Hyperbaric Chamber Overview Michael Natoli, MS, CHT Center for Hyperbaric Medicine and Environmental Physiology Duke University Medical Center Durham, NC 27710

Duke Pilot Chamber In the late ’50s, Boerema in Amsterdam showed that small pigs could survive with virtually no red blood cells on physically dissolved oxygen at 3 ata. In 1959-1960, he built a clinical chamber large enough to serve as an operating room at pressures up to 5 ata. At Harvard in 1962, the chamber originally used by Behnke was refurbished and used during operations on infants with congenital heart disease. The first hyperbaric chamber designed specifically for clinical studies was installed at Duke beginning in December of 1962 and became operational in June of 1963. This chamber was used for clinical research and hyperbaric oxygen therapy until the larger multipurpose complex was completed in 1968. Picture from: Brown IW Jr., Fuson RL, Mauney FM, Smith WW. Hyperbaric oxygenation (hybaroxia): current status, possibilities, and limitations. [Review] Advances in Surgery. 1:285-349, 1965.

Duke Chamber Complex Seven chambers can be operated independently or in combination G C H D F A B E Chambers A and B have a total length of 36 ft. with an internal diameter of 10 ft. 6 in. These chambers may be pressurized to 7.8 ATA (225 ft.) but also can be evacuated to a vacuum equivalent altitude of approximately or 1 torr. Chambers D, E, and F are designed for a pressure of 31.3 ATA (1000 ft.) provided by gases such as air, helium-oxygen or helium-nitrogen-oxygen. The D Chamber is a sphere 10 ft. 6 in. diameter with 35 in. access doors to the C and F chambers, and a 30 in. hatch connecting it to the wet chamber (E). The E Chamber has an internal diameter of 6 ft. 6 in., is 10 ft. 6 in. long and is internally insulated to permit simulated diving in cold water. The F chamber is an 18 ft. long cylinder with an internal diameter of 10 ft. 6 in. and is fitted with shower and toilet facilities. A, B, C - Clinical D, E, F, G – Research H – no longer attached

Duke Chamber Complex Main Deck Second Deck Golf Golf Foxtrot Delta Echo Charlie Bravo Alpha

Chamber Construction Chambers A and B have a total length of 36 ft. with an internal diameter of 10 ft. 6 in. These chambers may be pressurized to 7.8 ATA (225 ft.) but also can be evacuated to a vacuum equivalent altitude of approximately or 1 torr. The C chamber is a large sphere with 20 ft. diameter and a pressurization capability to 7.8 ATA (225 ft). The chamber is equipped for oxygen-helium as well as air, long duration, saturation exposures and is also large enough to support complex investigational procedures, surgery and multiple patient hyperbaric oxygen treatments. The lung lavages carried out on patients with cystic fibrosis, alveolar proteinosis and other diseases also are performed in this chamber. Chambers D, E, and F are designed for a pressure of 31.3 ATA (1000 ft.) provided by gases such as air, helium-oxygen or helium-nitrogen-oxygen. The D Chamber is a sphere 10 ft. 6 in. diameter with 35 in. access doors to the C and F chambers, and a 30 in. hatch connecting it to the wet chamber (E). The E Chamber has an internal diameter of 6 ft. 6 in., is 10 ft. 6 in. long and is internally insulated to permit simulated diving in cold water. The F chamber is an 18 ft. long cylinder with an internal diameter of 10 ft. 6 in. and is fitted with shower and toilet facilities.

Chamber Foundation Chambers D, E, and F are designed for a pressure of 31.3 ATA (1000 ft.) provided by gases such as air, helium-oxygen or helium-nitrogen-oxygen. The D Chamber is a sphere 10 ft. 6 in. diameter with 35 in. access doors to the C and F chambers, and a 30 in. hatch connecting it to the wet chamber (E). The E Chamber has an internal diameter of 6 ft. 6 in., is 10 ft. 6 in. long and is internally insulated to permit simulated diving in cold water. The F chamber is an 18 ft. long cylinder with an internal diameter of 10 ft. 6 in. and is fitted with shower and toilet facilities.

