Environmental Hazards Flashcards
3 types of Hazards
Physical
Infectious
Psychological
Types of Hazards
Waste Anesthetic Gases (WAG) Electrical/Fire Laser Radiation Chemicals Sharps Latex
Waste Gases: Vapors are
always present in the O.R.
No current evidence exists that proves Waste Anesthetic Gases are a health hazard.
Role of scavenging systems
Proper scavenging DECREASES Waste Anesthetic Gases
Is there evidence that gases wasted are health hazard?
No current evidence exists that proves Waste Anesthetic Gases are a health hazard.
1977 NIOSH recommendation:
No worker shall experience to halogenated agents at concentrations
>2ppm alone
>0.5 ppm when combined with nitrous oxide over a 1 hour sampling period.
Nitrous Oxide exposure shall not exceed time weighted average concentration of ____ppm during anesthetic administration when used alone.
Results of air sampling methods, locations, dates and concentration measured and results of leak tests shall be maintained for at least _______
25ppm
20 years.
Scavenger systems were equipped on anesthesia machines year ____
1980s:
Nitrous oxide is unique in its ability to inactivate __________an amino acid essential to production of _______This effect of prolonged exposure can result in bone marrow depression__________ Neuropathies, and other deficits.
methionine synthase; DNA; (MEGALOBLASTIC ANEMIA),
Because of the possibility of TERATOGENIC effect______ is often avoided in the anesthetic of pregnant women undergoing surgery.
N2O
Health Concerns with Chronic exposure
Neurological/Behavioral deficits
Liver and Kidney Toxicity
Spontaneous Abortion in Females in Infertility
Teratogenic in Animal Models
N2O < ______ppm
Halogenated Agents
25 ppm
2 ppm
0.5 ppm
100% Halothane =
1% Halothane =
.0002% Halothane = 2 ppm
1 million ppm
10,000 ppm
2 ppm
Things to do to limit exposure
- Avoid insufflation of gases with children
- Turn off your gases prior to intubation, but don’t forget to turn them back on!
- Tight mask seals with induction
- Don’t EVER “clear” your circuit to the environment
- Scavenging system
What are the elements of a Fire triange
Fuel
Oxygen
Energy source
OEA
Oxygen Enriched Atmosphere
OEA fires can include
- Tracheostomy
- Facial procedures under MAC
- Uncuffed endotracheal tubes
Tracheostomy involves risk of fire vs
Risk of fire vs. risk of hypoxemia
- Pulmonary condition
- Use of electrosurgical unit
- Difficulty of airway
Nasal Cannula OEA
Fire in airway due to OEA
Fire under drapes
ET tube fire on ____
Fire on entrance to trachea
Possibly catastrophic
Facial Procedures Under MAC
Consider room air
Consider level of sedation
If supplemental O2 needed consider cuffed ET tube
Fuels are (SUPPLIES)
Surgical drapes Gowns Gauze Pledgets Flammable anesthetics Bowel gas (methane) Body hair Petroleum Jelly
Fuels EQUIPMENT
Endotracheal tubes LMAs Masks, nasal cannulas, breathing circuits Endoscopes Gloves Smoke evacuator hoses Mattresses, egg-crates, blankets
Ignition Sources
ESU (BOVIE) Lasers Hot wire cautery Defibrillators Surgical drills, saws and burrs Fiberoptic light sources Static electricity
ESU (BOVIE)
Good contact with return plate
Clean contact frequently
Do not fire unless in contact with tissues
Communication
Fire Extinguishers: ABC Multi-Purpose Dry Chemical
Good for commercial and industrial uses
Poor for operating room
BC Dry ChemicalSodium Bicarbonate
Destroys sensitive electrical equipment
Not good for patients
Poor for OR
Pressurized Water
Type A
Good for trash, wood, paper
Not good for class C (electrical) fire
Poor for OR
CO2
BC
Good for sensitive equipment
Not good for patients, OR
Halon
ABC
Good choice
Being phased out because of ozone depletion
Water mist
Class A fires Good in class C (electrical) hazards Mist droplets do not conduct electricity Cools and soaks Non-toxic Non-ozone depleting
Electrical mishaps (3) Leads to (3)
Inadequate grounding devices
Faulty equipment
Overloaded circuits
Leads to:
Burns
Fire
Electrocution
OHMS LAW
E = ________
I = ____________
R = ___________
OHMS LAW E = I * R
E = electromotive force (volts)
I = current (amperes)
R = resistance (ohms)
I =
W/E
R=
E/I
IMPEDANCE (Z)
sum of forces that oppose electron movement in AC circuits
Conductor -
substance with low impedance
Insulator
Substance with High impedance
Capacitance
any two parallel conductors that are separated by an insulator.
INDUCTANCE
production of a magnetic field around a wire when current flows.
Disruption of electrical function of cells
a. contraction of muscles
b. alteration of brain function
c. paralysis of respiration
d. ventricular fibrillation
Macroshock -
Gross amounts of shock that will cause harm or death
Microshock
Amount of shock that will harm or kill a patient with a conduit to the heart
Frequency (cycles per second or Hz) is
an important factor in electrical safety -
Higher frequency current__________, current is generally regarded as safe up to. Very high-frequency currents do not excite contractile tissue.
e.g., 1,000,000 Hz ; 3 amp; excite contractile tissue.
