EXAM 1 Flashcards
Define radiation
-transfer of heat in the form of electromagnetic waves without direct contact between objects
what are significant numbers?
multiplied by factors of 10
basic formula for calculating drug dosages
desired dose / available concentration x volume
alternate method for drug dosage calculations?
drug on hand / given volume = desired dose / x
what is Brownian motion?
molecules of gas move freely and are in continuous motion
how is the internal pressure of a cylinder determined?
the number of molecular collisions against the walls of the cylinder per unit of time
when other variables are held constant, what is the correlation between the amount of oxygen molecules present in a cylinder and the internal pressure of the cylinder?
direct
what is Dalton’s law?
-law of partial pressure
-the total pressure of a mixture o gases is equal to the sum of the partial pressures of each individual gas
Ideal gas law
-theoretical gas composed of many randomly moving point particles that are not subject to interparticle interactions
-do not interact with any repulsive or attractant forces, partly, because in theory they lack mass and volume
when do ideal gas laws become more inaccurate?
higher pressures and lower temperatures
how does Dalton’s law allow for calculation of the partial pressure exerted by a gas?
multiplying its fractional concentration by total pressure of the gas mixture
how does Dalton’s law allow for calculation of the fractional composition of a gas within a mixture?
by dividing the partial pressure of the gas by the total pressure of the gas mixture
what is vapor pressure?
molecules in gas phase are in constant motion, bombarding the walls of the container to exert pressure – vapor pressure
what is saturated vapor pressure?
gas phase above the liquid phase is said to be saturated when it contains all the molecules it can hold at a given temp, at which point the pressure exerted by the gas is saturated vapor pressure
what is saturated vapor pressure at 37 C?
47 mm Hg or 6% atmospheric pressure
how do you determine the partial pressure of a gas at the level of the alveoli?
subtract SVP of water (47) from atm
why do we need to know and understand Dalton’s law?
to calculate the quantity of gases dissolved in the blood (dalton and henry)
account for differences in altitude as it pertains to inhaled anesthetic agents (ABG, Dalton, Fick)
radiation heat transfer?
via electromagnetic waves from the patient to the environment
-60% of total heat loss
conduction heat loss?
heat transferred via direct contact
convection heat loss
movement of fluid
warmer air, due to increased molecular movement is less dense and has a tendency to move away from the patient and is replaced by cold air
evaporation heat loss
energy is taken up when water moves from the liquid to the gas phase
reimbursement implications following general anesthesia and normothermia
patients must have a core temp greater than 35.5C either 30 mins prior to or 15 mins following anesthesia stop time
negative effects of hypothermia
-delayed emergence from anesthesia
-increased coagulopathy
- delirium
-shivering = increased metabolic demand and CV strain
-vasoconstriction = impaired wound healing
what fluid conducts electricity better?
normal saline
-electricity can bounce between the electrolytes
shock hazard of 150 microamps?
can cause v-fib if applied directly to the myocardium
shock hazard of 15-50 mA applied to the body surface?
muscle spasm and respiratory arrest
shock hazard of 75 mA applied to body surface?
v-fib
shock hazard of 5 amps?
aystole
how do line isolation monitors work?
notifies OR personnel if a fault is present
unipolar/monopolar electrocautery?
small electrode that produces high current at the cautery tip
requires a large area return electrode (grounding pad)
bipolar electrocautery?
two small electrodes incorporated in the device
does not require a grounding pad
what is an isotope?
same number of protons, but different number of neutrons
atoms with differing masses
how do radioactive isotopes decay?
by emitting neutrons and energy
what is non-ionizing radiation?
low energy photons
can be released in the form of heat
results in rotation, vibration, or excitation of electrons within atoms
what is ionizing radiation?
alpha particles, beta particles, gamma rays, xrays
displace electrons from atoms – forming ions
