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63 Cards in this Set
- Front
- Back
Name some combustable substances in the OR
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ETT
Tape plastic tubing hair gauze GI gas surgical drapes oils alcohol aerosol propellants acetone benzoin |
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Take 3 things for burning to occur (fire triangle) - name them.
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something that can burn
oxydizing agent heat source |
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What OR gases are combustion supporting?
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Air
O2 N2O |
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What OR gases are combustion squelching?
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N2
CO2 He |
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What are potential ignition sources in OR
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lasers
hot filaments sparks and arcs gas compression |
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What is the temperature to which a mixture must be raised for ignition to start? (term)
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Ignition temperature
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What is a mixture in which all the combustible vapor and oxidizing agent consumed?
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stoichiometric concentration = maximal efficient release of energy (cc gas/14.7cc air)
if lean = too much oxidizer if rich = too much fuel vapor |
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What is the stoichiometric ratio for cyclopropane?
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9 parts O2 + 2 parts C3H6
45 parts air + 2 parts C3H6 |
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What gas in air inhibits ignition?
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N2
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Sudden increase in pressure
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explosion (much higher temp than burn)
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What is the stoichiometric concentration of cyclopropane in O2?
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18% - explode (MAC was 15%!)
limits 2.5-63% |
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What is the stoichiometric concentration of cyclopropane in air?
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4.3%
burns b/w 2.5-10% doesn't burn outside that range; won't explode, but will burn at that range |
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What is the stoichiometric concentration of ethyl alcohol in air?
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6%
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If ethyl alcohol is burning what does it look like?
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cool blue flame, hard to see
(diethyl-ether also has blue flame) |
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What gases are in the gut?
(2) |
hydrogen
methane (if using N2O, then N2O also) if bowel is perfed with bovie can get an explosion (if mixture is right) |
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What can cause an O2 manifold to have a fire?
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ignition of oil/grease with high-pressure O2
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What is a very concentrated release of energy?
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spark
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Name 5 sources of sparks
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electosurgical equip
lasers compressed gas lines static electricity short circuits |
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If doing a laser case what should your ETT cuff be filled with?
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saline
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What is determined by number of protons?
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element
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What is determined by number of neutrons?
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isotopes
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What is determined by number of total number of protons and neutrons?
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mass number
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What is an unstable isotope called?
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radioisotope
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What is the emission of particles from an unstable nucleus, with the resultant change of the element?
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radioactive decay
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What is the unstable nucleus of an isotope called?
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radionuclide - used for medical purposes
(usually changes the number of protons, which changes the element) |
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Name the 2 common forces of nature
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gravitational
electromagnetic |
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Name the 2 uncommon forces of nature
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strong force - binds protons and neutrons together in nucleus
weak force - responsible for the expulsion of the electron (radioactive decay) |
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What are the isotopes of hydrogen?
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Hydrogen-2 (deuterium)
Hydorgen-3 (tritium) |
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What are beta particles?
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electrons
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What are alpha particles?
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the nuclei of a helium atom (2 protons and a neutron - heavy particle)
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Which particles are easily absorbed in the body?
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alpha and beta
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Which emission is a high energy electromagnetic radiation?
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gamma-ray emission
much more energietic, not readily absorbed from tissues - can go thru pt and still hit you |
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What is positron emission?
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Positively charged electron
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What is the time required for 1/2 of the radioactive atoms to disintegrate?
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half-life
rate of decay is proportional to mass ex: tritium 12 yr 1/2 life (787 yrs for whole thing to decay) |
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What is a scintillation counter?
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geiger counter - converts radiation into flashes of light, converted into electric current
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Name 3 uses of radioisotopes
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1.uterine implants for cancer (caesium-137)
2.thyrotoxicosis (Iodine-131) 3.prostate seed implants (Iodine-125) |
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What are diagnostic uses for radioisotopes?
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imaging, lung-scans, labeled RBC's, albumin, or fibrinogen
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Why is ionizing radiation named?
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b/c it knocks electrons out of orbit as it travels thru the body --> produce ions
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What is the 10 day rule?
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female who's fertile needs xray, should be first 10 days after menstrual cycle
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What are the 2 parts of the Xray machine?
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camera that projects x ray beam and the plate that catches it
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Xray machine should be positioned down to the pt or up to the patient?
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beam coming up from the bottom so that most of the scatter will go down to the floor
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What generates the xray?
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cathode against tungsten plate --> xrays go out
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What is xray scatter (compton scatter)?
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xray beam comes in and interacts with an atom --> outer orbit electrons excited, then that electron energized and emits it's own xray --> come out at a different pattern than initial xray
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What is the inverse square law?
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if the distance is doubled, the energy density is quartered (xray)
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What are the highest frequency waves?
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gamma
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What kind of radiation are these examples:
radio waves, infrared, UV light, visible light, and microwaves? |
Non-ionizing radiation
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What is the primary concern related to non-ionizing radiation?
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burns and skin cancer
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What is light amplification by stimulated emission of radiation?
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LASER
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What do all lasers have in common?(3)
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1.medium that needs to be excited
2.energy pump 3.2 mirrors that form resonator cavity |
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What is coherent light?
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sine waves that come out of laser are all in the same phase so they all add up and make and intense beam of light
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What are the characteristics of laser light?
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1. specific wavelength
2. intense parallel beam 3. coherent light 4. continuous or pulsed radiation |
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What are the different types of lasers?
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gas, solid state, organic dye, semi-conductor
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What is the most powerful laser used in the OR?
Its also the most common laser used in the OR for cutting |
CO2 (far infrared - strongly absorbed by tissues containing water)
when see red light that is the target light (can't see CO2 beam) |
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What are potential problems with the YAG?
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gets very hot and needs to be cooled. The coolant gas can get into pts tissue and embolize (potentially)
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What are the hazards of lasers?
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Laser plume (bacteria, etc)
perforation of a vessel embolism inappropriate energy transfer (ignition of ETT, drapes) |
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Name the response steps involved in airway fire
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1. d/c O2 source at Y peice and remove burning object from airway
2. irrigate site with water 3. ventilate pt by mask or reintubate (use low FiO2) 4. evaluate via bronch or laryngoscopy 5. reintubate or trach 6. monitor with oximetry, abg, cxr 7. use vent support, steroids, abx |
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Most common injury to OR personel with laser is to?
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eye
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How do you protect the pt's eyes during laser surgery?
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taped and covered with saline soaked gauze or metal shield
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How do you protect eyes for CO2 laser?
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any plastic or glass lens
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How do you protect eyes for other lasers?
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Nd/YAG - green filter
Ar & Kr - amber/orange |
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What gas should you avoid on a laser case?
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N2O and keep FiO2 as low as pt can tolerate
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What is a transparent material coted by a cladding layer, produces internal reflections due to acute angle of refraction?
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optical fibers
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What are the coils of the MRI immersed in?
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liquid helium (at ~4K)- this prevents resistance (superconductivity - instead of heat energy produced, all magnetic)
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