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Clostridial Myonecrosis (Gas Gangrene)

Clostridial Myonecrosis (Gas Gangrene)

Clostridial Myonecrosis (Gas Gangrene)


Treatment Protocol Guidelines

The following hyperbaric medicine treatment protocol is 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 oxygen therapy (HBOT). This discussion covers the Gas Gangrene (Clostridial Myonecrosis) diagnosis. Evidence-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 condition meets coverage indications per the National Coverage Determination (NCD) 20.29.[1] Continued HBOT  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. 


 Sample Physician Order   | $ ICD-10 Crosswalk   |  Treatment Table   Emergent / Urgent Indication 


Gas gangrene (also known as clostridial myositis, clostridial myonecrosis, or spreading clostridial cellulitis with systemic toxicity) is an acute, rapidly progressive, non-pyogenic, invasive clostridial infection of the muscles, characterized by profound toxemia, extensive edema, massive death of tissue, and a variable degree of gas production. Alpha and theta toxins, produced by Clostridium species, are directly involved in the pathogenesis of clostridial myonecrosis. Most commonly, gas gangrene is caused by C. perfringensOther pathogens include C. septicum, C. novyi, C. histolyticum, C. bifermentans, C. tertium, and C. fallax. Hyperbaric oxygen should not be used alone but is adjunctive to aggressive surgical and medical management. Early HBOT may reduce complexity of surgical procedures and prevent (or limit) major amputations. Regardless of HBOT involvement, mortality can be quite high in this patient population. 

Goals of HBOT

  • Increase tissue oxygen levels to more than 250 mmHg, thus reaching levels to stop the alpha-toxin activity  
  • Decrease production of toxins through the bacteriocidal/bacteriostatic effects on Clostridium species    
  • Augment antibiotic therapy, accelerate demarcation between potentially viable and non-viable tissue within 24 - 30 hours, thus reducing the total amount of tissue lost           


Definitive diagnosis requires demonstration of Clostridial species (gram-positive, spore-forming, not motile, rod-shaped organisms). Clinical signs include systemic toxicity (fever, malaise), local pain (especially in the absence of trauma), and tissue crepitus (presence of gas in soft tissues on physical exam or confirmed with imaging.

HBOT Criteria
  • Clinical signs of gas gangrene as described above
  • Positive Gram-stained smear of the wound fluid (without leukocytes)
  • Microscopic evaluation showing necrotizing and degenerating muscle tissue 


  • STAT Surgical consultation unless patient referred to HBOT for consultation
  • Typically, these patients are inpatient receiving critical care, therefore monitoring blood pressure, electrocardiogram (ECG), Ventilatory support, Intravenous fluids (vasopressors) and urinary output (Foley catheter) may be necessary
  • Past medical history (look for history of recent traumatic wound or surgery)
  • Physical examination (direct examination of involved tissues with findings described above)
  • Labs to order (Pending lab results should not delay the start of HBOT)
    • Complete Blood Count (CBC)
    • Arterial Blood Gas (ABG)
    • Blood chemistry profile (BCP)
    • C-reactive protein (CRP)
    • Urinalysis/Urine Myoglobin and Hemoglobin
    • Disseminated Intravascular Coagulation (DIC) profile
    • Punch Biopsy (or direct surgical pathology tissue)
    • Culture and Sensitivity (C&S); gram stain.
    • Tissue culture from OR, if possible.
  • Imaging:
    • X-Ray (may or may not see fascial bubbles)
    • Ultrasound, computerized tomography (CT), magnetic resonance imaging (MRI)
  • ECG
  • Daily wound evaluation and weekly photography 
  • Transcutaneous oxygen (TCOM) assessment to determine tissue oxygenation (if possible)
  • Evaluation of tympanic membranes pre-HBO and as needed. Consider emergent myringotomies


  • 3.0 ATA for 90 minutes of oxygen breathing (Table 4a) with 2 ten-minute air breaks at the 30 and 60-minute mark
  • 3 treatments are given within the first 24 hours. Avoid delays greater than 6 hours between each treatment, if at all possible.
  • Continue treatment twice daily post 24 hours up to 72 hours. Once the advancing necrosis has stopped, treatment pressures may be reduced to 2.4 ATA.
  • The wound will be serially monitored with the surgeon and infectious disease consultant    
  • Once the infection has stabilized and no further surgical debridements are necessary, the patient will be treated daily at 2.0 ATA for 90 minutes of oxygen breathing for 7-10 days.
  • If the patient shows evidence of deterioration, the more aggressive twice daily treatments can be extended or renewed.
  • These patients are typically inpatient receiving critical care, therefore, ventilatory support, blood pressure (arterial line), central pressures (Swan Ganz), ECG, and urinary output may be monitored as directed
  • Continue daily wound assessment with photography
  • The decision to discontinue HBOT will be based upon the patient's response to HBO therapy, findings at repeat wound debridement and assessment, and the absence of hemolysis and myonecrosis. This decision will be made in conjunction with the patients surgical specialists. 


