Patient-Reported Outcome Measures Following Hyperbaric Oxygen Therapy for Radiation Cystitis: Early Results From the Multicenter Registry for Hyperbaric Oxygen Therapy.

PURPOSE: Our purpose was to determine changes in patient-reported hematuria and urinary symptoms after hyperbaric oxygen (HBO2) treatment for radiation cystitis (RC). MATERIALS AND METHODS: We analyzed prospectively collected data from the Multicenter Registry for Hyperbaric Oxygen Therapy Consortium accumulated within a week of beginning and ending HBO2. Measures included the modified Radiation Therapy Oncology Group (RTOG) Hematuria Scale, Urinary Distress Inventory Short Form, and EuroQol Five Dimension Five Level instrument. RTOG hematuria and Urinary Distress Inventory Short Form scores were compared using the sign test. Logistic regression was used to evaluate characteristics associated with hematuria improvement. RESULTS: A total of 470 registry patients had RC. The median age, number of HBO2 sessions, and years after radiation were 73 (IQR 12) years, 39 (IQR 10) sessions, and 5 (IQR 8) years, respectively. Eighty-four percent of patients (393/470) had prostate cancer‒related radiation. EuroQol Five Dimension Five Level scores improved from 0.83 (IQR 0.14) to 0.85 (IQR 0.22; P < .001. Three hundred seventy patients had complete RTOG hematuria scores that improved from 2 (IQR 2) to 0 (IQR 2; P < .001. Two hundred forty-six patients had complete Urinary Distress Inventory Short Form ratings that decreased from 33.3 (IQR 44) to 22.2 (IQR 33; P < .001). Regression analysis of those with visible hematuria before HBO2 showed lower improvement odds associated with higher HBO2 hematuria scores (odds ratio [OR] 0.44, 95% CI 0.26-0.73; P < .01), a smoking history (OR 0.44, 95% CI 0.21-0.92; P = .03), or a nonprostate cancer history (OR 0.32, 95% CI 0.10-0.99; P = .05). CONCLUSIONS: HBO2 for RC improved reported hematuria, urinary function, and quality of life. Higher baseline hematuria scores, smoking, and nonprostate cancer history were associated with lower odds of hematuria improvement.

Adjunctive hyperbaric oxygen therapy for spinal cord ischemia after complex aortic repair.

OBJECTIVE: Spinal cord ischemia (SCI) with paraplegia or paraparesis is a devastating complication of complex aortic repair (CAR). Treatment includes cerebrospinal fluid drainage, maintenance of hemoglobin concentration (>10 g/L), and elevating mean arterial blood pressure. Animal and human case series have reported improvements in SCI outcomes with hyperbaric oxygen therapy (HBOT). We reviewed our center's experience with HBOT as a rescue treatment for spinal cord ischemia post-CAR in addition to standard treatment. METHODS: A retrospective review of the University Health Network's Hyperbaric Medicine Unit treatment database identified HBOT sessions for patients with SCI post-CAR between January 2013 and June 2021. Mean estimates of overall motor function scores were determined for postoperative, pre-HBOT, post-HBOT (within 4 hours of the final HBOT session), and at the final assessment (last available in-hospital evaluation) using a linear mixed model. A subgroup analysis compared the mean estimates of overall motor function scores between improvement and non-improvement groups at given timepoints. Improvement of motor function was defined as either a ≥2 point increase in overall muscle function score in patients with paraparesis or an upward change in motor deficit categorization (para/monoplegia, paraparesis, and no deficit). Subgroup analysis was performed by stratifying by improvement or non-improvement of motor function from pre-HBOT to final evaluation. RESULTS: Thirty patients were treated for SCI. Pre-HBOT, the motor deficit categorization was 10 paraplegia, three monoplegia, 16 paraparesis, and one unable to assess. At the final assessment, 14 patients demonstrated variable degrees of motor function improvement; eight patients demonstrated full motor function recovery. Seven of the 10 patients with paraplegia remained paraplegic despite HBOT. The estimated mean of overall muscle function score for pre-HBOT was 16.6 ± 2.9 (95% confidence interval [CI], 10.9-22.3) and for final assessment was 23.4 ± 2.9 (95% CI, 17.7-29.1). The estimated mean difference between pre-HBOT and final assessment overall muscle function score was 6.7 ± 3.1 (95% CI, 0.6-16.1). The estimated mean difference of the overall muscle function score between pre-HBOT and final assessment for the improved group was 16.6 ± 3.5 (95% CI, 7.5-25.7) vs -4.9 ± 4.2 (95% CI, -16.0 to 6.2) for the non-improved group. CONCLUSIONS: HBOT, in addition to standard treatment, may potentially improve recovery in spinal cord function following SCI post-CAR. However, the potential benefits of HBOT are not equally distributed among subgroups.

