UHM Journal Ahead of Print

Transcutaneous Oximetry Optimizes Clinical Management and Cost-Effectiveness of Diabetic Foot Ulcers Treated with Hyperbaric Oxygen: A Review of Point of Care Vascular Screening Options  Richard E. Clarke, CHT-ADMIN  National Baromedical Services, Columbia, South Carolina, USA CORRESPONDING AUTHOR: dickclarke@baromedical.com ABSTRACT  Hyperbaric oxygen therapy has been employed to treat diabetic foot ulcers for more than four decades. While supported by some high-quality evidence, sufficient conflicting data makes its use open to criticism. Even systematic and other reviews favorably disposed to this treatment adjunct invariably plead  for better patient selection. Common among several causes of non-healing ulcers is persistent hypoxia. Transcutaneous oximetry uniquely measures tissue oxygen tension. Combination air and oxygen testing provide an evidence-based approach to hyperbaric patient selection by demonstrating locally reversible hypoxia. Transcutaneous oximetry differentiates hyperbaric responders from non-responders early in their treatment course by detecting neo-angiogenesis, thereby providing the basis for continued hyperbaric dosing only in those benefiting. Finally, such testing guides therapeutic endpoint determination, namely normalized peri-ulcer oxygen tensions. This contrasts with continuing medically unnecessary and costly hyperbaric treatments until wound closure. Measurements of blood pressure and blood flow represent imperfect oxygen delivery surrogates and imperfect ones. Recently introduced near-infrared spectroscopy and long-wave infrared thermography provide insights into tissue oxygen saturation and changes in micro-vascular density, respectively. ..

ABSTRACT Background: Autologous bone grafting is essential in reconstructive surgeries, particularly orthopedic and maxillofacial applications, but graft integration can be challenging in high-risk patients. Hyperbaric Oxygen Therapy (HBOT) has been proposed to enhance bone graft integration by stimulating osteogenesis and vascularization. This systematic review and meta-analysis evaluated the efficacy of HBOT in promoting autologous bone graft integration and identified contexts where HBOT may be most beneficial.   Methods: A systematic search identified 11 studies meeting inclusion criteria, seven providing quantitative data for meta-analysis. The primary meta-analysis and an orthopedic-specific subgroup analysis used random-effects models to calculate pooled Standardized Mean Differences (SMD) and assess heterogeneity (I²). Results: HBOT demonstrated a significant positive effect on bone graft integration in the primary analysis (SMD: 1.476, 95% CI: 0.814–2.138). The orthopedic subgroup showed a stronger, consistent effect (SMD: 1.995, 95% CI: 1.117–2.873) with low heterogeneity (I² = 3.361%). Observational studies suggest potential benefits for maxillofacial grafts, but a lack of controlled data limits the evidence. One cranial study reported an anomalous negative result.   Conclusions: HBOT significantly enhances autologous bone graft integration, particularly in orthopedic applications and high-risk patients. Its ability to stimulate osteogenesis and vascularization highlights its value as an adjunctive therapy in complex reconstructions. However, the reliance on animal models and ..

Abstract Case Description We present a case of a 39-year-old healthy female scientific diver who developed cold urticaria (CU) 8 months prior, when immediately postpartum. She had extensive diving experience but discontinued diving during pregnancy and sought to resume diving. Before our consultation, she had seen a dermatologist and allergist for evaluation for an underlying etiology and management. Intervention Initial management included diphenhydramine and cetirizine with topical triamcinolone based on dermatology recommendations. Her allergist later advised discontinuing diphenhydramine and remaining on cetirizine 10mg up to 4 times daily, given breastfeeding concerns. Epinephrine was prescribed in case of anaphylaxis. Outcome The workup revealed no underlying pathology, and she was not cleared for diving until her CU was resolved. Despite antihistamines, she continues to be symptomatic, including in pools heated to 90⁰F. Although drysuit certified, we could not clear her for scientific diving and advised against recreational diving given the risk of anaphylaxis.  Discussion CU is an uncommon but under-reported and under-recognized condition with potentially fatal consequences for swimmers and divers. Although symptom management focuses on antihistamines, corticosteroids and omalizumab (Xolair®) may prove helpful. Nonetheless, the risk of anaphylaxis remains, so CU should be a disqualifying condition for divers. Associated and causative conditions require specialist evaluation, with many patients ..

