Hyperbaric Oxygen Theraphy: Recommended, Optional, Controversal and Non Indications

Posted on January 20, 2024  •  18 minutes  • 3689 words

Hyperbaric oxygen (HBO) therapy is a traditional and established treatment for patients suffering from tissue hypoxia. This method enhances oxygen levels in tissues, thereby boosting wound healing and tissue regeneration capabilities. It also reactivates cellular functions to improve survival rates and adjusts the anti-inflammatory and immunological responses of immune cells, aiding in the recovery from severe infections. HBO therapy is versatile in its applications, encompassing a variety of conditions such as carbon monoxide poisoning, hard-to-treat infectious diseases like necrotizing soft tissue infections, gas gangrene, osteomyelitis, traumatic ischemia, crush injuries, diabetic foot ulcers, and more. It is particularly effective in treating diving-related issues like gas embolism and decompression sickness, where it is known as recompression therapy. However, it’s important to understand that HBO therapy is not a standalone miracle treatment but rather a supplementary approach, enhancing the effectiveness of other treatment methods or working in conjunction with them.

Recommended indications

Dysbaric illness

Dysbaric Illness (DI) encompasses a wide array of complex pathophysiological conditions linked to decompression, although the exact causes are largely unknown. It is generally accepted that DI primarily results from the formation and/or release of gas in the body due to decompression. This gas can either be due to inert gas becoming supersaturated or can be a consequence of gas forcefully entering the arterial system as a result of pulmonary barotrauma. DI manifests in various ways, leading to the guideline that any symptoms or signs observed in people who have recently undergone a decrease in environmental pressure should be treated as potential indicators of DI until proven otherwise. There should be a strong level of suspicion in such cases. Modern evidence-based medicine has provided structured methods to evaluate treatments, which have been applied to both recompression therapy and supplementary treatments for DI.

Gas embolism

Gas embolism (GE) encompasses all medical conditions caused by the presence of gas bubbles in the vascular system. In modern times, GE is primarily an issue caused by medical interventions and can lead to significant health complications, including death. It can arise from a variety of medical procedures conducted across numerous clinical specialties such as heart surgery, neurosurgery, laparoscopy, endoscopy, hemodialysis, and central venous catheterization. Once introduced into the vascular system, these gas bubbles travel along with the blood flow until they block smaller blood vessels. GE can be categorized into venous or arterial types, depending on how the gas enters the vascular system. The clinical symptoms of GE vary based on where and how extensively the blood vessels are blocked and the severity of the resultant inflammatory responses in the body. Diagnosis typically involves the rapid onset of neurological and/or cardiac symptoms in situations known to carry a risk of GE. Immediate treatment is crucial upon suspicion of GE, which includes identifying and removing the source of the embolism, providing necessary life support, and administering Hyperbaric Oxygen Therapy as soon as possible. It is important for all medical professionals to be aware of the dangers of GE and to take proper preventative steps in situations where there is a potential risk of its occurrence.

Carbon monooxide poisoning

Carbon monoxide (CO) poisoning continues to be a significant public health issue in Europe. Beyond its well-known impact on hemoglobin, recent research has highlighted CO’s interaction with other hemoproteins like myoglobin and cytochrome a-a3. Additionally, the phase of reoxygenation following hypoxic injury can cause harmful effects, similar to those seen in ischemia-reperfusion injury.

Clinically, CO poisoning presents with neurological symptoms, cardiac arrhythmias, and respiratory and circulatory failure. These symptoms generally subside when the patient is removed from the CO-rich environment and given oxygen. However, there can be long-term neurological effects, leading to substantial functional impairment and disabilities.

The primary treatment for CO poisoning is oxygen therapy. Hyperbaric oxygen therapy (HBO) has been shown to be more effective than normobaric oxygen in preventing cognitive after-effects. HBO is particularly recommended for patients who are comatose upon hospital admission, those who lost consciousness during CO exposure, individuals with persistent neurological symptoms, and pregnant women exposed to CO. To reduce the incidence and impact of CO poisoning, well-structured prevention programs are urgently needed in various countries.

