Equipment And Safety Flashcards
What is ASME
ASME – American Society of Mechanical Engineers
o Organization that generates the documents regarding safe pressure vessel design
Chamber classifications
• Based on NFPA standards • Class A – multiplace o Multiple human occupancy o Must maintain less than 23.5% oxygen inside of multiplace chambers • Class B – monoplace • Class C – animal o No human occupancy • Duoplace – air filled two person chamber. Follows the class A rules • Lock – chamber compartment
What is BPVC
• BPVC – Boiler and pressure vessel code
o Governs material selection, fabrication, testing and stamping.
o Dictates the pressure relief required in chambers
What is PVHO
PVHO – pressure vessels for human occupancy
o Governs the acrylics and design standards.
What is hydrostatic pressure testing?
Fill with water, leaving small air space
o Pressurize the air space, if it fails, water sprays out, chamber does not explode.
o Done on new chamber designs to ensure safety.
Performed by BPVC
What are pressure relief valves
• Pressure relief valves – pop off valves
o Required by ASME
o Releases excess pressure from the chamber
What do you need to do with acrylics
• Acrylics – view ports and windows
o Rules for acrylics based on PVHO standards.
o Life is shortened by:
• Physical stress of compression and decompression
• UV radiation – sunlight
• Organic solvents – alcohol, adhesive remover (acetone is very hard on acrylics)
• Cleaners and disinfectants
o Easily gouged by hard objects – jewelry, external fixators, etc.
o Crazing – visual sign of weakness in physical structure of acrylic (tiny cracks in surface)
What are penetrators and name a special penetrator
• Penetrators
o Pipe, tubing, or wiring that crosses the pressure boundary of the chamber
o Can’t add new penetrators to chambers
o Special penetrator – light pipe or Canty light
• Invented by Mr. Canty
• Light shines onto a piece of acrylic that goes into chamber via a penetrator.
• Lighting for multiplace chambers, provides light without heat or electricity
Who is the CGA and what do they do?
- CGA – compressed gas association provides guidelines for gas handling
- Safe gas handling guidelines governing transport, connection, storage
- Standardized gas connectors
- Dictates the color marking and labeling of cylinders.
What is the color coding for gas cylinders? And who dictates it?
CGA Dictates the color marking and labeling of cylinders. o Air – yellow o Oxygen – black o Nitrogen – black o Nitrox – black with green band
What things is the CGA worried about with gases?
o Compression gas sources
o Breathing gas source
o Chamber environment
Why is liquid oxygen used in HBO, and how is it stored?
- Utilized in HBO because it has a 600:1 ratio – 1 L of LOX = 600 L of oxygen gas
- LOX stored at -273, released into evaporators where it becomes a gas
- As LOX becomes a gas, builds up in lines and creates pressure
How is compressed air used in HBO?
• Compressor - typically used
• Volume tank – holds the compressed air
• Typically have 2 compressors and 1 volume tank in multiplace setup
o Air compressor intakes located outside
o Located away from source of contaminants – ex car exhaust
o Periodic sampling of air required by NFPA standards
What grade air is used in multiplayer chambers? Who governs it?
• CGA – Grade D air specifications are specifications followed in multiplace chambers
o Oxygen required to be between 19.5-23.5%
o Carbon dioxide – 1000 parts per million
o Carbon monoxide – 10 parts per million
o Methane – none
o Oil/particles – 5 gm/ m3
o Odor – none
What do you do with an oxygen analyzer?
Oxygen analyzer
• Verify the oxygen content of LOX or cylinders
• Verify breathing gas delivered
• Sample chamber environment
o Multiplace chambers to maintain less than 23.5% oxygen
What are req on oxygen ventilation?
Chamber ventilation
• NFPA has minimum ventilation requirement for all chambers
• 3 actual cubic foot per person (acfm not square cubic foot per min) – depends on # of occupants
• Removes exhaled carbon dioxide
• Could use an carbon dioxide scrubber
What is BIBS and what kinds are there?
BIBS – built in breathing system • Hood or mask o Hoods most commonly used in multiplace o Isolated from chamber • Demand Mask o Breathing gas does not flow until you inhale
What is an overboard dump and how does it work?
• Overboard Dump
o Exhaust breathing gas to the outside
o Keeps carbon dioxide from building up inside the chamber
o Uses pressure differential for suction
What is a vacuum relief dump?
o Necessary in overboard dump
• Prevents suction injury from mask
• Prevents “shrink wrap” in the hood
What is a fire suppression system?
- Also known as FSS or FES
- NFPA code requires it for multiplace chambers
- Fire suppression water must be a higher pressure than the max pressure of the chamber
- Required to have a deluge system and a hand held line or hose
What are fss specs?
FSS performance specs • Function testing required semi-annually (Q 6 months) • Deluge system o Water must deliver in 3 seconds o 1 gal/min per sq foot of floor area o Last for 1 min • Hand lines o 50 psi over max chamber pressure o Deliver 5 gal/min simultaneously – 2 hand lines min.
Typical monoplane configuration?
Each chamber has individual gas and exhaust system
• If patients are getting air breaks, will have breathing system for air breaks
What is typical multiplace configuration?
