Opinions on the role of Hyperbaric Oxygen (HBO) in the treatment of non-healing tissues vary from the over enthusiastic to the outright
dismissive. The fact is that there are definite indications for HBO in this situation. The attitudes of some physicians may well have been clouded
by the use of HBO in too many conditions for a structured therapeutic approach to develop. Many of these attitudes are changing. Our lack of full understanding of oxygen’s effect in disease states also affects
opinion on HBO. Measurement of different cell functions make it apparent that oxygen can behave much like a drug - too little, hypoxia and cell death - too much, overdose and toxic effects. With a suitable regime, hyperoxia can
be used to stimulate growth of tissues.
Certain points can be presented that make outright rejection of
HBO for non-healing tissues ill considered. The experience of responsible physicians in the field, the vitality of HBO programs in established and respected centers in the country, books and work reported in peer
reviewed journals, success of national and international symposia on HBO and the willingness of third party payors including Federal agencies to reimburse for HBO treatment must be counted as supportive of a role for Hyperbaric
Oxygen in wound healing.
It must be stressed that HBO is an adjunctive therapy. Assuming the
patient is willing to undergo treatment, certain conditions must be met before it can be hoped that HBO will contribute to wound healing. Among these are:
- Systemic diseases such as diabetes must be adequately
treated.
- Nutritional needs must be met.
- Nicotine and heavy ethanol intake must be curbed.
- Contraindications and risks must be considered.
- Treatment for infection should be instituted.
- Major blood vessel flow must be present.
- Aggravating factors to the wound such as local pressure
or irritation should be minimized.
- Wound debridement concurrent with HBO therapy is
necessary.
- Sufficient HBO treatments must be undertaken before
efficacy of treatment is assessed.
Complete understanding of the mode of action of HBO awaits us.
When non-healing tissue with an environment of hypoxia is
exposed to intermittent hyperoxia, a change in the cycle
of cell growth results with increase in connective tissue
and microvasculature. Fibroblast proliferation with
collagen formation provides the structural support
required for angiogenesis. This promotes healing and is
probably part of the explanation of HBO effect. In
contrast where constant high levels of oxygen play
a role in retinopathy of prematurity and pulmonary oxygen
toxicity, the intermittent high levels of oxygen that
occur with HBO treatment will stimulate new tissue
growth. It should also be mentioned that concern has
been expressed that growth of a tumor might be
accelerated by HBO. This has not been found to be a
problem in clinical practice nor evidence produced
experimentally. It is now agreed by many authorities that
HBO can play a valuable roll in the terapy of non-healing
tissues.
HBO in the following conditions are recognized for reimbursement by third
party payors†D:
- Preparation of a site for a skin graft
- Preservation of a compromised skin graft
- Necrotizing infection*
- Soft tissue radionecrosis.
- Osteoradionecrosis
- Chronic refractory osteomyelitis
† Also listed are crush injuries, acute traumatic
ischemia, acute peripheral arterial
insufficiency.
D Other indications for HBO are not listed.
* Interpretation of this term available on referral.
Transcutaneous Oxygen (TcPO2)
Using special skin electrodes, TcPO2 is measured
at the site of a non-healing wound or graft and also at a
comparable healthy site while the patient inspires first
21% and then 40% oxygen. Results indicate the state of
the wound oxygenation under room air conditions, the
extent of major vessel flow to the wound and the rise in
oxygenation that can be achieved with HBO. Measurements
are made under carefully controlled conditions and trends
are of more value than absolute values for TcPO2.
Referring a Patient and Preliminary Work-Up
This can be done by letter or telephone (319-356-8220). Please
speak to the HBO therapist and ask for the HBO physician
on duty. Patients remain under the care of the
referring physician who assesses efficacy of treatments
("dives"). No consultation of other physicians
is undertaken without prior discussion with the referring
physician. When necessary for clarification third
party payors are requested to confirm the intention to
reimburse.
In treatment of an ulcer and/or preparation for a skin graft
a sufficient number of treatments should be allowed to
coincide with the surgical plans. Wound care must
accompany HBO. In compromised grafts the earlier HBO
treatment is instituted the better the chances of
success. Although HBO produces some vasoconstriction, it
has been found that any potential vasoconstriction is
outweighed by the tremendous increase in tissue oxygen
levels during treatment.