ABSTRACT Surface-orientated diving with nitrogen-oxygen breathing gases (nitrox) other than air will commonly be planned according to the Equivalent Air Depth (EAD) principle. EAD is the depth at which a diver breathing air will inhale the same pN2 as the nitrox-breathing diver. Using conventional air decompression tables based on the EAD depth will allow longer bottom times or shorter decompression times compared to air breathing at the same water depth. This scoping reviewed aimed to investigate the validity of the EAD principle. A literature review identified thirteen eligible studies reporting DCS incidence or vascular bubbles following air and nitrox exposures in human and experimental animals. Four experimental (N=1597mandives) and two epidemiological (N=249109 mandives) studies on humans did not disclose a higher DCS incidence or bubble scores following nitrox dives compared to air dives of similar EAD. Seven experimental animal studies consistently showed that a high pO2 (>2 atm) increased DCS susceptibility in goats and rats. This can likely be explained by the reduction of the “oxygen window” due to the high tissue and venous pO2. There is insufficient data from animal studies to conclude whether this can be reproduced within a pO2 range applicable for human operational diving (<1.6 atm). There is presently no ..

Abstract: Hyperbaric oxygen (HBO2) therapy has sparked increasing attention as a potential therapeutic intervention for traumatic brain injury (TBI), but the variability in findings necessitates a comprehensive analysis of recent literature. This review aims to evaluate the latest empirical evidence on the effectiveness of HBO2 therapy in treating TBI, focusing on its impact on neurological recovery, cognitive functions, and physiological markers. To achieve this, we extensively searched scholarly articles from reputable databases such as Scopus and Web of Science (WoS), focusing on studies published between 2015 and 2024—the study flow based on the PRISMA framework. The final dataset was limited to 74 (n=74) and was analyzed using both quantitative method (descriptive statistics) and qualitative techniques (thematic analysis). The findings were divided into three themes: (1) clinical efficacy of HBO2 therapy for TBI, (2) mechanisms of action and biological pathways in HBO2 therapy, and (3) evolving therapeutic applications of HBO2 in TBI. Results indicated mixed outcomes; while some studies reported significant cognitive, physiological, and clinical improvements, others raised concerns about methodological variability and limited reproducibility. Mechanistic studies highlighted HBO2's role in modulating pathways such as TLR4/NF-κB and VEGF/ERK, facilitating neuroprotection, angiogenesis, and synaptogenesis. Emerging therapies combining HBO2 with regenerative approaches, such as stem cell treatments, showed promise ..

ABSTRACT We present a case of severe CNS decompression sickness (DCS) that included Broca’s aphasia in a recreational diver, offering insights into the application of advanced non-invasive monitoring during hyperbaric oxygen therapy (HBO2). This 64-year-old male diver, following a rapid ascent after a deep dive, experienced the onset of expressive aphasia, vertigo, and right-sided hemiparesis about 30-120 minutes after surfacing. Initial monitoring with bispectral index (BIS) and density spectral array (DSA) revealed significant 2asymmetry between cerebral hemispheres, particularly in spectral edge frequency (SEF) values, with the left hemisphere showing marked reduction during air breaks at HBO2 pressures. This pattern resolved progressively over three HBO2 sessions, with full clinical recovery after four sessions coinciding with the resolution of this DSA hemispheric asymmetry. The case indirectly supports the theoretical role of microparticles and endothelial dysfunction as contributors to cerebral hypo-perfusion in DCS beyond the conventional focus on gas bubbles, reflected by the clinical findings, representing a clinical gradient. This novel application of BIS-DSA in hyperbaric medicine offers promising potential for real-time monitoring of cerebral involvement. It could enhance patient outcomes by guiding individualized treatment in neurologically compromised DCS cases. Keywords: bispectral index; brain; cerebral blood flow; decompression sickness; density spectral array; electroencephalography; microparticles