  • Wound assessment and photography 
  • If reconstructive skin grafting or flapping is performed, consider additional HBOT for compromised recipient bed.

Treatment Threshold

Concurrent review (After 10 total treatments); Third party review after15 treatments


Refer to the ICD-10 Guideline for the appropriate ICD-10 code


  • Although a three-pronged approach consisting of HBOT, surgery, and antibiotics is essential in treating gas gangrene, initial surgery can be restricted to opening of the wound. An initial fasciotomy may be undertaken but lengthy and extensive procedures in these very ill patients can usually be postponed, depending on how rapidly HBOT can be started. Debridement of necrotic tissue can be performed in between HBO treatments and should be delayed until clear demarcation between dead and viable tissue can be seen. It is not uncommon for these patients to have daily surgical debridement. Due to the nature of the bacterial disease, these surgeries would be performed as 'last cases' in operating rooms, so that the OR suite can be adequately disinfected/cleaned.
  • If diabetes mellitus, blood glucose should be checked within an hour prior to treatment and again immediately post-HBOT. 
  • Avoid petroleum-based dressings and ointments whenever possible. If these are a necessary part of the surgical dressing, ensure that they are not exposed and are completely covered with 100% cotton.
Primary Sources: Whelan and Kindwall [2]Weaver [3], National Baromedical Services [4]



Sample history of present illness (HPI) for Clostridial Gas Gangrene is provided below: 

"Sally S. is a 13-year-old female who was playing a "scratching game" with friends. Apparently, the youths take a safety pin or other sharp object and scratch initials on the forearm of another person. She was doing this yesterday afternoon. By midnight, she could not sleep and complained of excruciating pain on her left forearm with some swelling and skin changes. Her parents were concerned and brought her to the emergency room. 

The emergency room physician noted bronze colored bullae on the forearm with evidence of advancing infection. An x-ray of the arm was taken and demonstrated gas bubbles in the tissue planes of the distal left arm. A bullous ruptured and ER doctor noted "dishwater" fluid exuding from the skin. By the time the patient reached the emergency room, she could no longer make a fist or purposefully use her hand. A general surgeon and hand surgeon were called for consultation. By the time they arrived the advancing infection was just below the elbow. A presumptive diagnosis of Clostridial myonecrosis was made and emergency surgery for debridement and limb salvage planned.

In the operating room, the tissue destruction had evolved to the mid-biceps region. There was extensive tissue damage to the distal arm and considerable doubt about long-term viability. This is a limb and life-threatening infection. Tissue cultures have been sent. The clinical picture is one of Clostridial Gas Gangrene. A gram stain in the operating room showed scant organisms, but predominantly gram-positive rods. 

The patient remained intubated in the recovery room, and intensive care for sepsis and aggressive fluid management continues. We were consulted when the patient was taken to the operating room. We called in the critical care hyperbaric medicine team in order to treat this patient as soon as possible after surgery. We intend to treat this patient with adjunctive hyperbaric oxygen in order to stop the advancement of the toxins causing tissue destruction."

Physical Exam

Clinical signs include:

  • Systemic toxicity (fever, malaise)
  • Local pain (especially in the absence of trauma), and
  • Tissue crepitus (presence of gas in soft tissues on physical exam or confirmed with imaging) 

Gram stain of wound fluid shows:

  • Clostridial species (gram-positive, spore-forming, not motile, rod-shaped organisms) in wound fluid.


  • Clostridial Myonecrosis (Gas Gangrene) Refer to ICD-10 Crosswalk


A typical hyperbaric regimen for a patient diagnosed with gas gangrene consists of an aggressive treatment protocol of a 3.0 ATA pressure with 90 minutes of oxygen breathing administered 3 times in the first 24 hours followed by twice daily treatments. The wound will be serially monitored with the surgeon and infectious disease consultant. This schedule is usually continued for 48-72 hours. Once the infection has stabilized and no further surgical debridements are necessary, the patient will be treated daily at 2.0 or 2.4 ATA for 90-120 minutes of oxygen breathing for several additional days. If the patient shows evidence of deterioration, the more aggressive twice daily treatments can be extended or renewed.

