anesthesia final1
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- how many psig = 1 atm
- 14.7 psig = 1 atm
- 1 mmHg = ?? mmH2O
- 13.6 mm H2O
- What is the formula for flow:
- F = Q/t
- What is Poiseulle's Law?
- Q=(pi)(P)(d)^4 / 128 n l
- What part of Poiseulle's Law has the greatest effect on flow:
- diameter (it is to the 4th power)
- What is Laplace's Law
-
pressure gradient across wall of a TUBE = tension/radius
P=t/r - What is Laplace's Law equation for a sphere:
- P = 2t/r
- What is the formula to describe how surfactant affects Laplace's Law?
-
P = r/ 2t
surfactant reverses Laplaces Law. - Describe flow through a venturi:
- as gas moves throuhg the constriction it creates a change in potential energy to KINETIC energy and with it a huge drop in pressure (subatmospheric) and can be used to entrain air/gas into the system.
- Is the opening of a thorpe tube at LOW flow orificial or tubular, laminar/turbulent? Which quality of the gas is most important in determining flow?
- At low flows the flow is laminar and the opening is tubular. Density is the quality that will most affect flow.
- At high flows via flowmeter is the opening orificial/tubular and is flow laminar/turbulent? Which quality of the gas will most determine flow characteristics?
- At high flow the opening is orificial and flow is turbulent. Viscosity is the key quality that will determine flow.
- Boyles Law:
- at constant temp, pressure and vol are INVERSELY related
- Charles Law:
- at constant pressure, temp and vol are directly related
- Gay Lusac's Law:
- at constant vol, temp and pressure are directly related
- What is the combined gas law:
- P1 V1/ T1 = P2 V2/ T2
- What is Daltons Law of partial pressures
-
(P)total = P1 + P2 + ....
in a mix of gasses., the partial pressure exerted by each gas is the same as it would exert if it were alone in the container. - What is Avogadros hypoth
- equal volumes of gas at same temp and press have the same # molecules
- What is avogadros #
- 6.022 x 10 ^23
- 1 mole of a gas at stp will take up what vol?
- 22.4L
- Henry's Law:
- at a given temp, the amount of gas dissolved in a liq is directly proportional to the partial pressure of the gas in equilibrium with the liq.
- How does a gas' sol coeff affect it's alveolar partial pressure?
- The lower the solubility, the faster it will develop a high alveolar pressure gradient and hence will have a faster onset of action. This is based on Ficks Law which says that the rate of diffusion will increase as the conc gradient increases.
- Grahms Law:
- the rate of diffusion of a gas is inversely related to the square of it's molec wt
- What is a 1 Normal solution:
- 1 GAW/GMW of (nonionized)subst in 1 L of water.
- Raoults Law:
- the depression or reductin in vapour pressure of a *solvent is proportional to the molar conc of the *solute
- How much time do you have left on an E-cylinder of O2 if the gauge reads 700 psig and you're flowing gas at 4LPM?
- Just over an hour, +/- 61 min.
- What is the definition of partition coefficient:
- the ratio of a substance in two phases at equilibrium.
- Is the "failsafe valve" on an Ohmeda machine really foolproof in protecting the pt from a hypoxic mixture of gas?
- No. It merely ensures that the O2 system is pressurized but does not guarantee *FLOW of O2.
- What are some methods we use to prevent hypoxic gas mixture delivery to our pts?
-
-correct gas filling in the tank(not our job)
-pin index or diameter index system (connection safety)
-"failsafe" valve or OFPD
-Link-25 or ORMC
-FIO2 delivery gas analysis.
-Sao2/ABG
-Always on 200cc O2 flow.
-O2 as last gas on flowmeter assembly.