Hyperbaric Research Articles

Case report: Successful treatment of hyperbaric oxygen for radiation-induced hemorrhagic cystitis in a 95-year-old patient with bladder cancer

BackgroundSevere radiation-induced hemorrhagic cystitis (RHC) may ultimately require radical cystectomy. High-quality clinical evidence exists regarding the impact of hyperbaric oxygen therapy (HBOT) on RHC. However, there is a lack of reported data addressing the applicability of HBOT in very elderly patients (over 90 years old) with severe bleeding necessitating multiple blood transfusions.Case presentationThe patient is a 95-year-old male who suffered from severe hematuria due to RHC after 33 sessions of radiotherapy for muscle-invasive bladder cancer (T2N0M0, stage: II). After a series of subsequent therapies that failed to control the hematuria, the patient received 196 HBOTs between 11 October 2022 and 23 October 2023. Following a progressively adjusted HBOT protocol, the patient’s hematuria (urine red blood cell (RBC) count showed 210,859 RBC/μL at maximum) was effectively controlled, and his symptoms subsequently resolved after 69 HBOTs. After the 196th HBOT, pelvic MRI revealed a reduction in the size of the lesion on the left posterior wall of the bladder compared to prior assessments. This reduction was suggestive of diminished intravesical hematoma. As of 26 October 2023, it is noteworthy that the patient’s hemoglobin level has restored to the pre-hematuria level (106 g/L) with no need for blood transfusions for 8 consecutive months. Moreover, there was no recurrence of hematuria during the follow-up period. To the best of our knowledge, this report represents the first documented case of hematuria resolution in a patient over 90 years old with severe RHC.ConclusionThis case represents the first documented instance of successful hematuria resolution in a patient over 90 years of age with severe RHC. The positive therapeutic outcome achieved with personal protocol (1.4-1.6 ATA) in this 95-year-old patient, expands hyperbaric oxygen pressure options for elderly patients. Moreover, it also records a comprehensive dataset, including the time of the patient’s recurrence of hematuria and the subsequent trend of hematuria control, which contributes valuable evidence to the research on HBOT for the repair of bladder mucosal tissue.

Extracorporeal hyperoxygenation therapy (EHT) for CO poisoning: in vitro and in vivo feasibility of a full-scale batch system

Carbon monoxide (CO) poisoning is one of the most common causes of injury and death from poisoning. The primary objective of therapy is to eliminate CO from the patient as quickly as possible to prevent acute and long-term effects. The ideal treatment is hyperbaric oxygen in a pressure chamber. However, pressure chambers are scarce, and therefore, the most common treatment is normobaric oxygen (NBO), which, however, has limited efficacy. Here, we present a full-scale batch system for extracorporeal hyperoxygenation therapy (EHT), which facilitates CO elimination extracorporeally by increasing the dissolved oxygen concentration in the blood. The EHT was characterized in vitro, resulting in a minimum carboxyhemoglobin half-life of 3.26 ± 0.11 min. In large animal trials the EHT reduced the median carboxyhemoglobin half-life by 42% (29.77 min EHT vs. 70.8 min control (NBO)). However, the EHT also induced oscillations in hemodynamic pressures due to changes in the animals’ circulatory volume during operation. After optimization, the EHT could be a promising option for treating CO poisoning.

Skull base osteoradionecrosis: from pathogenesis to treatment.

This review aims to provide a comprehensive analysis of skull base osteoradionecrosis (ORN), a severe and rare complication of radiotherapy for head and neck malignancies. It explores pathogenesis, clinical presentation, diagnostic strategies, and management approaches, emphasizing the importance of multidisciplinary care in addressing this challenging condition. Skull base ORN results from radiotherapy-induced tissue damage, characterized by hypovascularity, hypoxia, and necrosis, often compounded by secondary infections. Advances in radiotherapy techniques, such as intensity-modulated radiotherapy and heavy particles, have reduced ORN incidence, though cases persist, particularly in high-dose radiotherapy fields. Emerging treatments, including hyperbaric oxygen therapy and the pentoxifylline-tocopherol protocol, show promise but lack robust evidence for standardized use. Surgical interventions, especially those incorporating vascularized tissue reconstruction, have demonstrated favorable outcomes in refractory cases. Recent studies underscore the utility of multimodal imaging techniques, including MRI and PET/CT, for distinguishing ORN from tumor recurrence. Skull base ORN represents a complex and potentially life-threatening condition requiring tailored, multidisciplinary management. Although advancements in diagnostics and therapeutics have improved outcomes, significant challenges remain, particularly in developing standardized protocols. Further research is needed to refine treatment strategies and improve evidence-based practices for this entity.