ABSTRACT:  We present a case of a patient with a history of chronic lymphocytic leukemia (CLL) and cutaneous B-cell lymphoma of the right leg. She had previously received radiation treatment to the affected area and subsequently developed radiation fibrosis with two non-healing ulcerations at the previous tumor sites. A biopsy revealed spongiotic and sparse superficial perivascular dermatitis. Due to poor wound healing, adjunctive hyperbaric oxygen (HBO2) therapy was initiated. However, shortly after beginning HBO2treatments, the wounds worsened. Repeat biopsies were performed, and the new areas were found to be consistent with cutaneous large B-cell lymphoma. Consequently, HBO2therapy was discontinued, and aggressive chemotherapy/immunotherapy was initiated. We recommend that patients with a history of cutaneous B-cell lymphoma be closely monitored for signs of tumor recurrence or disease worsening if they are to undergo adjunctive hyperbaric oxygen therapy.

ABSTRACT Introduction:  This is the first published study examining decompression illness (DCI) among divers in Algeria. DCI is a complex syndrome caused by bubbles of inert gas that form in the body due to an improper decompression process following exposure to increased pressure underwater. Algerian diving conditions pose significant challenges to divers. The study focuses on red coral diving, a popular and long-standing practice in eastern Algeria. We present three case reports describing osteonecrosis dysbaric of the humeral head with varying degrees of severity and presentation. Objectives: Dysbaric osteonecrosis (DON), a rare complication in professional divers and compressed-air workers, presents a controversial link to previous decompression sickness (DCS) with musculoskeletal pain (type 1 DCS). The potential for these ischemic lesions to progress to osteonecrosis after DCS remains unclear. Case Presentation: This report describes a professional diver who was declared permanently unfit for diving due to advanced dysbaric osteonecrosis of the shoulder, following type 1 DCS in the same region treated with hyperbaric oxygen therapy. This case highlights the potential association between these events and emphasizes the importance of close monitoring after acute type 1 DCS. Conclusion: Early magnetic resonance imaging (MRI) evaluation of all DCS cases with musculoskeletal pain is recommended to detect potential osteo-medullary damage. Such ..

ABSTRACT Watchman devices are increasingly implanted in patients with atrial fibrillation who cannot be anticoagulated. We report a case of a patient undergoing Watchman device insertion complicated by cerebral arterial gas embolism. The treatment was delayed because the diagnosis was not initially considered. The patient was eventually treated with hyperbaric oxygen but sustained permanent disabilities. Watchman device implantation has a near 1% risk of arterial gas embolism. The possibility of cerebral gas embolism should be considered in patients emerging from anesthesia with neurologic deficits.  Keywords: arterial gas embolism; hyperbaric oxygen therapy; watchman

ABSTRACT Introduction: The COVID-19 pandemic, being an airborne disease, posed a challenge in providing Hyperbaric Oxygen (HBO2) Therapy in multiplace chambers by increasing the risk of cross-infectivity while on air break inside the chamber. The standard regimen consisting of two air breaks was modified, and a new low-dose HBO2 therapy regimen with no air breaks was introduced to mitigate the risk of cross-infection. This study aimed to evaluate the efficacy of the modified HBO2 therapy regimen compared to the standard HBO2 therapy regimen for patients with soft tissue radiation injury.  Methods: A retrospective observational study compared the modified low-dose HBO2 therapy regimen of 2.4 Atmosphere Absolute (ATA) for 60 minutes without air-break vis-a-vis the standard regimen of 2.4 ATA for 100 minutes with two air breaks of five minutes each. Patients with soft tissue radiation injury in the form of radiation cystitis and radiation proctitis were selected for comparison in the study. Data was retrieved from patients who underwent the standard and modified regimen during the COVID-19 pandemic. Late Effects Normal Tissue (LENT)/ Subjective Objective Management Analytic (SOMA) questionnaire-based scoring was compared for 30 sessions of HBO2 therapy. Standard biostatistical methodology was used to compare the outcomes of both regimens.  Results: The mean LENT SOMA score decreased from the baseline to the ..

