vapor pressures for VAA’s are at what temperature?

20 degrees C

Whats the Vapor Pressure? Sevoflurane

170 mmHg (7-sevo0

Whats the Vapor Pressure? Enflurane

172 mmHg

Whats the Vapor Pressure? Isoflurane

240 mmHg

Whats the Vapor Pressure? Halothane

244 mmHg

Whats the Vapor Pressure? Desflurane

669 mmHg (des 6)

is the vapor pressure a function of volume, temperature, or pressure?

temperature

the pressure at which the gaseous state is in equilibrium with either the liquid or solid state, or with both is known as what?

the saturated vapor pressure (SVP)

Volatile agent in a flask is an ex of whose law

daltons

if Iso is added to a flask of Oxygen, what is the percent of oxygen and percent of iso In the flask above the liquid?

the VP of iso is 240 mmHg the Partial pressure of oxygen is 760 mmHg

The partial pressure of O2 after Iso is added is 520 mmHg (760-240=520mmHg)

%O2 = (520mmHg / 760 mmHg) x 100% = 68.4% O2

%iso = (240mmHg / 760 mmHg) x 100% = 31.6% iso

Formula is %gas = P gas / P total

Adding VAA to the wrong vaporizer:

what are the mnemonics?

HLH- high VP in Low VP = High concentration delivered

LHL- Low VP in High VP = Low concentration delivered

If halothane is added to Enflurane or servo what concentration will be delivered?

hal- 244 enf 172 Sevo 170

HLH

High concentration delivered

If halothane is added to iso vaporizer what concentration would be delivered?

Halothane 244 Iso 240

about the same

If ENF or Sevo added to Halothane or Iso vaporizer what concentration would be delivered?

ENF 172 sevo 170 Hal 244 iso 240

LHL

Low concentration

Desflurane vaporizer is heated to what temp

39 degrees C

why is des vaporizer heated

it is heated to almost 2 atmospheric pressures, this high pressure drives des to the gas outlet where it’s diluted

unit conversions:

1 mmHg = ____ cm H2O

1.36 cmH2O

unit conversions:

1 atm = ____ mmHg = ___psi = ___kPa = ___ bar

1 atm = 760mmHg = 14.7 psi = 101 kPa = 1 bar

1 psi = ____ mmHg

54mmHg

what are gauges that measure HIGH pressures (cylinder pressures)

bourdon gauges

do Bourdon pressure gauges measure th pressure relative to atmospheric pressure or the absolute pressue

the pressure relative to atmospheric pressure

when the Bourdon gauge reads 0 the pressure inside the cylinder is equal to what?

atmospheric pressure

what is the formula for the law of laplace? cylindrically- shaped structures

T=P x r

T= wall tension

P= pressure

r = radius

Law of laplace:

states that as the structure expands (radius increases) the tension (force) in the wall of the structure does what?

Increases

Law of laplace:

application

a cappillary will withstand a pressure of 100mmHg for better than a vein, b/c the capillary has a tiny radius compared to a vein, so the tension in the wall of the capillary is extraordinarily smaller than that in the vein

Law of laplace:

Application

an aortic aneurysm is much more likely to rupture than a normal segment of the aorta b/c the radius is much larger, thereby increasing the tension on the wall to the “breaking point”

who’s law states that the greater the tension in ventricular wall at end diastole, the greater the stroke volume

frank-starling law

law of laplace: Spherically shaped

what is an ex of a spherically shaped structure

alveoli

law of laplace: Spherically shaped

what is the formula

T= P x r / 2

or 2T= P x r

law of laplace: Spherically shaped

facts

tension is independent of radius for all spheres where there is a liquid-air interface (soap bubble. the pressure inside the bubble will change with its size. the smaller the radius of the bubble the greater the pressure inside the bubble.

how does the law of laplace: Spherically shaped apply to alveoli? with ARDS

b/c pressure in the smaller alveoli is higher than th larger alveoli.

the law of laplace explains why smaller alveoli empty into larger alveoli causing atelectasis in pts w/ ARDS

how does the law of laplace: Spherically shaped apply to alveoli? with Normal lungs

for alveoli with surfactant , tension increases w/ increases in radius, b/c alveolar wall tension increases in proportion to increases in radius, the pressure within the alveolus does not change. the law of laplace explains why small alveoli do not empty into larger alveoli

Flow of liquids:

Laminar (streamlined) flow is described mathematically by whose law

hagen-Poiseulle’s law

Flow of liquids:

with laminar flow where is flow the fastest

Middle

Flow of liquids:

w/ laminar flow, what is the flow like against the wall

zero flow (think of why plaque builds up in arteries)

what is the formula for flow

Q= pie x radius^4 x pressure gradient / 8 x viscosity x length

Look at page 306 to see pic

Flow of liquids:

doubling the radius increases flow by how much

16 times

Flow of liquids:

what factor alters flow the most?

radius

what is the property of a fluid that determines flow when the flow in laminar

viscosity

Flow of liquid:

is it directly or inversely proportional to radius

directly- doubling the radius increases flow by 16 times

Flow of liquid:

is it directly or inversely proportional to hydrostatic pressure gradient?

directly- rising the IV pole increases hydrostatic pressure in the fluid delivered to the pt via gravity.

Flow of liquid:

is it directly or inversely proportional to viscosity

Inversely- thicker blood slower flow

Flow of liquid:

is it directly or inversely proportional to length

inversely- reducing the needle length increases flow.

Flow of liquid:

what is the formula for resistance

R= change in pressure / flow

what are 4 things that increase turbulent flow

Faster flow

Bigger tubes

Density increased

Viscosity decreased

resistance to flow (increases or decreases) when flow becomes turbulant

increases

what is the name the predicts when flow through a cylinder tube changes from laminar to turbulent

Reynolds number

when the Reynolds number exceeds _____ - _____ flow changes from laminar to turbuilant

1500-2,000 (2,000 is the magical number)

when flow in turbulent what determines flow?

density

-this is why we use helium (its density is lower and and better for obstructions)

who’s principle does the venturi effect full under

Bernoulli’s principle

when fluid flows through a constricted region of a tube (venturi tube) the velocity of the flow does what?

increases (think of a narrowing of a stream - it gets faster)

when fluid flows through a constricted region of a tube (venturi tube) the velocity of the flow INCREASES and the lateral pressure (pressure exerted by the fluid on the walls of the tube) does what?

Decreases (think thats why you can park a boat on a deck int he river the walls have less pressure)

when fluid flows through a constricted region of a tube (venturi tube) the velocity of the flow INCREASES and the lateral pressure (pressure exerted by the fluid on the walls of the tube) DECREASES what effect is this termed

Bernoulli effect