OR Hazards Flashcards
Electrical shock occurs when a
person becomes part of/or completes an electrical circuit.
BOVIE
- 1926 by Professor Bovie
- Hastened end of explosive anesthetic agents
- interferes with EKG monitoring
- potentially interferes w/Pulse ox and pace makers
- may cause vfib (w/a stray when activated @50-60hz)
3 components of a fire:
- ) ignition source (surgeon/bovie)
- ) Fuel (nurse/ prep)
- ) Oxygen (anesthesia/oxidizer)
Products of combustion are called:
Toxicants
examples of Toxicants
Co2 Ammonia Hydrogen Chloride Cyanide *byproducts of burning materials like plastics
Common injuries from Toxicants
Airway and lung tissues, asphyxia
OR Fire Priority
Evacuation!
*a lot of smoke and heat must be produced before sprinklers detect fire
Two Types of OR Fires:
Type 1 - IN or ON the patient
Type 2 - Remote from patient (equipment)
Most common type of OR Fire?
Type 1
Common Type 1 Fires:
- ET Fires
- oropharynx during T&A
- in breathing circuit
- during laparoscopy
- in high risk procedures in which an ignition source is used in O2 rich environment.
- b/c of O2 spread faster and burn vigorously
Fires on patients involve:
- head and neck
- can happen under regional/MAC where pt receiving high O2 deliveries
- surgical towels
- drapes
- body hair
- body reservoirs where prep may pool (belly button, sternal notch)
Solutions to reduce Type 1 Fires:
Wet Laps in O2 rich environments
-if surgeon needs lung inflated –> do it with CPAP with AIR instead of O2
ET Fire Need to knows
- DEVASTATING!
- disasterous
- O2 & N2O produce a blowtorch type flame
- severe injury to trachea, lungs, and surrounding tissues
Produces a blowtorch type flame
O2 & N2O when ignited
Situation:
Uncuffed ETT in Ped T&A; use of laser to CAUTERIZE tonsil bed.
-What could happen?
-What can you do to prevent/decrease Risk?
- Spark!
- no cuff = O2 free flowing around airway
Prevent - cut O2 with air or decrease
Majority of OR Fires occur with?
MAC during Head and neck surgery
75% of surgical fires are:
O2 enriched
What % of O2 is safest ideally to prevent MAC fires?
If not, do what?
<30% O2 if possible
if not - add room air to reduce concentration
or consider LMA/ETT
How do PREPS contribute to OR fires?
- Interventions to reduce?
- Iodaphor has 74% Isopropyl Alcohol = very Flammable
- be aware of prep pooling
- allow prep to DRY COMPLETELY 4-5 mins
Can undergo EXOTHERMIC Chemical Reaction with desiccated CO2 Absorber (warm!)
SEVO
Sevoflurane is
Volatile (at room temp liquid volatizes into vapor)
but considered “nonflammable”
Sevo is nonflammable in….. (but….)
AIR
but can serve as fuel at concentrations as low as 11% O2 and 10% N2O
Manufacturers of SEvo suggest:
- avoid desiccated co2 absorbents
- monitor temp of absorbers and insp Sevo concentration.
- sudden/unexpected influx of sevo inhalation –> Remove circuit and assess for thermal/chemical injuries
- Use absorbents w/o strong alkali
example of absorbent w/o strong alkali?
AMSORB
contains Calcium Hydroxide and Calcium Chloride
- no strong alkali
- unreactive with volatiles
- doesn’t produce CO or Compound A
- no interaction w/Sevo or cause exothermic reaction
What do you do in ETT Fire? (steps/order)
INTERRUPT THE FIRE TRIAD
- ) O2 OFF - flowmeters off, d/c circuit from ETT and machine,
- ) Remove ETT - examine for missing pieces
- ) Flood/Flush - saline or sterile H20; extinguish any embers
- Resume ventilation w/AIR preferably (avoid O2 & N2O) - ) Re-establish Airway - will swell.