Necrotizing soft tissue infections

Anaerobic soft tissue infections, although less common today, continue to pose a serious life-threatening risk. These infections are particularly severe due to their potential to cause major systemic effects, which can lead to patient mortality if not quickly identified and aggressively managed. The sources of these infections are frequently traumatic or surgical in nature, but they can also arise from ulcers or minor wounds, especially in high-risk individuals such as those with diabetes or peripheral vascular disease. Key contributing factors include hypoxia, traumatic muscle injury, heavy bacterial contamination, and errors in antibiotic prophylaxis. The treatment strategy encompasses antibiotics targeting both anaerobic and associated aerobic bacteria, early and extensive surgical debridement, and intensive Hyperbaric Oxygen Therapy (HBO). A significant challenge in managing these infections is the lack of sufficient awareness among physicians regarding their early signs, leading to inadequate initial treatment. To prevent these infections, stringent preventive measures are essential.

Intra-cranial abcess

In medical literature, intracranial abscesses, including cerebral abscesses, epidural, and subdural empyemas, are reported to have a mortality rate ranging from 10 to 36%. A significant number of survivors continue to experience persistent neurological deficits. Beginning with an anecdotal case, our group has treated 21 consecutive patients with intracranial abscesses (ICA) using adjuvant hyperbaric oxygen therapy (HBO). Our findings show a 0.0% mortality rate, with only one patient left with severe disabilities.

Based on these results, both the European Committee for Hyperbaric Medicine (ECHM) and the Undersea and Hyperbaric Medical Society (UHMS) have endorsed the use of HBO for ICAs under certain conditions. These include cases with multiple abscesses, an abscess in a deep or critical location, patients with compromised immune systems, situations where surgery is contraindicated or the patient presents a high surgical risk, and cases where there is no improvement or worsening condition despite standard surgical (like 1-2 needle aspirations) and antibiotic treatments.

Crush injury and other active traumatic ischemia

Crush injuries and other forms of acute traumatic ischemia create a detrimental cycle involving ischemia, hypoxia, edema, disrupted microcirculation, and secondary ischemia in the tissue surrounding the initial injury site. In hypoxic environments, the body’s ability to control infections and heal is compromised, leading to an increased risk of infection and challenges in wound healing compared to other types of injuries. The restoration of blood flow can further complicate matters by causing reperfusion injury. Hyperbaric oxygen therapy (HBOT) helps mitigate the effects of acute traumatic ischemia through four key mechanisms: increasing oxygen levels, causing vasoconstriction, impacting reperfusion, and affecting host factors. Proper shock management, immediate surgical intervention for debridement, repair of damaged soft tissues and vessels, and stabilization of bones are critical. Early administration of adjuvant HBOT is vital; when applied promptly, it can prevent extensive ischemic necrosis, reduce the frequency and severity of amputations, decrease edema, fight infection, aid healing, and protect against reperfusion injury. However, it is crucial to start HBOT early and apply it rigorously, without compromising established surgical treatments and intensive care therapies.

Compromised skin graft and flap

Hyperbaric oxygen has been successfully employed as a supplementary treatment in the wound healing process for both acute and chronic surgical cases. This process often involves the use of skin grafts or flaps to cover or reconstruct complex wounds. These transferred tissues may face various challenges that require effective treatment. One such challenge is hypoxia, resulting from insufficient oxygenation of the grafted tissue, where hyperbaric oxygen serves as an adjunct therapy. Both experimental and clinical studies on hyperbaric oxygen have shown favorable outcomes in supporting the attachment of compromised grafted tissues. The beneficial effects of hyperbaric hyperoxia include increased capillary growth, protection against reperfusion injury, reduction of edema, improvement in capillary rheology, and enhanced protection against infection. Determining the cause of tissue compromise and the appropriate timing for hyperbaric oxygen therapy is crucial. This requires close cooperation between the plastic surgeon and the hyperbaric physician to achieve the best possible results.

Radio-induced lesion in normal tissues

Late complications significantly restrict the effectiveness of radiotherapy, and there isn’t a standardized approach for their treatment. Hyperbaric oxygen (HBO) therapy has been employed for over fifty years to address these late complications. This use of HBO led the European Society for Therapeutic Radiotherapy and Oncology, along with the European Committee for Hyperbaric Medicine, to convene a consensus conference in October 2001. The conference focused on the role of HBO in treating and preventing late complications associated with radiotherapy. The conclusions drawn were based on an updated literature review. Despite the limited number of controlled trials, HBO has shown potential as a treatment option, especially when combined with surgery for mandibular osteoradionecrosis, in managing hemorrhagic cystitis resistant to conventional treatments, and in preventing osteoradionecrosis following dental extractions. The evidence for these applications is noteworthy, though further randomized trials are still needed to fully establish HBO’s efficacy in these areas.

