Draft Policy On Medical Supervision During HBO Treatments
On behalf of SAUHMA HBO Workshop By Dr W.A. Meintjes & Dr Frans J. Cronje

Hyperbaric oxygen therapy (HBOT) is a well-established, conventional medical treatment. It is not without risks, nor is it invariably beneficial. Appropriate patient selection and medical supervision are therefore critical to ensure its safe, cost-effective and ethical application.

The most obvious risks of HBOT are associated with the physical effects of pressurisation and depressurization, an elevated fire hazard, and the potential for explosion of pressure vessels. Patients undergoing HBOT may also suffer several possible medical complications and side-effects1-6. Of these, middle ear barotrauma is the most common: it affects up to 9.2% of patients). Other effects include changes in visual acuity; hypoglycemia, oxygen toxicity, dizziness, anxiety reactions, dyspnoea and chest pain (in 0.5-1.5% of patients); and pulmonary barotrauma-related complications. Several medical conditions represent relative or absolute contra-indications for HBOT (e.g. current pneumothorax and previous Bleomycin therapy), and should be specifically screened for before therapy is initiated.

In addition to the physical and medical implications, there are also economic ones. HBOT is relatively costly, which is why its use should be based on sound medical- and scientific justification. HBOT is therefore subject to the same statutory and ethical medical principles that govern other aspects of health care – including medical facilities, -devices and pharmaceuticals.

As representative association for the medical application of HBO, SAUHMA considers it a foundational ethical requirement for a medical practitioner (who is trained in the use of HBOT) to (1) select patients for HBOT, and (2) supervise each and every treatment that is provided. By extension, SAUHMA considers unsupervised HBOT treatments to be potentially life-threatening, intrinsically unethical and therefore completely ineligible for reimbursement by either patients or third-party payers.

To clarify the role and function of the medical practitioner responsible for HBOT, however, and to clearly define what the scope and nature of medical supervision should look like in practice, SAUHMA has developed a Policy on Medical Supervision for HBOT. This Policy represents the consensus statements formulated at a SAUHMA HBOT Workshop in February 2016.

DEFINITION OF “MEDICAL SUPERVISION” OF HYPERBARIC TREATMENTS

Upon appropriate assessment and selection of a patient for HBOT (by a suitably trained hyperbaric physician), supervision of each HBO treatment is to include supportive, personally undersigned documentation, clearly indicating that:

• Full professional medical responsibility has been assumed formally by an individual medical practitioner, for the safety of the hyperbaric system for the period of treatment; this may include, but is not limited to:
  • Signing off each hyperbaric treatment session;
  • Signing off on the safety checks of the facility at the beginning of the day;
  • Providing clinical notes on each treatment session for each individual patient, in which there is clearly stated that:
    • Prior to HBOT:
      • Every patient is fit for each HBOT session, and that
      • The indication for HBOT remains appropriate, including identifying and documenting the need for any additional testing, assessment or adjunctive medical-, surgical- or wound care;
    • During HBOT: Any complications and side-effects were managed appropriately;
    • After HBOT:
      • No complications / side-effects occurred; or
      • If complications or side-effects did arise, that these were properly documented, appropriately managed; and that
      • Ongoing HBOT treatments were based on the outcome / progress of the preceding HBOT sessions, with due consideration to the true need / justification for further HBOT, additional testing, and/or for adjunctive medical-, surgical- or wound care.

In order to meet these obligations, the responsible Medical Practitioner may delegate duties to another medical practitioner, who is adequately trained, able and willing to perform them. Irrespective of whether or which duties have been delegated, however, immediate advanced life support and emergency medical care must be available at all times during HBOT.

Also, notwithstanding any of the above, the responsibility for operating a clinical hyperbaric chamber for patient treatments may not be delegated to any person who is not a current, registered healthcare professional. Physical operation of the chamber may be performed by a person not registered with a health professional council on the condition that the responsible health care professional is able to personally and continuously monitor the health and wellbeing of the patients in the chamber.

MINIMUM TEAM SIZES

Monoplace Chamber Operations: The minimum on-site team of staff shall consist of two persons of which at least one is registered with a health professions council. Teams typically consist of a medical practitioner (to supervise the treatment and for emergency assistance - if necessary), and a registered nurse or emergency medical technologist to operate the chamber.Multiplace Chamber Operations: The mimimum on-site team shall consist of (1) two persons who are registered with a health professions council – usually a hyperbaric physician (for supervision of the treatment and for emergency assistance, if necessary) and a medical attendant for taking care of patients inside the chamber (under pressure); and (2) a chamber operator to conduct the hyperbaric treatment from outside; the operator does not need to be a registered healthcare professional.