Hyperbaric oxygenation improve red blood cell deformability in patients with acute or chronic inflammation.

INTRODUCTION: Red blood cells (RBC) are one of the key elements of the microcirculation. Their ability to pass through capillaries and to deliver oxygen to cells is due to their large degree of deformability linked to the characteristics of the RBC membrane. Alterations in RBC deformability as a result of membrane damage, linked in part to increased synthesis of reactive oxygen species (ROS), can be observed in several diseases, such as sepsis, and may contribute to the altered microcirculation observed in these pathologies. Hyperbaric oxygen therapy (HBOT), with inhalation of 100 % oxygen, has been proposed in several acute or chronic pathologies, including carbon monoxide poisoning. OBJECTIVE: We investigated the effects of HBOT on oxidative stress from ROS produced by myeloperoxidase (MPO) and on RBC deformability in patients with acute or chronic inflammation (n = 10), in patients with acute carbon monoxide poisoning (n = 10), and in healthy volunteers (n = 10). METHODS: RBC deformability was evaluated before and after HBOT in the various populations using the ektacytometry technique (Laser-assisted Optical Rotational Red Cell Analyzer - LORRCA). Deformability was determined by the elongation index (EI) in relation to the shear stress (SS) over a range of 0.3 to 50 Pa. Oxidative stress was estimated through changes in proteins (chlorotyrosine and homocitrulline) induced by MPO activity measured by liquid chromatography-tandem mass spectrometry analysis. RESULTS: Before HBOT, EI was significantly lower in patients with acute or chronic inflammation than in healthy volunteers and patients with acute carbon monoxide poisoning for the majority of SS values studied. After one session of HBOT, the EI was significantly higher than before HBOT for SS values of 1.93 Pa or higher in patients with acute or chronic inflammation. This effect remains constant after 10 sessions. There were no differences before and after HBOT in protein or amino acid oxidation due to ROS generation mediated by MPO in the three populations. CONCLUSIONS: Our results confirm altered RBC deformability in patients with acute and chronic conditions associated with an underlying inflammatory process. HBOT improves deformability only after one session and therefore may improve microcirculation in this population. According to our results, this improvement does not seem mediated by the ROS pathway via MPO. These results need to be confirmed in a larger population.

Early hyperbaric oxygen therapy is associated with favorable outcome in patients with iatrogenic cerebral arterial gas embolism: systematic review and individual patient data meta-analysis of observational studies.

BACKGROUND: Iatrogenic cerebral arterial gas embolism (CAGE) caused by invasive medical procedures may be treated with hyperbaric oxygen therapy (HBOT). Previous studies suggested that initiation of HBOT within 6-8 h is associated with higher probability of favorable outcome, when compared to time-to-HBOT beyond 8 h. We performed a group level and individual patient level meta-analysis of observational studies, to evaluate the relationship between time-to-HBOT and outcome after iatrogenic CAGE. METHODS: We systematically searched for studies reporting on time-to-HBOT and outcome in patients with iatrogenic CAGE. On group level, we meta-analyzed the differences between median time-to-HBOT in patients with favorable versus unfavorable outcome. On individual patient level, we analyzed the relationship between time-to-HBOT and probability of favorable outcome in a generalized linear mixed effects model. RESULTS: Group level meta-analysis (ten studies, 263 patients) shows that patients with favorable outcome were treated with HBOT 2.4 h (95% CI 0.6-9.7) earlier than patients with unfavorable outcome. The generalized linear mixed effects model (eight studies, 126 patients) shows a significant relationship between time-to-HBOT and probability of favorable outcome (p = 0.013) that remains significant after correcting for severity of manifestations (p = 0.041). Probability of favorable outcome decreases from approximately 65% when HBOT is started immediately, to 30% when HBOT is delayed for 15 h. CONCLUSIONS: Increased time-to-HBOT is associated with decreased probability of favorable outcome in iatrogenic CAGE. This suggests that early initiation of HBOT in iatrogenic CAGE is of vital importance.