Non-healing wounds

There is substantial pathophysiological evidence that highlights the positive impact of Hyperbaric Oxygen (HBO) therapy in reversing delayed wound healing processes. Clinical experiences also affirm its effectiveness in treating patients with non-healing wounds. The use of Transcutaneous Oxygen Pressure (TcPO2) measurements has proven to be a useful tool for selecting patients, monitoring treatment progress, and conducting follow-ups.

The European Committee for Hyperbaric Medicine (ECHM) reaffirmed its endorsement of HBO as an adjunctive treatment in the management of selected cases of delayed healing. This includes diabetic foot lesions, arterial ulcers, compromised skin grafts, and musculocutaneous flaps, as highlighted in their 7th European Consensus. Despite these recommendations, there remains a need for more comprehensive randomized controlled studies to further strengthen the evidence base supporting these guidelines.

Persistent osteomyelitis

Chronic persistent osteitis or osteomyelitis is an acute bone infection that continues for more than six weeks, even with appropriate treatment. This type of infection can potentially last a lifetime. It has been observed that infected tissues with reduced blood flow can benefit from hyperbaric oxygen (HBO) therapy. Treating osteomyelitis often requires multiple surgical procedures and long-term antibiotic treatment. In some cases, saving the affected limb may not be feasible. The use of HBO in the treatment of various orthopedic conditions is well-established. Particularly in the case of chronic osteitis or osteomyelitis, HBO therapy serves as an effective adjunct within a comprehensive, multidisciplinary treatment approach.

Sudden deafness

Idiopathic Sudden Sensorineural Hearing Loss (ISSHL), also known as “sudden deafness” (SD), is characterized by a sudden or rapidly progressing loss of hearing where the cause of the sensorineural hearing impairment remains unidentified. The hearing loss originates purely from damage to the cochlea. There are four primary theories proposed to explain this condition: vascular issues, viral infections, rupture of the round window, and autoimmune disorders. While these theories are debated, the most plausible explanation seems to be impaired oxygen delivery to the organ of Corti. The functioning of the cochlea relies heavily on energy, which is driven by oxygen metabolism. It is well documented that the oxygen tension in the perilymph significantly drops in patients with SD.

In light of these pathophysiological findings, various therapeutic agents like steroids, vasodilators, and hemodilution, which are thought to improve rheology and oxidative metabolism, have been suggested. Similarly, due to its overall and specific effects, hyperbaric oxygen therapy (HBO) can enhance perilymphatic oxygen pressure, restoring oxidative metabolism in the stria vascularis and protecting the neurosensory cells. These treatments and techniques have been tested individually or in combination for many years. Despite the outcomes of retrospective and prospective studies, it’s challenging to conclusively determine their therapeutic effectiveness, partly due to the high rate of spontaneous recovery in such cases. This chapter extensively discusses both conventional therapies and HBO, along with evidence from relevant literature.

Neuroblastoma

Hypoxia is widely acknowledged as a key factor in the failure of radiotherapy. In the field of clinical oncology, a range of treatment methods have been implemented to address tumor hypoxia. These methods aim to either boost oxygen delivery to tumor cells, using approaches like carbogen and hyperbaric oxygen, or to employ treatment in conjunction with agents that mimic oxygen to sensitize hypoxic cells, such as misonidazole. Among these strategies, the use of hyperbaric oxygen (HBO) to enhance radiation therapy appears particularly promising, especially in the treatment of patients with recurrent Neuroblastoma stage IV. This is particularly notable in the context of unsealed source radionuclide brachytherapy, indicating a significant potential for this approach in such clinical scenarios.

Optional indications

Burns

The integration of hyperbaric oxygen therapy (HBO) in the treatment of thermal burns is not widely agreed upon in the medical community. While there is a considerable amount of experimental evidence from animal studies suggesting positive impacts of HBO on various aspects of severe burn pathophysiology, there is a notable lack of clinical studies in humans to confirm these findings. This gap is largely attributed to the practical and logistical challenges involved in organizing such studies. Given the existing knowledge, it is advised that HBO should be employed strictly according to well-defined protocols. This approach aims to maximize the potential benefits of the therapy while minimizing any additional risks involved.

Anoxic encephalopathy

Even though there hasn’t been a double-blind randomized study conducted, Hyperbaric Oxygen (HBO) therapy has been recommended and utilized as a supplementary treatment for anoxic encephalopathy for over three decades. Recent studies at both the cellular and animal levels have provided support for this approach.

