Prognostic Factors in Idiopathic Sudden Sensorineural Hearing Loss: The Experience of Two Audiology Tertiary Referral Centres.

Background and Objectives: Although different hypotheses have been proposed over time, there is a dearth of information on factors able to predict the response to treatment for idiopathic sudden sensorineural hearing loss (ISSNHL) and hearing recovery. The aim of this study was to apply univariate and multivariate statistical models in a retrospective clinical setting of patients given therapy for ISSNHL at our tertiary academic audiological centers to investigate the prognostic value of clinical signs, symptoms, and comorbidities in relation to hearing recovery. Materials and Methods: The inclusion criteria were: history of ISSNHL diagnosed and treated at the Padova or Modena tertiary academic audiological centers; age ≥ 18 years; availability of clinical and audiological outcome data. The exclusion criteria were: hearing loss in acoustic schwannoma, endolymphatic hydrops, meningitis, trauma (head trauma, temporal bone fracture, acoustic trauma), barotrauma, perilymphatic fistula; exposure to noise levels ≥ 80 dB in the work environment; any unilateral or bilateral hearing loss (except for presbycusis) prior to ISSNHL diagnosis; any disorders affecting the external or middle ear; any previous ear surgery; refusal to make medical data available for research purposes. Eighty-six consecutive patients (38 females, 48 males; median age: 58 years; interquartile range: 47.00-69.00 years) were included. A systemic steroid therapy was administered to all patients, either orally with prednisone or intravenously with methylprednisolone. Second-line therapy included intratympanic steroid injections and/or hyperbaric oxygen therapy. Results: A multivariate logistic regression model was used, including the non-multicollinear clinical and audiological variables, which showed a p-value < 0.10 at the univariate analyses (namely age at diagnosis, time to diagnosis, oral steroid dose, and PTA on the affected side). Only PTA on the affected side retained its statistical significance (OR: 1.0615, 95% CI: 1.0185-1.1063, p = 0.005). Conclusions: The analysis of our data showed an association between the hearing threshold before treatment and the recovery from ISSNHL. Further studies on larger cohorts (especially in a prospective setting) are needed to shed more light on the prognostic role of clinical parameters in patients with ISSNHL. In a correct counseling setting, with regard to the patient's concern about not being able to recover hearing, it is important to offer perspectives of appropriate hearing rehabilitation approaches.

Quantification of referrals received at two emergency-capable hyperbaric medicine centers.

Emergency hyperbaric oxygen treatment capability is limited in the United States, and there is little documentation of calls received by centers available 24 hours a day, seven days a week, 365 days a year. Our study aimed to calculate the number of calls received for urgent hyperbaric oxygen (HBO2). We logged calls from two HBO2 chambers on the East Coast of the United States that serve a densely populated region in 2021. The total number of emergency calls was 187 at the University of Maryland (UMD) and 127 at the University of Pennsylvania (UPenn). There were calls on 180/365 (46%) days during the study period at UMD and 239/365 (63%) days at UPenn. The most common indication was carbon monoxide toxicity. The peak month of calls was March. Emergency HBO2 calls are common, and more centers must accept emergency cases. Data from geographically diverse centers would add generalizability to these results and capture more diving-related emergencies.

Trends in Medicare Costs of Hyperbaric Oxygen Therapy, 2013 through 2022.

