Hyperbaric oxygen therapy for severe ulcerative colitis

Role of hyperbaric oxygen therapy in patients with inflammatory bowel disease

PURPOSE OF REVIEW

Hypoxia is a known contributor to inflammation in inflammatory bowel diseases (IBD), and a growing interest has emerged in pharmacologically targeting hypoxia response pathways to treat IBD. The most basic form of treatment for hypoxia is delivering higher amounts of oxygen to the intestinal mucosa. In this review, we summarize the evidence in support of hyperbaric oxygen therapy (HBOT), a mechanism to deliver high amounts of oxygen to tissue, for treating IBD.

RECENT FINDINGS

Two phase 2 clinical trials in hospitalized ulcerative colitis patients suffering from moderate-to-severe flares have demonstrated that HBOT improves responsiveness to steroids and avoidance of rescue medical and surgical therapy. Outpatient cohort studies in perianal fistulizing Crohn's disease and fistulizing complications of the pouch have demonstrated improved healing, particularly for complex fistulae. Several systematic reviews have now been completed, and HBOT has been observed to be well tolerated with low rates of adverse events.

SUMMARY

HBOT may be considered as an adjunctive treatment for hospitalized ulcerative colitis flares and Crohn's disease-related fistulae. Higher quality trials are needed to confirm efficacy.

Addition of hyperbaric oxygen therapy versus usual care alone for inflammatory bowel disease: A systematic review and meta-analysis

Objective

Inflammatory bowel disease (IBD) is a chronic idiopathic inflammatory disease that includes ulcerative colitis (UC) and Crohn's disease (CD). Hyperbaric oxygen therapy (HBOT) involves breathing pure oxygen in a pressurized environment. Existing literature suggests that HBOT may be an effective therapy for IBD, but a quantitative analysis is lacking. This study aims to estimate the adjunctive role of HBOT in treating IBD and lowering its recurrence rate.

Design

Systematic review and meta-analysis.

Methods

The Cochrane Library, EMBASE, PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), China Science and Technology Journal Database (VIP), and Wanfang databases were systematically searched by two reviewers independently. Meta-analyses were performed using Review Manager (RevMan, version 5.3). A random-effects model was applied due to the heterogeneity between studies.

Results

Twenty-nine out of the initially identified 606 articles were covered in this review, with a total of 2151 patients (2071 for UC and 80 for CD). No randomized data of HBOT for CD were included. Among UC patients, usual care plus HBOT were more likely to achieve a clinical response than usual care alone (risk ratio [RR], 1.24; 95% confidence interval (CI), 1.17 to 1.31; P < 0.001). Subgroup analysis showed that the number of HBOT sessions had no statistically significant effect on overall efficacy (P > 0.05). The pooled data showed a lower recurrence rate in the usual care plus HBOT group (RR, 0.35; 95% CI, 0.24 to 0.53; P < 0.001). The standardized mean difference in the serum tumor necrosis factor level between HBOT and non-HBOT groups was -2.13 (95% CI, -3.09 to -1.18; P < 0.001). No severe adverse events of HBOT were observed.

Conclusions

HBOT might be an effective and safe adjunctive treatment for IBD. Further studies are required to investigate the optimal protocol of HBOT in IBD treatment.

Hyperbaric Oxygen Therapy in Systemic Inflammatory Response Syndrome

(1) Background: Systemic inflammatory response syndrome (SIRS) can occur due to a large number of traumatic or non-traumatic diseases. Hyperbaric oxygen therapy (HBOT) may be used as a main or adjuvant treatment for inflammation, leading to the main aim of this study, which was to verify the applicability of HBOT as a safe and tolerable tool in SIRS-positive dogs. (2) Methods: This prospective cohort study included 49 dogs who showed two or more parameters of SIRS, divided into the Traumatic Study Group (n = 32) and the Non-Traumatic Study Group (n = 17). All dogs were submitted to HBOT for 60–90 min sessions, with 2.4–2.8 ATA. (3) Results: This study revealed that 73.5% (36/49) of dogs showed improvement, and the minimum number of HBOT sessions was two, with a mean of 12.73. The number of days between diagnosis and the beginning of HBOT showed statistical significance (p = 0.031) relative to the clinical outcome. No dogs showed any major side effects. (4) Conclusions: We concluded that HBOT may be safe and tolerable for SIRS-positive dogs, and that it should be applied as early as possible.

Exploring the Early Phase of Crohn's Disease

The development of Crohn's disease (CD) is characterized by a breakdown of homeostatic immune-bacterial communication, which takes place at the intestinal mucosa when environmental triggers impact genetically predisposed individuals. Converging lines of evidence support the hypothesis that this pathogenetic model develops through sequential, although inter-related, steps that indicate failure of mucosal defense mechanisms at various stages. In this context, immunologic phenomena that mediate the initial appearance of inflammatory lesions across the intestinal tissue may differ substantially from those that mediate and perpetuate chronic inflammatory responses. A compromise in the integrity of the epithelial barrier is among the earliest events and leads to accelerated influx of intraluminal antigens and intact microorganisms within the immunologically rich lamina propria. Inadequate clearance of invading microorganisms also may occur as a result of defects in innate immunity, preventing the timely and complete resolution of acute inflammatory responses. The final step is the development of persistent adaptive responses, which also differ between early and late Crohn's disease. Current progress in our ability to delineate single-cell transcriptomics and proteomics has allowed the discovery of cellular and molecular mechanisms that participate in each sequential step of CD development. This not only will advance our understanding of CD pathogenesis, but also facilitate the design of targeted therapeutic approaches.