Our team has conducted extensive research on post-hanging anoxic encephalopathy. We have observed that while the neurological outcomes are largely dependent on the initial severity of the anoxic damage, in a study of 305 patients, 67% fully recovered, 25% passed away, and 8% experienced lasting effects. These findings are encouraging and highlight the need for further research in this area.

Pleuropulmonary anaerobic infections

Anaerobic bacteria frequently act as pathogens in the lungs, especially in cases of aspiration pneumonia and its associated suppurative complications, such as lung abscesses and empyema. While the majority of patients typically respond positively to antibiotic treatments coupled with proper drainage, about 5-10% may continue to suffer from persistent infections. Drawing from our experience with 13 patients, we suggest considering hyperbaric oxygen (HBO) therapy as an additional treatment option in carefully chosen cases.

Post vascular procedure reperfusion and syndrome and limb replantation

There is a wealth of level 1 in vitro and experimental data suggesting that Hyperbaric Oxygen (HBO) can mitigate the harmful effects of reperfusion injury following the restoration of circulation. Regrettably, there has been no human clinical trial conducted to investigate this issue in a methodologically rigorous, evidence-based manner. The author believes that the strong foundation of experimental evidence warrants a randomized clinical study to more definitively ascertain the effectiveness of HBO in treating reperfusion injury.

Acute ischemic opthalmological disorders

In ophthalmology, hyperbaric oxygenation therapy (HBO) has shown promising results in treating conditions such as retinal artery occlusions, non-arteriitic optic neuropathy, and macular edema caused by retinal vein occlusion or uveitis. This discussion will cover the pathology of retinal vascular occlusions and explore how HBO can be effectively utilized in treating these eye conditions.

Pneumatosis cystoides intestinalis

Pneumatosis cystoides intestinalis is a condition marked by the presence of multiple gas-filled cysts within the walls of the gastrointestinal tract. The primary form of this condition is exceedingly rare. In the more common secondary form, the small intestine and right side of the colon are predominantly affected, with underlying causes ranging from gastrointestinal to pulmonary or immunological issues. The cysts have fragile walls and are prone to rupturing, often leading to pneumoperitoneum due to spontaneous breakage. Symptoms can be vague, and when pneumatosis occurs alongside other disorders, the symptoms may align more with the coexisting condition. About 3% of cases experience complications such as volvulus, intestinal obstruction, hemorrhage, and perforation. Pneumoperitoneum, when it occurs in these patients, is more commonly linked to small bowel pneumatosis than to large bowel involvement.

Pneumatosis cystoides intestinalis is one of the rare instances of sterile pneumoperitoneum and should be considered in patients with free abdominal air but no signs of peritonitis. Diagnosis is typically achieved through radiographic methods like plain abdominal or barium studies, with computed tomography further confirming the diagnosis. Ultrasound has also been used to visualize intestinal cysts. Most cases with radiological evidence of pneumoperitoneum are managed conservatively and do not necessitate surgical intervention. Surgery is reserved for acute complications such as perforation, peritonitis, bowel necrosis, or tension pneumoperitoneum.

Hyperbaric oxygen therapy has been reported to be beneficial in managing pneumatosis cystoides intestinalis. It’s important to note that this therapy should be continued until the cysts are resolved, not just until symptomatic improvement is noted. In contrast, normobaric oxygen treatment requires inhaling large amounts of 100% oxygen over extended periods, which can lead to pulmonary oxygen toxicity.

Controversal and non indications

Femoral head necrosis

Femoral head necrosis (FHN) occurs when the blood flow to the femoral head is disrupted, resulting in the death of cells in both the marrow and the bone. This condition hampers the normal functions of osteoblasts and osteoclasts, leading to a loss of structural integrity in the femoral head. Treating FHN remains a challenging issue in orthopedics, and a variety of methods are employed to manage it. Hyperbaric Oxygen (HBO) therapy is one such approach, providing oxygen to the marrow cells and aiding in bone remodeling. This is achieved by reducing edema and stimulating the growth of new blood vessels (angioneogenesis).