Adjunctive Hyperbaric Oxygen Therapy for Patients with Chronic Refractory Osteomyelitis: A Report of Treatment Outcomes and Risk Factors for Treatment Failure.

To evaluate the effect of hyperbaric oxygen (HBO) therapy on the outcomes of patients with chronic refractory osteomyelitis (CRO) when combined with modern antibiotics with modern delivery methods and/or surgical treatments. The authors conducted a retrospective review on 58 patients with CRO from a single institution who underwent HBO therapy along with standard treatment between January 2009 and December 2019. To investigate associations with binary outcomes of interest, they estimated logistic regression models. All models were adjusted for sex, smoking status, and pertinent comorbidities. Exponentiated logistic regression model coefficients were interpreted as odds ratios for each outcome of interest. Multivariable logistic regression was used to control for potential confounding variables. When controlling for multiple confounding factors, patients who completed HBO treatment had 7.76 times the odds of having improvement of their CRO compared with patients who started HBO treatment but did not complete it (P = .015). Further, patients who completed HBO treatment had 7.7 times the odds of experiencing CRO improvement when controlling for CRO stage (P = .006). However, completion of HBO did not statistically significantly impact the resolution of CRO or the odds of further surgery or amputation. Patients with diabetes, peripheral vascular disease, and congestive heart failure had increased odds of having an amputation (Ps = .026, .037, and .024, respectively). Patients who completed HBO treatment had increased odds of experiencing improvement of their CRO compared with patients who started HBO treatment but did not complete it. Patients with CRO who had diabetes and congestive heart failure had increased odds of undergoing an amputation.

Abstract TP18: Hyperbaric oxygen treatment improves visual outcome in patients with non-arteritic central retinal artery occlusion: an observational retrospective study

Abstract TP18: Hyperbaric oxygen treatment improves visual outcome in patients with non-arteritic central retinal artery occlusion: an observational retrospective study

High-Dose Intravenous Epoprostenol and Adjunct Therapies for Refractory Raynaud’s Phenomenon Associated with Anti-Jo-1 Antibodies: A Case Report

This case report highlights the use of intravenous high-dose Epoprostenol for managing severe digital ischemia in a patient diagnosed with antisynthetase syndrome (ASyS) exhibiting anti-Jo1 antibodies positivity, emphasizing its vasodilatory benefits and challenges with tolerability at higher doses. A multi-modal treatment strategy, including calcium channel blockers, phosphodiesterase inhibitors, hyperbaric oxygen therapy, and prostacyclin analogs, was critical for optimizing outcomes in refractory Raynaud’s phenomenon. This case underscores the importance of individualized treatment regimens and the need for ongoing monitoring and adjustments to balance therapeutic efficacy with patient safety. The report contributes to the limited literature on the management of severe digital ischemia in ASyS and emphasizes the potential role of adjunct therapies in improving patient outcomes.

Hyperbaric Oxygen Therapy (HBOT) for Management of Complex Regional Pain Syndrome (CRPS).