Compression system for air compressor – separate line for each lock
• Each compartment has separate exhaust system
• Oxygen source for each lock for oxygen delivery
o Multiple hoods or air masks for oxygen delivery
• Backup air and oxygen system
• Fire suppression system
What is a sound powered phone?
Sound powered phone
• No battery or electrical component
• Backup communication in multiplace and diving systems
• Not usually used in multiplace chambers
What are monoplace equipment requirements? Who governs that?
• Monoplace equipment limited by NFPA standards to wiring and equipment is limited to communications and physiologic monitoring leads.
How is equipment used in monoplace chamber?
Equipment is outside the chamber in a monoplace
o Use penetrators to separate the patient interface from the rest of the equipment
o Might be able to have equipment inside multiplace but can have outside multiplace as well
What concerns are there for equipment in multiplace chamber?
o Potential hazards
• Pressure breaks the equipment (Boyle’s law)
• Heat or spark production (NFPA limits which equipment can go inside the chamber for this reason.)
o Malfunction
• Potential that equipment won’t operate at all
• Touch pad buttons all press at once due to the pressure
• Incorrect rate or volume may be delivered
Where can EKG monitoring be performed?
- Can be done outside the chamber if penetrator port available for the leads, as no electricity will enter the chamber
- Monitor might be ok inside a multiplace chamber if meets criteria
Considerations for taking BP with chambers
Blood Pressure – “NIBP”
• Special NIBP monitor compensates for pressure differential
• Only 1 machine can do this
• In multiplace – most brush monitors in NIBP machines not allowed by NFPA, but BP can be taken manually.
Where is TCOM performed?
• Done from outside of the chamber.
IV therapy in monoplace chamber
IV therapy
• Special IV pump – must pump harder to overcome the chamber pressure.
• Special IV tubing – fits penetrators in the chamber, pressure tubing, back flow precaution, locking connectors
IV therapy in multiplace chamber
• Drip rate affected by chamber pressure
• Multiplace
o Can hang IV to gravity and let it drip
o Can’t use glass bottles in the chamber, will fill with compressed gas and potentially explode
o Drip column is affected by pressure
• During compression the drip column space will fill with fluids and you won’t be able to see the drips
• During decompression the column is affected by pressure and air can be pushed into tubing.
Ventilators in chambers
Ventilators
• Pneumatic vents are the most common
o Do not use electricity, only gas pressure
o Performance is affected by pressure change – may not get the same volume you do at surface.
Suction and HBO
Suction
• At 3 ATA, the vacuum created by pressure difference between chamber interior and outside the chamber is 30 psi. Normal wall suction is 4 psi
• This difference requires that suction inside the chamber has a “back pressure regulator” to reduce the vacuum force.
Defibrillation and HBO
- Should be done outside of the chamber after decompression in the monoplace chamber
- Possible to have a defibrillator wired into a multiplace chamber, but that is not common.
- In either chamber, need to move the patient away from the oxygen source (chamber door)
- Strip off the O2 saturated clothing and bedding
- Wait about 30 seconds after that before defibrillating to help clear some of the O2
What do you so with drains in HBO?
• Need to open any drains that require suction in the chamber during the pressure change (hemovac, penrose, Jackson-pratt drains)
What do you do with trachs and ET tubes?
Air cuff used to hold into place will shrink during decompression (Boyle’s Law)
• Will need to replace air with fluid
Fire information
Fire Safety
• For a fire need O2, an ignition source, and a fuel source. Prevent fire by not allowing an ignition source into chamber.
Burning rate increases in an HBO chamber • From the pressure • From the higher oxygen % Ignition Material Temperature F in air Temperature F in HBO Paper drape 879 770 Cotton Sheet 869 680 Treated cotton sheet 1067 590 Nomex fabric 71112 968
Potential ignition sources
- Arc from electric wiring
- Open flame
- Discharged of stored energy (battery, capacitor)
- Hand warmer or pocket warmer (either a chemical or flame warmer)
Historic chamber fires
• Before 1980
o Mostly caused by electrical sources
• After 1980
o Mostly caused by things introduced into the chamber – toys, hand warmers, etc.
What are fire safety standards?
NFPA (National Fire Protection Associates) – governing body for fire safety
o NFPA 99 standards govern our operations – the section on health care facility
o Chap 20 governs hyperbaric facilities
What does NFPA 99 chap 20 govern?
Minimum standards for the protection of patients
• Focuses on prevention of fire
o Limits the type of burnables allowed in chamber
o Limites the quantities of burnables allowed in chamber
o Keeps energy levels in the chamber low
o Tightly control ignition sources
Grounding requirements by NFPA standards
“The chamber shall be grounded to the building”
• “Resistance shall not exceed 10 hm”
• “All furniture permanently installed in the hyperbaric chamber shall be grounded.”
• A patient grounding strap or wrist strap is required by NFPA 99 standards when O2 is > 23.5% (monoplace chambers)
NFPA limits
NFPA 99 limits:
• 23.5% of O2 in a mutliplace chamber
• 185 F is max temp of equipment in a multiplace chamber
• 140 F is the max temp of equipment in the monoplace chamber
• 28 volts allowed in the communication system
• No petroleum products are allowed in the chamber