Prevalence of Carbon Monoxide Poisoning and Hyperbaric Oxygen Therapy in Korea: Analysis of National Claims Data in 2010-2019.

This study aimed to investigate the prevalence of carbon monoxide (CO) poisoning and the provision of hyperbaric oxygen therapy (HBOT) in South Korea. We used data from the Korea Health Insurance Review and Assessment service. In total, 44,361 patients with CO poisoning were identified across 10 years (2010-2019). The prevalence of CO poisoning was found to be 8.64/10,000 people, with a gradual annual increment. The highest prevalence was 11.01/10,000 individuals, among those aged 30-39 years. In 2010, HBOT was claimed from 15 hospitals, and increased to 30 hospitals in 2019. A total of 4,473 patients received HBOT in 10 years and 2,684 (60%) were treated for more than 2 hours. This study suggested that the prevalence of both CO poisoning and HBOT in Korea gradually increased over the past 10 years, and disparities in prevalence were observed by region.

Effect of Hyperbaric Oxygen Therapy on the Survival Rate of Autologous Fat Transplantation.

OBJECTIVE: To investigate whether hyperbaric oxygen therapy can improve the survival rate of fat transplantation and analyze the possible mechanisms. METHODS: Ninety SD rats were randomly divided into 3 groups. All the rats were cut into pieces with about 5 mL of fat from the abdominal cavity, rinsed with normal saline for 3 times, and cleaned with cotton pad adsorption method. Then, 3 ml was removed, divided into 3 parts, and injected into three adjacent but not touching parts of the back. Group A received 1h/d hyperbaric oxygen therapy, group B received 2 h/d hyperbaric oxygen therapy, and group C received no hyperbaric oxygen therapy. The hyperbaric oxygen therapy lasted for 10 consecutive days. Fat grafts from one site were randomly removed at 2, 4, and 6 weeks after surgery, respectively. ① the survival rate of fat transplantation in three groups was compared. ② observe the pathological section; ③ immunohistochemistry was used to detect and compare the expression of vascular endothelial growth factor. RESULTS: The survival rate of fat transplantation in group A was the highest. After subcutaneous transplantation of 1 ml of fat and 1 hour/day of continuous hyperbaric oxygen treatment for 10 days, the fat survival rates were 0.796 ± 0.071 ml, 0.644 ± 0.151 ml, and 0.473 ± 0.127 ml at the second, fourth, and sixth weeks, respectively. The survival rate of fat transplantation in group B was the second. After subcutaneous transplantation of 1 ml of fat and 2 hour/day of continuous hyperbaric oxygen treatment for 10 days, the survival rate of fat was 0.624 ± 0.220 ml, 0.494 ± 0.125 ml, and 0.329 ± 0.153 ml at the second, fourth, and sixth weeks, respectively. The survival rate of fat transplantation in group C was the lowest. After subcutaneous transplantation of 1 ml of fat and no hyperbaric oxygen treatment for 10 days, the fat survival rates were 0.461 ± 0.132 ml, 0.290 ± 0.112 ml and 0.169 ± 0.091 ml at the second, fourth, and sixth weeks, respectively. We have made changes in the abstract of the article and marked in red color. CONCLUSION: Hyperbaric oxygen therapy is conducive to the survival of transplanted fat. Importantly, a short period of hyperbaric oxygen therapy (1 h/d) can promote the survival of transplanted fat. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Hyperbaric Oxygenation Prevents Loss of Immature Neurons in the Adult Hippocampal Dentate Gyrus Following Brain Injury.

