Undersea and Hyperbaric Medicine最新文献

Introduction: A chronic leg ulcer is a serious complication of sickle cell anemia. The ulcers are treatment- resistant, recur frequently, and are associated with more severe disease. Treatment options for chronic leg ulcers in patients with sickle cell disease are limited. Hyperbaric oxygen (HBO₂) therapy is a promising therapy for the management of sickle cell chronic leg ulcers as it relieves hypoxia, promotes angiogenesis, and reduces wound inflammation.

Case: A 35-year-old male with sickle cell anemia with a chronic leg ulcer for one year, despite regular wound dressing and antibiotics, was then successfully managed through HBO₂ therapy followed by skin grafting.

Conclusion: HBO₂ therapy was effective in this case and has also shown effectiveness as an adjunct therapy in the management of sickle cell-related chronic leg ulcers in other case reports. This supports the need for further research in this area.

Introduction: Divers are reported to have a lower ventilatory response to elevated levels of carbon dioxide (CO₂) than non-divers. Hypoventilation with CO₂ retention during diving is potentially dangerous. It is unknown if CO₂ retention is largely inherited or develops during diving training. We aimed to investigate if a military dive training course would influence the ventilatory response to CO₂.

Methods: Novice rebreather Divers with Amphibious Rangers as controls were tested at baseline, after 12 weeks of water exercise training, and after 15 weeks of diving: participants rebreathed in a Douglas bag filled with an initial 100% oxygen, resulting in increasing levels of inspiratory CO₂ (iCO₂). The test was performed until symptom-limitation or an expiratory CO₂ of 8.0 kPa. To decrease conscious control of breathing, participants were distracted with a memory game during the test. Differences between groups and over time were analyzed using independent and paired t-tests.

Results: Ten Divers and six Amphibious Rangers completed baseline testing and eight Divers completed all tests. Divers had a statistically significant higher Minute Ventilation (V'E) after dive training, compared to after water exercise training and baseline, at all levels of iCO₂. However, the change in Hypercapnic ventilatory response (HCVR) before and after dive training across pCO₂ values 5.0-7.9, did not reach statistical significance. At baseline, Amphibious Rangers had a non-significant higher V'E compared to Divers at higher levels of iCO₂.

Conclusion: A military rebreather diving program might be associated with increased ventilatory response to CO₂.

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.

Conclusion: Our results suggest that administering caffeine and astaxanthin before hyperbaric oxygen exposure delays hyperoxia-induced seizures.

Introduction: Medical ozone therapy, which involves topical or systemic administration of ozone gas, is promoted as a treatment for various infections and inflammatory conditions, although evidence supporting its clinical effectiveness in humans is limited. Medical ozone administration is also associated with serious adverse effects, including gas embolus and fatality. We present the case of a patient who experienced dermatologic complications after receiving medical ozone therapy. The complications were managed with surgical intervention and hyperbaric oxygen therapy.

Case report: A 43-year-old female was administered medical ozone therapy injections to the temples and central forehead by a dermatologist to enhance hair growth and collagen formation. After the procedure, the patient experienced worsening alopecia and scarring in the treated areas. She eventually underwent surgical excision and closure that was performed by a plastic and reconstructive surgeon. Intraoperatively, she was noted to have significantly fibrotic, scarred, and poorly vascularized tissue, which raised concern for poor wound healing. Her plastic surgeon referred her for adjunctive hyperbaric medicine evaluation to treat presumed skin flap vascular compromise. She completed a course of forty hyperbaric oxygen treatments before returning to the plastic surgeon for scar tissue excision and local tissue rearrangement that ultimately resulted in acceptable cosmesis.

Conclusion: While medical ozone therapy may result in favorable effects on a cellular level, the treatment is associated with significant clinical risks that may outweigh its potential therapeutic benefits. Systemic hyperbaric oxygenation may enhance vascularity and improve the quality of devitalized tissue in areas previously treated with medical ozone therapy.

Hyperbaric oxygen therapy has been employed to treat diabetic foot ulcers for more than four decades. While supported by some high-quality evidence, there is sufficient conflicting data to render 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 provides an evidence-based approach to hyperbaric patient selection through demonstration of locally reversible hypoxia. Transcutaneous oximetry differentiates hyperbaric responders from non- responders early in their treatment course by detecting neoangiogenesis, thereby providing a basis for continuing hyperbaric dosing only in those who benefit. 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 are imperfect surrogates for oxygen delivery. Recently introduced near-infrared spectroscopy and long-wave infrared thermography provide insights into tissue oxygen saturation and changes in micro-vascular density, respectively. Neither, however, guides clinically efficacious and cost-effective hyperbaric oxygenation in the manner afforded by transcutaneous oximetry. This paper describes evidence-based guidance on hyperbaric oxygen dosing for diabetic foot ulcers, reviews point-of-care screening options, and argues for the continued superiority of transcutaneous oximetry in the current era.