Complex regional pain syndrome remains a challenging condition characterized by severe, persistent pain and a variety of inflammatory and trophic symptoms. This study aimed to analyze the current literature to evaluate hyperbaric oxygen therapy (HBOT)'s efficacy in treating complex regional pain syndrome (CRPS), focusing on both sympathetically-maintained pain (SMP) and sympathetically-independent pain (SIP) subtypes. A comprehensive literature search was conducted in PubMed Clinical Queries using the MeSH term "Complex Regional Pain Syndromes" OR the keyword "CRPS" AND "Hyperbaric Oxygen Therapy" OR the keyword "HBOT". The selected publication types included a randomized controlled trial, a retrospective observational study, a comparative study, a retrospective case series and case reports. The search was restricted to articles published in English between January 1994 and October 2024. The results from the search were used to compile this review. Patients were categorized into SMP, SIP, or indeterminate groups based on the presence of prior sympathetic nerve block history or disease duration. Thirteen studies involving 280 subjects were reviewed. Of the patients, 42.5% were categorized as SMP, 48.2% as SIP, and 9.3% as indeterminate. HBOT treatment ranged from 3 to 63 sessions, typically using 2.4 ATA for 90 minutes. The results indicated significant symptom relief and functional improvement across both SMP and SIP subtypes, suggesting the broad efficacy of HBOT for CRPS management. This review of the current literature suggests that HBOT may offer significant symptom relief, regardless of CRPS subtype or disease duration. HBOT's anti-inflammatory and neuroplasticity promoting properties make it a valuable non-invasive option for CRPS patients, potentially improving outcomes when combined with other therapeutic modalities. Further research is necessary to refine patient selection and optimize treatment protocols.

Successful treatment with hyperbaric oxygen therapy for ulcerative esophageal stricture after chemoradiotherapy: A case report.

Severe esophageal strictures resulting from chemoradiotherapy pose persistent therapeutic challenges despite the availability of treatments such as endoscopic balloon dilation and medications. Hyperbaric oxygen therapy (HBOT) has emerged as a promising treatment option for refractory radiation-induced injury to several organs. Herein, we present the case of a 79-year-old male patient with refractory radiation-induced ulcerative esophageal strictures after chemoradiotherapy. Despite multiple interventions, including endoscopic balloon dilation, steroids, and proton-pump inhibitors, the patient remained unable to tolerate oral intake. HBOT was initiated, leading to significant improvement in the esophageal ulcers and strictures within 1 month. HBOT was well tolerated; the patient experienced a sustained improvement in his quality of life. Two years after HBOT, esophagogastroduodenoscopy confirmed persistent improvement in esophageal ulcers and strictures. This case highlights the potential of HBOT as a therapeutic option for ulcerative esophageal strictures unresponsive to conventional treatments.

Treating cryptogenic anorectal fistulas with hyperbaric oxygen therapy - an unexplored area with potential.

Treating cryptogenic anorectal fistulas with hyperbaric oxygen therapy - an unexplored area with potential.

A Rare Case of Calciphylaxis: A case report

Introduction: Calciphylaxis is a rare and severe disorder characterized by obstructive small vessel disease in the subcutaneous adipose tissue and skin, leading to necrotic skin lesions. The condition poses a significant risk of mortality due to infectious and ischemic complications. Case presentation: We present the case of a 60-year-old woman, with a history of renal lithiasis, hypertension, and end-stage renal disease on hemodialysis complicated by hyperparathyroidism and aortic valve replacement. She developed extensive necrotic lesions on both lower limbs and upper extremities, prompting a diagnosis of calciphylaxis. Radiographic and biopsy findings supported the diagnosis, revealing characteristic calcifications. Treatment involved antibiotics, oral thiosulfate, daily hemodialysis, hyperbaric oxygen therapy, and discontinuation of calcium and alfacalcidol, with alendronate initiation. Unfortunately, despite these interventions, the patient experienced a rapid clinical decline, developing septic shock necessitating bilateral leg amputations. Regrettably, she succumbed to the disease ten days later. Conclusion: This case underscores the challenging prognosis of calciphylaxis and the need for effective therapeutic options, including surgical intervention and access to injectable thiosulfate.