A growing body of evidence suggests that hyperbaric oxygenation (HBO) may affect the activity of adult neural stem cells (NSCs). Since the role of NSCs in recovery from brain injury is still unclear, the purpose of this study was to investigate the effects of sensorimotor cortex ablation (SCA) and HBO treatment (HBOT) on the processes of neurogenesis in the adult dentate gyrus (DG), a region of the hippocampus that is the site of adult neurogenesis. Ten-week-old Wistar rats were divided into groups: Control (C, intact animals), Sham control (S, animals that underwent the surgical procedure without opening the skull), SCA (animals in whom the right sensorimotor cortex was removed via suction ablation), and SCA + HBO (operated animals that passed HBOT). HBOT protocol: pressure applied at 2.5 absolute atmospheres for 60 min, once daily for 10 days. Using immunohistochemistry and double immunofluorescence labeling, we show that SCA causes significant loss of neurons in the DG. Newborn neurons in the subgranular zone (SGZ), inner-third, and partially mid-third of the granule cell layer are predominantly affected by SCA. HBOT decreases the SCA-caused loss of immature neurons, prevents reduction of dendritic arborization, and increases proliferation of progenitor cells. Our results suggest a protective effect of HBO by reducing the vulnerability of immature neurons in the adult DG to SCA injury.

Hyperbaric oxygen mitigates KIM-1 and inflammatory cytokine levels in kidney transplantation.

Background: The aim of this study was to investigate the effect of hyperbaric oxygen (HBO2) administration during cold ischemic time to organs removed from donors before kidney transplantation. A total of 24 rats were divided into three groups: Group 1 was the control group, Group 2 received 60 minutes of HBO2 at 2.5 atmospheres absolute, and Group 3 received 120 minutes of 2.5 ATA HBO2. The renal artery was entered with a polyethylene catheter and perfused with a standard organ preservation solution. Falcon tubes containing organs obtained from rats in Groups 2 and 3 were placed in a box supported by ice blocks. The temperature was kept constant at 4°C and the box was placed in a pressure tank with 2.5 ATA HBO2. HBO2 was applied for 60 and 120 minutes, respectively. Organ samples were harvested at the end of 24 hours for histopathological evaluation, immunohistochemical analysis of TNF-α and IL-18, TUNEL analysis for apoptosis, and gene expression levels of kidney injury molecule-1 (KIM-1) and caspase-3. In histopathological examinations, hematoxylin and eosin staining was performed and samples were evaluated for tubular necrosis and vacuolization criteria. Group 2 and Group 3 had significant decreases compared to Group one in this regard. Immunohistochemical staining was performed for TNF-α, IL-18, and apoptosis levels; significant decreases were found in Groups 2 and 3. There were significant decreases in Groups 2 and 3 for KIM-1 and caspase-3 gene expression levels compared to Group 1, as well. Thus, it was demonstrated that during the cold ischemic period before kidney transplantation, HBO2 administration to organs removed from donors can reduce apoptotic cell numbers, inflammatory cytokine release, and histopathological damage to the organs as well as decreasing the expression of the KIM-1 gene, which is an indicator of kidney damage.

What is the evidence for oxygenation during kidney preservation for transplantation in 2021? A scoping review.