Background: Autologous bone grafting is crucial in reconstructive surgeries, yet high-risk patients often face challenges in achieving robust graft integration. Hyperbaric Oxygen Therapy (HBO₂) has been proposed to improve graft outcomes by enhancing osteogenesis and vascularization. This systematic review and meta-analysis evaluated HBO₂'s efficacy in promoting autologous bone graft integration and identified contexts in which HBO₂ may be most beneficial.

Methods: A systematic search identified 11 studies that met the inclusion criteria, of which seven provided quantitative data for meta-analysis. Random-effects models generated pooled Standardized Mean Differences (SMD) and assessed heterogeneity (I²). Subgroup analysis focused on orthopedic applications.

Results: Compared to control groups, HBO₂ demonstrated a moderate to strong effect on bone graft integration in the primary analysis (SMD: 1.476, 95% CI: 0.814-2.138). However, heterogeneity was substantial (I² ≈ 77%), reflecting diverse protocols and patient populations. A subgroup of orthopedic studies showed a stronger, consistent effect (SMD: 1.995, 95% CI: 1.117-2.873) with low heterogeneity (I² = 3.361%). Although observational data suggest potential benefits in maxillofacial grafts, many studies in this domain are small or lack controls. One cranial study reported a negative result, indicating possible variability in craniofacial contexts.

Conclusions: HBO₂ appears to substantially enhance autologous bone graft integration, particularly in orthopedic and high-risk patients, by stimulating osteogenesis and vascularization. Nonetheless, reliance on animal models, limited human data in maxillofacial settings, and considerable heterogeneity underscore the need for further research, standardized protocols, and well-powered clinical trials to confirm HBO₂'s effectiveness across diverse grafting scenarios.

Introduction: Sternoclavicular septic arthritis with pyomyositis is a relatively rare condition. While most cases of septic arthritis are caused by gram-positive organisms, such as Staphylococci and Streptococci spp., a small number of patients present with gram-negative organisms as the cause of their condition. Signs and symptoms can be non-specific, and although CT imaging aids in diagnosis, a timely identification relies primarily on a high index of clinical suspicion.

Case description: We present a case of a 44-year-old female patient with a history of poorly controlled diabetes mellitus who presented with a chronic, non-healing wound that developed on a background of non-traumatic sternoclavicular septic arthritis, chronic osteomyelitis of the clavicle and manubrium, and concomitant pectoralis pyomyositis caused by a gram-negative pathogen. The use of HBO₂ as an addition to this patient's treatment regimen hastened the healing process.

Conclusion: Given the rarity of this condition, we consider that adding to the body of literature with regards to the diagnosis and treatment of this condition can help clinicians develop a keen eye for it, decreasing the morbidity and mortality associated with it.

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 HBO₂ treatments, the wounds worsened. Repeat biopsies were performed, and the new areas were consistent with cutaneous large B-cell lymphoma. Consequently, HBO₂ therapy 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.

A 52-year-old male undergoing pulmonary lesion cryoablation developed transient intraprocedural and postprocedural hypotension, transient ST elevations on telemetry with associated bradyarrhythmia, and computed tomography imaging revealing arterial gas embolism within the left ventricle and aorta. Coordinated multidisciplinary efforts involving interventional radiology, anesthesiology, cardiology, critical care, and hyperbaric medicine were employed to ensure a successful recovery, alongside important management considerations aimed at minimizing adverse outcomes.

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 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 changes in consciousness (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 for patients with DNS (p<0.001). Interestingly, myocardial injury was more common in non-DNS elderly patients than in DNS patients (p<0.001); only coma time was an independent risk factor for patients with LNS (p<0.001). There was no significant difference between HBO₂ (p=0.19) and NBO (p=0.38) in the occurrence of DNS and LNS in elderly patients with CO poisoning. Therefore, initial GCS score and coma time (GCS scores<8) may be the risk factors of DNS, and coma time may be a high-risk factor for poor prognosis in elderly patients with CO poisoning. Moreover, HBO₂ treatment did not show benefit or harm to those patients. Special attention should be given, and follow-up should be performed on elderly patients, particularly those who have longer coma time and CO exposure time and lower initial GCS scores in acute CO poisoning.