A Review of Hyperbaric Oxygen Therapy for Inflammatory Bowel Disease

IBD (inflammatory bowel disease) characterized by chronic inflammation of the gastrointestinal (GI) tract is one of the chronic diseases the prevalence of which has been increasing globally. In the past few decades, significant improvements were made in the treatments relating to IBD which have reduced the hospitalization and mortality rates; however, there is still room for improvement with other alternative therapies. HBOT (hyperbaric oxygen treatment) is one of the effective therapies used in treating various conditions including wounds, decompression sickness, stroke, etc. Several studies have reported the role of HBOT as an adjunctive treatment to IBD, while adopting conventional treatment procedures. There is an increasing trend of research in this particular area. Studies have shown that HBOT reflects its therapeutic effect by controlling inflammation, reducing oxidation stress, improving the process of cleaning damaged cells and recruiting the cells involved in repair; thereby improving the immunity response system. In this context, the purpose of this review is to summarize past clinical and experimental studies and to understand the role of hyperbaric treatment for IBD. The findings from the review have suggested that hyperbaric therapy can be an effective adjunctive approach for IBD, based on which some ideas for future clinical and research work are provided.

The role of hyperbaric oxygen therapy in inflammatory bowel disease: a narrative review

Inflammatory bowel disease is a group of chronic recurrent diseases in the digestive tract, including ulcerative colitis and Crohn's disease. Over the past few decades, the treatment of IBD has made great progress but there is still a lot of room for improvement. Hyperbaric oxygen therapy (HBOT) was defined as the therapeutic effect of inhaling 100% oxygen higher than one atmosphere and reported to be used in stroke, decompression sickness and wound healing. Since several authors reported the role of HBOT as an adjunct to conventional medical treatment in patients with refractory IBD, the relevant research has shown an increasing trend in recent years. Clinical and experimental studies have revealed that HBOT may exert its therapeutic effect by inhibiting inflammation and strengthening the antioxidant system, promoting the differentiation of colonic stem cells and recruiting cells involved in repair. The purpose of this review is to summarize the past clinical and experimental studies and to understand the impact of HBOT in the treatment of IBD more deeply. In addition, we also hope to provide some ideas for future clinical and research work.

Hyperbaric Oxygen Increases Stem Cell Proliferation, Angiogenesis and Wound-Healing Ability of WJ-MSCs in Diabetic Mice

Hyperbaric oxygen therapy (HBOT) is effective for the medical treatment of diverse diseases, infections, and tissue injury. In fact, in recent years there is growing evidence on the beneficial effect of HBOT on non-healing ischemic wounds. However, there is still yet discussion on how this treatment could benefit from combination with regenerative medicine strategies. Here we analyzed the effects of HBOT on three specific aspects of tissue growth, maintenance, and regeneration: (i) modulation of adult rodent (Mus musculus) intestinal stem cell turnover rates; (ii) angiogenesis dynamics during the development of the chorio-allantoic membrane (CAM) in Gallus gallus embryos; (iii) and wound-healing in a spontaneous type II diabetic mouse model with a low capacity to regenerate skin. To analyze these aspects of tissue growth, maintenance, and regeneration, we used HBOT alone or in combination with cellular therapy. Specifically, Wharton Jelly Mesenchymal Stem cells (WJ-MSC) were embedded in a commercial collagen-scaffold. HBOT did not affect the metabolic rate of adult mice nor of chicken embryos. Notwithstanding, HBOT modified the proliferation rate of stem cells in the mice small intestinal crypts, increased angiogenesis in the CAM, and improved wound-healing and tissue repair in diabetic mice. Moreover, our study demonstrates that combining stem cell therapy and HBOT has a collaborative effect on wound-healing. In summary, our data underscore the importance of oxygen tension as a regulator of stem cell biology and support the potential use of oxygenation in clinical treatments.

Hyperbaric oxygen therapy stimulates colonic stem cells and induces mucosal healing in patients with refractory ulcerative colitis: a prospective case series

BACKGROUND

Hyperbaric oxygen (HBO) is used as part of treatment in a variety of clinical conditions. Its use in the treatment of ulcerative colitis has been reported in few clinical reports.

OBJECTIVE

We report the effect of HBO on refractory ulcerative colitis exploring one potential mechanism of action.

DESIGN

A review of records of patients with refractory ulcerative colitis who received HBO was conducted. Clinical and histopathological scoring was utilised to evaluate the response to HBO therapy (HBOT).