ABSTRACT COVID-19 has been associated with an increased risk of avascular necrosis (AVN), which affects various joints such as the hip, vertebrae, knee, and jaw. Understanding AVN's pathogenesis and risk factors as a consequence of COVID-19 is essential for improving treatment and identifying preventive measures. This retrospective cohort study aims to assess the impact of COVID-19 on AVN etiology and raise awareness among clinicians. The study analyzed patients diagnosed with AVN and treated with Hyperbaric Oxygen Therapy at Gülhane Training and Research Hospital from January 2018 to January 2023. Patients were categorized into two groups: those admitted before the pandemic (control group) and those admitted after (study group). The results showed a significant increase in AVN cases during the post-pandemic period, with a higher incidence of femoral head involvement and more advanced stages of AVN in patients with a history of COVID-19. The findings suggest that COVID-19 and high-dose steroid use may increase AVN risk, highlighting the need for careful steroid management and monitoring for joint pain in these patients. Further research is recommended to explore the link between COVID-19 and AVN, the duration of symptoms, and the prognostic implications.

ABSTRACT Background Decompression illness (DCI) poses significant risks for divers, particularly in remote locations with limited resources. Few randomized controlled trials (RCTs) exist, necessitating a review to consolidate current evidence and support evidence-based treatment protocols. This review evaluates RCT evidence on the effectiveness of recompression treatment and adjunctive therapies for diving-related DCI.   Methods This review included RCTs assessing recompression treatment or adjunctive therapies in managing DCI. Exclusions were non-human studies, trials on DCI prevention, non-English publications, incomplete trials, and those involving non-diving DCI. Databases searched from inception to May 15, 2023, included Ovid MEDLINE, CENTRAL, CINAHL, and EMBASE. Citation chasing was performed on June 1, 2023, using Web of Science. Risk-of-bias assessments were guided by considering the Cochrane risk-of-bias tool for randomized trials.   Results Two RCTs were identified. One trial (n=180) indicated that tenoxicam might reduce the number of required recompressions from three (range 1-8) to two (range 1-6). The other trial (n=41) showed that a shorter initial recompression treatment table could decrease the number of recompressions (median one vs. two) in cases of mild DCI.   Discussion Limitations included unblinded participants, small participant numbers, non-protocol interventions, participant blinding, and incomplete outcome data. Recommendations for future research include reaching a consensus on a universal scoring system to support ..

ABSTRACT Background: Central nervous system oxygen toxicity (CNS-OT) is a critical concern for Navy divers using closed-circuit rebreathers who are subjected to prolonged exposure to hyperbaric oxygen levels. We explored the potential of specific dietary supplements, caffeine, and astaxanthin, to delay the onset of CNS-OT. Methods: Experiments were conducted using male C57BL/6 mice exposed to pure oxygen at 507 kPa, with latency to tonic-clonic seizures recorded. Mice were orally administered caffeine (1.25, 2.5, or 5 mg/kg), astaxanthin (8 mg/kg), or a vehicle (water).  Results: Caffeine and astaxanthin significantly extended the latency period to seizure onset (P<0.03). Notably, combining caffeine and astaxanthin (P<0.001 vs. control) provided better protection against CNS-OT than either substance alone. Conclusions: Our results suggest that administering caffeine and astaxanthin before hyperbaric oxygen exposure delays hyperoxia-induced seizures. KEYWORDS: dietary supplements; hyperbaric oxygen; hyperemia; reactive oxygen species