G-Chamber Addition A short tunnel connects D chamber to G chamber which is 94” diameter and capable of pressures up to 109 ATA (3600 ft.). This chamber was built in 1977, installed in 1978, and became operational in March of 1979. The lower section of the G chamber is a 80” deep, 69” diameter wet compartment with access through a hatch on the metal floor.

Main Control Console Don Bordeaux, 2005

Design Specifications and Operational Guidelines ASME: BPV sec. VIII & PVHO-1 American Society of Mech. Eng. Boiler and Pressure Vessel Code Pressure Vessels for Human Occupancy PVHO-2: In service guidelines for PVHO acrylic windows ASME BPV – VIII – Division 1 “Boiler and Pressure Vessel Code, Section VIII, Unfired Pressure Vessels” Minimum requirement, originally instituted to protect personnel outside the chamber ANSI/ASME - PVHO - 1 “Safety Standards for Pressure Vessels for Human Occupancy” NFPA - 99 “Standard for Health Care Facilities” (Ch. 19 - Hyperbaric Facilities) NFPA 70 “The U.S. National Electrical Code” NFPA 53M “Fire Hazards in Oxygen-Enriched Atmospheres” CGA - Compressed Gas Association American Society of Mechanical Engineers (ASME) United Engineering Center 345 East 47th Street New York, NY 10017 National Fire Protection Association (NFPA) 1 Batterymarch Park PO Box 9101 Quincy, MA 02269-9904 Compressed Gas Association Inc., (CGA) 1235 Jefferson Davis Highway Arlington, VA 22202 NFPA – 99 and 53 M National Fire Protection Agency CGA (multiple) Compressed Gas Association

Certifying Agencies US Navy Department of Health and Human Services Inspected every three years Department of Health and Human Services Food and Drug Administration (FDA) Center for Medicare and Medicaid Services Clinical Laboratory Improvement Amendments (CLIA) Certifying organizations US Navy System Certification of Procedural and Material Adequacy (3 years) Joint Commission on Accreditation of Healthcare Organizations (JCAHO) DUMC Risk Management Office Durham Casualty Company State Department of Labor Boiler Safety Bureau Health and Human Services Center for Medicaid and Medicare Services Clinical Laboratory Improvement Amendments (CLIA) U.S. Food and Drug Administration (FDA) The requirements of the Good Manufacturing Practices (GMPs) as defined by CFR 21 Part 820 for Class II medical devices College of American Pathologists (CAP) UHMS - Accreditation State of North Carolina Department of Labor – Boiler Safety Bureau

Certifying Agencies (cont.) Joint Commission on Accreditation of Healthcare Organizations (JCAHO) College of American Pathologists (CAP) Undersea and Hyperbaric Medical Society (UHMS)

US Navy Pipe Color Coding Originally developed in 1928 American Standards Association. (Now ANSI) Oxygen Nitrogen Special Gas Helium Air Exhaust Vacuum Potable Water Fire Deluge System Color coding Oxygen - green Nitrogen - gray Helium - buff Air - black Exhaust - silver Vacuum - yellow Potable water - blue Fire suppression water - red Paint Epoxy paint (zinc containing) Imron (Dupont) Phenoline (Carboline) or other epoxy paint Pressurize chamber three times to max. depth for eight hours each time Wait 72 hours, draw gas sample

Air Quality Standards US Navy Guidelines O2 20 - 22 % CO2 < 500 ppm CO < 20 ppm Hydrocarbons < 25 ppm Particulate and oil mist < .005 mg/liter Moisture < .02 mg/liter Air quality Hydrocarbon, oil mist, and other contaminants determined by testing at an independent laboratory (every 6 months) Independent laboratory test every 6 months.

Compressors Built by Norwalk 1936 Four stage HP Water cooled 100 cuft/min Synthetic oil lubricated (Anderol 500) Three Norwalk compressors built in 1936, used in the Navy, and surplused after WWII. Each has over 19,000 hrs of operation. Each outputs 100 cuft / min.