RESULTS

All patients manifested clinical improvement by the 40th cycle of HBOT. The median number of stool frequency dropped from seven motions/day (range=3-20) to 1/day (range=0.5-3), which was significant (z=-4.6, p<0.001). None of the patients manifested persistent blood passage after HBOT (z=-3.2, p=0.002). The severity index significantly improved after HBOT (z=-4.97, p<0.001). Histologically, a significant reduction of the scores of activity was recorded accompanied by a significant increase in the proliferating cell nuclear antigen labelling index of the CD44 cells of the colonic mucosa (p=0.001).

CONCLUSIONS

HBOT is effective in the setting of refractory ulcerative colitis. The described protocol is necessary for successful treatment. HBOT stimulates colonic stem cells to promote healing.

Pathway-based approaches to the treatment of inflammatory bowel disease

Crohn's disease and ulcerative colitis, collectively termed inflammatory bowel disease (IBD), are immunologic disorders that represent the prototypes of chronic intestinal inflammation. Their pathogenesis involves the dysregulated interaction between the intestinal microbiota and the gut-associated mucosal immune system that takes place when genetically predisposed individuals are exposed to detrimental environmental triggers. In recent years, the therapeutic dogma in IBD has shifted away from the administration of nonspecific immunosuppressives toward a pathway-based approach. In this review, we present an outlook of IBD treatment based on this new conceptual approach. Firstly, we will provide an overview of the major aspects of IBD pathogenesis with emphasis on specific pathway-based defects. Secondly, we will examine in detail the development of novel therapeutic approaches that can be used to target genetics, dysbiosis, the epithelial barrier, proinflammatory cytokines, and leukocyte trafficking. Most of these strategies are still in the developmental phase, but promising approaches include fecal microbiota transplantation as a means to correct IBD-related dysbiosis; administration of modified phosphatidylcholine to enhance the function of the intestinal mucous and tighten the defective epithelial barrier; the reduction of over-reactive proinflammatory pathways through the blockade of novel, nontumor necrosis factor inflammatory mediators via monoclonal antibodies against the common p40 chain of interleukin (IL-12) and IL-23, Janus kinase inhibitors, or antisense oligonucleotides against inhibitors of the immunosuppressive cytokine transforming growth factor-β1; and finally, inhibition of leukocyte trafficking to the gut via neutralization of the gut-specific α4β7 integrin. Availability of such diverse treatment modalities with specific pathway-based targets will increase the therapeutic options for patients with IBD.

Hyperbaric oxygen therapy ameliorates TNBS-induced acute distal colitis in rats

BACKGROUND

This study investigated the therapeutic effects of hyperbaric oxygen in experimental acute distal colitis focusing on its effect on the production of pro-inflammatory cytokines, nitric oxide and hypoxia-inducible factor 1alpha.

METHODS

Colitis was induced with a rectal infusion of 150 mg/kg of TNBS under anesthesia with Ketamine (50 mg/kg) and Xylazine (10 mg/kg). Control animals received only rectal saline. After colitis induction, animals were subjected to two sessions of hyperbaric oxygen and were then euthanized. The distal intestine was resected for macroscopic analysis, determination of myeloperoxidase activity, western-blotting analyses of inducible nitric oxide synthase and cyclooxygenase-2 expression and immunohistochemical analysis of hypoxia-inducible factor 1alpha and cyclooxygenase-2. Cytokines levels in the distal intestine were measured using an enzyme-linked immunosorbent assay.

RESULTS

Hyperbaric oxygen therapy attenuated the severity of acute distal colitis, with reduced macroscopic damage score. This effect was associated with prevention in the increase of pro-inflammatory cytokine production; myeloperoxidase activity, in the expression of inducible nitric oxide synthase and cyclooxygenase-2. Finally, hyperbaric oxygen inhibited the acute distal colitis-induced up-regulation of hypoxia-inducible factor 1alpha.

CONCLUSIONS

The results indicate that hyperbaric oxygen attenuates the severity of acute distal colitis through the down-regulation of pro-inflammatory events.

Hyperoxygenation attenuated a murine model of atopic dermatitis through raising skin level of ROS

