WoundReference Improves Wound & Hyperbaric Care
It is the trusted resource to support wound treatment decisions at the point of care.​

HBO Treatment Indication With Protocol

HBO Treatment Indication With Protocol


The purpose of this topic is to provide practitioners of Hyperbaric Oxygen Therapy (HBO) an in-depth summary of HBO indications and common HBO treatment protocols. For an introduction to HBO, refer to An Introduction to Hyperbaric Oxygen Therapy

Treatment Protocol Guidelines

The following hyperbaric medicine treatment protocols are based upon the recommendations of the Hyperbaric Oxygen Committee of the Undersea and Hyperbaric Medical Society.  Clinical protocols and/or practice guidelines are systematically developed statements that help physicians, other practitioners, case managers and clients make decisions about appropriate health care for specific clinical circumstances.  

Protocols allow health providers to offer evidence-based, appropriate, standardized diagnostic treatment and care services to patients undergoing hyperbaric therapy.  Evidenced-based medicine offers clinicians a way to achieve improved quality, improved patient satisfaction, and reduced costs.  Utilization Review should be initiated when clinical decisions result in deviation from or modification of treatment protocols.  This includes any course of treatment at or above the recognized threshold limits. 

Medical Necessity

Medicare.gov defines “medically necessary” as “health-care services or supplies needed to prevent, diagnose, or treat an illness, injury, condition, disease, or its symptoms and that meet accepted standards of medicine.” 

The following conditions meet coverage indications per the National Coverage Determination (NCD) 20.29.[1] Continued HBO therapy without documented evidence of effectiveness does not meet the Medicare definition of medically necessary treatment. Thorough re-evaluation should be made at least every 30 days for documentation of response to therapy. 


By Indication

See all indications below in "Evidence-based indications accepted by the UHMS, approved by Medicare" and "Evidence-based indications accepted by the UHMS, NOT approved by Medicare"

By Treatment Protocol

Table 1: 90 minutes of oxygen breathing at 2 ATA without air break 

Table 1 based on Kindwall and Whelan [2] and National Baromedical Services [3]


Table 2: 90 minutes of oxygen breathing at 2 ATA with air break 

(patients with high seizure risk)

Table 2 based on Kindwall and Whelan [2] and National Baromedical Services [3]


Table 3: 90 minutes oxygen breathing at 2.5 ATA with 2 air breaks 

Table 3 based on Kindwall and Whelan [2] and National Baromedical Services [3]


Table 4a: 90 minutes oxygen breathing at 3 ATA with 2 air breaks

Table 4a based on Kindwall and Whelan [2] and National Baromedical Services [3]



Sample Physician Order

HBO request requirements checklist and sample EMR documentation

  Acute Carbon Monoxide Poisoning



  Clostridial Myonecrosis (Gas Gangrene)



Table 4b: Weaver Protocols for Carbon Monoxide Poisoning 

Table 4b based on Weaver et al [4]

Table V

Adapted from the U.S. Navy Diving Manual  [5]

  1. Descent Rate – 20 ft/min.
  2. Ascent Rate – Not to exceed 1 ft/min. Do not compensate for slower ascent rates. Compensate for faster rates by halting the ascent.
  3. Time on oxygen begins on arrival at 60 feet.
  4. If oxygen breathing must be interrupted because of CNS Oxygen Toxicity, allow 15 minutes after the reaction has entirely subsided and resume schedule at point of interruption
  5. Treatment Table may be extended two oxygen-breathing periods at the 30-foot stop. No air break required between oxygen-breathing periods or prior to ascent.
  6. Tender breathes 100% O2 during ascent from the 30-foot stop to the surface. If the tender had a previous hyperbaric exposure in the previous 12 hours, an additional 20 minutes of oxygen breathing is required prior to ascent.

Note: In a hyperbaric monoplace chamber operating on psi measurements, decompress at a rate of: 1 psi/2 min

  • 30 fsw = 13.3 psi (1.9 ATA)
  • 60 fsw = 26.7 psi (2.8 ATA)

Table VI

Adapted from the U.S. Navy Diving Manual [5]

  1. Descent Rate – 20 ft/min.
  2. Ascent Rate – Not to exceed 1 ft/min. Do not compensate for slower ascent rates. Compensate for faster rates by halting the ascent.
  3. Time on oxygen begins on arrival at 60 feet.
  4. If oxygen breathing must be interrupted because of CNS Oxygen Toxicity, allow 15 minutes after the reaction has entirely subsided and resume schedule at point of interruption
  5.  Table 6 can be lengthened up to 2 additional 25-minute periods at 60 feet (20 minutes on oxygen and 5 minutes on air), or up to 2 additional 75-minute periods at 30 feet (15 minutes on air and 60 minutes on oxygen), or both.
  6. Tender breathes 100% O2 during the last 30 minutes at 30 fsw and during ascent to the surface for an unmodified table or where there has been only a single extension at 30 or 60 feet. If there has been more than one extension, the O2 breathing at 30 feet is increased to 60 minutes. If the tender had a hyperbaric exposure within the past 12 hours, an additional 60-minute O2 period is taken at 30 feet.

