# Physics Old Exams Flashcards Preview

## Physics > Physics Old Exams > Flashcards

Flashcards in Physics Old Exams Deck (70)
1
Q

the solubility coefficient most often used in anesthesia is?

A

Otswald

2
Q

effect of giving 3% saline solution on blood volume?

A

0.9% is normal, so it would expand blood by 3x

3
Q

which humidifier is most efficient?

A

ultrasonic nebulizer

4
Q

what is the normal osmotic pressure of blood colloids?

A

30 mmHg

5
Q

what will the effect be when infusing 1 L of fluid @ 4*C into a 70kg patient?

A

drops body temp by 0.5*C

6
Q

The solubility of a substance at a given temperature is described by which law?

A

Henry’s law

7
Q

the partial pressure of isoflurane in tissue at 1 MAC

A

(1.15 x 760) / 100 = 8.7mmHg

8
Q

calculating combined MAC of nitrous with other agents

A

(N2O flow / total flow) = MAC N2O + other agents

ex. 1.5% Iso + 36% Nitrous

9
Q

blood pressure required for efficient brain function….. kidney function

A

MAP = 60mmHg –Brain

MAP = 70mmHg –Kidneys

10
Q

Desflurane vaporizer is classified as what type?

A

dual circuit

11
Q

define specific heat

A

amount of energy (calories) required to raise the temp of 1g of a substance by 1*C

12
Q

law which describes heat transfer from electromagnetic radiation

A

steffan-boltzman

13
Q

Duration of O2 from a E cylinder when pressure is 750 on gauge if running at 5 L/min

A

Full E cylinder has P= 2200psi V=660L

Using daltons law : V2 / V1 = P2 / P1

V2 = P2/P1 x V1 = 750/2200 x 660 = 225L

5 L/min would last : 45 min

14
Q

what is the concentration of saturated isoflurane within the vaporizing chamber of a vaporizer at RTP?

A

31%

241/760 = 31%

15
Q

normal human serum has an osmotic pressure approximately equal to how many atmospheres?

A

8 atm

0.3 osm x 25.4 L = 8 atm

16
Q

what is the value of normal urine osmolarity?

A

1000 mosm/L

17
Q

what is the water vapor pressure in the trachea at 37*C?

A

47 mmHg

18
Q

the movement of a substance across a unit area (M/x), is described by which law?

A

Fick’s law

19
Q

What is normal plasma osmolarity?

A

285 mosm/L

20
Q

which anesthetic agent would have he slowest build up of alveolar concentration (at 1 MAC inspired concentration)?

A

Halothane

21
Q

using the “vaporizer equation,” determine how much oxygen must flow through the vaporizing chamber in order to provide a set percent of agent at a fixed gas flow

A

VO2= [Va (Pbar - VPa)] / VPa

Va = % agent delivered (2% halo @ 5 lpm = 5000ml x 0.02)

VPa = vapor pressure of anesthetic

22
Q

What kind of vaporizer is this?

A

tec 4

23
Q

what kind of vaporizer is this?

A

tec 5

24
Q

what kind of vaporizer is this?

A

tec 6

25
Q

calculation of MAC percent at various altitudes (formula)

A

(actual mmHg for 1 MAC) / (barometric pressure)

26
Q

graph of uptake of agents. list from top to bottom in terms of speed of uptake

A

N2O

Des

Sevo

Iso

Halothane

27
Q

actual heat capacity of human tissue is what multiple of water?

A

0.85

28
Q

why are large quantities of metal used to make anesthetic vaporizers?

A

high heat capacity and high metal (thermal) conductivity

29
Q

what uses conductivity to measure a temperature change?

A

thermistor and heated wire

30
Q

what is the max diameter (in micrometers) of water particles that are deposited in the alveoli?

A

3.0 mcm

31
Q

osmotic pressure induces motion of what?

A

the solvent

32
Q

what effect will limited pulmonary diffusion capacity have on CO2 and O2?

A

more likely to become hypoxic than hypercarbic (CO2 diffusion is quicker than O2)

33
Q

what is the relative importance of factors determining the diffusion of drugs

A

solubility

molecule size

liquid vs. gas

34
Q

what does the second gas effect do?

A

potent agents delivered with N2O so that they will be delivered in a greater concentration to the alveoli as N2O is absorbed by pulmonary blood (only for ~2 breaths)

35
Q

atelectasis =?