TRAINING OF MEDICAL PRACTITIONERS

A medical practitioner qualified to provide HBO treatment is one who has undergone specific training in this field of medicine.  Current competence in the management of acute cardiopulmonary emergencies relevant to HBOT (e.g., current ATLS training which includes the placement of intercostal drainage sets) is essential.

Suitable training may include, at a minimum, the following:

• Training, experience and privileges within the health care facility or -institution to manage acute cardiopulmonary emergencies, including advanced cardiac life support, and emergency myringotomy;
• Completion of a recognized hyperbaric medicine training program as established by SAUHMA.  The two programmes currently meet this requirement in South Africa, namely the
  • "Diving and Hyperbaric Medicine Staff Training Course” as accredited with the UHMS, and
  • First two modules of the BScMedScHons (Hyperbaric Medicine) programme of the University of Stellenbosch.
• Other international programmes may be submitted to the SAUHMA Executive Committee to confirm equivalency.
• Continuing medical education in hyperbaric medicine of a minimum of 16 hours every 4 years after initial credentialing.

Certain duties may be delegated by the responsible medical practitioner, to medical practitioners who are not trained in hyperbaric medicine, on the proviso that they have (1) received appropriate in-post training at the facility, and (2) have acknowledged their formal, informed acceptance of the delegated duty based, and (3) are competent to do so.

REFERENCES:

1. Hadanny A, Meir O, Bechor Y, Fishlev G, Bergan J, Efrati S. The safety of hyperbaric oxygen treatment--retrospective analysis in 2,334 patients. Undersea Hyperb Med 2016; 43(2): 113-22.
2. Skeik N, Porten BR, Isaacson E, et al. Hyperbaric oxygen treatment outcome for different indications from a single center. Ann Vasc Surg 2015; 29(2): 206-14.
3.  Camporesi EM. Side effects of hyperbaric oxygen therapy. Undersea Hyperb Med 2014; 41(3): 253-7.
4. Seidel R, Carroll C, Thompson D, et al. Risk factors for oxygen toxicity seizures in hyperbaric oxygen therapy: case reports from multiple institutions. Undersea Hyperb Med 2013; 40(6): 515-9.
5. Biddle C. Oxygen: the two-faced elixir of life. AANA J 2008; 76(1): 61-8.
6. Ambiru S, Furuyama N, Aono M, Otsuka H, Suzuki T, Miyazaki M. Analysis of risk factors associated with complications of hyperbaric oxygen therapy. J Crit Care 2008; 23(3): 295-300.

OBJECTIVES

To reduce bubble size and eliminate gas nuclei. To maximize the diffusion gradient for elimination of inert gas and thereby accelerate gas ‘wash-out’. Hyperoxygenation of hypoxic and/or ischemic tissue. Reduction of oedema. Attenuation of ischemia-reperfusion injury.

DIAGNOSIS

Onset of musculoskeletal pain, cutaneous manifestations, central or peripheral neurological lesions or cardiopulmonary symptoms within 24 hours of completing a dive or series of dives to a depth that exceeds 9 metres sea water. Consider altitude provocation. The ability to differentiate decompression sickness from cerebral arterial gas embolism in the acute treatment phase is no longer considered critical.
Diagnosis to be confirmed by a medical practitioner trained in diving medicine.

CRITERIA FOR HBO THERAPY
 
Symptom onset within 24 hours of completing a dive that involved moderate to high gas loading. Dives to the limit of or exceeding no decompression time frames. Obvious violation of decompression guidelines. Treatment should not be commenced more than 14 days after exposure.

WORK-UP CONSIDERATIONS

1. Continue administration of 100% oxygen via non-rebreather mask, naso- or endo-tracheal tube for up to 16 hours.
2. Complete dive history, including staged decompression and repetitive diving profiles.
3. Past medical history.
4. Physical examination including, but not limited to, a full neurological examination.
5. Special examinations: Exclude pneumothorax before recompression; chest x-ray mandatory if lung overexpansion is suspected. Other special examinations as required.
6. Signed informed consent for HBOT.