Note:  In a hyperbaric monoplace chamber operating on psi measurements, decompress at a rate of: 1 psi/2 min

  • 30 fsw = 13.3 psi (1.9 ATA)
  • 60 fsw = 26.7 psi (2.8 ATA)

By Threshold Level

For a separate view of the table below, along with the treatment tables, see  HBO Threshold Levels


Threshold Levels


Lower Limit

Upper Limit / Utilization Review

Elective - Chronic


Chronic Refractory Osteomyelitis



Diabetic Ulcer Lower Extremity



Intracranial Abscess



Late Radiation Tissue Injury Prophylaxis



Mandibular Osteoradionecrosis



Preparation of Wounds for Grafting



Problem Wound Support



Soft Tissue Radionecrosis



Emergent – Acute


Acute Carbon Monoxide Poisoning



Acute Exceptional Blood Loss Anemia

Until satisfactory hematocrit or pt. stable, asymptomatic, 

or transfusion becomes possible

Acute Peripheral Ischemia/Crush Injury



Acute Retinal Artery Insufficiency



Acute Thermal Burns



Cerebral Arterial Gas Embolism



Clostridial Myonecrosis (Gas Gangrene)



Compromised Skin Grafts and Flaps



Decompression Sickness



Necrotizing Soft Tissue Infections



Reattachment Limb/Digits



Selected Invasive Fungal Infections



Idiopathic Sudden Sensorineural Hearing loss 1 20

      *   If the patient receives less than the indicated lower treatment threshold, a case audit is to be undertaken. For these disorders, too few treatments may be unlikely to have sufficient therapeutic effect and potentially waste resources. Reasons for early termination of HBO therapy may include: death; misdiagnosis; non-compliance; deterioration, or failure to perceive improvement.

  **   For patients treated more than three days after clinical plateau.

  ‡   Recommendations of the Undersea and Hyperbaric Medical Society, Hyperbaric Oxygen therapy Indications 13th Edition, 2014.


  • 99183 Physician or other qualified health care professional attendance and supervision of hyperbaric oxygen therapy, per session (PROFESSIONAL CHARGE)
  • G0277 Hyperbaric oxygen under pressure, full body chamber, per 30 minute intervaL (FACILITY CHARGE)


By Algorithm

Hyperbaric wound healing referrals undergo a comprehensive work-up, including a detailed medical history, physical examination, and selected diagnostic testing. Baseline transcutaneous oxygen screening is followed up in an algorithmic manner in those patients whose risk-benefit ratio is in favor of a trial of hyperbaric oxygen therapy. Algorithm 2 addresses four essential questions:

  1. Is wound healing complicated by hypoxia?
  2. When present, is hypoxia reversible?
  3. Is the patient responding to hyperbaric oxygen therapy?
  4. Has the patient reached a therapeutic endpoint?

1).  Is wound healing complicated by hypoxia?

  1. Normal lower extremity transcutaneous oxygen values exceed 50 mmHg*  [6] [7] 
  2. Values ranging from 35-40 mmHg, and higher, are considered sufficient to support oxygen-dependent wound healing. [8] [9] [10] 
  1. Values below this range represent a risk of healing compromise, the degree of which increases as value decreases.  [11] [12]

* when recorded at sea level pressure (760 mmHg)

2)  When present, is hypoxia reversible?

For hyperbaric oxygen, a systemic method of dose delivery, to be effective, a certain degree of regional perfusion must be present.

  1. Breathing 100% oxygen at normobaric pressure, following the recording of a steady-state ambient air breathing value, evaluates regional arterial inflow capacity.
  2. Oxygen challenge values in excess of 300 mmHg represent essentially uncompromised regional perfusion.
  3. Screening values in excess of approximately 100 mmHg are suggestive of sufficient regional perfusion for limb viability, and reflect a suitable candidate for in-chamber follow-up transcutaneous oxygen testing.
  4. Screening values that fail to reach 100 mmHg are consistent with a significant inflow abnormality, and warrant further arterial work-up. The decision to incorporate hyperbaric oxygen therapy into the treatment plan would be made on a case by case basis, in these circumstances and following decisions regarding any flow augmentation options, and as identified in Algorithm 1.

3) Is patient responding to hyperbaric oxygen therapy?