Hyperbaric Oxygen Therapy for the Treatment of Bone-Related Diseases

Abstract: Hyperbaric oxygen therapy (HBOT) is a therapeutic modality that enhances tissue oxygenation by delivering 100% oxygen at pressures greater than 1 absolute atmosphere. In recent years, HBOT has shown considerable potential in the treatment of bone diseases. While excess oxygen was once thought to induce oxidative stress, recent studies indicate that when administered within safe limits, HBOT can notably promote bone healing and repair. Extensive basic research has demonstrated that HBOT can stimulate the proliferation and differentiation of osteoblasts and encourage bone angiogenesis. Furthermore, HBOT has been shown to exert a beneficial influence on bone metabolism by modulating the inflammatory response and redox status. These mechanisms are closely related to core issues of bone biology. Specifically, in the context of fracture healing, bone defect repair, and conditions such as osteoporosis, HBOT targets the key bone signaling pathways involved in bone health, thereby exerting a therapeutic effect. Several clinical studies have demonstrated the efficacy of HBOT in improving bone health. However, the optimal HBOT regimen for treating various bone diseases still requires further definition to expand the indications for its clinical application. This paper outlines the mechanisms of HBOT, focusing on its antioxidant stress, promotion of bone vascularization, and anti-inflammatory properties. The paper also describes the application of HBOT in orthopedic diseases, thereby providing a scientific basis for the development of precise and personalized HBOT treatment regimens in clinical orthopedics.

Abstract A001: A prospective study of anemia in cancer patients undergoing chemoradiation using serial hemoglobin measurement in North Central region, Nigeria

Abstract Background: Multiple Studies have suggested that aside from its important role in quality of life (QOL) issues, anemia constitutes an independent prognostic factor of survival, response to treatment, loco-regional control and recurrence in patients with cancer concurrent chemotherapy and radiotherapy (i.e. Chemoradiation). This treatment modality is for selected cancer types and patients but may be complicated, especially in low and middle income countries where nutritional anemia is already prevalent. Aim: A prospective study of anemia in cancer patients undergoing chemoradiation using serial hemoglobin measurement. Materials and Method: The study consists of 38 patients with solid cancers who meet inclusion criteria. The baseline hemoglobin (Hb) level was taken and recorded on first day of consultation. Their Hb level was measured every 2 weeks during concurrent radiotherapy and chemotherapy. The blood film pictures at pre-treatment and ongoing treatment were examined and analyzed by a team of Ha Hematologists. The whole process was terminated after 3 consecutive Hb measurement or after week 6. Anemia was classified for this study as follows: Less than10g/dl– Severe Anemia 10–10.9g/dl–Moderate Anemia 11–11.9g/dl–Mild Anemia 12–12.9g/dl–No Anemia. Results: 38 out of 72 cancer patients recruited for this study met inclusion criteria. Age range was 25–75 years with median age of 50years. 27/38 (71/1%) of patients were female while 11/38 (28.9%) were male with ratio of 2:1. 61.2% had Pelvic and 38.8% had head and neck regions as cancer sites that received chemoradiation. More than 75% of patients presented with stage III diseases which was evident of advanced stage and a strong indication for chemoradiation. At week 6, 39.6% cancer patients undergoing chemoradiation had mean haemoglobin value of 10-10.9g/dl. At p value >0.05 there was no statistical significance in distribution of mean Hb, standard deviation based on sex for cancer patients on chemoradiation. Conclusion: The prevalence of anaemia in 38 cancer patients undergoing concurrent chemoradiation was 73.6%. With adequate Hb monitoring during therapy, chemoradiation has no significant effect on Hb level. At 95% confidence interval, the impact of chemoradiation on Hb level during therapy i.e. week 6 was 10.98-11.3g/dl. Despite this result, anemia remains a big challenge to overall quality of life and survival in cancer patients especially in resource constrained environment like Nigeria where nutritional anemia is common and blood transfusion services may be in adequate in certain areas with attendant out of pocket health care cost of blood transfusion. Recommendation: This paves way for more questions and need for further research on our patient population on the relationship between anemia, hypoxia, use of hyperbaric oxygen, radiosensitizers, antihelminthics etc. as anemia remains independent prognostic factor in patients with cancer in our environment. Citation Format: Simeom Chinedu Aruah. A prospective study of anemia in cancer patients undergoing chemoradiation using serial hemoglobin measurement in North Central region, Nigeria. [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Translating Targeted Therapies in Combination with Radiotherapy; 2025 Jan 26-29; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2025;31(2_Suppl):Abstract nr A001.