Objective: To analyze Hyperbaric Oxygen Therapy Registry (HBOTR) data to estimate the Medicare costs of hyperbaric oxygen therapy (HBO2) based on standard treatment protocols and the annual mean number of treatments per patient reported by the registry. Methods: We performed a secondary analysis of deidentified data for all payers from 53 centers registered in the HBOTR from 2013 to 2022. We estimated the mean annual per-patient costs of HBO2 based on Medicare (outpatient facility + physician) reimbursement fees adjusted to 2022 inflation using the Medicare Economic Index. Costs were calculated for the annual average number of treatments patients received each year and for a standard 40-treatment series. We estimated the 2022 costs of standard treatment protocols for HBO2 indications treated in the outpatient setting. Results: Generally, all costs decreased from 2013 to 2022. The facility cost per patient per 40 HBO2 treatments decreased by 10.7% from $21,568.58 in 2013 to $19,488.00 in 2022. The physician cost per patient per 40 treatments substantially decreased by -37.8%, from $5,993.16 to $4,346.40. The total cost per patient per 40 treatments decreased by 15.6% from $27,561.74 to $23,834.40. In 2022, a single HBO2 session cost $595.86. For different indications, estimated costs ranged from $2,383.4-$8,342.04 for crush injuries to $17,875.80-$35,751.60 for diabetic foot ulcers and delayed radiation injuries. Conclusions: This real-world analysis of registry data demonstrates that the actual cost of HBO2 is not nearly as costly as the literature has insinuated, and the per-patient cost to Medicare is decreasing, largely due to decreased physician costs.

The use of hyperbaric oxygen for avascular necrosis of the femoral head and femoral condyle: a single centre's experience over 30 years.

Introduction: Avascular necrosis (AVN) is a rare progressive degenerative disease leading to bone and joint destruction. Patients often require surgical intervention. Femoral AVN is the most common anatomical location. Hyperbaric oxygen treatment (HBOT) has been shown to be effective in AVN. We present data collected from one centre over a 30-year period and compare the results with other published data. Methods: A retrospective chart review of all patients receiving HBOT for AVN at Fremantle and Fiona Stanley Hospitals since 1989 was performed. The primary outcome was radiological appearance using the Steinberg score, with secondary outcomes being subjective improvement, the need for joint replacement surgery and rates of complications. Results: Twenty-one joints in 14 patients (14 femoral heads and seven femoral condyles) were treated with HBOT since 1989. Two patients were excluded. Within the femoral head group, nine of the 14 joints (64%) had stable or improved magnetic resonance imaging (MRI) scans post treatment and at six months (minimum); 10 joints (71%) had good outcomes subjectively, three joints required surgical intervention, and three patients developed mild aural barotrauma. Within the femoral condyle group, all five joints had stable or improved post-treatment MRI scans (four had visible improvement in oedema and/or chondral stability), four joints reported good outcomes subjectively, none of the patients required surgical intervention (follow-up > six months). Conclusions: This single centre retrospective study observed prevention of disease progression in femoral AVN with the use of HBOT, comparable to other published studies. This adds to the body of evidence that HBOT may have a significant role in the treatment of femoral AVN.

Survey comparing the treatment of central retinal artery occlusion with hyperbaric oxygen in Australia and New Zealand with the recommended guidelines as outlined by the Undersea and Hyperbaric Medical Society.

Introduction: Central retinal artery occlusion (CRAO) presents suddenly causing painless loss of vision that is often significant. Meaningful improvement in vision occurs in only 8% of patients with spontaneous reperfusion. Hyperbaric oxygen treatment (HBOT) is considered to be of benefit if commenced before retinal infarction occurs. The Undersea and Hyperbaric Medical Society (UHMS) guidelines on the management of CRAO were last amended in 2019. This survey questioned Australian and New Zealand (ANZ) hyperbaric medicine units (HMUs) about the incidence of CRAO cases referred and compared their subsequent management against the UHMS guidelines. Methods: An anonymous survey via SurveyMonkey® was sent to all 12 ANZ HMUs that treat emergency indications, allowing for multiple choice and free text answers regarding their management of CRAO. Results: One-hundred and forty-six cases of CRAO were treated in ANZ HMUs over the last five years. Most (101/146) cases (69%) were initially treated at a pressure of 284 kPa. This was the area of greatest difference noted in CRAO management between the UHMS guidelines and ANZ practice. Conclusions: Few ANZ HMUs strictly followed the UHMS guidelines. We suggest a more simplified management protocol as used by the majority of ANZ HMUs.

Effects of Oxygen Therapy on Patients with a Chronic Wound: A Systematic Review and Meta-analysis.