Cerebrovascular incidents (stroke)

Over the past four decades, a range of experimental and clinical studies have indicated that hyperbaric oxygenation (HBO) might be effective in treating strokes at various stages: acute, sub-acute, and chronic. In cases of acute stroke, factors such as timing, HBO dosage, and the absence of specific pathophysiological stratification might be obscuring HBO’s potential effectiveness in certain stroke patient groups. Anecdotally, HBO seems most beneficial for small, sub-cortical, non-hemorrhagic strokes where early perfusion recovery is observed or where the clinical symptoms fluctuate, indicating a possible functional penumbra.

While using HBO for acute and sub-acute strokes appears feasible and safe, the current scientific evidence does not support recommending it as a standard treatment. In the context of chronic stroke, the high cost of HBO is a significant consideration, especially given the prevalence of the condition. However, the potential for increased independence and productivity in patients who respond well to HBO might offset the cost, making it a viable treatment option. Despite this possibility, recommending HBO for chronic stroke is premature at this stage, except as a promising area for further investigation.

Post-sternotomy mediastinitis

Post-sternotomy mediastinitis remains a significant complication following open heart surgery. This hospital-acquired infection is associated with a notable mortality rate of 15% to 25%, prolongs hospital stays, and consequently increases healthcare costs. Due to its proven effectiveness in treating severe infectious diseases, hyperbaric oxygen (HBO) therapy has been suggested as an adjunct treatment for several years. A review of existing literature indicates that patients treated with HBO generally experience better clinical outcomes and less morbidity compared to those receiving conventional treatments. Additionally, HBO may play a preventative role in stopping the escalation of a localized infection into full-blown mediastinitis. Despite the lack of a unified consensus on its usage, HBO should still be considered an important option in the treatment of infected sternotomies.

Sickle cell disease

Sickle cell anemia, a genetic disorder inherited in an autosomal recessive pattern, arises due to high levels of hemoglobin S. This abnormal hemoglobin leads to a distortion in red blood cells and significantly reduces their flexibility, causing vaso-occlusive events. Hyperbaric oxygen (HBO) therapy has been suggested as a treatment option for its potential benefits in ischemic tissues, improving red blood cell deformability, and reducing cell adhesion and activation. Possible applications of HBO may include treating vaso-occlusive crises, eye complications, and chronic leg ulcers associated with sickle cell anemia. However, the lack of comprehensive clinical studies on this matter means that a definitive endorsement for HBO in these cases cannot yet be made.

Brain injury and spinal cord injury

Several evidence-based reviews have been conducted on the use of Hyperbaric Oxygen (HBO) therapy for spinal cord injuries (SCI) and head injuries (HI). These reviews consistently conclude that while there is strong experimental evidence supporting HBO’s potential effectiveness in treating SCI and HI, clinical data, particularly from randomized controlled trials (RCTs), is limited and inconsistent. The existing RCTs vary in their treatment protocols and have reported conflicting outcomes. The need for high-quality RCTs is emphasized, focusing on standardizing HBO dosage (including session duration, pressure levels, and total number of sessions), and meticulously documenting any adverse effects. This is crucial to demonstrate that HBO treatment, including patient transportation to the chamber, does not exacerbate the condition of the patients with SCI or HI.

Myocardial infarction

Even when treated promptly, acute myocardial infarction often leads to the well-known issue of reperfusion injury. There is a body of experimental and animal research providing level 1 evidence that hyperbaric oxygen (HBO) therapy can diminish the severity of myocardial necrosis. Studies exploring two distinct reperfusion approaches—one employing thrombolysis and the other using percutaneous coronary intervention alongside a single HBO session—have both demonstrated beneficial effects.

Malignant otitis externa

Malignant otitis externa continues to be a potentially life-threatening condition even in modern times. For over two decades, hyperbaric oxygen (HBO) has been utilized as a supplementary treatment. However, the literature on this topic is limited to case reports. Given the infrequency of this disease, a multi-center randomized study would be necessary to definitively determine the efficacy of HBO in the treatment of malignant otitis externa.

Other controversal or non indications

The application of Hyperbaric Oxygen (HBO) therapy has been explored in various disorders, including cerebral palsy and multiple sclerosis. Some uncontrolled studies with lower levels of evidence have hinted at potential positive effects of HBO in these conditions. However, well-conducted randomized controlled trials (RCTs) have either failed to demonstrate any significant impact on the progression of these diseases or have not been conducted at all. Based on these findings, it should be acknowledged that HBO may not have a beneficial effect and could potentially be harmful in treating conditions like cerebral palsy and multiple sclerosis.

References

1. Handbook of Hyerbaric Medicine

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