The above patient selection process does not predict outcome. It identifies those patients who have the physiologic capacity to deliver high oxygen tensions to the wound bed. There has been an unsuccessful effort to incorporate transcutaneous oximetry as an outcome predictor.  [13] [14] [15] [16] [17] This should not be to surprising, given the complexity of such lesions, particularly in the diabetic patient. Improvement in ambient (21% O2) transcutaneous oximetry over time probably remains the best indicator of therapeutic response. [14]Absence of increasing tissue oximetry values alerts the clinician to a potential non-responder. This should prompt evaluation of other possible impediments to wound repair, thereby avoiding an otherwise lengthy, unsuccessful and expensive course of therapy.

Hyperoxic-induced angiogenic responses have been monitored transcutaneously in tissues rendered ischemic secondary to therapeutic radiation. [9]. A distinct “rapid rise phase” in transcutaneous oximetry occurs following 8-10 treatments. This rise tends to plateau at 20-22 treatments. We have selected 14 treatments, essentially midway through this period of rapid change in tissue oximetry, as a point of re-evaluation. If neovascularization is being produced it should be evident by improved baseline (21% O2) peri-wound values.

  1. If values are increasing, the patient is considered a responder, and hyperbaric treatments are continued to Step 4.
  2. If there has been no change, or if deterioration is evident, the patient undergoes further work-up for etiologies other than hypoxia. Hyperbaric oxygen therapy may be held at this point.

The goal of Step 3 is to reduce the likelihood of lengthy and ultimately unsuccessful courses of hyperbaric oxygen therapy.

4).  Has the patient reached the endpoint?

In this era of evidence-based medicine and cost containment, greater scrutiny is being directed at the health care delivery system in general. It is important, therefore, that the decision to utilize hyperbaric oxygen therapy be mediated, in part, by its financial impact. In carefully selected patients, managed along algorithmic and evidence-based lines, hyperbaric oxygen therapy provides generally encouraging and clinically enduring outcomes, while reducing the patient’s total health care cost. When used in a largely indiscriminate manner, it can be expensive and of questionable clinical value.

In terms of the wound referral, transcutaneous oxygen monitoring holds great promise as an algorithmic management and cost containment tool. Well oxygenated chronic wounds are directed to management strategies other than hyperbaric oxygenation. Hypoxic wounds that are the consequence of high-grade regional ischemia are likewise referred from the hyperbaricist for flow augmentation. In those patients entered into a hyperbaric treatment protocol, non- responders are identified early, rather than following many weeks, or even months, of treatment.  The final step is to identify when a course of hyperbaric oxygen therapy has produced sufficient angiogenesis to support further and spontaneous healing. It is not necessary, nor is it cost effective, to treat such wounds to complete resolution. Once the environment around the wound has been “normalized”, and the patient converted to a locally host-competent state, hyperbaric oxygen can be stopped. Peri-wound transcutaneous oxygen values that reach or exceed 40 mmHg suggest adequate neovascularization has been formed. Typically, clinical evidence of healing responses will be apparent at this time. The wound may not be completely healed, however. At this point, hyperbaric oxygen therapy can be stopped. Standard wound care measures remain in force, and the patient is followed for continued healing responses. If the wound plateaus, or regresses, hyperbaric oxygen therapy is reinstituted. This is uncommon. In the setting for which this protocol is designed, the chronic and refractory skin ulceration, withholding hyperbaric therapy for one or two weeks is unlikely to represent a limb-threatening event. Should there be very significant improvement in wound quality, yet not all peri-wound values have reached the 40 mmHg threshold, a one week treatment hold, with the above evaluation schedule, would be appropriate.

Algorithm 1. Normobaric Transcutaneous Algorithm

National Baromedical Services [3]

Algorithm 2. In-Chamber & Follow-Up Transcutaneous Algorithm

National Baromedical Services [3]


93922-52- TCOM, 1-2 levels, unilateral no provocative maneuvers

93922 – TCOM, 1-2 levels, unilateral with provocative maneuvers or 3 or > levels unilateral

93923 – TCOM, bilateral, 3 or more levels, with provocative maneuvers


Evidence-based indications accepted by the UHMS, approved by Medicare

Elective – Chronic Indications

Emergent/Urgent – Acute Indications

Evidence-based indications accepted by the UHMS, NOT approved by Medicare

Elective – Chronic Indications

Emergent/Urgent – Acute Indications

Official reprint from WoundReference® woundreference.com ©2018 Wound Reference, Inc. All Rights Reserved
Use of WoundReference is subject to the Subscription and License Agreement. ​
NOTE: This is a controlled document. This document is not a substitute for proper training, experience, and exercising of professional judgment. While every effort has been made to ensure the accuracy of the contents, neither the authors nor the Wound Reference, Inc. give any guarantee as to the accuracy of the information contained in them nor accept any liability, with respect to loss, damage, injury or expense arising from any such errors or omissions in the contents of the work.