OBJECTIVE: To synthesize the effects of oxygen-based therapy on patients with a chronic wound. DATA SOURCES: The authors searched PubMed, EMBASE, and Cochrane Central Register of Controlled Trials for relevant randomized controlled trials from database inception. Investigators measured risk of bias using the Cochrane Collaboration's Risk of Bias tool. STUDY SELECTION: The included randomized controlled trials focused on the effects (short- or long-term wound healing, amputation rate, percentage of reduction in ulcer size, and poststudy transcutaneous oxygen measurement [TcPO2]) of oxygen-based therapy (including hyperbaric oxygen therapy, topical oxygen therapy, and continuous diffusion of oxygen) on patients with a chronic wound. DATA EXTRACTION: Researchers extracted information regarding participant characteristics and primary and secondary outcomes from the included studies. DATA SYNTHESIS: Pooled effects of 31 included studies showed that patients treated with oxygen had better short-term wound healing (risk ratio [RR], 1.544; 95% CI, 1.199 to 1.987), a higher percentage reduction in the ulcer area (standardized mean difference [SMD], 0.999; 95% CI, 0.439 to 1. 599), lower amputation rates (RR, 0.529; 95% CI, 0.325 to 0.862), shorter wound healing time (SMD, -0.705; 95% CI, -0.908 to -0.501), and higher poststudy TcPO2 (SMD, 2.128; 95% CI, 0.978 to 3.278) than those in the control group. For long-term wound healing, there was no statistically significant difference (RR, 1.227; 95% CI, 0.976 to 1.542). CONCLUSIONS: Oxygen-based therapy improves short-term parameters of wound healing in patients with chronic wounds.

Reported outcome measures in necrotising soft tissue infections: a systematic review.

Introduction: There are inconsistencies in outcome reporting for patients with necrotising soft tissue infections (NSTI). The aim of this study was to evaluate reported outcome measures in NSTI literature that could inform a core outcome set (COS) such as could be used in a study of hyperbaric oxygen in this indication. Methods: A systematic review of all NSTI literature identified from Cochrane, Ovid MEDLINE and Scopus databases as well as grey literature sources OpenGrey and the New York Academy of Medicine databases which met inclusion criteria and were published between 2010 and 2020 was performed. Studies were included if they reported on > 5 cases and presented clinical endpoints, patient related outcomes, or resource utilisation in NSTI patients. Studies did not have to include intervention. Two independent researchers then extracted reported outcome measures. Similar outcomes were grouped and classified into domains to produce a structured inventory. An attempt was made to identify trends in outcome measures over time and by study design. Results: Three hundred and seventy-five studies were identified and included a total of 311 outcome measures. Forty eight percent (150/311) of outcome measures were reported by two or more studies. The four most frequently reported outcome measures were mortality without time specified, length of hospital stay, amputation performed, and number of debridements, reported in 298 (79.5%), 260 (69.3%), 156 (41.6%) and 151 (40.3%) studies respectively. Mortality outcomes were reported in 23 different ways. Randomised controlled trials (RCTs) were more likely to report 28-day mortality or 90-day mortality. The second most frequent amputation related outcome was level of amputation, reported in 7.5% (28/375) of studies. The most commonly reported patient-centred outcome was the SF-36 which was reported in 1.6% (6/375) of all studies and in 2/10 RCTs. Conclusions: There was wide variance in outcome measures in NSTI studies, further highlighting the need for a COS.

Refractory Osteomyelitis in a Military Service Member Resolved With Adjunctive Hyperbaric Oxygen Therapy.

Refractory osteomyelitis is typically defined as a chronic infection that persists or recurs despite definitive surgical management and antibiotic therapy. Cases often involve complex wounds or fractures and can be challenging to treat, resulting in multiple courses of broad-spectrum antibiotic therapy and numerous surgeries over periods of months to years. Adjuncts to improve resolution of these complicated infections are sorely needed. Here, we describe the case of a 47-year-old active duty military member who sustained an open right ankle fracture during a skydiving accident that was subsequently complicated by refractory osteomyelitis. The patient failed more than three courses of combined medical and surgical management over a 9-month period before undergoing adjunctive hyperbaric oxygen therapy (HBOT), ultimately resulting in resolution of the infection. Adjunctive HBOT for treatment of conditions such as refractory osteomyelitis may be an underutilized resource in part because of a general paucity of high-quality data in the literature supporting its use, as well as a relative lack of availability of this resource. Nonetheless, the overall accumulating body of evidence indicates that the use of adjunctive HBOT in select patients with refractory osteomyelitis is safe and effective and further research may be warranted given its relevance and potential impact to military populations.