Grounding
a. Hot and neutral wires from FPL.
b. Neutral wire is connected to neutral bus bar which returns to electrical company ground and is also connected to a grounding pipe.
c. Grounding wire is connected to neutral bus bar and ground.
d. Circuit breakers - protect from overload of electrical wires - does not protect from shock.
e. Hot wire distributed through building to electrical devices.
f. 120 volt potential difference between hot and any object referenced to ground, neutral, ground or any grounded object.
g. For current to flow, there must be a closed loop to ground.
h. Circuit can be completed from hot wire to neutral or ground.
i. To get a shock, there must be contact with the loop in two places–one is ground so only one additional contact point is needed to complete the circuit.
Safety Outlets : 3 prong plug
Three prong plug provides a low resistance path to carry a short circuit to ground. It will prevent a large current flow from improperly energized equipment through person.
Line Isolation Monitor -
for ungrounded electrical systems
LM functions
(1) Measures the total leakage in the system to ground
(2) Does not measure actual current flow but how much would flow in the event of a fault
(3) If either side of the isolated power system has < 60,000 ohms impedance to ground LIM will alarm
(4) LIM will not detect a faulty equipment ground wire
Ground Fault Interrupter - For grounded electrical systems
(1) Measures both sides of grounded system to see that flow is equal. If it is not a breaker will trip
(2) Disadvantage is that faulty equipment is not usable unlike in LIM where alarm sounds but power does not shut off.
MICROSHOCK 1,2
- Catheters or wires near the heart provide pathway for a small amount of electricity to have a large current density in the heart
- Currents that are not perceptible may cause ventricular fibrillation in sensitive part
MICROSHOCK 3,4
- Equipment ground wire important in taking stray capacitance to ground so that no current can flow to patient
- To provide additional safety from microshock direct patient inputs are isolated
ELECTROSURGERY : BOVIE A-C
ESU generates a current of __________
The tip of the Bovie pencil ___________ it _____
The greater the current density ____________
A. ESU generates a current of > 500,000 Hz
B. The tip of the Bovie pencil does not heat up - it directs a current through tissues
C. The greater the current density, the more heat is generated in the tissues
ELECTROSURGERY : BOVIE D-F
D______________does not cause ventricular fibrillation or excite contractile cells - see
E. Current returned through ___________dispersive plate - improperly called _________
F. If dispersive plate is not properly applied or if return wire is faulty the current will ________________
D. High frequency current does not cause ventricular fibrillation or excite contractile cells - see
E.Current returned through large surface area dispersive plate - improperly called grounding pad
F.If dispersive plate is not properly applied or if return wire is faulty the current will seek an alternate pathway
ELECTROPHYSIOLOGY : BOVIE G-I
G. If the surface area of the of the alternate pathway is ________ the current density will be_______________
H. Modern ESUs have __________________
I. Return plates must have ________________
G. If the surface area of the of the alternate pathway is small, the current density will be high and a burn will result
H. Modern ESUs have isolated power systems for additional safety but are not foolproof
I. Return plates must have proper gel, be applied properly and have intact return wire
ELECTROPHYSIOLOGY : J-M
J. Careful of using ESU when_______Such as _____
K. If surgeon is requesting very high power levels _________Should be inspected
L. If unit is dropped, it should be _____________
M. Bipolar ESU needs______________
J. Careful of using ESU when flammable solutions are used, e.g., benzoin, alcohol, collodium, ether, acetone
K. If surgeon is requesting very high power levels return plate should be inspected
L. If unit is dropped, it should be inspected by qualified technician
M. Bipolar ESU needs no return plate
When possible, use \_\_\_\_\_\_\_\_with\_\_\_\_\_\_patients When in doubt, get a\_\_\_\_\_\_\_\_\_\_ Know type of\_\_\_\_\_\_\_\_\_ Have\_\_\_\_\_\_\_ available if appropriate Check \_\_\_\_\_\_\_\_\_ before and \_\_\_\_\_surgery Take the time to \_\_\_\_\_\_\_\_\_\_\_
bipolarpacemaker patients. cardiac consult pacemaker magnet pacemaker before and after Turn in and report faulty equipment
REMEMBER that blood and _______do _________
electrolyte solutions do conduct electricity
Increasing prevalence of
laser surgery
Unique advantages of Laser Surgery
Highly precise microsurgery
Confined and difficult sites
Rapid vaporization of tissue
Dry surgical field with instantaneous sealing of small vessels and lymphatics
Types of Lasers
Carbon dioxide (gas)
Widely used, long wavelength
Poor penetration in tissue
Argon (gas)
Nd:YAG (solid)
Neodymium yttrium aluminum garnet
Dye (liquid)
Less commonCO2 effects are localized due to its
high water absorbency, and wavelength
OPHTALMOLOGY
Argon beam
Treatment of macular degeneration and open-angled glaucoma
Gynecology
CO2 laser
Genital tract lesions, laparoscopy