  1. CMS. National Coverage Determination (NCD) for Hyperbaric Oxygen Therapy (20.29) . Date of publication 2017;.
  2. Harry T. Whelan, Eric Kindwall et al. Hyperbaric Medicine Practice 4th Edition Best Publishing Company. Date of publication 2017;volume fourth():.
  3. National Baromedical Services. Introduction to Hyperbaric Medicine Primary Training Manual .;.
  4. Weaver LK, Hopkins RO, Chan KJ, Churchill S, Elliott CG, Clemmer TP, Orme JF Jr, Thomas FO, Morris AH et al. Hyperbaric oxygen for acute carbon monoxide poisoning. The New England journal of medicine. Date of publication 2002;volume 347(14):1057-67.
  5. U.S. Navy. Chapter 17. Diagnosis and Treatment of Decompression Sickness and Arterial Gas Embolism in U.S. Navy Diving Manual , 7th ed. . Date of publication 2017;.
  6. Dowd, G S; Linge, K; Bentley, G et al. Measurement of transcutaneous oxygen pressure in normal and ischaemic skin. The Journal of Bone and Joint Surgery. Britis.... Date of publication 1983;volume 65(1):79-83.
  7. Dowd GS, Linge K, Bentley G et al. The effect of age and sex of normal volunteers upon the transcutaneous oxygen tension in the lower limb. Clinical physics and physiological measurement : an official journal of the Hospital Physicists.... Date of publication 1983;volume 4(1):65-8.
  8. Hunt TK, Winkle WV et al. Wound Healing Normal Repair. In: Dunphy JE, editor. Fundamentals of Wound Management in Surgery: Wound Healing, Normal Repair. South Plainfield, NJ: Cirurgecom; p. 1–68. . Date of publication 2017;.
  9. Pai, M P; Hunt, T K et al. Effect of varying oxygen tensions on healing of open wounds. Surgery, gynecology & obstetrics. Date of publication 1972;volume 135(5):756-758.
  10. Davis JC, Hunt TK. et al. Problem wounds in oral and maxillofacial surgery: The role of hyperbaric oxygen: In: Davis JC, Hunt TK, editors. Problem wounds: the role of oxygen. illustrated. Elsevier; . Date of publication 2017;.
  11. Padberg, F T; Back, T L; Thompson, P N; Hobson, R W et al. Transcutaneous oxygen (TcPO2) estimates probability of healing in the ischemic extremity. The Journal of Surgical Research. Date of publication 2017;volume 60(2):365-369.
  12. Reiber, G E; Pecoraro, R E; Koepsell, T D et al. Risk factors for amputation in patients with diabetes mellitus. A case-control study. Annals of Internal Medicine. Date of publication 2017;volume 117(2):97-105.
  13. Wattel F, Mathieu D, Cogel JM. et al. Prediction of final outcome with transcutaneous oxygen measurements of problem wounds treated with hyperbaric oxygen. In: 2nd European Conference on Hyperbaric Medicine, editor. 2nd European Conference on Hyperbaric Medicine. Basel: European committee for Hyperbaric Medicine;. . Date of publication 2017;.
  14. Fife, Caroline E; Buyukcakir, Cem; Otto, Gordon H; Sheffield, Paul J; Warriner, Robert A; Love, Tommy L; Mader, Jon et al. The predictive value of transcutaneous oxygen tension measurement in diabetic lower extremity ulcers treated with hyperbaric oxygen therapy: a retrospective analysis of 1,144 patients. Wound Repair and Regeneration. Date of publication 2002;volume 10(4):198-207.
  15. Dooley, J; Schirmer, J; Slade, B; Folden, B et al. Use of transcutaneous pressure of oxygen in the evaluation of edematous wounds. Undersea & hyperbaric medicine : journal of t.... Date of publication 1996;volume 23(3):167-174.
  16. Strauss, Michael B; Bryant, Brandon J; Hart, George B et al. Transcutaneous oxygen measurements under hyperbaric oxygen conditions as a predictor for healing of problem wounds. Foot & Ankle International. Date of publication 2002;volume 23(10):933-937.
  17. Sheffield PJ, Dunn JM. et al. Continuous monitoring of tissue oxygen tension during hyperbaric oxygen therapy. In: 6th International Congress on Hyperbaric Medicine, editor. 6th International Congress on Hyperbaric Medicine. Scottland: European Committee on Hyperbaric Medicine;. p. 125–9. . Date of publication 2017;.