The role of after-hours house-call medical service in the treatment of COVID-19 patients awaiting hospital admission: A retrospective cohort study.

ABSTRACT: Due to the increasing number of coronavirus disease 2019 (COVID-19) cases in Japan, hospitals are unable to provide admission and immediate inpatient care. The after-hours house call (AHHC) service offers telephone consultations and in-home care to patients awaiting admission. Currently, there is no report on the management of COVID-19 patients when inpatient beds are insufficient.We aimed to describe the clinical characteristics and outcomes of COVID-19 patients treated by an AHHC medical service in Osaka and Tokyo, between April and May 2021 (during the fourth wave in Japan). Patients were classified into 2 groups: Moderate I and Moderate II, according to the severity of infection under Japanese guidelines. A retrospective study of the hospital records and follow-up telephone consultations was performed.The AHHC treated a total of 55 COVID-19 patients (17 with Moderate I, 38 with Moderate II disease). The median ages (interquartile range) were 63 (49-80.5) and 64 (50.8-81), respectively. In each group, approximately 30% of AHHC patients received out-of-hospital oxygen therapy for the duration of their treatment until it was no longer required. Major symptoms, including shortness of breath or difficulty breathing (47.1% and 78.9%, respectively) and fever or chills (41.2% and 76.3%, respectively) were lower in the Moderate I group than in the Moderate II group. Overall, 16.4% of patients died, with 17.6% in the Moderate I group and 15.8% in the Moderate II group.We found the proportion of mortality in patients treated by the AHHC was slightly higher to that of patients treated in Japanese hospitals. This study will provide an alternative management of patients requiring oxygen in situations where hospital beds are in short supply.

A novel hyperbaric swimming respirometer allows the simulation of varying swimming depths in fish respirometry studies.

The understanding of swimming physiology and knowledge on the metabolic costs of swimming are important for assessing effects of environmental factors on migratory behavior. Swim tunnels are the most common experimental setups for measuring swimming performance and oxygen uptake rates in fishes; however, few can realistically simulate depth and the changes in hydrostatic pressure that many fishes experience, e.g. during diel vertical migrations. Here, we present a new hyperbaric swimming respirometer (HSR) that can simulate depths of up to 80 m. The system consists of three separate, identical swimming tunnels, each with a volume of 205 L, a control board and a storage tank with water treatment. The swimming chamber of each tunnel has a length of 1.40 m and a diameter of 20 cm. The HSR uses the principle of intermittent-flow respirometry and has here been tested with female European eels (Anguilla anguilla). Various pressure, temperature and flow velocity profiles can be programmed, and the effect on metabolic activity and oxygen consumption can be assessed. Thus, the HSR provides opportunities to study the physiology of fish during swimming in a simulated depth range that corresponds to many inland, coastal and shelf waters.

Real-world effectiveness of hyperbaric oxygen therapy for delayed neuropsychiatric sequelae after carbon monoxide poisoning.

To assess real-world effectiveness of hyperbaric oxygen therapy (HBOT) on delayed neuropsychiatric sequelae (DNS) after carbon monoxide (CO) poisoning we conducted a retrospective review of patients with CO poisoning admitted to Linkou Chang-Gung Memorial Hospital, Taiwan's largest medical center, during 2009-2015. We included patients developing DNS after CO poisoning and compared improvements in neuropsychiatric function, with and without HBOT, after 12 months post-DNS to understand differences in recovery rates. DNS improvement-associated factors were also evaluated. We used receiver operating characteristic (ROC) curve analysis to assess the role of time elapsed between DNS diagnosis and HBOT initiation in predicting DNS improvement. A total of 62 patients developed DNS, of whom 11 recovered while the rest did not. Possible factors predicting DNS improvement included receiving HBOT post-DNS (72.7% vs 25.5%; P = 0.006), and treatment with more than three HBOT sessions during acute stage CO poisoning (81.8% vs 27.5%; P = 0.003). The relevant area under the ROC curve was 0.789 (95% CI 0.603-0.974), and the best cut-off point was 3 days post-DNS diagnosis, with 87.5% sensitivity and 61.5% specificity. Early HBOT in patients who developed DNS after CO poisoning significantly improved their DNS symptoms, with treatment effects sustained for 1 year after DNS diagnosis.