TREATMENT

• Fluid resuscitation (IV for severe cases. Avoid dextrose containing solutions.)
• Urine output monitoring. Exclude urinary retention; catheterize if necessary. Maintain at least 1-2 mL/kg/hr.
• Consider oral Tenoxicam or equal NSAID during recompression for musculo-skeletal DCS. DVT prophylaxis critical for paralysed divers. Sedation only if essential.
• Monitor vital signs.
• Prompt HBO with compression to 2.8 ATA:
  • USNTT5 (or equivalent) only for asymptomatic, omitted decompression or pain-only DCS, with complete relief within 10 minutes at 2.8 ATA otherwise treat on USNTT 6.
  • USNTT6 (or equivalent) for all other DCS including neurological or cardiopulmonary manifestations.
  • Consider extensions at 2.8 ATA and/or 1.9 ATA where indicated.
• In case of CNS oxygen toxicity, interrupt oxygen breathing and allow 15 minutes of air breathing after reaction has entirely subsided. Resume treatment schedule at point of interruption.
• Retreat after 6 – 24 hours if residual symptoms remain:
  • Major symptoms: Consider 1 – 2 further USNTT6.
  • Minor symptoms: HBO at 2.0-2.4 ATA for 90 minutes daily.
• Refer patients with residual symptoms for rehabilitation.
• Risk assessment for return to diving, as indicated.
• Consider PFO screening where indicated.

SUGGESTED TREATMENT THRESHOLD

Approximately 75% of cases have complete resolution following the 1st USN TT6.
To be determined in consultation with DANSA. Stop treatment if no functional improvement after 2 consecutive treatments

ICD 10 CODES

T70.3 Caissons disease (decompression sickness).
T70.0 Otitic barotrauma
T70.1 Sinus barotrauma
T70.8 Other effects of air pressure and water pressure. Blast injury syndrome.
T70.9 Effect of air pressure and water pressure, unspecified
T79.7 Traumatic subcutaneous emphysema
S27.0 Traumatic pneumothorax
J98.1 Pulmonary collapse
J98.2 Mediastinal emphysema
I26 Pulmonary oedema
W94 Exposure to high and low air pressure and changes in air pressure

LEVEL OF EVIDENCE

Level C. All authorities consider it unethical to subject this indication to a randomized controlled trial with a non-treatment control group.

CHAMBER CLOTHING
SELECTING SUITABLE CHAMBER CLOTHING MATERIALS A REVIEW OF THE RELEVANT CONSIDERATIONS Francois Burman Pr. Eng. MSc

Much has been written about, speculated on, and even mandated as to what clothing materials are suitable for use in a hyperbaric chamber. This article provides some of the factual and practical considerations when deciding on what materials to select for regular chamber clothing.

All clothing fabrics burn; especially in the presence of elevated concentrations of oxygen. There are also other considerations to take into account, including static-electricity control, comfort, fit, functionality, appearance, soil-resistance, laundering suitability and even control of dedicated clothing within a unit.  However, the overriding consideration remains fire safety and this often affects the final decision.

Traditionally, and as still evident in many hyperbaric standards and guidelines, cotton has been the material of choice.  This is largely based on perceptions that cotton burns slower, does not release especially toxic combustion products, and does not melt onto human skin.  However, this is only partially true. In fact the fire-safety record of cotton needs to be reviewed in more detail.

The main factors that render cotton more or less burnable are the density of the weave, the thickness of the material, the presence of a fluffy or loose pile, and the individual fit on the person.   Being an open-cell or porous material, cotton does not retain oxygen once the environment changes.  Lastly, cotton does not promote a build-up of static electricity, rendering it less likely to serve as a source of ignition energy. In comparing like-for-like materials, in terms of weave, thickness and fit, cotton is not highly-rated in terms of time to actually ignite.

In addition to cotton, there are two alternative, practical options, viz. (1) a ‘suitable’ blend of cotton and synthetic (polyester) material, and (2) the new generation fire-safe materials – such as a blend of viscose* and natural fibre (an example of which is a fabric made of wool and viscose – used to produce children’s nightwear).
* Viscose is a natural polymer made from wood pulp, often referred to as Rayon, and commonly referred to as a semi-synthetic fibre.