Hyperbaric oxygen therapy and corticosteroids as combined treatment for acute acoustic trauma.

Acute acoustic trauma (AAT) is a sudden sensorineural hearing loss (SNHL) due to exposure to high intensity impulse noise. There are no acceptable treatment guidelines, although several studies showed steroids could be effective in restoring hearing levels. A recent report suggested that steroids combined with hyperbaric oxygen therapy (HBOT) are a superior regiment for AAT. The purpose of the current study is to investigate the effectiveness of steroids and HBOT for AAT treatment. the medical records 90 patients (118 ears) afflicted with AAT and treated with steroids and HBOT were retrospectively reviewed. Inclusion criteria were sensorineural hearing loss of at least 30 dB at the high frequency range (> 3,000Hz) following exposure to intense sound. Patients who started treatment within 7 days were classified as "Early treatment" group whereas patients who started treatment ≥ 8 days after AAT were classified as "Late treatment". The high frequency (3-8kHz) Pure Tone Average (hPTA) of the entire study population (n = 118) was 40.26 ± 15.42 dB pretreatment vs. 24.99 ± 15.83 dB post treatment (Wilcoxon matched-pairs test, P < 0.0001). Pre-treatment hPTA was not statistically different between early and late study groups, 39.87 ± 16.00 vs. 40.86 ± 14.35 dB in the early vs. late group, respectively (ANOVA, F[3,232] = 22.574, P > 0.05). The post-treatment hPTA on the other hand, was significantly lower in the early vs. late treatment groups (21.93 ± 15.38 vs.31.19 ± 15.09 dB, respectively; ANOVA, F[3,232] = 22.574, P < 0.05). Combination treatment with corticosteroids and HBOT is highly beneficial in improving hearing outcomes following AAT, when initiated within 7 days. This study was retrospectively registered on July 19th 2020 and assigned the identifier number NCT04482998.

P0900 Hyperbaric oxygen therapy downstages refractory perianal fistulizing Crohn’s disease and allows for surgical closure

Abstract Background Hyperbaric Oxygen Therapy (HBOT) has previously shown benefit in treatment-refractory perianal fistulizing Crohn’s disease (PFCD). However, the biological mechanisms underlying therapy response remain poorly understood. In this prospective study, we aimed to assess the feasibility, efficacy, and safety of HBOT followed by surgical closure, while also investigating translational changes associated with HBOT. Methods Patients with active PFCD refractory to 6 months of optimized medical therapy were included. After receiving a seton, patients started HBOT (40 sessions, 110 minutes each with 5-minute air breaks, 100% oxygen at 2.4 atmosphere). Half-way, at week 4, the seton was removed and surgical closure of the internal fistula opening was attempted. All patients continued stable dose of medical treatment during the study. Response was assessed clinically, by pelvic MRI and by patient-reported QoL. RNAseq data of surgical biopsies of the internal fistula opening were explored between patients after completion of HBOT and matched non-HBOT patients. Results Sixteen patients completed HBOT and all of them could undergo a technically successful surgical procedure at week 4 (See Table 1). Clinical remission (no draining fistula openings) was achieved in 43% (W9), 42% (W26) and 70% (W52), and PDAI remission (≤4) was achieved by 31% (W9), 58% (W26) and 70% (W52) (Figure 1). MRI remission (MAGNIFI-CD ≤6) was achieved by 42% (W26) and 57% (W52), and MRI healing (MAGNIFI-CD = 0) was achieved by 8% (W26) and 40% (W52). Quality of Life (CAFQOL) improved significantly with a mean improvement of 10.7 (SE 3.9) by W26 and 22.7 (SE 6.0) by W52. (S)AEs included one patient with a potential oxygen toxicity seizure without long term effects, and one patient reported claustrophobia, no new AEs were reported. Surgical biopsies obtained after HBOT displayed increased expression of cornification markers including CRNN, KRT4, KRT13 and SPRR2B. Pathway analysis confirmed biological activity of ‘keratinization’ and ‘dermal development’ in post-HBOT samples. This is similar to those observed previously in cryptoglandular fistulas. In contrast, patients without HBOT on stable medical treatment mainly showed general immune activation. Conclusion HBOT resulted in downstaging of active PFCD, which became amenable to surgical closure. The combined treatment approach resulted in sustained clinical and MRI remission in patients with refractory disease. HBOT resulted in enhanced activity of pathways associated with keratinization and dermal development. These data support a model where HBOT shifts an active Crohn’s disease fistula towards a more manageable cryptoglandular-like phenotype.