The effect of total compression time and rate (slope) of compression on the incidence of symptomatic Eustachian tube dysfunction and middle ear barotrauma: a Phase II prospective study.

Eustachian tube dysfunction (ETD) and middle ear barotrauma (MEB) are common reported complications during hyperbaric oxygen treatment. Our Phase I study data was the first to demonstrate a statistically significant decrease in the occurrence of symptomatic ETD and MEB. The Phase I Trial suggested the total time interval and rate (slope) of compression (ROC) may be a determining factor in ETD and MEB. This Phase II study investigates an optimal rate of compression to reduce ETD and MEB when considering each multiplace treatment (with multiple patients) as the unit of observation as a group, rather than for each individual patient. Data were collected prospectively on 1,244 group patient-treatment exposures, collectively including 5,072 individual patient-treatment/exposures. We randomly assigned patient-treatment group exposures to four different time interval and rate (slope) of compression. These compression rates and slopes were identical to those used in the Phase I trial. All patients experiencing symptoms of MEB requiring compression stops were evaluated post treatment for the presence of ETD and MEB using the O'Neill Grading System (OGS) for ETD. Data were analyzed using the IBM-SPSS statistical software program. A statistically significant decrease in the number of compression holds was observed in the 15-minute compression schedule, correlating to the results observed in the Phase I trial. The 15-minute linear compression profile continues to demonstrate the decreased need for patient symptomatic compression stops (as in the Phase I trial) using a USN TT9 during elective hyperbaric oxygen treatments in a Class A multiplace hyperbaric chamber. Trial Registration: ClinicalTrials.gov Identifier: NCT04776967.

Multiple and early hyperbaric oxygen treatments enhance muscle healing after muscle contusion injury: a pilot study.

BACKGROUND: The optimal timing of hyperbaric oxygen (HBO2) treatments for the best recovery following muscle injury has yet to be determined. Thus, the optimal number and timing of HBO2 treatments for maximal muscle regeneration were explored. METHODS: The HBO2 treatment protocol consisted of 2.5 ATA 100% oxygen for 120 minutes. Muscle-injured rats were randomized to one of 10 groups: single HBO2 treatment immediately after injury (HBO 1T day 0), one day (HBO 1T day 1), three days (HBO 1T day 3) and five days (HBO 1T day 5) after injury; three HBO2 treatments from immediately after injury to two days after injury (HBO 3T day 0-2), from one to three days after injury (HBO 3T day 1-3), from three to five days after injury (HBO 3T day 3-5), from five to seven days after injury (HBO 3T day 5-7); five daily HBO2 treatments (HBO 5T); and no treatment (NT). RESULTS: HBO 5T and HBO 3T day 0-2, days 1-3 and days 3-5 significantly promoted CD206-positive cell infiltration, satellite cell differentiation and muscle regeneration compared to the NT group. CONCLUSION: Five HBO2 treatments and three HBO2 treatments within three days of injury promote muscle regeneration.

Hyperbaric oxygen for refractory osteomyelitis.