PURPOSE: The main objective of static cold storage is to reduce cellular metabolic demands to extend the period of ischaemia prior to transplantation. Hypothermia does not halt metabolism and the absence of oxygen causes a cellular shift toward anaerobic respiratory pathways. There is emerging evidence that the introduction of oxygenation during organ preservation may help ameliorate the degree of ischaemia reperfusion injury and improve post-transplantation outcomes. This review aims to appraise and summarise all published literature that utilises oxygenation to improve kidney preservation for purposes of transplantation. METHODS: We performed a scoping review of the literature using the bibliographic databases Embase and MEDLINE. The final date for searches was 20 March 2021. All research studies included were those that reported oxygen delivery during kidney preservation as well as providing a description of the oxygenation technique. RESULTS: 17 human and 48 animal studies met the inclusion criteria. The oxygen delivery methods investigated included hypothermic oxygenated machine perfusion (HOPE), oxygen carriers, two-layer method, venous systemic persufflation, hyperbaric oxygenation, normothermic machine perfusion and sub-normothermic machine perfusion. The COMPARE trial was the only study carried out with the most methodological robustness being a randomised, double blind, controlled, phase III trial that investigated the efficacy of HOPE versus HMP. CONCLUSION: A variety of studies reflect the evolution of oxygenation with useful lessons and encouraging outcomes. The first in human studies investigating HOPE and oxygen carriers are most robustly investigated strategies for oxygenation during kidney preservation and are, therefore, the best clinical references.

German S3 Guideline: Oxygen Therapy in the Acute Care of Adult Patients.

BACKGROUND: Oxygen (O2) is a drug with specific biochemical and physiological properties, a range of effective doses and may have side effects. In 2015, 14% of over 55,000 hospital patients in the UK were using oxygen. 42% of patients received this supplemental oxygen without a valid prescription. Health care professionals are frequently uncertain about the relevance of hypoxemia and have low awareness about the risks of hyperoxemia. Numerous randomized controlled trials about targets of oxygen therapy have been published in recent years. A national guideline is urgently needed. METHODS: A national S3 guideline was developed and published within the Program for National Disease Management Guidelines (AWMF) with participation of 10 medical associations. A literature search was performed until February 1, 2021, to answer 10 key questions. The Oxford Centre for Evidence-Based Medicine (CEBM) System ("The Oxford 2011 Levels of Evidence") was used to classify types of studies in terms of validity. Grading of Recommendations, Assessment, Development and Evaluation (GRADE) was used for assessing the quality of evidence and for grading guideline recommendation, and a formal consensus-building process was performed. RESULTS: The guideline includes 34 evidence-based recommendations about indications, prescription, monitoring and discontinuation of oxygen therapy in acute care. The main indication for O2 therapy is hypoxemia. In acute care both hypoxemia and hyperoxemia should be avoided. Hyperoxemia also seems to be associated with increased mortality, especially in patients with hypercapnia. The guideline provides recommended target oxygen saturation for acute medicine without differentiating between diagnoses. Target ranges for oxygen saturation are based depending on ventilation status risk for hypercapnia. The guideline provides an overview of available oxygen delivery systems and includes recommendations for their selection based on patient safety and comfort. CONCLUSION: This is the first national guideline on the use of oxygen in acute care. It addresses health care professionals using oxygen in acute out-of-hospital and in-hospital settings.

The role of hyperbaric oxygen therapy in Fournier's Gangrene: A systematic review and meta-analysis of observational studies.

PURPOSE: Management of Fournier's Gangrene (FG) includes broad-spectrum antibiotics with adequate surgical debridement, which should be performed within the first 24 hours of onset. However, this treatment may cause significant loss of tissue and may delay healing with the presence of ischemia. Hyperbaric oxygen therapy (HBOT) has been proposed as adjunctive therapy to assist the healing process. However, its benefit is still debatable. Therefore, this systematic review and meta-analysis aimed to evaluate the effect of HBOT as an adjunct therapy for FG. MATERIALS AND METHODS: This study complied with the Preferred Reporting Items for Systematic Reviews and Meta-analyses protocol to obtain studies investigating the effect of HBOT on patients with FG. The search is systematically carried out on different databases such as MEDLINE, Embase, and Scopus based on population, intervention, control, and outcomes criteria. A total of 10 articles were retrieved for qualitative and quantitative analysis. RESULTS: There was a significant difference in mortality as patients with FG who received HBOT had a lower number of deaths compared to patients who received conventional therapy (Odds Ratio 0.29; 95% CI 0.12 - 0.69; p = 0.005). However, the mean length of stay with Mean Difference (MD) of -0.18 (95% CI: -7.68 - 7.33; p=0.96) and the number of debridement procedures (MD 1.33; 95% CI: -0.58 - 3.23; p=0.17) were not significantly different. CONCLUSION: HBOT can be used as an adjunct therapy to prevent an increased risk of mortality in patients with FG.