Atopic dermatitis (AD) is a chronic inflammatory skin disease resulting from excessive stimulation of immune cells. Traditionally, reactive oxygen species (ROS) have been implicated in the progression of inflammatory diseases, but several opposing observations suggest the protective role of ROS in inflammatory disease. Recently, we demonstrated ROS prevented imiquimod-induced psoriatic dermatitis through enhancing regulatory T cell function. Thus, we hypothesized AD might also be attenuated in elevated levels of ROS through tissue hyperoxygenation, such as by hyperbaric oxygen therapy (HBOT) or applying an oxygen-carrying chemical, perfluorodecalin (PFD). Elevated levels of ROS in the skin have been demonstrated directly by staining with dihydroethidum as well as indirectly by immunohistochemistry (IHC) for indoleamine 2,3-dioxygenase (IDO). A murine model of AD was developed by repeated application of a chemical irritant (1% 2,4-dinitrochlorobenzene) and house dust mite (Dermatophagoide farinae) extract on one ear of BALB/c mice. The results showed treatment with HBOT or PFD significantly attenuated AD, comparably with 0.1% prednicarbate without any signs of side effects, such as telangiectasia. The expressions of interleukin-17A and interferon-γ were also decreased in the AD lesions by treatment with HBOT or PFD. Enhanced expression of IDO and reduced level of hypoxia-inducible factor-1α, in association with increased frequency of FoxP3⁺ regulatory T cells in the AD lesions, might be involved in the underlying mechanism of oxygen therapy. Taken together, it was suggested that tissue hyperoxygenation, by HBOT or treatment with PFD, might attenuate AD through enhancing skin ROS level.

Systematic review: The safety and efficacy of hyperbaric oxygen therapy for inflammatory bowel disease

BACKGROUND

Hyperbaric oxygen therapy (HBOT) provides 100% oxygen under pressure, which increases tissue oxygen levels, relieves hypoxia and alters inflammatory pathways. Although there is experience using HBOT in Crohn's disease and ulcerative colitis, the safety and overall efficacy of HBOT in inflammatory bowel disease (IBD) is unknown.

AIM

To quantify the safety and efficacy of HBOT for Crohn's disease (CD) and ulcerative colitis (UC). The rate of adverse events with HBOT for IBD was compared to the expected rate of adverse events with HBOT.

METHODS

MEDLINE, EMBASE, Cochrane Collaboration and Web of Knowledge were systematically searched using the PRISMA standards for systematic reviews. Seventeen studies involving 613 patients (286 CD, 327 UC) were included.

RESULTS

The overall response rate was 86% (85% CD, 88% UC). The overall response rate for perineal CD was 88% (18/40 complete healing, 17/40 partial healing). Of the 40 UC patients with endoscopic follow-up reported, the overall response rate to HBOT was 100%. During the 8924 treatments, there were a total of nine adverse events, six of which were serious. The rate of adverse events with HBOT in IBD is lower than that seen when utilising HBOT for other indications (P < 0.01). The risk of bias across studies was high.

CONCLUSIONS

Hyperbaric oxygen therapy is a relatively safe and potentially efficacious treatment option for IBD patients. To understand the true benefit of HBOT in IBD, well-controlled, blinded, randomised trials are needed for both Crohn's disease and ulcerative colitis.

Reactive oxygen species prevent imiquimod-induced psoriatic dermatitis through enhancing regulatory T cell function

Psoriasis is a chronic inflammatory skin disease resulting from immune dysregulation. Regulatory T cells (Tregs) are important in the prevention of psoriasis. Traditionally, reactive oxygen species (ROS) are known to be implicated in the progression of inflammatory diseases, including psoriasis, but many recent studies suggested the protective role of ROS in immune-mediated diseases. In particular, severe cases of psoriasis vulgaris have been reported to be successfully treated by hyperbaric oxygen therapy (HBOT), which raises tissue level of ROS. Also it was reported that Treg function was closely associated with ROS level. However, it has been only investigated in lowered levels of ROS so far. Thus, in this study, to clarify the relationship between ROS level and Treg function, as well as their role in the pathogenesis of psoriasis, we investigated imiquimod-induced psoriatic dermatitis (PD) in association with Treg function both in elevated and lowered levels of ROS by using knockout mice, such as glutathione peroxidase-1^−/− and neutrophil cytosolic factor-1^−/− mice, as well as by using HBOT or chemicals, such as 2,3-dimethoxy-1,4-naphthoquinone and N-acetylcysteine. The results consistently showed Tregs were hyperfunctional in elevated levels of ROS, whereas hypofunctional in lowered levels of ROS. In addition, imiquimod-induced PD was attenuated in elevated levels of ROS, whereas aggravated in lowered levels of ROS. For the molecular mechanism that may link ROS level and Treg function, we investigated the expression of an immunoregulatory enzyme, indoleamine 2,3-dioxygenase (IDO) which is induced by ROS, in PD lesions. Taken together, it was implied that appropriately elevated levels of ROS might prevent psoriasis through enhancing IDO expression and Treg function.

New therapeutic avenues in ulcerative colitis: thinking out of the box

Ulcerative colitis (UC) is a chronic idiopathic inflammatory disease of the gastrointestinal tract that affects the mucosal lining of the colon. Recent epidemiological data show that its incidence and prevalence are increasing in many parts of the world, in parallel with altered lifestyles, improved access to health, improved sanitation and industrialisation rates. Current therapeutic strategies for treating UC have only been moderately successful. Despite major recent advances in inflammatory bowel disease therapeutic resources, a considerable proportion of patients are still refractory to conventional treatment. Less than half of all patients achieve long-term remission, many require colectomy, and the disease still has a major impact on patients' lives. Moreover, recent data point to slightly raised mortality. While these outcomes could be partly improved by optimising current therapeutic strategies, they clearly highlight the need to develop new therapies. Currently, a number of promising and innovative therapeutic approaches are being explored, some of which will hopefully survive to reach the clinic. Until such a time arrives, it is important that a better understanding of the clinical particularities of the disease, an improved knowledge of the host-microbiome negative interactions and of the environmental factors beyond disease development is achieved to obtain the final and desired outcome: to provide better treatment and quality of life for patients with this disabling disease.