Refractory osteomyelitis is defined as a chronic osteomyelitis that persists or recurs after appropriate interventions have been performed or where acute osteomyelitis has not responded to accepted management techniques [1]. To date, no randomized clinical trials examining the effects of hyperbaric oxygen (HBO2) therapy on refractory osteomyelitis exist, and the number of new osteomyelitis clinical trials conducted over the past decade has been limited. However, based on a comprehensive review of the scientific literature, the addition of HBO2 therapy to routine surgical and antibiotic treatment of previously refractory osteomyelitis appears to be both safe and ultimately improves infection resolution rates. In most cases, the best clinical results are obtained when HBO2 treatment is administered in conjunction with culture-directed antibiotics and initiated soon after clinically indicated surgical debridement. Where extensive surgical debridement or removal of fixation hardware is relatively contraindicated (e.g., cranial, spinal, sternal, or pediatric osteomyelitis), a trial of culture-directed antibiotics and HBO2 therapy prior to undertaking more than limited surgical interventions provides a reasonable prospect for osteomyelitis cure. HBO2 therapy is ordinarily delivered on a once daily basis, five-seven days per week, for 90-120 minutes using 2.0-3.0 atmospheres absolute (ATA) pressure. Where prompt clinical improvement is seen, the existing regimen of antibiotics and HBO2 therapy should be continued for approximately four to six weeks. Typically, 20-40 HBO2 sessions are required to achieve sustained therapeutic benefit. In contrast, if prompt clinical response is not noted or osteomyelitis recurs after this initial treatment period, then continuation of the current antibiotic and HBO2 treatment regimen is unlikely to be effective. Instead, clinical management strategies should be reassessed and additional surgical debridement and/or modification of antibiotic therapy considered. Subsequent reinstitution of HBO2 therapy will again help maximize the overall chances for treatment success in these persistently refractory patients.

Effect of Hyperbaric Oxygen Therapy Initiation Time in Acute Carbon Monoxide Poisoning.

OBJECTIVES: Hyperbaric oxygen therapy (HBO2) is recommended for symptomatic patients within 24-hour postcarbon monoxide poisoning. Previous studies have reported significantly better outcomes with treatment administered within 6 hours after carbon monoxide poisoning. Thus, we aimed to compare the neurocognitive outcomes according to HBO2 delay intervals. DESIGN: Retrospective analysis of data from our prospectively collected carbon monoxide poisoning registry. SETTING: A single academic medical center in Wonju, Republic of Korea. PATIENTS: We analyzed the data of 706 patients older than 16 years treated with HBO2 with propensity score matching. Based on carbon monoxide exposure-to-HBO2 delay intervals, we classified patients into the early (control, less than or equal to 6 hr) and late (case, 6-24 hr) groups. The late group was further divided into Case-1 (6-12 hr) and Case-2 (12-24 hr) groups. We also compared mild (nonintubated) and severe (intubated) groups. INTERVENTIONS: HBO2. MEASUREMENTS AND MAIN RESULTS: After propensity score matching, Global Deterioration Scale scores at 6 months postcarbon monoxide exposure showed significantly fewer poor outcome patients in the early than in the late group (p = 0.027). The early group had significantly fewer patients with poor outcomes than the Case-2 group (p = 0.035) at 1 month and than the Case-1 (p = 0.033) and Case-2 (p = 0.004) groups at 6 months. There were significantly more patients with poor prognoses at 6 months as treatment interval increased (p = 0.008). In the mild cohort, the early group had significantly fewer patients with poor 6-month outcomes than the late group (p = 0.033). CONCLUSIONS: Patients who received HBO2 within 6 hours of carbon monoxide exposure had a better 6-month neurocognitive prognosis than those treated within 6-24 hours. An increase in the interval to treatment led to an increase in poor outcomes.

Clinical characteristics, treatment, and prognosis of 74 2019 novel coronavirus disease patients in Hefei: A single-center retrospective study.