- consider bronchoscopy (assess damage)
- tx for smoke inhalation and possible tx to burn center
You remove an ETT after airway fire, what do you do with ETT?
examine it for missing pieces
Is it important what order your Flush an airway or Pull an ETT after airway fire?
M/M says no as long as done immediately if not at teh same time
-Hammon: remove tube — then flood/flush airway with saline or sterile water
Cotton Huck Towels
O2% and ignition speed
TYPE 2 Fire - remote of pt
- 21% O2 ignition 12 seconds
- 95% O2 ignition 0.1 seconds
Two major ignition sources for OR fires are?
barash p. 376
the ESU (electrosurgical unit) & Laser -the ends of some fiberoptic light cords can also become hot enough they can start a fire if placed on paper drapes.
Preventing ESU (electrosurgical unit) burns is the responsibility of: barash p. 361
All OR staff
Most important factor for preventing ESU fires?
barash p. 362
proper application of the return plate
- Place the return plate as close as possible to the site of the operation.
- ECG pads as far from site as feasible.
- essential that the return plate has appropriate amt of gel and an intact return wire.
- reusable plates must be cleaned after each use.
- disposable plates checked to ensure the electrolyte gel has not dried out.
Hospital Grade plugs are marked by a
Green Dot
Hospitals must test their emergency power supply systems (generators) how frequently?
Once a month for at least 30 mins
The best way to prevent any fire?
keep the three legs of the fire triad from coming together.
- ignition
- oxidizer
- fuel
Laser light can be…
reflected off any metal surface
-all or personnel should wear protective goggles
flammable gases that are frequently present in bowel gas?
Methane (~56%)
Hydrogen (~69%)
ERASE:
Extinguish -the fire Rescue- pt and all other persons/evacuate activate- fire alarm shut - OR Doors and medical gas shut off evaluate - for injury
In the OR, electrical equipment should always be:
Grounded
Supplying ungrounded power to the OR requires the use of an
Isolation transformer
What continuously monitors the isolated power to ensure that it is indeed isolated from ground, and the device has a meter that displays a continuous indication of the integrity of the system?
the LIM (Line Isolation monitor)
The LIM (line isolation monitor) is a device that
continuously monitors the integrity of an IPS (isolated power system)
There is one instance in which it is acceptable for a piece of equipment to have only a two-prong and not a three prong plug. This is permitted when the instrument has what is termed _______ ________.
Double insulation
Tell me what a macroshock is
involves relatively large amounts of current applied to the surface of the body.
(the current is conducted through all the tissues in proportion to their conductivity and area in a place perpendicular to the current.
Shock from very small currents
microshock
What kind of patients are at greater risk for microshock?
one who has a direct, external connection to the heart, such as through a CVP catheter or TVP wires.
even very small amounts of current applied directly to the myocardium will cause
v.fib.
all materials burn in the presence of an
oxygen-enriched environment
at 21% O2, how fast can a cotton huck towel ignite?
12 seconds
at 95% O2, how fast can a cotton huck towel ignite?
0.1 seconds
Laser is the acronym for
Light Amplification by Stimulated Emission of Radiation
PASS acronym
to effectively use a fire extinguisher: Pull the pin Aim at the base of the fire Squeeze the trigger Sweep the extinguisher back and forth across the base of the fire.
RACE Acronym
when responding to a Fire: Rescue Alarm Confine Extinguish
The reading on the LIM Meter does not mean ….
that current is actually flowing
Is the reading on the LIM telling us the current?
no
it indicates how much current WOULD flow in the event of a first fault.
How much current would flow in the event of a first fault is read by what device?
LIM (Line isolation monitor)
The LIM is actually measuring the impedance to the ground of each side of what?
the IPS
A basic principle of electricity is known as
Ohm’s Law (Voltage = current x resistance)
Voltage = current x resistance is
Ohm’s Law
To have a completed circuit necessary for current flow what must exist?
A closed loop must exist and a voltage source must drive the current through the impedance.