A

shunt

36
Q

one mol of gas at RTP will occupy what volume?

A

24L

1. 4L @ STP
2. 4L @ BTP
37
Q

what effects do hydrostatic pressure changes have on the blood pressure?

A

+/- 1.8 per inch moved

38
Q

how many liters are in an adult circuit?

A

5L

39
Q

What is a dalton?

A

A unit used in expressing the molecular weight of proteins, equivalent to atomic mass unit.

40
Q

P = F/a

A
41
Q

Who’s law deals with circles?

A

Leplace’s Law

42
Q

What is Laplace’s Law?

A

P = T/R (cylinders)

P = 2T/R (spheres)

43
Q

Smaller aveoli would collapse into larger aveoli if not for what?

This is an example of who’s law?

A

Surfactant

Laplace’s Law of P = 2T/R

44
Q

What is the Fruahast-Linquist Effect?

A

When RBCs line up in small vessels, lowering the viscosity, and thus increasing flow through the vessel

45
Q

Give the equation and tell whos equation describes laminar flow?

What is the number for laminar flow?

A

Q = π Pr^4 / 8 n l

Hagen-Poiseuille equation

Reynolds number of < 2000

46
Q

Give the equation and tell whos equation describes turbulent flow?

What is the number for turbulent flow?

A

Q^2 = K P 4 π^2 r^5 / p l

Fanning equation

Reynolds number > 2000

47
Q

What is Bernoulli’s Equation and what does it give us?

A

E = P + pgh + 1/2 pv^2

Energy of a fluid

48
Q

V1 x a1 = V2 x a2 is what equation?

A

Continuity equation

49
Q

What does HAFOE mask stand for?

A

High Air flow with oxygen Entrainment mask

L of Air entrained / liters of oxygen

EQUATION: 1.0 - FiO2 / FiO2 - 0.21

50
Q

What is always true about flow?

what is usually true about flow?

A

ALWAYS TRUE: flow is from area of higher energy to area of lower energy

Usually true: flow is from area of higher pressure to area of lower pressure

51
Q

Boyles Law

A

TB: temp constant

V1 / P1 = V2 / P2

52
Q

Charles Law

A

CP: constant pressure

V1 / T1 = V2 / T2

53
Q

Don’s Law

A

VD: volume constant

P1 / T1 = P2 / T2

54
Q

Vx / Vy = Px / Py is what equation?

A

Dalton’s Law of Partial pressures

55
Q

What is the filling ration in the US of N2O ?

A

0.68

56
Q

What are STP conditions?

A

T : 273 K

0* C

P : 760 mmHg

1 mol occupies 22.4 L

57
Q

What are RTP conditions?

A

T: 293 K

20* C

P : 760 mmHg

1 mol occupies 24.0 L

58
Q

What are BTP conditions?

A

T: 310 K

37* C

P : 760 mmHg

1 mol occupies 25.4 L

59
Q

Know how to calculate how much N2O left available in cylinder

A

Take weight of N2O cylinder: 3.4 kg at STP

Weight of N2O : molecular weight (N= 14 x 2, O= 16) = 44gm

3400 g x 1 mol/ 44g = 77.27 mol

77.27 mol x 22.4 L / mol = 1730.9 L

60
Q

What is the partial pressure of O2 (PaO2) when patient on room air (0.21 O2)?

A

100 mmHg

61
Q

What is the partial pressure of O2 (PaO2) when patient on 50% O2?

A

300 mmHg

62
Q

What is the partial pressure of O2 (PaO2) when patient on 100% O2?

A

660 mmHg

63
Q

How much V-Q mismatch does the average patient have?

A

10-20%

64
Q

What is the alveolar oxygen equation?

A

PaO2 = FiO2 (Pb - PaH2O) - (PaCO2 / R)

where R = 0.8

65
Q

Define the critical temp of something?

What is critical temp of N2O?

A

Temperature above which liquidification cannot occur

36.5* C

66
Q

What is the heat of vaporization?

A

amount of heat (calories) required to convert 1 gram of liquid agent into a vapor

67
Q

What is O2 solubility in plasma?

A

0.0031

68
Q

How long is the diffusion time from blood to lung of CO2?

A

0.2 seconds

69
Q

How long is the diffusion time of O2 from the lung to the blood?

A

0.4 seconds

70
Q

Easy conversion from kPa to mmHg?

A

1 kPa = 7.5 mmHg