ABSTRACT: Since December 2019, pneumonia caused by a novel coronavirus (SARS-CoV-2), namely 2019 novel coronavirus disease (COVID-19), has rapidly spread from Wuhan city to other cities across China. The present study was designed to describe the epidemiology, clinical characteristics, treatment, and prognosis of 74 hospitalized patients with COVID-19.Clinical data of 74 COVID-19 patients were collected to analyze the epidemiological, demographic, laboratory, radiological, and treatment data. Thirty-two patients were followed up and tested for the presence of the viral nucleic acid and by pulmonary computed tomography (CT) scan at 7 and 14 days after they were discharged.Among all COVID-19 patients, the median incubation period for patients and the median period from symptom onset to admission was all 6 days; the median length of hospitalization was 13 days. Fever symptoms were presented in 83.78% of the patients, and the second most common symptom was cough (74.32%), followed by fatigue and expectoration (27.03%). Inflammatory indicators, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) of the intensive care unit (ICU) patients were significantly higher than that of the non-ICU patients (P < .05). However, 50.00% of the ICU patients had their the ratio of T helper cells to cytotoxic T cells (CD4/CD8) ratio lower than 1.1, whose proportion is much higher than that in non-ICU patients (P < .01).Compared with patients in Wuhan, COVID-19 patients in Anhui Province seemed to have milder symptoms of infection, suggesting that there may be some regional differences in the transmission of SARS-CoV-2 between different cities.

Mechanistic Rationale and Clinical Efficacy of Hyperbaric Oxygen Therapy in Chronic Neuropathic Pain: An Evidence-Based Narrative Review.

Background: Chronic neuropathic pain is a condition affecting an increasing proportion of the general population and its management requires a comprehensive, multidisciplinary program. A growing body of evidence supports the use of hyperbaric oxygen therapy (HBOT) in several chronic neuropathic pain conditions; however, its role and efficacy remain unclear. Purpose: To summarize current evidence for the mechanistic rationale of HBOT in chronic neuropathic pain conditions and to evaluate its clinical efficacy. Methods: This narrative review was conducted after searching the following databases (Medline, Embase, Cochrane, PsycINFO, the Web of Science, Scopus, ClinicalTrials. gov, WHO ICTRP, and ProQuest Digital Dissertation) from January 1946 to March 2020. Articles published in English that involved either animal or human studies with acute or chronic neuropathic pain evaluating any HBOT-related intervention were included. Results: A total of 2971 citations were identified. A total of 29 studies were included in this review. The mechanisms of action for HBOT use in neuropathic conditions included the primary effects of hyperoxia and edema resolution, as well as the secondary effects pertinent to the production of oxygen and nitrogen reactive species (serving as pain signaling molecules), nitric oxide-dependent release of opioid peptides, and reduction of inflammatory mediators. A robust evidence for HBOT use in the clinical setting was associated with chronic regional pain syndrome and chronic primary bladder pain syndrome. Some evidence supported its use for chronic secondary (peripheral) neuropathic pain including radiation-induced plexus neuropathies, postherpetic neuralgia, and trigeminal neuralgia. Conclusions: HBOT has been shown to have antinociceptive and analgesic effects in animal models of inflammatory, neuropathic, and chronic pain. Human studies demonstrated beneficial effects of HBOT in improving clinical outcomes such as pain scores, pain-related symptoms, and quality of life. A systematic methodology of HBOT application is necessary to confirm its safety and efficacy.

Hyperbaric oxygen therapy for chronic diabetic foot ulcers: An overview of systematic reviews.

OBJECTIVES: Hyperbaric oxygen therapy in the treatment of diabetic foot ulcer has been widely used in medical practice, but its clinical effect is not clear. The purpose of this overview of systematic reviews is to evaluate the clinical evidence of hyperbaric oxygen therapy in the treatment of diabetic foot ulcers. METHODS: PubMed, Cochrane Library, Web of Knowledge, Embase, MEDLINE, Chinese National Knowledge Infrastructure Database, the Chongqing VIP Database, Chinese Biomedical Database, and Wanfang Database were searched in 1st December 2020. Systematic reviews (SRs) evaluating the effects of Hyperbaric oxygen therapy in people with diabetic foot ulcer were included. Methodological quality of the included SRs was assessed using the AMSTAR-2 tool. The quality of evidence of the primary studies was assessed using GRADE. The integrity of the included SRs was assessed using PRISMA. The bias risk of each SR was assessed using ROBIS evaluation tool. RESULTS: Eleven SRs/MAs met all inclusion criteria. According to the results of the AMSTAR-2, only 1 included review were rated critically as being of high quality, 6 included review were rated critically as being of medium quality. With PRISMA, the reporting checklist was relatively complete, but some reporting weaknesses remained in the topics of the protocol and registration, search strategy, and additional analyses. Based on the ROBIS tool, only five SRs/MAs had a low risk of bias. With the GRADE system, no high-quality evidence was found, and only 13 outcomes provided moderate-quality evidence. CONCLUSIONS: There is limited clinical evidence to support hyperbaric oxygen therapy in the treatment of diabetic foot ulcers, it is not recommended to routinely apply hyperbaric oxygen therapy to all patients with diabetic foot ulcers, especially those with non-ischemic diabetic foot ulcers. Hyperbaric oxygen therapy has certain potential to promote ulcer healing and reduce amputation rate in patients with ischemic diabetic foot ulcers, but due to the low quality and small quantity of the SRs/MAs supporting these results, high-quality studies with rigorous study designs and larger samples are needed before widespread recommendations can be made.