Yuehong Ma1,2, Wenying Lv3, Huijun Hu2, Shuyi Pan2, Dazhi Guo2 1 Department of Hyperbaric Oxygen, School of Medicine, South China University of Technology, Guangzhou, 510006, China 2 Department of Hyperbaric Oxygen, 6th Medical Center of PLA General Hospital, Beijing, 100048, China 3 Department of Hyperbaric Oxygen, Southern Medical University, Guangzhou, 510145, China   ABSTRACT Carbon monoxide (CO) poisoning is one of the common causes of poisoning and can result in significant neurological sequelae. However, few studies have focused on the elderly patient population. We retrospectively reviewed elderly (age≥65 years) with CO poisoning from non-fire accidents and non-suicide at the 6th Medical Center PLA General Hospital in China from 2013 to 2023. A total of 167 patients were enrolled. The annual case number decreased from 2013 to 2023, particularly during the cold months (November to February). The most common source of exposure was coal heating (90%). The most common presenting symptoms were consciousness changes (90%). Eighty-eight patients (52%) developed delayed neurological sequelae (DNS), of which sixty-nine (78%) converted to long-term neurological sequelae (LNS). The most common imaging manifestations were hypoxic-ischemic damage in the basal ganglia (54%) and demyelination in white matter (46%). After multivariate analysis, initial GCS score and coma time (GCS scores＜8) were the independent risk factors ..

ABSTRACT Objectives: Hyperbaric Oxygen (HBO2) Therapy has been associated with some risks and adverse events. Previous studies examining otologic complications from HBO2 therapy vary in their reported incidence of adverse events. This study aims to systematically review the otologic complications associated with HBO2 therapy and investigate contributing risk and protective factors. Review Methods: A systematic review was conducted to identify studies reporting otologic adverse effects due to HBO2 therapy. Utilizing PRISMA 2020 guidelines, titles and abstracts were screened before conducting a full-text analysis. Studies reporting incidence of otologic complications and studies reporting risk or protective factors for otologic complications were included. Results: A search for articles on HBO2 therapy otologic complications yielded 2,027 articles, of which 183 were relevant to the research question. Ultimately, 54 studies met the inclusion criteria. Fifteen percent of the 18,284 patients treated with HBO2 therapy experienced adverse events. Of the middle ear barotrauma (MEB) that occurred, 42.8% was mild, and 6.4% was severe. The major risk factors were increasing age, female sex, head and neck pathology, sensory neuropathy, and pre-treatment difficulty equalizing ear pressure. The main protective factor was experience with effective equalization techniques. Conclusions: 15% of patients experienced otologic complications due to HBO2 therapy. Older age, female sex, and history of ..

ABSTRACT Methemoglobinemia is a rare but potentially serious condition characterized by an increased level of methemoglobin in the blood, which impairs oxygen delivery to tissues. It occurs when hemoglobin’s ferrous iron (Fe2+) is oxidized to ferric iron (Fe3+), rendering it unable to bind oxygen effectively. This leads to tissue hypoxia, which can manifest clinically as cyanosis, shortness of breath, fatigue, and, in severe cases, organ dysfunction. Nitrofurantoin-induced hemolytic anemia and methemoglobinemia in patients with glucose-6- phosphate dehydrogenase (G6PD) deficiency are rare but potentially life-threatening complications. We present the case of a 64-year-old female with G6PD deficiency who developed acute hemolytic anemia and methemoglobinemia following nitrofurantoin therapy for a urinary tract infection. Her initial symptoms included fatigue, jaundice, and dyspnea, progressing rapidly to severe anemia and cyanosis. Laboratory investigations confirmed hemolysis and elevated methemoglobin levels. Although methemoglobinemia is commonly treated with methylene blue, its use in G6PD- deficient patients can exacerbate hemolysis. In this case, we promptly discontinued nitrofurantoin and managed the patient with hyperbaric oxygen therapy, intravenous ascorbic acid, and other supportive measures. Despite aggressive treatment, she required blood transfusion support and prolonged hospitalization. This case underscores the importance of recognizing the potential for nitrofurantoin-induced hemolytic anemia and methemoglobinemia in G6PD-deficient individuals, highlighting the ..