Hyperbaric oxygen therapy does not improve the effects of standardized treatment in a severe attack of ulcerative colitis: a prospective randomized study

BACKGROUND AND AIMS

Complementary therapy options are needed in the treatment of active ulcerative colitis (UC). Hyperbaric oxygen therapy (HBOT) has been shown to have positive effects in experimental models of colitis and perianal Crohn's disease.

METHODS

In the present prospective randomized open-label study, HBOT in addition to conventional medical treatment was compared with conventional treatment alone. The primary objective in this study was improved clinical outcome evaluated by Mayo score, laboratory tests and fecal weight. The secondary objectives were improvement in health-related quality of life, avoidance of colectomy and evaluation of HBOT safety.

RESULTS

The authors found no statistically significant differences between the treatment groups in any of the assessed variables.

CONCLUSION

The study results do not support the use of HBOT as a treatment option in a severe attack of UC.

Hyperbaric oxygen treatment for inflammatory bowel disease: a systematic review and analysis

Background

Traditionally, hyperbaric oxygen treatment (HBOT) has been used to treat a limited repertoire of disease, including decompression sickness and healing of problem wounds. However, some investigators have used HBOT to treat inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis.

Methods

Comprehensive searches were conducted in 8 scientific databases through 2011 to identify publications using HBOT in IBD. Human studies and animal models were collated separately.

Results

Thirteen studies of HBOT in Crohn's disease and 6 studies in ulcerative colitis were identified. In all studies, participants had severe disease refractory to standard medical treatments, including corticosteroids, immunomodulators and anti-inflammatory medications. In patients with Crohn's disease, 31/40 (78%) had clinical improvements with HBOT, while all 39 patients with ulcerative colitis improved. One study in Crohn's disease reported a significant decrease in proinflammatory cytokines (IL-1, IL-6 and TNF-alpha) and one study in ulcerative colitis reported a decrease in IL-6 with HBOT. Adverse events were minimal. Twelve publications reported using HBOT in animal models of experimentally-induced IBD, including several studies reporting decreased markers of inflammation or immune dysregulation, including TNF-alpha (3 studies), IL-1beta (2 studies), neopterin (1 study) and myeloperoxidase activity (5 studies). HBOT also decreased oxidative stress markers including malondialdehyde (3 studies) and plasma carbonyl content (2 studies), except for one study that reported increased plasma carbonyl content. Several studies reported HBOT lowered nitric oxide (3 studies) and nitric oxide synthase (3 studies) and one study reported a decrease in prostaglandin E₂ levels. Four animal studies reported decreased edema or colonic tissue weight with HBOT, and 8 studies reported microscopic improvements on histopathological examination. Although most publications reported improvements with HBOT, some studies suffered from limitations, including possible publication and referral biases, the lack of a control group, the retrospective nature and a small number of participants.

Conclusions

HBOT lowered markers of inflammation and oxidative stress and ameliorated IBD in both human and animal studies. Most treated patients were refractory to standard medical treatments. Additional studies are warranted to investigate the effects of HBOT on biomarkers of oxidative stress and inflammation as well as clinical outcomes in individuals with IBD.

Controlled evaluation of the effects of hyperbaric oxygen therapy on the behavior of 16 children with autism spectrum disorders

Hyperbaric oxygen therapy (HBOT) has been used to treat individuals with autism. However, few studies of its effectiveness have been completed. The current study examined the effects of 40 HBOT sessions at 24% oxygen at 1.3 ATA on 11 topographies of directly observed behavior. Five replications of multiple baselines were completed across a total of 16 participants with autism spectrum disorders. No consistent effects were observed across any group or within any individual participant, demonstrating that HBOT was not an effective treatment for the participants in this study. This study represents the first relatively large-scale controlled study evaluating the effects of HBOT at the level of the individual participant, on a wide array of behaviors.

Increased expression of hypoxia-inducible factor 1alpha in coeliac disease

Previously, it has been suggested that hypoxia-inducible factor (HIF) 1 signaling may play determinative role in the maintenance of the barrier function of the intestinal epithelium in inflammatory bowel disease. Our aim was to depict the alteration of HIF-1alpha and related genes in celiac disease (CD) where the importance of the barrier function is well known. Duodenal biopsy specimens were collected from 16 children with untreated CD, 9 children with treated CD and 10 controls. HIF-1alpha, trefoil factor 1 (TFF1), ecto-5-prime nucleotidase (CD73), and multi drug resistance gene 1 (MDR1) mRNA and HIF-1alpha protein expression were determined by real-time PCR and Western blot, respectively. Localization of HIF-1alpha was determined by immunofluorescent staining. We found increased HIF-1alpha and TFF1 mRNA and HIF-1alpha protein expression in the duodenal mucosa of children with untreated CD compared with controls or children with treated CD (p < 0.05). In untreated CD children, HIF-1alpha staining was present in cytoplasmic and nuclear region of the villous enterocytes. In treated CD mRNA expression of CD73 and MDR1 were increased compared with controls (p < 0.01 and 0.05, respectively). Our results of increased mucosal HIF-1alpha expression in CD children suggest the contribution of this signaling pathway in the pathomechanism of CD.