Risk and Benefit of Hyperbaric Oxygen Therapy 

  • Please refer to topic "Documentation HBO: Risks and Benefits"

Indication for Hyperbaric Oxygen Therapy (HBOT)

The paragraphs below serve as documentation statements to support indication of HBOT as an adjunctive treatment of Gas Gangrene"

"Gas gangrene (also known as clostridial myositis, clostridial myonecrosis, or spreading clostridial cellulitis with systemic toxicity) is an acute, rapidly progressive, non-pyogenic, invasive clostridial infection of the muscles, characterized by profound toxemia, extensive edema, massive death of tissue, and a variable degree of gas production. The infection is caused by anaerobic, spore-forming, Gram-positive, encapsulated bacilli. The most common organism is Clostridium perfringens, however, there are more than 150 clostridial species which can cause the disease. While there are many toxins produced in this infection, the alpha-toxin (lecithinase and phospholipase-C) cause most of the tissue destruction. 

Hyperbaric oxygen therapy increases tissue oxygen levels to more than 250 mmHg, thus reaching levels to stop the alpha-toxin activity. Hyperbaric oxygen has been shown to be bacteriocidal/bacteriostatic to the Clostridium organisms. Hyperbaric oxygen should not be used alone, however, is adjunctive to aggressive surgical and medical management. Early hyperbaric oxygen treatment is 1) lifesaving because less heroic surgery needs to be performed, and 2) it is limb- and tissue-saving because no major amputations are performed prematurely. Hyperbaric oxygen treatments clarify the demarcation between viable and dead tissue, thus the total amount of tissue lost is greatly reduced."

Sample Order

  •  See Sample Physician Order

Documentation by Certified Hyperbaric Nurse and Certified Hyperbaric Technologist 

The certified hyperbaric technologist (CHT) and certified hyperbaric nurse (CHRN) should maintain an accurate record of the care and related support services delivered during each patient’s course of hyperbaric oxygen therapy. The patient's chart is a legal document and as such, must reflect in meaningful terms the patient's condition, progress, and care rendered. The provider and nurse's notes must be concise, accurate, and support medical necessity for the treatment ordered. The notes must reflect responsibility for the care rendered. For details, see topic "Documentation: Hyperbaric Treatment Notes by the CHRN and CHT"

Daily treatment should include, but is not limited to the following: 

  • Physician Order - confirm daily HBO treatment order.
  • Patient Assessment (by the CHRN or CHT) 
  • Pre-treatment Safety Check (by the CHRN or CHT)
  • Documentation of the Treatment Log (by the CHRN or CHT)
  • Physician Supervision (by the CHRN or CHT)
  • Care Provided (by the CHRN or CHT)
  • Plan of Care (by the CHRN or CHT, based on physician orders)


  • 2C For patients with gas gangrene, we suggest use of adjunct HBOT in addition to standard care (i.e., surgical debridement, ICU care and appropriate antibiotics) to help symptoms and signs of gas gangrene subside, instead of standard care alone.(Grade 2C)
    • Rationale: Evidence for the use of adjunctive HBOT has been published through case reports and small case series, in which hundreds of patients survived serious gas gangrene infection with adjunctive HBOT. As far as we are aware, there have been no randomized trials using adjunctive HBOT.[5][6] In fact, given the number of case and case series reports, a randomized trial may be unethical. As a result, the gas gangrene (Clostridial myonecrosis) indication was added to the list of "UHMS Approved" indications in the late 1970s. Related research showed that tissue oxygen levels must approach (or be higher than) 300 mmHg for gas gangrene to be treated. Researchers at Duke University also demonstrated in their 49 patient case series that 3 ATA hyperbaric oxygen treatment was required for the best outcome when treating gas gangrene.[7]
    • Coverage: Adjunct HBOT is covered by Medicare for treatment of gas gangrene. Concurrent review is recommended after 10 total treatments and third party review after 15 treatments.


Providing HBOT in a safe manner is the primary objective with each and every treatment. The clinical team (physician, CHT, CHRN, etc) providing HBOT strives to ensure patient safety with every treatment. A summary of operational considerations pertaining to adjunct HBOT for Clostridial Myonecrosis (Gas Gangrene) is provided below:

Chamber Inspections

  • Prior to treating patients with gas gangrene (or any other patient), it is important to ensure that routine chamber inspections are being conducted. The goal of each inspection is to confirm that chamber maintenance procedures are in place to provide safe operations of all equipment during HBO therapy.
    • To ensure the safety of the environment in the hyperbaric medicine facility, chamber inspections are to be performed routinely (i.e. daily, monthly, semi-annually, as needed). Processes and systems that meet standards set forth by The Joint Commission (TJC) and the Undersea and Hyperbaric Medical Society (UHMS) should be utilized, and elements that have been developed within the field (in some cases through “near misses”) may be incorporated. These processes and systems can be implemented through customized patient-centered checklists. Checklists have a wide range of applications, with the potential to improve patient education, pre-procedure planning, discharge instructions, care coordination, chronic care management, and plans for staying well. 
    • For resources on chamber inspections, see the topic "HBO Safety Inspections".