Observation on the Clinical Effect of Hyperbaric Oxygen Therapy on Postoperative Recovery of Patients with Kashin-Beck Disease in Plateau Areas After Total Knee Arthroplasty (TKA)

Background: When the altitude is 0 meters above sea level, the oxygen concentration in the air is approximately 21%. As the altitude increases, the oxygen concentration gradually decreases. At an altitude of 3,000 meters, the oxygen concentration in the air is about 15%. The low oxygen concentration seriously affects the recovery after knee joint surgery and is more likely to lead to postoperative complications. This study aims to explore the efficacy of hyperbaric oxygen therapy on the early postoperative recovery of patients with Kashin-Beck disease in high-altitude areas after undergoing total knee arthroplasty (TKA). Methods: The clinical data of 58 patients with Kashin-Beck Disease who were hospitalized and underwent TKA in Ruoergai County People&amp;apos;s Hospital at an average altitude of 3,500 meters were retrospectively analyzed. According to whether hyperbaric oxygen therapy was used after surgery, they were divided into two groups: the hyperbaric oxygen group (HO group, hyperbaric oxygen therapy was administered daily from the 1st to the 7th day after surgery) and the conventional group (GO group, only normal pressure oxygen inhalation was carried out without hyperbaric oxygen therapy after surgery). Finally, a total of 56 patients were included in the study, with 22 patients in the HO group and 34 patients in the GO group, and the evaluation was carried out based on the recovery status of all selected patients at the time of discharge after surgery. Results: There was no significant difference in the general clinical data between the two groups; the overall incidence of adverse reactions after surgery in the HO group was significantly lower than that in the GO group (P&amp;lt;0.01); the postoperative quality of recovery score (QoR-40) of the HO group was significantly higher than that of the GO group on the 3rd, 7th, and 14th days after surgery (P&amp;lt;0.01); although there was no significant difference in the pain (NRS) score, knee joint score, and surgical satisfaction between the two groups at 2 hours, 12 hours, 24 hours, 48 hours, and 72 hours after surgery, the length of hospital stay in the HO group was significantly shorter than that in the GO group, and this difference was statistically significant (P&amp;lt;0.05). Conclusion: Hyperbaric oxygen therapy for patients with Kashin-Beck Disease in plateau areas after TKA is beneficial to the early postoperative recovery process, can reduce the incidence of postoperative complications, and shorten the length of hospital stay, which has significant clinical application value.

Mechanism of hyperbaric oxygen therapy downregulating H-type angiogenesis in subchondral bone of knee osteoarthritis through the PHD2/HIF-1α pathway