Hyperbaric treatment for children with autism: a multicenter, randomized, double-blind, controlled trial

Background

Several uncontrolled studies of hyperbaric treatment in children with autism have reported clinical improvements; however, this treatment has not been evaluated to date with a controlled study. We performed a multicenter, randomized, double-blind, controlled trial to assess the efficacy of hyperbaric treatment in children with autism.

Methods

62 children with autism recruited from 6 centers, ages 2–7 years (mean 4.92 ± 1.21), were randomly assigned to 40 hourly treatments of either hyperbaric treatment at 1.3 atmosphere (atm) and 24% oxygen ("treatment group", n = 33) or slightly pressurized room air at 1.03 atm and 21% oxygen ("control group", n = 29). Outcome measures included Clinical Global Impression (CGI) scale, Aberrant Behavior Checklist (ABC), and Autism Treatment Evaluation Checklist (ATEC).

Results

After 40 sessions, mean physician CGI scores significantly improved in the treatment group compared to controls in overall functioning (p = 0.0008), receptive language (p < 0.0001), social interaction (p = 0.0473), and eye contact (p = 0.0102); 9/30 children (30%) in the treatment group were rated as "very much improved" or "much improved" compared to 2/26 (8%) of controls (p = 0.0471); 24/30 (80%) in the treatment group improved compared to 10/26 (38%) of controls (p = 0.0024). Mean parental CGI scores significantly improved in the treatment group compared to controls in overall functioning (p = 0.0336), receptive language (p = 0.0168), and eye contact (p = 0.0322). On the ABC, significant improvements were observed in the treatment group in total score, irritability, stereotypy, hyperactivity, and speech (p < 0.03 for each), but not in the control group. In the treatment group compared to the control group, mean changes on the ABC total score and subscales were similar except a greater number of children improved in irritability (p = 0.0311). On the ATEC, sensory/cognitive awareness significantly improved (p = 0.0367) in the treatment group compared to the control group. Post-hoc analysis indicated that children over age 5 and children with lower initial autism severity had the most robust improvements. Hyperbaric treatment was safe and well-tolerated.

Conclusion

Children with autism who received hyperbaric treatment at 1.3 atm and 24% oxygen for 40 hourly sessions had significant improvements in overall functioning, receptive language, social interaction, eye contact, and sensory/cognitive awareness compared to children who received slightly pressurized room air.

Trial Registration

clinicaltrials.gov NCT00335790

The effect of iNOS inhibitors and hyperbaric oxygen treatment in a rat model of experimental colitis

AIM

Our aim was to investigate the effectiveness of aminoguanidine (AMG), an inducible nitric oxide synthase inhibitor, and hyperbaric oxygen (HBO) treatment in an experimental colitis model.

METHODS

We induced colitis in rats. In the control group, we applied 2 ml serum physiologic intraperitoneally for 7 days. In the HBO group, 100% oxygen at 2.4 atm pressure was applied for 7 days. In the AMG group, 100 mg/kg AMG was applied intraperitoneally for 7 days. In the HBO + AMG group, HBO and AMG were applied, respectively. At the end of 7 days, rats were sacrificed and the distal 10 cm part of colon was examined macro- and microscopically.

RESULTS

Severity of colitis and NO activities were reduced by AMG, HBO, and HBO + AMG application. There was histologically significant improvement, especially in the HBO + AMG group.

CONCLUSIONS

Both HBO and AMG were significantly effective in preventing weight loss, reducing NO activities, and severity of colitis, when comparing HBO and AMG separately.

The effects of hyperbaric oxygen therapy on oxidative stress, inflammation, and symptoms in children with autism: an open-label pilot study

Background

Recently, hyperbaric oxygen therapy (HBOT) has increased in popularity as a treatment for autism. Numerous studies document oxidative stress and inflammation in individuals with autism; both of these conditions have demonstrated improvement with HBOT, along with enhancement of neurological function and cognitive performance. In this study, children with autism were treated with HBOT at atmospheric pressures and oxygen concentrations in current use for this condition. Changes in markers of oxidative stress and inflammation were measured. The children were evaluated to determine clinical effects and safety.