Comparison of the efficacy of multiple antioxidant and hyperbaric oxygen treatments in the prevention of ischemia and necrosis of local random McFarlane skin flap.

OBJECTIVE: The aim of this study was to compare the efficacy of multiple antioxidant (Proxeed Plus (PP) with Carnitine, Selenium, Zinc, Coenzyme Q10, Vitamin C, Folic Acid, Vitamin B12) on local random skin flap healing with the hyperbaric oxygen (HBO) therapy. METHODS: Fourty rats were equally divided into five groups (Control, PP, HBO, HBO + PP, PP + HBO + PP). Local random McFarlane skin flap was applied to all rats. Following the applications, evaluations were made biochemical (TAS, TOS, OSI, IL-1ß, IL-6, TNF-α, TGF-ß, VEGF) and histopathological parameters. RESULTS: Necrosis percentage was found to be lower in the PP + HBO + PP group than all other groups whereas the necrosis percentages of PP and HBO groups were similar. Oxidative stress rates were significantly higher in the control group compared to the other groups whereas it was lower in the PP + HBO + PP group than all other groups. The inflammation parameters were the highest in the control group and the lowest in the PP + HBO + PP group. Growth factors were higher in the PP + HBO + PP group than all other groups. Epithelialization and wound healing were better in the HBO and PP groups than in the control group. The greatest healing, epithelialization and vascularization was seen in the PP + HBO + PP group. The histopathological findings in the PP + HBO + PP group were better in each inner region than in the other groups. CONCLUSION: Biochemical and histopathological parameters have shown that PP reduces ischemia and necrosis and increases oxygenation in flap healing by providing significant improvement thanks to the multiple molecular structures in its content.

Seizure during hyperbaric oxygen therapy: experience at a single academic hospital in Korea.

Background: Hyperbaric oxygen (HBO2) therapy is a safe and well-tolerated treatment modality. Seizures, one of the most severe central nervous system side effects of HBO2 therapy, can occur. Episodes of seizures during HBO2 therapy have not yet been reported in countries such as Korea, where hyperbaric medicine is still in the developmental stage. Methods: The registry data of all patients treated with HBO2 therapy in a tertiary academic hospital in Korea were prospectively collected, and patients who developed seizures during HBO2 therapy between October 2016 and December 2019 were evaluated. In addition, we reviewed previous studies on occurrence of seizures during HBO2 therapy. Results: During the study period, a total of 10,425 treatments were provided to 1,308 patients. The most frequently treated indication was carbon monoxide (CO) poisoning ABSTRACT (n=547, 41.8%). During the HBO2 therapy sessions (total: 10,425), five seizure episodes occurred (patients with CO poisoning: n=4; patients with arterial gas embolism [AGE]: n=1). The frequency of seizures in patients with CO poisoning (0.148%) and AGE (3.448%) was significantly higher than that in patients with all indications (0.048%) (p=0.001). None of the patients had lasting effects due to the seizures. Conclusion: Our study revealed a similar frequency rate in terms of all indications and CO poisoning, and a slightly higher rate in AGE. Seizures were observed in patients with CO poisoning and AGE. Therefore, if clinicians plan to operate a hyperbaric center in a country like Korea, where there are several patients with acute CO poisoning, they should be prepared to handle seizures that may occur during HBO2 therapy.