To receive a shock, one must do what? What else must happen?
One must contact the electrical circuit at two points, and there must be a voltage source what causes the current to flow through the individual.
Grounding is applied in two separate concepts:
- ) grounding of electrical power
2. ) grounding of electrical equipment
To provide an extra measure of safety from gross electrical shock (macroshock), the power supplied to most ORs is grounded or ungrounded?
UNgrounded.
The line isolation monitor is a device that does what?
continuously monitors the integrity of an isolated power system.
What is a popular device used to prevent individuals from receiving an electrical shock in a grounded power system?
The ground fault circuit interrupter
What does the ground fault circuit interrupter do?
prevents individuals from receiving an electrical shock in a grounded system.
An electrically susceptible patient is:
one who has a direct, external connection to the heart
Who may be at risk from very small currents (Microshock)?
electrically susceptible patients (direct, external connection to the heart)
Problems can arise if the electrosurgical return plate is:
- improperly applied to patient
- cord connecting the return plate to ESU is damaged or broken
What is just as much of a danger in the OR today as they were 100 years ago when patients were anesthetized with flammable anesthetic agents?
OR Fires
ESU and the Laser are to major source for:
Ignition sources for OR Fires
Who should be familiar with the location and operation of fire extinguishers?
all OR personnel
What can react with sevoflurane to produce a fire?
desiccated carbon dioxide absorbent
Dessicated carbon dioxide absorbent can produce a fire if a reaction with what agent were to occur?
Sevoflurane
50-60hz
may cause vfib (w/a bovie stray)
Oxygen rich atmospheres lower what?
the temperature at which fuel will ignite
These fires will burn more vigorously and spread faster
oxygen rich
Cases involving what, can easily result in high concentrations of O2 in the cavity when lung is reinflated due to gas leakage?
stripping of the pleura or resection of pulmonary blebs
What percentage of surgical fires are O2 enriched?
75%
Iodaphor is mixed with
74% isopropyl alcohol
What type of reaction can Sevo undergo with desiccated CO2 absorber? Endothermic or Exothermic?
Exothermic
What device provides a significant amount of protection from macroshocks?
IPS (isolated power system)
The LIM is not designed to provide protection from what?
microshock
-mA currents involved in microshock are far below the LIM threshold of protection
the main oxidizers in the OR are:
air, oxygen, and N20
what oxidizers function equally well?
oxygen and N2O
a combo of 50% O2 and 50% N2O would avidly support combustion, as would 100% O2
Fuel sources of PREP agents:
alcohol degreasers (acetone, ether) adhesives (benzoin, aeroplast) CHG (hibitane) Iodophor (dura prep)
Fuel sources of Drapes & Covers agents:
pt drapes equipment drapes blankets and sheets pillows, mattresses, padding gowns masks shoe covers gloves clothing compression stockings
Fuel sources of PATIENT agents:
hair
alimentary tract gases (methane and hydrogen)
desiccated tissue
Fuel sources of DRESSING agents:
gauze and sponges petrolatum-impregnated dressings xeroform adhesive tape elastic bandages stockinettes sutures steri-strips Collodion
Fuel sources of OINTMENTS agents:
petrolatum abx (bacitracin, neomycin, plymyxin B) Nitropaste EMLA lip balms
Fuel sources of ANESTHESIA EQUIPMENT:
breathing circuit masks ETT oral and nasal airways laryngeal mask airways NGT's suction catheters and tubing scavenger hoses volatile anesthesics CO2 absorbers IV tubing monitor tubing and transducers
Fuel sources of EQUIPMENT:
charts cardboard packing materials fiberoptic cable covers wire covers BP cuffs and tubing stethoscopes vascular shunts dialysis and extracorporeal circulation circuits mops/brooms books, instruction manuals, and materials
fires in the breathing circuit are what type of fire?
type 1
fires during laparoscopy are what type of fire?
type 1
ETT fires are what type of fire?
type 1
fire of a piece of equipment is a type of fire?
type 2