Methods

Eighteen children with autism, ages 3–16 years, underwent 40 hyperbaric sessions of 45 minutes duration each at either 1.5 atmospheres (atm) and 100% oxygen, or at 1.3 atm and 24% oxygen. Measurements of C-reactive protein (CRP) and markers of oxidative stress, including plasma oxidized glutathione (GSSG), were assessed by fasting blood draws collected before and after the 40 treatments. Changes in clinical symptoms, as rated by parents, were also assessed. The children were closely monitored for potential adverse effects.

Results

At the endpoint of 40 hyperbaric sessions, neither group demonstrated statistically significant changes in mean plasma GSSG levels, indicating intracellular oxidative stress appears unaffected by either regimen. A trend towards improvement in mean CRP was present in both groups; the largest improvements were observed in children with initially higher elevations in CRP. When all 18 children were pooled, a significant improvement in CRP was found (p = 0.021). Pre- and post-parental observations indicated statistically significant improvements in both groups, including motivation, speech, and cognitive awareness (p < 0.05). No major adverse events were observed.

Conclusion

In this prospective pilot study of children with autism, HBOT at a maximum pressure of 1.5 atm with up to 100% oxygen was safe and well tolerated. HBOT did not appreciably worsen oxidative stress and significantly decreased inflammation as measured by CRP levels. Parental observations support anecdotal accounts of improvement in several domains of autism. However, since this was an open-label study, definitive statements regarding the efficacy of HBOT for the treatment of individuals with autism must await results from double-blind, controlled trials.

Trial Registration

clinicaltrials.gov NCT00324909

Current management of severe ulcerative colitis

Approximately 15% of patients with ulcerative colitis develop an acute attack of severe colitis, and 30% of these patients require colectomy. Severe ulcerative colitis is therefore considered a medical emergency, the management of which requires close collaboration between gastroenterologists and surgeons. The mortality rate for patients with severe ulcerative colitis is now <1% in specialist centers, but it was high before intravenous steroid therapy and early surgery were introduced; indeed, mortality is still high in nonspecialized centers. As colectomy severely affects quality of life, therapy with intravenous ciclosporin and, more recently, infliximab has been introduced to try to avoid the need for surgery. Ciclosporin induces short-term remission, but the long-term benefit remains unsatisfactory as colectomy is often only delayed. A significant short-term reduction in the colectomy rate has, however, been observed after infliximab treatment. The use of infliximab versus ciclosporin in patients with severe ulcerative colitis remains to be defined. The timing of surgery remains a cardinal decision in the management of severe ulcerative colitis; increased morbidity resulting from prolonged ineffective medical treatment and, therefore, a delay in surgical treatment should be avoided.

Hyperbaric oxygen therapy might improve certain pathophysiological findings in autism

Autism is a neurodevelopmental disorder currently affecting as many as 1 out of 166 children in the United States. Numerous studies of autistic individuals have revealed evidence of cerebral hypoperfusion, neuroinflammation and gastrointestinal inflammation, immune dysregulation, oxidative stress, relative mitochondrial dysfunction, neurotransmitter abnormalities, impaired detoxification of toxins, dysbiosis, and impaired production of porphyrins. Many of these findings have been correlated with core autistic symptoms. For example, cerebral hypoperfusion in autistic children has been correlated with repetitive, self-stimulatory and stereotypical behaviors, and impairments in communication, sensory perception, and social interaction. Hyperbaric oxygen therapy (HBOT) might be able to improve each of these problems in autistic individuals. Specifically, HBOT has been used with clinical success in several cerebral hypoperfusion conditions and can compensate for decreased blood flow by increasing the oxygen content of plasma and body tissues. HBOT has been reported to possess strong anti-inflammatory properties and has been shown to improve immune function. There is evidence that oxidative stress can be reduced with HBOT through the upregulation of antioxidant enzymes. HBOT can also increase the function and production of mitochondria and improve neurotransmitter abnormalities. In addition, HBOT upregulates enzymes that can help with detoxification problems specifically found in autistic children. Dysbiosis is common in autistic children and HBOT can improve this. Impaired production of porphyrins in autistic children might affect the production of heme, and HBOT might help overcome the effects of this problem. Finally, HBOT has been shown to mobilize stem cells from the bone marrow to the systemic circulation. Recent studies in humans have shown that stem cells can enter the brain and form new neurons, astrocytes, and microglia. It is expected that amelioration of these underlying pathophysiological problems through the use of HBOT will lead to improvements in autistic symptoms. Several studies on the use of HBOT in autistic children are currently underway and early results are promising.

Hyperbaric oxygenation ameliorates indomethacin-induced enteropathy in rats by modulating TNF-alpha and IL-1beta production

The effect of hyperbaric oxygenation (HBO2) was investigated in a rat model of indomethacin-induced enteropathy. Enteropathy was induced by two subcutaneous injections of indomethacin (7.5 mg/kg) 24 hr apart. Six groups of rats (n=8) were treated with and without HBO2 (100% oxygen at 2.3 atm absolute) for 1 hr once or twice a day for 2 or 5 days. Disease activity index (DAI) and total ulcer length were measured. Other rats were randomized into two groups (n=16) with and without HBO2 (1 hr once a day) and four rats were killed in each group at 12, 24, 48, and 72 hr after the final injection of indomethacin. Serum and intestinal mucosal TNF-alpha, IL-1beta, myeloperoxidase (MPO), and iNOS expression was measured. HBO2 treatment significantly attenuated indomethacin -induced intestinal ulceration and improved DAI. Indomethacin increased MPO activity and iNOS expression, and these were reduced by HBO2 treatment, with a concomitant reduction in TNF-alpha and IL-1beta. Our data suggest that HBO2 treatment has a beneficial effect on indomethacin-induced enteropathy and this effect is possibly mediated by decreased production of TNF-alpha and IL-1beta.