Influence of the COVID-19 pandemic on causes for the development of carbon monoxide intoxications.

Introduction: Several causes can lead to carbon monoxide (CO) intoxication. A first-line treatment option for such intoxications is hyperbaric oxygenation (HBO2) therapy. The COVID-19 pandemic has been changing everyday life in Germany since March 2020, mainly caused by statutory provisions. Our aim was to review whether these changes have an influence on the causes and frequency for the development of CO intoxication. Methods: We retrospectively analyzed the data of patients who were treated for CO intoxication in our institution between April 2019 and March 2021. Besides demographic data, we compared the overall number and documented causes for each CO intoxication in the period of April 2020 to March 2021 with the period between April 2019 and March 2020. Results: After applying inclusion and exclusion criteria, 139 patients were included. We found a significant decrease in the overall number of patients who needed treatment since the beginning of the COVID-19 pandemic. However, the share of CO intoxication caused by the indoor use of coal stoves, coal barbecue, or suicide attempts increased. In contrast, the share of cases caused by apartment or house fire, smoking waterpipe, or gas stoves decreased. Conclusion: The COVID-19 pandemic and the associated restrictions lead to a significant reduction in the number of patients in need for HBO2 therapy due to CO-Intoxication. The causes leading to CO intoxication also changed since the beginning of the COVID-19 pandemic. We observed a shift toward causes related to the indoor use of coal-fired stoves and barbecues as well as suicide attempts.

Benign subcutaneous emphysema treated with hyperbaric oxygen therapy after surgical exploration.

Benign subcutaneous emphysema of the upper limb is extremely uncommon. Patients with this condition that involves the limbs usually present with local symptoms, and they are systematically well. We report a case of 18-year-old male presented after a minor cut wound in the forearm with diffuse subcutaneous emphysema. The patient was treated with hyperbaric oxygen therapy after wound exploration. Recovery was uneventful. Infectious etiology by gas-forming organisms should be ruled out before considering other causes.

Responses of matrix metalloproteinases to hyperbaric oxygen treatment: changing for good or ill?

Background: Hyperbaric oxygen (HBO2) is currently emerging as a promising therapeutic option for diseases involving impaired tissue repair and remodeling. In this regard, HBO2 has been shown to modulate signaling pathways responsible for matrix metalloproteinases (MMPs) regulation, which makes the MMPs interesting targets for investigation. However, the understanding regarding how HBO2 treatment affects the expression and activity of the MMP family members in different tissues and diseases needs to be clarified. The precise roles of MMPs in the physiopathology of various tissue repair disorders also remain unclear. Because of potential off-target systemic effects of the HBO2 on MMPs, researchers and physicians should carefully consider whether their patients could be affected adversely by HBO2 exposure. Aims: This narrative review provides an overview of MMP biology (structure, function, and regulation) and summarizes available data showing how MMPs respond to HBO2 in different tissues and pathologies, also highlighting possible mechanisms.

Kcnk3, Ggta1, and Gpr84 are involved in hyperbaric oxygenation preconditioning protection on cerebral ischemia-reperfusion injury.

