Physics Old Exams Flashcards
the solubility coefficient most often used in anesthesia is?
Otswald
effect of giving 3% saline solution on blood volume?
0.9% is normal, so it would expand blood by 3x
which humidifier is most efficient?
ultrasonic nebulizer
what is the normal osmotic pressure of blood colloids?
30 mmHg
what will the effect be when infusing 1 L of fluid @ 4*C into a 70kg patient?
drops body temp by 0.5*C
The solubility of a substance at a given temperature is described by which law?
Henry’s law
the partial pressure of isoflurane in tissue at 1 MAC
(1.15 x 760) / 100 = 8.7mmHg
calculating combined MAC of nitrous with other agents
(N2O flow / total flow) = MAC N2O + other agents
ex. 1.5% Iso + 36% Nitrous
blood pressure required for efficient brain function….. kidney function
MAP = 60mmHg –Brain
MAP = 70mmHg –Kidneys
Desflurane vaporizer is classified as what type?
dual circuit
define specific heat
amount of energy (calories) required to raise the temp of 1g of a substance by 1*C
law which describes heat transfer from electromagnetic radiation
steffan-boltzman
Duration of O2 from a E cylinder when pressure is 750 on gauge if running at 5 L/min
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
what is the concentration of saturated isoflurane within the vaporizing chamber of a vaporizer at RTP?
31%
241/760 = 31%
normal human serum has an osmotic pressure approximately equal to how many atmospheres?
8 atm
0.3 osm x 25.4 L = 8 atm
what is the value of normal urine osmolarity?
1000 mosm/L
what is the water vapor pressure in the trachea at 37*C?
47 mmHg
the movement of a substance across a unit area (M/x), is described by which law?
Fick’s law
What is normal plasma osmolarity?
285 mosm/L
which anesthetic agent would have he slowest build up of alveolar concentration (at 1 MAC inspired concentration)?
Halothane
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
VO2= [Va (Pbar - VPa)] / VPa
Va = % agent delivered (2% halo @ 5 lpm = 5000ml x 0.02)
VPa = vapor pressure of anesthetic
What kind of vaporizer is this?
tec 4
what kind of vaporizer is this?
tec 5
what kind of vaporizer is this?
tec 6
calculation of MAC percent at various altitudes (formula)
(actual mmHg for 1 MAC) / (barometric pressure)
graph of uptake of agents. list from top to bottom in terms of speed of uptake
N2O
Des
Sevo
Iso
Halothane
actual heat capacity of human tissue is what multiple of water?
0.85
why are large quantities of metal used to make anesthetic vaporizers?
high heat capacity and high metal (thermal) conductivity