Compressors and Filters Intake filter Relief valve Dew Pt. Monitor Compressors CO Monitor #1 To chambers 1200 psig Back Press. Valve Charcoal filter #2 Drying towers Coalescing filter Cooling coil To storage Filters are cleaned or replaced yearly Oiling rate checked yearly CO monitor calibrated weekly – alarms at 3 and 5 ppm Dew Pt monitor calibrated semi-annually Roughing filter #3 Final filter Cyclone separator Drains

Air Storage Banks 24 storage cylinders Primary air source 2x air required to pressurize chamber to max treatment depth + 1 hr vent Secondary air source 1x air required to pressurize chamber to max treatment depth + 1 hr vent 42 cu. ft. per cylinder 8 cylinders per bank 336 cu. ft. per bank 64,000 cu. ft. per bank when compressed to 2800 psig 190,00 cu. ft total 218,000 cu. ft. total at 3000 psig 46,000 cu. ft. per bank over operating pressure of 800 - 2800 psig A chamber = 1200 x 6 ata = 7200 B chamber = 760 x 6 ata = 4560 C chamber =4188 x 6 ata = 25,128 D chamber =600 x 6 ata =3600 E chamber =300 x 6 ata =1800 F chamber =1430 x 6 ata =8580 G chamber = 390.5 x 6 ata =2343 Visually inspected every 5 yrs for dust, rust, and crust 24 storage cylinders 42 cu. ft. per cylinder water capacity 218,000 cu. ft. at 3,000 psi

Air Delivery To chambers Reference Control From Compressors Bank 1 Electrically Operated By-pass Bank 3 Emergency Main Reducing Back-up Main Air regulator shifted annually Control air is 100 psi Emergency air is 200 psi Reference air is 200 psi Main Air 450 psi High pressure relief = 3000 psi Low pressure relief = Bypass Emergency storage Relief valve

Air Delivery Reducing Station

Control Console Rate Selector Spray Valve Ventilation Rate Emergency Stop Control Method Gauges checked with dead weight tester annually Clock checked quarterly (not shown) Three modes of operation Manual Semi-automatic Automatic Control Rate Reference Controlling Valve DP Cell Polarity Gauge DP Cell Isolation

Pressurization Control Gauge on console Proportional control valve Muffler in place to minimize noise as per OSHA requirements Muffler From reducing station 450 psig Emergency stop valve Manual Chamber wall Manual (back-up)

Decompression Control Manual Proportional control valve To exhaust duct Emergency stop valve Ventilation valve Flow meter

Internal Environmental Control Pneumatic valves Muffler Cold water Heating / Cooling Coils Hot water Lubrication level Blower Internal system Water-filled heat exchanger beneath flooring Blower motor is outside the chamber Reduces noise Eliminates heat and spark potential of the electric motor Penetrates the chamber hull through a water cooled shaft seal Electric motor Air flow Shaft seal Temperature indicator Thermistor

External Environmental Control Blower Thermistor Temperature controller External system Water-filled heat exchangers, CO2 absorbent. The tubing is rated to an equivalent pressure to that of the chamber. The CO2 absorbent canister may be isolated in order to change the absorbent when it is exhausted. Cold water CO2 absorbent Hot water

Breathing Gas Systems Air Oxygen Special Gas Chamber compression, air breaks, emergency facemask, ventilator. Oxygen Treatment protocols, tender decompression. Air used for emergency facemask, ventilator, air breaks Special Gas 50-50 for Table 6A, NITROX, Special Gas 50/50 for Table 6A, Nitrox for various studies.