The present study aimed to explore the potential mechanism of the effect of hyperbaric oxygenation (HBO) preconditioning on cerebral ischemia and reperfusion injury (CIRI). GSE23160 dataset was used to identify differentially expressed genes (DEGs) from striatum between the middle cerebral artery occlusion (MCAO)/reperfusion and sham rats. The gene clusters with continuous increase and decrease were identified by soft clustering analysis in Mfuzz, and functional enrichment analysis of these genes was performed using clusterProfiler package. The intersection set of the genes with significantly altered expression at post-reperfusion 2, 8, and 24 h were screened in comparison to 0 h (sham group), and the expression of these genes was detected in the MCAO/reperfusion model and HBO preconditioning groups by real-time PCR (RT-PCR) and western blotting. A total of 41 upregulated DEGs, and 7 downregulated DEGs were detected, among which the expression of Gpr84 and Ggta1 was significantly upregulated at each reperfusion phase as compared to the sham group, while the expression of Kcnk3 was significantly downregulated except in the postreperfusion 8 h in the striatum group. RT-PCR and western blotting analyses showed that the expression of Ggta1, Gpr84, and Kcnk3 genes between the MCAO/reperfusion and sham rats were consistent with the bioinformatics analysis. In addition, the HBO preconditioning reduced the expression of Ggta1 and Gpr84 and increased the expression of Kcnk3 in MCAO/reperfusion rats. Kcnk3, Ggta1, and Gpr84 may play a major role in HBO-mediated protection of the brain against CIRI.

From dermatological conditions to COVID-19: Reasoning for anticoagulation, suppression of inflammation, and hyperbaric oxygen therapy.

COVID-19 generates a complex systemic inflammatory response that can lead to death due to wide macrophage activation, endothelial damage, and coagulation in critically ill patients. SARS-CoV-2-induced lung injury due to inflammatory mediated thrombosis could be similar to the livedoid vasculopathy in the skin, supporting a translational comparison of these clinical settings. In this article, we discuss anticoagulation, suppression of inflammatory response, and hyperbaric oxygen therapy in the context of severe COVID-19 and livedoid vasculopathy.

Hippocampal cerebral blood flow increased following low-pressure hyperbaric oxygenation in firefighters with mild traumatic brain injury and emotional distress.

BACKGROUND: Recent evidence suggests that hyperbaric oxygenation (HBO), which has been used as an effective treatment for certain types of tissue injury, may change neural activities in the human brain and subsequently improve symptoms of psychiatric disorders. To scrutinize the neural mechanism of HBO in the human brain, we investigated whether 20 sessions of HBO changed regional cerebral blood flow (rCBF) of the limbic system in firefighters with mild traumatic brain injury (mTBI) and subjective emotional distress. METHODS: Twenty firefighters with mTBI and mild emotional distress were treated with HBO at a relatively low pressure of 1.3 atmospheres absolute for 45 min a day for 20 consecutive days (the mild emotional distress group). The rCBF of the limbic system was measured using an arterial spin labeling perfusion magnetic resonance imaging before and after the HBO. Analyses were performed on the data from fourteen individuals who completed the study and 14 age- and sex-matched healthy firefighters (the comparison group). RESULTS: Firefighters in the mild emotional distress group showed increase rCBF following HBO in a cluster encompassing the right hippocampal and parahippocampal regions (peak t = 4.31; cluster size = 248 mm3)(post-hoc analysis, z = 5.92, p < 0.001) that had lower rCBF relative to the comparison group at baseline (post-hoc analysis, t = -2.20, p = 0.04). CONCLUSION: The current study demonstrated that low-pressure HBO might increase rCBF of the hippocampal and parahippocampal regions, suggesting a potential underpinning mechanism of HBO in the human brain.

Optimal sessions of hyperbaric oxygen therapy in patients with carbon monoxide poisoning: A prospective observational study.