Ground testing 

  • According to the NFPA 99, all hyperbaric chambers should be grounded
  • Likewise, patients inside chambers filled with 100% oxygen should be grounded as well.
    • Wrist continuity tests prior to each treatment and daily chamber checks including chamber stud to wall measurements and patient ground jack to chamber stud measurements ensure ongoing continuity. 

Prohibited Item(s), Assessment and Authorization

  • Wound dressings, devices, and other objects that go in the hyperbaric chamber with a patient being treated for gas gangrene may raise important safety concerns, including the production of heat, production of static electricity, production of flammable vapor, ignition temperature, and total fuel load. 
  • Frequently, questions arise in regard to which items are prohibited, restricted or allowed inside a hyperbaric chamber during HBOT. The NFPA 99 2018 edition, chapter 14 "Hyperbaric Facilities", provides the process for effectively managing patient care product(s) during HBOT.  The NFPA 99 2018 edition - states “Physician and Safety Director approval to use prohibited items shall be stated in writing for all prohibited materials employed”. [8]
    • Each hyperbaric facility should maintain an internal list of items that are approved for use, should be used with caution and should not be used in the chamber. For items that should be used with caution, an authorization form signed by the Medical Director is required.
      • To facilitate risk assessment, clinicians might opt to utilize the Go-No-Go Risk Assessment Tool. The tool is an interactive process that enables hyperbaric technologists, Safety and Medical Directors to document the product information necessary to complete the risk assessment process. Upon completion of the process, the user will have the ability to print or email the document. Clinicians may also review sample lists of items that are approved for use, should be used with caution and should not be used in the chamber. See " Go-No-Go Lists / Prohibited Items" and "Go-No-Go : Frequently  Asked Questions". 

Ancillary Equipment

  • All equipment utilized by the hyperbaric medicine facility must be maintained through a program of regular preventative maintenance. The manufacturer maintains the hyperbaric chambers during the regularly scheduled service contract. Ancillary equipment (e.g. cardiac monitor leads, TCOM sensors) should be serviced by the Hospital's Biomedical Department and maintained in accordance with the recommendations of the manufacturer.  See the topics "Ear Exam - Barotrauma" and "Ancillary Equipment"    

Air Breaks

  • During HBOT for gas gangrene, it is necessary to provide an alternative air-breathing source. This may also be necessary to reduce the risk of central nervous system oxygen toxicity.  The air-breathing system consists of an independent high-pressure air source, capable of providing flow that is sufficient to meet the patient's inspiratory demand. Air-breathing systems may be provided by an institutional gas outlet (wall outlet) or via portable "H" cylinders utilizing a diameter index safety system (DISS) regulator.  Delivery of the air break to the patient may be provided by disposable non-rebreather mask, demand valve, and resuscitation mask or trach collar.  For purposes of infection control, masks should be single patient use and cleaned or replaced (per patient) as needed. 
  • While the use of air breaks to decrease the incidence of CNS oxygen toxicity has not been directly demonstrated, there is a large amount of published data on the cause of oxygen toxicity related directly to a combination of the treatment pressure, FiO2, and time. As such, these air breaks limit the interval time exposure and are expected to decrease the risk of oxygen toxicity. [9]

Infection Control - Cleaning/ Disinfection of the Hyperbaric Chamber 

  • Cleaning and disinfection of the hyperbaric chamber is particularly important prior to and after treating patients with gas gangrene. As stated above, gas gangrene is caused by direct inoculation of Clostridial bacterial species into the body (e.g., via a traumatic wound). Clostridial species are ubiquitous in dirt and soil in its spore form. Once inoculated, spores germinate under specific local wound conditions facilitated by disrupted or necrotic tissue. While gas gangrene does not naturally spread from person to person, the bacteria causing it can still be spread through poor infection control practices, such as bacteria being passed from patient to patient via contaminated surgical instruments or gloves.[10] 
  • Particular attention should be given to cleaning and disinfection of the hyperbaric chamber acrylic, stretcher, and associated equipment, including observing the specific kill times of the solution used prior to and after the delivery HBOT. See topic: "Cleaning and Disinfection of Hyperbaric Oxygen Monoplace Chamber" 
  • The cleaning and disinfection of acrylic monoplace chambers should be done with caution because many commercial biohazard-cleaning agents contain alcohol. While alcohol is adequate to kill many pathogens, it is destructive to acrylic and can produce flammable fumes and vapors creating a fire hazard in the chamber and the immediate area. Therefore, only manufacturer-approved cleaning products are used for the disinfection of the hyperbaric chamber and accompanying equipment. Particular cleaning and disinfecting tasks are divided among staff from environmental services, equipment or biomedical device services, respiratory services, nursing, and other departments of the health care team.