Breathing Gas Systems BIBS Panel Built in Breathing System Inline micron filters from high pressure sources cleaned annually

Oxygen System Liquid O2 Tank Liquid level O2 manifold Evaporators O2. reg. 80 psi over bottom Fill point Main O2 reg. 250 psig High press. reg. 180 psig No ball valves in systems of > 125 psi Liquid tank contains 900 gallons ~ 100,000 scuft Lasts about two months Piping must be O2 cleaned Use non-hydrocarbon based lubricants such as fluorocarbons or halocarbon or krytox Soft goods need to be replaced more often than in air systems – viton is used as opposed to BUNA N or rubber Aviator grade > USP medical > Industrial Liquid N2 Contains 3600 cu ft at 200 psi Reduced to 120 psi Check valves Relief valves High Press. O2 back-up

Patient Oxygen Delivery Systems Head tent Recirculating Single Pass Scott Duo-Seal Face mask Single hose Overboard dump Oxygen delivery Plastic disposable face masks are loose fitting and should not be used at pressure T-pieces are used for patients with endotracheal tubes Ambu-bags are used during compression and decompression Ventilator / Ambu-bag

Oxygen Delivery - Recirculating Head Tent Eduction Oxygen Purge Venturi Eduction Line 30 20 40 Purge Line 10 50 Sample 60 Venturi Sample Line Bubbler Recirculating head tent system Employs a venturi to increase flow and create a suction Uses a Sodasorb canister to absorb exhaled CO2 An ice bucket with a hollow jacket cools the gas after leaving the Sodasorb canister A bubbler provides back pressure to keep the plastic tent blown up The venturi is supplied with ~ 30 psi by an oxygen regulator A purge line allows a high flow of oxygen to blow up the tent initially Uses less oxygen More upkeep involved Flow through a Mark V hardhat venturi has a 20:1 flow ratio Sodasorb Canister Ice Bucket Condensate Drain Ice Water Drain Latex Neckseal

Oxygen Delivery - Single Pass Head Tent Eduction Oxygen Patient Sample Line Oxygen Supply Regulator Oxygen Dump Regulator Single pass head tent system Employs an oxygen supply regulator to administer ~ 40 lpm of oxygen into the head tent A dump regulator connected to the overboard dump line exhausts exhaled gas outside the chamber Simple operation Uses more oxygen Overboard dump line set to 10 in H2O suction @ all depths Latex Neckseal

Oxygen Eduction System Differential Pressure Converter Reducing valve 20 psig Safety Shut Off Flow Fuse Diaphragm Exhaust from patient 100 psig Signal air Flow fuse set at 1 cm H2O Filter 5 L Bag Drain Valve

O2 Eduction

Eduction Manifold Description Outside Building 50 ft Foxtrot Delta Air Amplifier Charlie 1” pipe Bravo Each dump system was connected outside the chamber via 2.5 cm (1 in) internal diameter (ID) pipe to a 5.1 cm (2 in) ID eduction manifold. The manifold was configured as a “Y”, open to room air at its origins and connected to the building exhaust at its termination. The fan was placed between the manifold termination and the building exhaust, a 61 cm2 (4 ft2) exhaust duct. 3” pipe Alpha 4 ft2 Chamber Exhaust Duct Manifold Inlet

Oxygen Eduction Air Amplifier manifold Building Exhaust Duct Air Amplifier Dry compressed air is connected to the inlet of the annular ring. The 2” inlet of the air amplifier is connected to the termination of the manifold and the outlet of the air amplifier is connected to the building exhaust duct. A differential pressure gauge is used to verify suction at the inlet of the O2 eduction manifold

Fire Suppression System Relief valve 200 psig reg. check valve 450 psig air Muffler OFF Fire Suppression Tank Pneumatic valve Air mask Overhead sprinklers An oxygen-enriched atmosphere is defined as an environment where the surface equivalent oxygen concentration exceeds 23.45% (the NFPA lists this as 23.5%). The reason why this number has been chosen, is that the only survivable fires in hyperbaric chambers occurred where the oxygen percentage was below 23,5%. Manual Pump ON Level sensor Hand-held hose Drain

Fire Suppression Water Source

Fire Suppression Equipment Inside the Chamber

Nitrogen Purge

Explosion proof housing low wattage Power and Lighting Explosion proof housing low wattage Canty Light Ground fault interrupter Isolation transformer Power Isolation transformers Ground faults Indicators Interrupters Emergency backup Lighting Canty lights Eliminates heat source in chamber Explosion proof casing Low wattage - 35 watts OR lights Doppler 120 volts Ground fault indicator