Reviewing the intrinsic properties of these materials provides additional, relevant information, such as a comparable measure for determining flame resistance, also called the Limiting Oxygen Index or LOI.  This measure indicates whether material is appropriate for hyperbaric operating conditions, especially as these indices represent the minimum concentration of oxygen required at the ambient environmental pressure to ignite the materials. Once again, it is the relative scale that is important rather than the absolute values.

In essence, the term ‘flame resistance’ – when applied to the use of clothing in hyperbaric facilities – should rather be read as “time to act”; a precious commodity in the event of a chamber fire.

As with most decisions, there are a multitude of factors that influence the final choice.  In determining the most suitable, the safest and the most compliant product, the following decision factors need to be taken into account and prioritized according to actual situational requirements and existing risk factors:

• Permanent flame resistance regardless of how many times the garment is laundered
• Reasonable protection against radiant and convective heat
• Tight weave construction
• Good wear comfort
• Breathable and irritant-free for most patients
• Suitable for dyes and colours to enable regular laundering
• Durable for repeated use
• Control of static electricity
• Soil resistant (should not stain especially easily)
• Acceptable cost

The author has three personal recommendations regarding clothing that do not relate specifically to the material of selection, but do having bearing on clothing with respect to fire.
 

• It is preferable to select clothing that can be removed relatively easily without having to be pulled over a person’s head.  Garments that can be removed easily in the event of a fire will result in less severe burns, or possibly avoid burns completely. It has to be accepted, however, that the various fixtures such as buttons (which tend to get lost) or ties (which tend to result in modesty issues) are not ideal.
• Pockets should not be installed in any chamber clothing. The added control requirement is one more step that can go wrong and too often pockets may be used to carry contra-band into the chamber; usually completely unwittingly.
• The more close-fitting the garments, the lower the flame spread rates tend to be; accordingly, this fit of garment is recommended.  Interestingly, and as a result of analyzing the Florida fire of 2009, the least burned surfaces of both patients were the areas covered by synthetic undergarments. This tends to support this opinion.

So, what about tie-strings versus elasticized waist bands?  In theory, loose pieces of clothing will ignite more easily; yet elasticized materials contain especially hazardous synthetic materials.  The best path to follow is that of full analysis and selection of materials that are most suitable, e.g., a tight-weave draw-string, or an elastic material with natural rubber and fire-resistant fibre.  However, in both cases, as long as these materials are kept away from direct exposure to a source of ignition and are surrounded by other known fire-resistant material, the actual additional risk is not significant.

And what about static electricity? This natural phenomenon results in the discharging of 3000V+ electric sparks - sometimes between unsuspecting personnel or patients and any grounded object (like the chamber). Apart from being a source of surprise, it is a possible ignition source.  In general, natural fibers (cotton) tend not to produce a significant static charge, whereas polyester-containing materials are more inclined to do so. There is an almost direct relationship between the polyester content and the amount of charge.  Therefore, additional controls may be needed where static is a known issue, and these apply to both the inside and the outside of the chamber.  These could include grounding straps (which may be wrist, heel or shoes-based); washing with a suitable fabric softener or spraying materials with a 30:1 dilution of water-to-softener; applying a suitable anti-static spray; or using grounding mats located at key places (especially at the entrance to chambers).

CONCLUSION

It is evident that there is no cookie-cutter answer to the best choice of materials to use in a hyperbaric chamber. This short article has simply attempted to highlight the important considerations and to provide a basis for reaching an appropriate decision.  The latter should only be taken on the basis of sufficient knowledge of what has been selected, and this decision-making process should be recorded in writing, and maintained with the facility’s documented safety program.

No materials are perfect, and none can mitigate general negligence.

RESOURCES

• Library files at American Kynol, Inc., Pleasantville, NY
• Flammability of Textile Products in Canada, Health Canada, 2003 ISBN 0-662-67236-4
• ASTM D 1230-61: Standard Test Method for Flammability of Apparel Textiles, ASTM International, West Conshohocken, PA, 1994.
• Australian Government Articles on Clothing Fabrics.
• Lenzing Fibres Sales and Marketing Library, Germany.
• NFPA 99: Health Care Facilities, Quincy, MA, 2015.
• New Zealand Standard 8777: 1973 Men’s Industrial Overalls for General Purposes.
• Risk Assessment Guide, International Atmo, Inc. San Antonio, Texas, 2015.
• U.S. Consumer Product Safety Commission, Flammable Fabrics Act.

Dr Cecilia Roberts

St Augustine's Hyperbaric Medicine & Wound Care Centre