  • Assessment of the patient and their past medical history is necessary to identify and minimize the risk of barotraumas. If the patient has history of sinus, tooth, and ear problems, compress slowly and observe patient for signs of pain.
  • Middle-ear barotrauma: The most common type of barotrauma experienced by patients receiving HBOT is middle-ear barotrauma (MEB). Normally, the middle ear is a closed, vascular lined space and therefore subject to pressure change. The normal means by which the middle ear remains at an equal pressure with the surrounding tissue is through the opening of the Eustachian tube. During descent, the increasing pressure of the surrounding water leads to “middle-ear squeeze.” If a patient is suffering from Eustachian tube dysfunction, he or she likely will be unable to equalize and will subsequently develop middle-ear barotrauma.[2] 
  • Pneumothorax: A complete and accurate pulmonary assessment is essential to avoid or prevent gas expansion problems. Assessing the patient with a significant pulmonary history is a key starting point. Identify any history of asthma, chronic obstructive pulmonary dysfunction (COPD), fibrosis, spontaneous pneumothorax, or chest trauma.
    • The absolute contraindication for HBOT is the unvented pneumothorax. 
    • Signs and symptoms of pneumothorax include: Sudden shortness of breath, Sudden stabbing chest pain, Tracheal shift to affected side in cases of tension, Asymmetrical chest movement (lack or reduced chest excursion on affected side), Increase in respiratory distress with decompression, with relief on recompression.[2]

Blood Glucose Level and HBOT

  • Patients with gas gangrene can present with sepsis and septic patients may have associated hyperglycemia. As such, it is necessary to ensure that patients with gas gangrene have their blood glucose level carefully monitored. 
  • For non-septic patients, it is important to ensure that patients currently being treated for irregular blood glucose levels do not experience a hypoglycemic event as a result of ongoing HBOT. Most studies suggest that blood glucose decreases in patients with diabetes who undergo HBOT. This decrease in blood glucose is estimated at 50 mg/dl. HBOT might not be as effective in patients with non-insulin dependent diabetes mellitus patients, compared to patients without diabetes. [2]
    • If diabetes mellitus is present, blood glucose should be checked within 1 hour prior to treatment and immediately post-HBOT. The goal is to ensure that all patients who are currently being treated do not experience a hypoglycemic event as a result of ongoing HBOT.  Hypoglycemia in the hyperbaric environment may present similar symptoms as oxygen toxicity, including but not limited to sweating, pale skin, shakiness, anxiety, tingling, or numbness of the tongue or cheek. See section 'Blood Glucose Level and HBOT' in the topic "Patient Care".

Medications in the Hyperbaric Environment 

  • Patients with gas gangrene may require drugs whose physiological effects can be enhanced or decreased by HBOT. The hyperbaric environment creates numerous considerations for the use of drug therapies within it. Physiologic changes to the body due to HBOT may lead to pharmacokinetic changes in drug disposition. In addition, HBO acting as a drug can interact and enhance or lessen the physiologic effect of the drug. Most drugs will not interact unfavorably with oxygen. Unless specific contraindications or precautions have been addressed, it is generally safe to assume a medication can be used.[3]  Pharmacodynamic interactions result in modification of the pharmacologic effect of the drug after administration. These interactions will increase or decrease the effects of oxygen or the drug.[3] 
  • For potential interactions of drugs administered to patients with gas gangrene, see topic "Medications In The Hyperbaric Environment".

Oxygen Toxicity

  • The hyperbaric staff should be skilled in reducing the potential for and management of oxygen toxicity for the patient receiving HBOT. 
  • Central Nervous System (CNS) oxygen toxicity can occur in patients breathing oxygen at pressures of 2.0 ATA (atmosphere absolute) or greater. Convulsions may occur abruptly or may be preceded by other signs of central nervous system irritability.[3] Early estimates of the seizure rate during therapeutic oxygen exposures at 2-3 ATA reported a convulsion incidence of about one per 10,000 therapies or 0.01%. [2]
  • The hyperbaric physician will be notified immediately if a patient experiences signs or symptoms of oxygen toxicity during HBOT.