Redundant Communication Systems Plantronics Headset Telex Wireless System Audio communications REDUNDANCY Headsets Provide better communication during compression, ventilation, and decompression Provide privacy and clear communication in emergencies No switches inside chamber Cross connection allows clear communication during lock in / out procedures Two-way speakers Open microphone inside the chamber allows audible monitoring EMERGENCY Sound powered phones Visual communications Viewports Closed-circuit Television Two-way Mic/Speaker Box Sound-powered Phone

Closed Circuit Patient Monitoring

Breathing Gas Analysis Vital for fire safety and personnel safety Chamber Atmosphere O2 = 20.5% - 23.5% CO2 < 1.0% SEV Breathing gas analysis Documents that patients are receiving proper treatment Vital for fire safety and personnel safety Helps identify problems with gas delivery equipment An oxygen-enriched atmosphere is defined as an environment where the surface equivalent oxygen concentration exceeds 23.45% (the NFPA lists this as 23.5%). The reason why this number has been chosen, is that the only survivable fires in hyperbaric chambers occurred where the oxygen percentage was below 23,5%. Documents that patients are receiving proper treatment Patients O2 > 98.0% CO2 < 1.0% SEV

Breathing Gas Analysis Chamber O2 Patient O2 Patient CO2 Servomex Servomex 21.0 98.0 0.0 5.0 % O2 % O2 zero span zero span Oxygen Analyzer 572 Oxygen Analyzer 572 Chamber atmosphere Maintained via ventilation of the chamber, oxygen addition, and CO2 scrubbing Patients Breathing gas analysis performed at least every 30 min Oxygen and carbon dioxide levels checked to ensure oxygen delivery equipment is performing properly Patient sample Chamber sample

Breathing Gas Analysis Chamber atmosphere Maintained via ventilation of the chamber, oxygen addition, and CO2 scrubbing Patients Breathing gas analysis performed at least every 30 min Oxygen and carbon dioxide levels checked to ensure oxygen delivery equipment is performing properly

Critical Care Monitoring EKG Blood pressure Respirations Temperature Cardiac Output and wedge pressure Oxygen Saturation Transcutaneous O2 monitors

Defibrillator

Blood Gas Determination at Pressure

Ultrasonic Assessment Doppler ultrasonic venous bubble detector Two-dimensional ultrasonic arterial bubble detector

Suction

Medical Lock

Special Equipment Considerations Patient Stretcher Patient Chair

Altitude Controls

Chamber Cleaning Ultraviolet lights UV lights have been used in the past to disinfect a chamber after treating patients with bacterial infections UV light can degrade acrylic viewports Ultraviolet lights UV lights have been used in the past to disinfect a chamber after treating patients with bacterial infections UV light degrade acrylic viewports Cleaning agents Alcohol and acetone based products should not be used Acceptable cleaning solutions for inside chambers Sanimaster 3 Benzalkonium choloride swabs Up to 10% Clorox solution Acceptable agents Sanimaster 3 Benzalkonium choloride swabs Up to 10% Clorox solution Pressure washing

Chambers Here, There, and Everywhere 

Toronto Canada: Toronto General Hospital

Bermuda: King Edward II Hospital

Providenciales: Menzies Medical Clinic

Panama Canal: ACP Panama Canal Authority

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References US Navy Diving Manual Revision 5 15 August 2005 www.bestpub.com National Fire Protection Association NFPA 99 NFPA 53 www.nfpa.org Safety Standards for Pressure Vessels for Human Occupancy ASME PVHO – 1 – 1997 www.asme.org Compressed Gas Association www.cganet.com

Outline Duke Chamber Complex Design Specifications and Operational Guidelines Certifying Agencies Chamber Operations Breathing Gas Systems Fire Suppression Systems Communications Patient care equipment References