Gas Laws

Question 1

Henry’s Law

Answer 1

• the solubility of a gas in a liquid is directly proportional to the partial pressure of the gas

Question 2

Application of Henry’s Law

Answer 2

• Using the partial pressure of O2 or CO2 to find out how much O2 and CO2 is dissolved in blood.
• multiple the PaO2 and PaCO2 by the coefficient to find Solubility
• increasing FiO2
• over-pressuring the vaporizer

Question 3

Solubility coefficient for oxygen

Answer 3

0.003

Question 4

Solubility coefficient of CO2

Answer 4

0.067

Question 5

Graham’s Law

Answer 5

• The rate a molecule diffuses at is inversely related the square root of its molecular weight
• smaller molecules diffuse faster

Question 6

Application of Graham’s Law

Answer 6

-Nitrous oxide diffusing into air filled cavities
(nitrous diffusing into endotracheal tube cuffs)
-apneic oxygenation
(The continual diffusion of oxygen in the blood strictly from concentration gradient from the ventilator circuit into the alveoli)

Question 7

Fick’s Law

Answer 7

• The rate of diffusion of a gas across a semipermeable tissue is related to :
  1) partial pressure of the gas (directly related)
  2) the membrane solubility of the gas (directly related)
  3) the area of the membrane (directly related)
  4) membrane thickness (indirectly related)
  5) molecular weight (indirectly related)

Question 8

Application of Fick’s Law

Answer 8

-2nd gas effect of nitrous oxide

Question 9

Pressure Equivalents

Answer 9

1atm = 1bar = 760 mmHg = 760 torr = 14.7 psi = 1020 cm H2O = 100KpA

Question 10

Boyles Law

Answer 10

P1 * V1 = P2 * V2

Question 11

Example of Boyle’s Law

Answer 11

• ventilating with reservoir bag
• spontaneous breathing
• bellows on vent

Question 12

Charles Law

Answer 12

V1/T1 = V2/T2

Question 13

Application of Charles Law

Answer 13

-

Question 14

Guy Lussac’s Law

Answer 14

P1/T1 = P2/T2

Question 15

Application of Guy Lussac’s Law

Answer 15

-Gas leaving the E-cylinder creates a frost on the outside of it

Question 16

Universal gas law

Answer 16

PV = nRT

Question 17

Application of Universal Gas Law

Answer 17

• as an e-cylinder of a tank empties, the pressure decreases

Question 18

Avogadro #

Answer 18

6.02 E23

Question 19

1 mole of any substance occupies how much space in L

Answer 19

22.4L

Question 20

Avogadro’s Law

Answer 20

V1/n1 = V2/n2

Question 21

Application of Avogadro’s Law

Answer 21

• vaporizer calibration
  Ex: molecular weight of sevoflurane is 200g. 200g = 1mole of sevo. That would take up 22.4L due to ideal gas law. If we put 20g of sevo in the vaporizer how much space would it take up?

20g/1 * 1mole/200g * 22.4L/1mole = 2.24L

Question 22

Dalton’s Partial Pressure Law

Answer 22

-the total pressure of a gas mixture of the sum of the partial pressures of each gas component

Question 23

Application of Daltons Law

Answer 23

• If air is 21% oxygen and 79% nitrogen what is the Partial pressure of nitrogen at 1 atm?

760mmHg * .79 = 600.4mmHg

Question 24

Critical Temperature

Answer 24

• if the ambient temperature is above the critical temperature, no amount of pressure could liquify said gas

Question 25

Critical temperature of oxygen

Answer 25

-119 degrees Celsius

Question 26

Critical temp of nitrous oxide

Answer 26

39.5 degrees Celsius

Question 27

Room temp

Answer 27

~20 degrees Celsius

Question 28

ADIABATIC cooling

Answer 28

- change in temperature of matter without gaining or losing heat (energy) - N2O cylinder cracked and open fully, frost forms on cylinder opening

Question 29

Joule Thompson Effect

Answer 29

- the expansion of gas causes cooling

Question 30

Application of the Joule Thompson Effect

Answer 30

-as gas leave the cylinder, the expansion cools the surrounding area, causing condensation of moisture on the cylinder

Question 31

Pouseuille’s Law

Answer 31

``` - Flow is related to: Pressure gradient across length of tube (direct) Radius4 (direct) Length (indirect) Viscosity (indirect) ```

Question 32

Application of Pousielle’s Law

Answer 32

- IV flow - airway (inflammation of the cricoid) - laminar flow in a blood vessel - Thorpe Tubes at low flow

Question 33

When flow is laminar what determines flow?

Answer 33

Viscosity

Question 34

What flow is turbulent what determines flow?

Answer 34

- density | - ex: heliox in narrow airways

Question 35

Reynolds number >2000 means?

Answer 35

Turbulent flow

Question 36

How can you change flow from laminar to turbulent?

Answer 36

-bend in tube

Question 37

Bournoulli’s Theorem

Answer 37

- relates how pressure and velocity interact - narrow diameter = decreased lateral wall pressure = increased speed - wider diameter = increased lateral wall pressure = decreased speed

Question 38

Venturi Effect

Answer 38

- as the diameter of the tube decreases, velocity increases, as velocity increases, the pressure surrounding the flow DROPS

Question 39

Applications of Bernoulli and Venturi

Answer 39

- nebulizers | - jet ventilation

Question 40

Beers Law

Answer 40

- the absorption of a gas is determined by the: Absorption rate of the gas (direct) Concentration of the gas (direct) Thickness (inverse)

Question 41

Application of Beers Law

Answer 41

-pulse ox

Question 42

Law of LaPlace

Answer 42

- tension is related to pressure (direct) radius (indirect)

Question 43

Application of LaPlace Law

Answer 43

- alveoli | - aneurysm

Question 44

Ohm’s Law

Answer 44

Resistence = potential / current Voltage = current / resistance

Question 45

Application of Ohm Law

Answer 45

-transducers

Question 46

2% lidocaine = ? mg/mL

Answer 46

20 mg/mL

Question 47

1% lidocaine = ? mg/mL

Answer 47

10mg/mL

Question 48

7.5% bupivicaine = ? mg/mL

Answer 48

7.5mg/mL

Question 49

1:100,000 Epinephrine = ? mcg/mL

Answer 49

10mcg/mL

Question 50

1:1000 neostigmine = ? mg/mL

Answer 50

1mg/mL

Question 51

1:10,000 Epinephrine = ? mcg/mL

Answer 51

10mcg/mL