ObjectiveTo explore the mechanism of hyperbaric oxygen therapy in inhibiting subchondral bone angiogenesis and delaying the progression of osteoarthritis through the PHD2/HIF-1α signaling pathway.MethodsMice were randomly divided into three groups (control group, osteoarthritis group, and hyperbaric oxygen treatment group). The effect of hyperbaric oxygen therapy on osteoarthritis was evaluated using Micro-CT, Safranin O-Fast Green staining, and detection of osteoarthritis inflammation markers (MMP-13, ADAMTS-5, Col2a1, and Aggrecan). The activation relationship between PHD2 and downstream signaling pathways was investigated through gene knockout and overexpression experiments. Finally, cell scratch assays, tube formation assays, and chondrogenic differentiation experiments were conducted to verify the mechanism of the PHD2/HIF-1α signaling pathway under hyperbaric oxygen stimulation.ResultsHyperbaric oxygen therapy delayed the progression of osteoarthritis in mice. It promoted chondrogenic differentiation of mesenchymal stem cells, inhibited angiogenesis, enhanced PHD2 expression, and suppressed the production of HIF-1α and VEGFA. Silencing/overexpression of PHD2 resulted in increased/decreased production of HIF-1α and VEGFA, respectively.ConclusionThe hyperbaric oxygen environment promotes the expression of PHD2, accelerates the degradation of HIF-1α, and inhibits the production of VEGFA, thereby reducing the generation of type H vessels in subchondral bone.

P0780 Impact of Hyperbaric Oxygen Therapy on Perianal Fistulas in Crohn’s Disease: Clinical Outcomes and Remission Rates

Abstract Background Crohn's disease (CD) is a chronic inflammatory bowel disorder with debilitating complications such as perianal fistulas, affecting 14-38% of patients (1). Conventional treatments often achieve limited success, necessitating adjunctive approaches (2,3). Hyperbaric Oxygen Therapy (HBOT), known for its wound-healing and anti-inflammatory properties, has emerged as a potential therapy for complex CD cases (4,5). This study evaluates the efficacy of HBOT in combination with standard treatments for reducing perianal fistula activity and achieving clinical remission in patients with CD. Methods A cohort of 11 patients with CD-associated perianal fistulas underwent surgical preparation followed by 30 sessions of HBOT (2.5 ATA, 90 minutes per session). Disease activity was assessed using the Crohn’s Disease Activity Index (CDAI), Simple Endoscopic Score for Crohn’s Disease (SES-CD), Perianal Disease Activity Index (PDAI), and laboratory markers (CRP, fecal calprotectin, hemoglobin, and serum iron). Outcomes were evaluated at baseline, post-treatment (6 weeks), and follow-up (9 months). Results Clinical Improvement: 81.8% of patients demonstrated a significant reduction in CDAI scores. Remission Rates: 54.5% achieved remission (SES-CD, PDAI). 72.8% exhibited normalized fecal calprotectin levels (≤250 µg/g). Improvements were maintained 9 months post-treatment. Minimal side effects, including transient hearing impairment and headaches, were reported. Conclusion HBOT as an adjunctive therapy significantly improves clinical outcomes in CD patients with perianal fistulas. It enhances remission rates, reduces inflammation, and sustains benefits over long-term follow-up. This study highlights the potential of HBOT as a therapeutic option for refractory CD cases. Further randomized controlled trials are warranted to validate these findings.

P0535 Crohn’s Anal Fistula - Quality of Life (CAFQOL) for disease control and remission in patients with perianal fistulizing Crohn’s disease: a new standard in assessing clinical outcome?