CNS toxicity

  • Observe patient closely for premonitory signs and symptoms of CNS Oxygen Toxicity such as:
    • V : vision-visual changes, blurred vision, visual hallucinations
    • E : Ears- Auditory hallucinations, ringing in the ears
    • N : Nausea- May include emesis
    • T : Twitching- Restlessness, numbness, focal twitching (note time, duration and site)
    • I : irritability- Change in personality
    • D : Dizziness- Vertigo
    • C : Convulsions- Seizure activity
    • C : Change in mentation - Change in affect
    • or of a non-descriptive complaint like, “I just don’t feel right” [2]

Pulmonary Oxygen Toxicity

  • Most current applications of HBOT do not cause pulmonary symptoms or clinically significant pulmonary functional deficits.[11]  Prolonged exposure to oxygen pressures greater than 0.5 ATA is associated with the development of intratracheal and bronchial irritation.  Pulmonary oxygen toxicity is not expected from routine daily HBOT. The possibility of development does exist with prolonged exposure most typically related to long treatment tables such as US Navy Treatment Table 6 used for decompression illness, but even these cases would be mild and self-limiting.[12]  
    Continued oxygen exposure may lead to impaired pulmonary function and eventually Acute respiratory distress syndrome (ARDS). Symptoms include:
    • Substernal burning
    • Chest tightness
    • Cough
    • Dyspnea
  • These changes are seen over the course of days to weeks at lower oxygen pressures and occur more rapidly as the oxygen pressure is increased.[2] 

Ocular Oxygen Toxicity

  • Vision changes as a side effect of HBOT have been observed in patients undergoing prolonged periods of daily HBOT. The rate of these changes has been reported in the literature to be ∼0.25 diopter per week and progressive throughout the course of ongoing treatment. Myopia has been reported in 25-100% of patients undergoing HBOT after several weeks at pressures of 2.0 ATA and greater.[12]  When providing HBO for the patient being treated for gas gangrene it is important to discuss the risks, hazards and potential side effects with the patient and family.  Documentation of this discussion and patient/ family's understanding should be clearly stated in the patient record. For further information See topic: "Hyperbaric Oxygen Therapy and Visual Acuity" 


Nursing interventions that are relevant for adjunct HBOT for gas gangrene are presented below.[13] For further information see the topic "Nursing Interventions".

Knowledge deficit related to hyperbaric oxygen therapy and treatment procedures

  • Patients with gas gangrene are typically inpatient receiving critical care. Nevertheless, clinicians should assess and document the patient and/or family's understanding of the purpose and goals of hyperbaric oxygen therapy (HBO), procedures involved, and potential hazards of HBO.
    • Utilize the teach-back method to confirm understanding and identify and address barriers to learning. Involve an interpreter if indicated, apply age-specific teaching, consider cultural/religious factors, assess readiness to learn, and identify expectations of treatment. 
  • See section 'Knowledge deficit related to hyperbaric oxygen therapy and treatment procedures' in topic "Nursing Intervention"

Potential for pain related to hyperbaric oxygen treatment and patient's associated medical problems

  • Patients with traumatic gas gangrene typically present with sudden onset of severe pain at the site of surgery or trauma.[14] 
  • Assess pain level and document according to facility guidelines and the patient's needs related to pain. In addition, assess the patient's experience of pain and whether pain is increased during HBO treatment.  Avoid intramuscular medications (IM) immediately prior to treatment due to vasoconstriction effect from HBO treatments
  • See section "'Potential for pain related to hyperbaric oxygen treatment and patient's associated medical problems' in topic Nursing Intervention"

Potential for adverse events related to hemodynamic changes secondary to hyperbaric oxygen treatment

  • Patients with sepsis, severe congestive heart failure (CHF) or a history of CHF exacerbations may be at risk of worsening hemodynamic changes in the hyperbaric environment due to vasoconstrictive effects of hyperbaric oxygen. The hyperbaric provider should evaluate individual risk, evaluate that risk against the potential benefit of HBO therapy, and reassess the patient throughout the treatment.
    • For patients with CHF, the baseline left ventricular ejection fraction (EJF) is not a predictor of CHF outcomes. The EJF percentage ought not to be used as a criterion for inclusion or exclusion from HBO.[2]
  • See section 'Potential for adverse events related to hemodynamic changes secondary to HBO treatment' in topic "Nursing Intervention"

Potential for unstable blood glucose level related to hyperbaric oxygen therapy and disease pathology

  • Literature notes hyperbaric oxygen therapy carries its own mechanism for increased glucose usage through oxygen-mediated transport of glucose into muscle cells and may also increase insulin sensitivity. Prevention of acute hypoglycemia in the hyperbaric chamber is vital for patient safety.  Follow facility policy and procedure guidelines for pre and post-treatment glucose control.  Prior to treatment assess the patient's knowledge level, recent hypoglycemic events, and patient-specific symptoms of hypoglycemia.  Proper glucose control < 200mg/dL is vital for wound healing.  Consider timing of short and long-acting glycemic control medications when scheduling HBO to avoid peak action time while at depth in the chamber 
  • See section 'Potential for unstable blood glucose level related to hyperbaric oxygen therapy and disease pathology' in topic "Nursing Intervention"