Hyperbaric oxygen therapy may improve symptoms in autistic children

Autism is a neurodevelopmental disorder that currently affects as many as 1 out of 166 children in the United States. Recent research has discovered that some autistic individuals have decreased cerebral perfusion, evidence of neuroinflammation, and increased markers of oxidative stress. Multiple independent single photon emission computed tomography (SPECT) and positron emission tomography (PET) research studies have revealed hypoperfusion to several areas of the autistic brain, most notably the temporal regions and areas specifically related to language comprehension and auditory processing. Several studies show that diminished blood flow to these areas correlates with many of the clinical features associated with autism including repetitive, self-stimulatory and stereotypical behaviors, and impairments in communication, sensory perception, and social interaction. Hyperbaric oxygen therapy (HBOT) has been used with clinical success in several cerebral hypoperfusion syndromes including cerebral palsy, fetal alcohol syndrome, closed head injury, and stroke. HBOT can compensate for decreased blood flow by increasing the oxygen content of plasma and body tissues and can even normalize oxygen levels in ischemic tissue. In addition, animal studies have shown that HBOT has potent anti-inflammatory effects and reduces oxidative stress. Furthermore, recent evidence demonstrates that HBOT mobilizes stem cells from human bone marrow, which may aid recovery in neurodegenerative diseases. Based upon these findings, it is hypothesized that HBOT will improve symptoms in autistic individuals. A retrospective case series is presented that supports this hypothesis.

Hyperbaric oxygen enhances the efficiency of 5-aminosalicylic acid in acetic acid-induced colitis in rats

The aim of this study was to assess the efficiency of hyperbaric oxygen alone and in combination with 5-aminosalicylic acid in the acetic acid-induced colitis model, a well-known experimental model of inflammatory bowel disease in rats. Rats were randomly divided into five groups. In the noncolitis control group, rats were given isotonic saline, while in the other groups rats were treated by intracolonic administration of 4% acetic acid. In group 2, the untreated control group, no additional therapy was applied. In groups 3, 4, and 5 hyperbaric oxygen, 5-aminosalicylic acid. and 5-aminosalicylic acid + hyperbaric oxygen therapies were applied, respectively. Administration of acetic acid caused an inflammatory response in all animals. Histopathologic score was significantly higher in group 2 than in any other group. 5-Aminosalicylic acid and hyperbaric oxygen significantly decreased the histopathologic score (P < 0.05). Myeloperoxidase activity was also reduced significantly by 5-aminosalicylic acid (P < 0.05) but not by hyperbaric oxygen. The most prominent ameliorative effect, however, was seen in group 5 and the histopathologic score and myeloperoxidase activity were significantly lower than in groups 3 (P < 0.05) and 4 (P < 0.001). Hydroxyproline level also increased significantly in group 5, but not in groups 3 and 4 (P < 0.001). These findings indicate that hyperbaric oxygen therapy is effective in reducing the extent of colitis induced by acetic acid, although it is not as potent as 5-aminosalicylic acid. The combination of hyperbaric oxygen and 5-aminosalicylic acid, however, led to a much more prominent reduction in the severity of colitis. Hyperbaric oxygen may have a promising place in the treatment of inflammatory bowel disease.

A new look at toxic megacolon: an update and review of incidence, etiology, pathogenesis, and management

Toxic megacolon (TM) is an infrequent but devastating complication of colitis. Numerous forms of colonic inflammation can give rise to TM but the majority occur in individuals with inflammatory bowel disease (IBD). Recently there has been a marked increase in the number of reports of TM associated with pseudomembranous colitis. Because of the associated high morbidity and mortality, early recognition and management of TM is of paramount importance. The mechanisms involved in development of TM are not clearly delineated, but chemical mediators such as nitric oxide and interleukins may play a pivotal role in the pathogenesis. New evidence suggests that TM and its associated morbidity may be predicted by the extent of small bowel and gastric distension in patients with colitis. CT scanning may also play an important role the management of TM, in that it may be the only noninvasive mode to detect subclinical perforations and abscesses. Management involves close medical attention, supportive care, and treatment of the underlying colitis. Possible exacerbating factors such as narcotic and anticholinergic medications must be withdrawn, and colonic decompression via tube drainage or positional techniques must be considered. Signs of progression or complications of the disease must be treated aggressively with surgical intervention, as delay is associated with even greater risk of mortality.