Abstract Background Perianal Fistulizing Crohn’s Disease (PFCD) has a major impact on quality of life (QOL). QOL improvement is a key clinical goal, whether the aim is surgical repair, or symptom control. This prospective study evaluated the CAFQOL (Crohn’s Anal Fistula-QOL) questionnaire for disease monitoring in PFCD patients. Methods This study included patients with PFCD starting on anti-TNF therapy, mesenchymal stem cell injection, or hyperbaric oxygen therapy followed by surgical closure. We collected patient-reported CAFQOL and IBDQ-32, as well as Fistula Drainage Assessment (FDA), Perianal Disease Activity Index (PDAI) and MRI (MAGNIFI-CD) outcomes at baseline, and at weeks 9, 26, and 52. QOL changes over time were analyzed using a linear mixed-effects model, and correlations between outcomes were assessed using Spearman correlation coefficients. Internal consistency was assessed with Cronbach’s alpha. The underlying structure of CAFQOL was evaluated with exploratory factor analysis (EFA) to identify distinct dimensions of quality of life. Responsiveness of CAFQOL and PDAI were reported in standardized response mean (SRM). Target CAFQOL values at week 52 for patients in complete remission by week 26 (PDAI≤4, MAGNIFI-CD=0) were calculated with a linear mixed-effects model. Receiver Operating Characteristic (ROC) model was used to evaluate CAFQOL in relation to clinical remission (FDA). Results We included 62 patients with a mean CAFQOL of 59.8 (SD 16.4) at baseline (Table 1). CAFQOL showed significant improvement over time, with average improvements of 8 points (95% CI 4 – 11) at week 9, 12 points (95% CI 8 - 16) at week 26, and 22 points (95% CI 18 - 26) at week 52 (all p&amp;lt;0.0001) (Figure 1). CAFQOL was strongly correlated with IBDQ-32 (r = -0.78; p&amp;lt;0.001) supporting convergent validity, while correlations with FDA (r = 0.48; p&amp;lt;0.0001), PDAI (r = 0.33; p=0.131), and MAGNIFI-CD (r = 0.11; p=0.548) were weak to negligible, supporting discriminant validity. A Cronbach’s alpha of 0.80 supported internal consistency. EFA revealed three main factors: social-practical impacts, emotional-mental health impacts, and physical discomfort explaining 53% of the QOL variance. By week 52, SRM of CAFQOL and PDAI were -1.26 and -1.79 respectively, suggesting large effect sizes. CAFQOL ≤ 37 was associated with complete fistula remission (PDAI≤4, MAGNIFI-CD=0), and was able to detect clinical remission with 80% (95% CI: 58–92) sensitivity and 56% (95% CI 39–71) specificity (AUROC=0.735; p=0.0038). Conclusion The CAFQOL is a reliable and consistently responsive tool that captures meaningful changes in quality of life over time regardless of the treatment modality.

Carbon monoxide poisoning is associated with increased risk of migraine in the long term: a nationwide population-based cohort study

ObjectiveCarbon monoxide poisoning can cause migraine-like attacks. However, the association between carbon monoxide poisoning and the risk of migraine has not been thoroughly studied. This study aimed to investigate the long-term risk of migraine in patients with carbon monoxide poisoning.MethodsThis nationwide, population-based cohort study was conducted using the administrative database of the National Health Insurance Service of Korea from 2002 to 2021. Patients with carbon monoxide poisoning with at least one visit documented according to the International Classification of Diseases, 10th Revision code T58 were included. Patients were only included if they had the same diagnostic code at two or more outpatient clinic visits. The primary outcome of this study was the incidence of migraine after carbon monoxide poisoning.ResultsThe overall risk of migraine was higher in the carbon monoxide poisoning group regardless of age, sex, or use of hyperbaric oxygen therapy (adjusted hazard ratio, 1.37; 95% confidence interval, 1.28–1.48). The carbon monoxide poisoning group had a persistently higher cumulative incidence of migraine during the observation period than the control group.ConclusionCarbon monoxide poisoning was associated with an increased overall risk of developing migraine during long-term follow-up.

Oxy-inflammation in hyperbaric oxygen therapy applications.

Hyperbaric oxygen therapy (HBOT) is a non-invasive method of O2 delivery that induces systemic hyperoxia. Hyperbaric chamber consists of a pressure vessel and a compressed breathing gas supply, which can regulate internal pressure. The chamber delivers 100% O2 to patients according to predetermined protocols and is monitored by trained personnel. HBOT relies on increasing the inspired O2 fraction (fiO2) and elevating the partial pressure of O2 (pO2). O2 is typically administered at pressures between 1.5 and 3.0 ATA for 60 to 120 minutes, depending on the clinical presentation. Currently, there are 15 indications for HBOT approved by the Undersea and Hyperbaric Medicine Society, categorized into three groups: emergency medicine, wound healing acceleration, and antimicrobial effects. The present narrative review aims to elucidate the mechanisms action underlying HBOT, particularly oxy-inflammation, in various pathologies within these categories.