO2 is 300 mmHg, then 300 mmHg x 0.003= 0.9 ml O2/100 ml blood
laminar flow
change in P/airway resistance
airway resistance = 8 x length x viscosity
------------------------
pi x radius to the 4th power
Reynolds number
Re =linear velocity x diameter x fluid density
--------------------------------------------
viscosity
low reynolds # (<1000) = laminar flow
high reynolds # (>1500) = turbulent flow
poiseuille's law
-used for laminar flow
F = (pi r4 change P)/(8 viscosity length)
Bernoulli's Principle
- r/t laminar flow
- based on total conservation of energy
E = PV + mgh + 1/2 mv2
in a narrowing, assuming constant flow, resistance & press will decrease in the narrowing
R = change in P/ F
R = 8(viscosity)(lenght)/(pi r4)
causes of turbulent flow
- rough tubing walls or kinks
- flow through orifice
- high velocity flow
flow exiting the narrowing becomes turbulent
turbulent flow is inversely related to density
absolute humidity
mass of water vapr in a given volume of air
relative humidity %
(actual vapor press/saturated vapor press) x 100
ohm's law
energy = current (amperes) x resistance (ohms)
E = IR
% inspired air
% of inhaled air that is occupied by anesthetic has
-controlled by anesthetic machine
alveolar partial press
used as a determinant of brain partial press