Imbalanced nutrition/ intake of nutrients insufficient to meet metabolic needs

  • Patient's nutrient intake must be sufficient to meet basal needs and improve healing. It is well documented that wound healing is impaired without sufficient metabolic energy and nutrients. The patients baseline nutritional status should be assessed initiating adjunctive HBO.  The need for nutritional supplementation should be coordinated with the primary care physician and/or referring service.  Provide nutritional education with consideration to the patient's needs and dietary preferences. For more information see the topic: "Nutritional Screening for Wound Care and Hyperbaric Oxygen Therapy".
  • See section 'Imbalanced nutrition/less than body requirements related to intake of nutrients insufficient to meet metabolic needs' in topic "Nursing Intervention"

Anxiety-related to hyperbaric oxygen treatments or other medical problems 

  • Patients with gas gangrene may be in septic shock or may have systemic signs of toxicity that mask signs/symptoms related to anxiety.
  • If the patient is conscious and oriented to place and time, assess the patient for a history of confinement anxiety and implement preventative measures as appropriate. It is important to reinforce to the patient that someone will always be with them, and the staff are well trained for emergency procedures. Identify signs of symptoms of anxiety before and during HBO treatment such as:
    • Patient states they are anxious
    • Tense appearing facial/body posturing
    • Complaint of nausea or diarrhea
    • Feelings of being confined or smothered
    • Defensive or argumentative attitude
    • Hyperventilation
    • Diaphoresis and hyperventilation
    • Tachycardia
    • Restlessness
    • Sudden feeling of being hot
  • See section 'Anxiety related to hyperbaric oxygen treatments or other medical problems' in topic "Nursing Interventions" 

Potential for injury related to central nervous system oxygen toxicity or seizure secondary to 100% oxygen at increased atmospheric pressure

  • Provide patient and family with education about oxygen toxicity risks, and the signs/symptoms of central nervous system oxygen toxicity.  Assess the patient prior to treatment for increased risk factors such as:
    • Elevated core temperature
    • History of seizures
    • History of brain injury/surgery
    • Acute carbon monoxide poisoning
    • Use of medications that may lower seizure threshold
    • Metabolic acidosis
    • Dehydration
    • Hypoglycemia

  • Monitor the patient during HBOT and document signs/symptoms of central nervous system oxygen toxicity.  Reinforce to the patient the importance of notifying the chamber operator if they feel different or funny in the chamber.  If any symptoms occur including a seizure, follow the facility emergency guidelines. 
  • See section 'Operational Considerations: Oxygen Toxicity' above and section 'Potential for injury related to central nervous system oxygen toxicity or seizure secondary to 100% oxygen at increased atmospheric pressure' in topic "Nursing Intervention"

Potential for ineffective individual coping related to stresses of illness and/or poor psychosocial support systems

  • Assist the patient and family to identify coping skills, available support systems, cultural and spiritual values. Provide emotional support, including active listening and acknowledgment of concerns and offer other support systems as needed and as available in the facility. 
  • See section 'Potential for ineffective individual coping related to stresses of illness and/or poor psychosocial support systems' in topic "Nursing Intervention"

Potential for injury within the hyperbaric facility related to transferring the patient in and out of the chamber

  • Prior to transfer of the patient assess fall risk and safety precautions. When transferring a patient that is being treated for gas gangrene, provide assistance with transfers as needed to ensure compliance with institutional/facility policy. 
  • See section 'Potential for injury within the hyperbaric facility related to transferring the patient in and out of the chamber' in topic "Nursing Intervention"

Potential for injury related to fire within the hyperbaric chamber

  • Fuel sources in an oxygen-enriched environment are an unavoidable circumstance of HBOT and include linens, equipment, dressings, and the patient. The fire triangle consists of oxygen, fuel, and an ignition source(heat).  In HBOT an ignition source is needed to complete the fire triangle. This may occur due to a spark in the chamber. Follow facility fire prevention steps and NFPA chapter 14 probes for Class A and Class B hyperbaric chambers. 
  • HBOT teaching and consent should include the risks of fire in the chamber.  Provide the patient and family with written instructions regarding the risk of prohibited materials during HBOT.  Prior to each hyperbaric treatment, staff should perform and document the pre-treatment safety checklist. Ensure this has been performed and time-stamped prior to descent.  
  • Patients receiving treatment for gas gangrene may have surgical dressings that are ordered to remain intact.  A risk assessment per the Safety Director in collaboration with the Medical Director to determine if they may enter the chamber on a case by case basis. Safety measures should be initiated if the risk assessment allows for items to enter the chamber as well as completion of a prohibited item's authorization form signed by the Safety and Medical Directors.
  • See section 'Potential for injury related to fire within the hyperbaric chamber' in topic "Nursing Intervention"