Examination of a recent chest x-ray is necessary before HBO
therapy, to exclude air containing cavities in the chest,
e.g., bullae which are likely to contract and re-expand
on treatment. Absolute contraindications to HBO are
unusual and virtually all may be regarded as relative
when considering the need and/or urgency for therapy.
Foremost contraindications are acute lung infection, history
of acute asthma, untreated pneumothorax and presence of
air containing cavities such as pneumoencephalus. Chronic
pulmonary disease or history of spontaneous pneumothorax
must always be identified before HBO therapy.
Other conditions that give rise to concern are the presence
of or repeated episodes of middle ear infection. 90% of
awake cooperative patients can compensate for middle ear
pressure changes using simple measures. In those who
cannot equalize pressures, myringotomy may be required,
but will not be done without the agreement of the
referring physician and the otolaryngologist who is
requested to perform the procedure.
Seizures are a rare complication of exposure to high levels of oxygen. This risk is minimized by "air breaks" during the treatment. Patients
with seizure disorders must have their seizures
adequately controlled before HBO treatment. The risk of
an oxygen seizure is increased by heavy ethanol intake
which must be avoided. The very rare occurrence of a
seizure can be controlled by decreasing the inspired
oxygen concentration. It is worth recalling that a
seizure in an hyper-oxygenated state is different than a
convulsion breathing room air. The use of anticonfulsants
is not needed for most HBO induced seizures.
A history of angina should be sought but rarely poses a
problem in HBO therapy. Anxious patients may receive
sedation during a dive. Claustrophobia is not a
significant difficulty with patients due to our ability
to accompany them during the treatment.
Optic neuritis is a rare contraindication. It is however,
appropriate to warn patients that myopia may occur
following therapy and must be monitored. This regresses
spontaneously over a period of weeks.
The effects of HBO in pregnancy has not been identified and its
relevance needs to be evaluated on a case per case basis.
Features of Our HBO Service
1. Referring physician remains the patient’s
physician. He/She also assesses efficiency of
treatment by these observations:
- Inflammation should diminish and wounds assume a
noninfected appearance. (The antibacterial
effect of HBO is not covered in this
brochure.)
- Treatments should increase areas of granulation tissue
in the wound.
- Wound edges become better defined and wound size
begins to decrease.
- During preparation for and salvage of a compromised
graft, deterioration of the site should be arrested and appearances occur as above.
2. HBO is done together with other treatments.
3. Certified HBO physicians and respiratory therapists in
attendance during treatment.
4. A series of photographs of lesions are always taken to
monitor treatment.
5. The hyperbaric chamber is large enough to accommodate
up to six patients comfortably in addition to a
therapist, who accompanies patients on all
treatments.
6. Our Hyperbaric Medicine Service has experience with
over 8500 treatments. Results of wound healing
have been consistently satisfactory.
Typical Treatment Regime with Minimal Number of Treatments
A standard treatment = 100% O2 (with air
breaks) at 2.4 atmospheres for 90 minutes.
- Wounds and grafts - a minimum of 20 treatments is
recommended. Post operative treatments
may be indicated when necessary.
- Prevention of osteonecrosis for tooth extraction in
irradiated areas - 20 treatments, extraction - 10 treatments.
- Healing of oro-cutaneous fistula - 30 treatments.
- Augmentation of elective-maxillo-facial reconstruction -
20 treatments, surgery - 10 treatments.
- Treatment of osteoradionecrosis of mandible- Marx-Univ.
of Miami Protocol - Stages II, III, IIIR - 20 treatments - Surgery - 10 treatments.
- Healing of tissue radionecrosis - areas other than
head and neck -a minimum of 20 treatments.
Hyperbaric oxygen is a cost effective adjunctive to other therapy in
the above conditions.
The Hyperbaric Medicine Service has a library of books and
references on HBO. Requests from clinicians for reference
list or reprints (provided the condition to be treated is
specified) will be answered.
For those who are considering referring a patient or are interested in
HBO as a future option, the Hyperbaric Medicine Service
will be happy to show our facilities, demonstrate
illustrated case histories or answer any questions.
If you have questions or would like to refer a patient; call 319-356-8220 or call UI Hospitals and Clinics' information at 319-356-1616. Ask for the Hyperbaric medical doctor.
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