INTRODUCTION: Hyperbaric oxygen (HBO) therapy may be a useful treatment to prevent the development of delayed neuropsychiatric sequelae (DNS) in patients with acute carbon monoxide (CO) poisoning. However, there is no clear consensus regarding the optimal number of HBO therapy sessions in patients with CO poisoning. Here, we compared the development of DNS after 3 and > 3 sessions of HBO therapy in patients with acute CO poisoning. METHODS: This prospective observational study recruited 299 patients with CO poisoning. Demographic and clinical information were obtained, including comorbidities, vital signs, and symptoms. Patients were divided into two groups according to whether they received 3 or > 3 sessions of HBO therapy (3 HBO vs. >3 HBO). A propensity score-matching process was used to balance potential prognostic factors in both groups. RESULTS: Of the 299 patients with acute CO poisoning enrolled in this study, 183 (59.0%) were included in the analysis. Patients were excluded for the following reasons: age < 18 years, not underwent HBO therapy, discharged against medical advice, and loss to follow-up. The overall rate of DNS development was 17.5%. The >3 HBO group had a higher incidence of DNS development compared to the 3 HBO group (36.3% vs. 16.3%; p = 0.09). Propensity score-matching analysis revealed similar incidences of DNS (31.3% vs. 28.1%, respectively; p > 0.99). CONCLUSIONS: There is a critical need to determine the optimal number of HBO therapy sessions for patients with acute CO poisoning. This study showed no difference in DNS development after 3 and > 3 sessions of HBO therapy.

Hyperbaric Oxygenation in the Treatment of Fournier's Gangrene: A Systematic Review.

INTRODUCTION: Fournier's gangrene (FG) is a sporadic, life-threatening, necrotizing infection affecting the perineum, perineal region, and genitals. Hyperbaric oxygenation (HBO) improves tissue perfusion and promotes angiogenesis and collagen synthesis. Despite these positive effects of HBO, the indication and the effects on outcome as adjunct therapy in FG remain controversial. Consequently, we decided to perform a systematic review to compare the treatment of FG with or without the use of HBO as an adjunct therapy. MATERIALS AND METHODS: We performed a systematic review following the recommendations provided in the Cochrane Handbook of systematic Reviews and the PRISMA reporting guidelines. Due to the paucity of data and a suspected lack of randomized controlled trials, we considered all the available information for this systematic review. RESULTS: The literature search for primary studies yielded 79 results. Finally, 13 studies were considered, which included a total of 376 patients with FG, of whom 202 received HBO therapy. Five of these studies had a retrospective case-control design. However, these 5 studies included a total of 319 patients; 145 of these patients were treated with adjunct HBO therapy. Overall, this leads to a mortality rate of 16.6% in the HBO group and 25.9% in the non-HBO group. Overall, risk of bias was assessed as moderate to high. CONCLUSIONS: We conclude that despite the risk of bias, HBO has potential as an adjunct in FG treatment, but it is challenging to carry out further studies, mainly due to the rareness of FG and availability of HBO.

Survival of dental implants and occurrence of osteoradionecrosis in irradiated head and neck cancer patients: a systematic review and meta-analysis.

OBJECTIVES: This systematic review assesses dental implant survival, calculates the incidence rate of osteoradionecrosis, and evaluates risk factors in irradiated head and neck cancer patients. MATERIALS AND METHODS: Various databases (e.g., Medline/Embase using Ovid) and gray literature platforms were searched using a combination of keywords and subject headings. When appropriate, meta-analysis was carried out using a random effects model. Otherwise, pooled analysis was applied. RESULTS: A total of 425 of the 660 included patients received radiotherapy. In total, 2602 dental implants were placed, and 1637 were placed in irradiated patients. Implant survival after an average follow-up of 37.7 months was 97% (5% confidence interval, CI 95.2%, 95% CI 98.3%) in nonirradiated patients and 91.9% (5% CI 87.7%, 95% CI: 95.3%) after an average follow-up of 39.8 months in irradiated patients. Osteoradionecrosis occurred in 11 cases, leading to an incidence of 3% (5% CI 1.6%, 95% CI 4.9%). The main factors impacting implant survival were radiation and grafting status, while factors influencing osteoradionecrosis could not be determined using meta-analysis. CONCLUSION: Our data show that implant survival in irradiated patients is lower than in nonirradiated patients, and osteoradionecrosis is-while rare-a serious complication that any OMF surgeon should be prepared for. The key to success could be a standardized patient selection and therapy to improve the standard of care, reduce risks and shorten treatment time. CLINICAL RELEVANCE: Our analysis provides further evidence that implant placement is a feasible treatment option in irradiated head and neck cancer patients with diminished oral function and good long-term cancer prognosis.