Potential for injury related to changes in atmospheric pressure within the hyperbaric chamber

  • Assess patient's and inside attendant's knowledge of ear clearing techniques and ability to equalize pressure. Collaborate with provider to assess tympanic membrane (TM) for suspected barotrauma prior to and after the first HBO treatment and per patient complaint.  Collaborate with the provider to describe and document observations including color and visibility of TM, presence of wax, blood/fluid/air and any hearing deficits or changes.   Methods to equalize pressure in the middle ear during HBO treatment include: yawning, swallowing, jaw thrust, head tilt, Valsalva, Toynbee, Roydhouse, Frenzel, etc.  Reinforce the importance of notifying the chamber operator immediately when pressure or fullness is felt in the middle ear.

Discomfort related to temperature and humidity changes inside the hyperbaric chamber

  • To ensure patients will tolerate the internal climate of the hyperbaric chamber, provide patient education related to temperature changes with compression and decompression.  It is necessary to periodically assess patient's comfort with temperature changes. As appropriate and according to institutional policy, offer patient comfort measures such as extra sheet, increasing ventilation in the chamber or use of environmental control system (multiplace chamber). The room temperatures should be monitored according to the NFPA guidelines.
  • See section 'Discomfort related to temperature and humidity changes inside the hyperbaric chamber' in topic "Nursing Interventions" 


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Systematic reviews and meta-analyses 

  • A 2015 Cochrane review [6] evaluated use of HBOT as an adjunctive intervention for gas gangrene. Authors identified only 1 RCT that compared 10 days of topical oxygen (TopOx) and standard care (debridement and antibiotic therapy) with 10 days of systemic HBOT and standard care. Authors found no evidence of difference between the two groups; RR of 1.10 (95% CI 0.25 to 4.84). According to the GRADE assessment, evidence was considered of very low quality due to risk of bias and imprecision. Of note, the RCT did not compare adjunctive use of systemic HBOT plus standard care with standard care only.


This topic has been reviewed and approved by the National Board of Diving and Hyperbaric Medical Technology (NBDHMT) for one (1) Category A Credit. 'Meeting the Category A requirement related directly to any combination of hyperbaric operations, related technical aspects and chamber safety.'

To claim the credit: 

  • 1. Read the topic
  • 2. Answer the examination and course critique questions. 
    • Take the quiz via SurveyMonkey 
  • 3. Receive the certificate by e-mail. A passing score of 70% is required (please allow up to 8 business days for processing)

For more information on Category A continuing education credits see blog post " Hyperbaric Certification and Continuing Education for Technicians & Nurses".


7/11/20Added Category A Continuing Education Credit by the NBDHMT
6/07/20Added section 'Operational Considerations' and 'Nursing Interventions'
6/11/19Added section on Clinical Evidence and Recommendations
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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.


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  4. National Baromedical Services. Introduction to Hyperbaric Medicine Primary Training Manual .;.
  5. Bakker DJ. Clostridial myonecrosis (gas gangrene). Undersea and Hyperbaric Medicine : Journal of the Undersea and Hyperbaric Medical Society. 2012;volume 39(3):731-7.
  6. Yang Z, Hu J, Qu Y, Sun F, Leng X, Li H, Zhan S et al. Interventions for treating gas gangrene. The Cochrane Database of Systematic Reviews. 2015;.
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  8. National Fire Protection Association. "Hyperbaric Facilities" Chapter 14, NFPA 99 Health Care Facilities, 2018 Edition. . 2018;.
  9. Lambertsen CJ, Dough RH, Cooper DY, Emmel GL, Loeschcke HH, Schmidt CF et al. Oxygen toxicity; effects in man of oxygen inhalation at 1 and 3.5 atmospheres upon blood gas transport, cerebral circulation and cerebral metabolism. Journal of Applied Physiology. 1953;volume 5(9):471-86.
  10. World Health Organization. Gas gangrene not contagious, cases reported in earthquake zone. . 2008;.
  11. E. Thorsen, L. Aanderud, T.B. Aasen et al. Effects of a standard hyperbaric oxygen treatment protocol on pulmonary function. European Respiratory Journal. 1998;.
  12. Heyboer, Marvin; Sharma, Deepali; Santiago, William; McCulloch, Norman et al. Hyperbaric oxygen therapy: side effects defined and quantified. Advances in Wound Care. 2017;volume 6(6):210-224.
  13. Baromedical Nurses Association. Baromedical Nurses Association Guidelines of Nursing Care for the Patient Receiving Hyperbaric Oxygen Therapy . 2022;.
  14. Weinstein L, Barza MA et al. Gas gangrene. The New England Journal of Medicine. 1973;volume 289(21):1129-31.
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