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.

Adjunctive hyperbaric oxygen therapy in the management of severe lower limb soft tissue injuries: a systematic review

PURPOSE

Traumatic crush injuries of the lower limb often accompany severe complications. The incorporation of hyperbaric oxygen therapy to standard trauma care may have the potential to diminish injury-related complications and improve outcome in such cases. This systematic review aims to evaluate the effectiveness of hyperbaric oxygen therapy in the management of severe lower limb soft tissue injuries.

METHODS

The electronic databases Medline, Embase and Cochrane Library were searched to identify studies involving patients with crush-associated sever lower limb soft tissue injuries who received hyperbaric oxygen therapy in conjunction with standard trauma care. Relevant data on type of injury, hyperbaric oxygen therapy protocol and outcome related to wound healing were extracted.

RESULTS

In total seven studies met the inclusion criteria, involving 229 patients. The studies included two randomized clinical trials, one retrospective cohort study, three case series and one case report. The randomized placebo-controlled clinical trial showed a significant increase in wound healing and decrease in the need for additional surgical interventions in the patient group receiving hyperbaric oxygen therapy when compared to those undergoing sham therapy. The randomized non-placebo-controlled clinical trial revealed that early hyperbaric oxygen therapy reduces tissue necrosis and the likelihood of long-term complications. The retrospective cohort study indicated that hyperbaric oxygen therapy effectively reduces infection rates and the need for additional surgical interventions. The case series and case report presented beneficial results with regard to wound healing when hyperbaric oxygen therapy was added to the treatment regimen.

CONCLUSION

Hyperbaric oxygen therapy is generally considered a safe therapeutic intervention and seems to have a beneficial effect on wound healing in severe lower limb soft tissue injuries when implemented as an addition to standard trauma care.

Effect of hyperbaric oxygen on the growth and susceptibility of facultatively anaerobic bacteria and bacteria with oxidative metabolism to selected antibiotics

Wild strains of Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis were tested in an experimental hyperbaric chamber to determine the possible effect of hyperbaric oxygen on the susceptibility of these strains to the antibiotics ampicillin, ampicillin + sulbactam, cefazolin, cefuroxime, cefoxitin, gentamicin, sulfamethoxazole + trimethoprim, colistin, oxolinic acid, ofloxacin, tetracycline, and aztreonam during their cultivation at 23 °C and 36.5 °C. Ninety-six-well inoculated microplates with tested antibiotics in Mueller-Hinton broth were cultured under standard incubator conditions (normobaric normoxia) for 24 h or in an experimental hyperbaric chamber (HAUX, Germany) for 24 h at 2.8 ATA of 100% oxygen (hyperbaric hyperoxia). The hyperbaric chamber was pressurised with pure oxygen (100%). Both cultures (normoxic and hyperoxic) were carried out at 23 °C and 36.5 °C to study the possible effect of the cultivation temperature. No significant differences were observed between 23 and 36.5 °C cultivation with or without the 2-h lag phase in Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis. Cultivation in a hyperbaric chamber at 23 °C and 36.5 °C with or without a 2-h lag phase did not produce significant changes in the minimum inhibitory concentration (MIC) of Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis. For the tested strains of Pseudomonas aeruginosa, the possible effect of hyperbaric oxygen on their antibiotic sensitivity could not be detected because the growth of these bacteria was completely inhibited by 100% hyperbaric oxygen at 2.8 ATA under all hyperbaric conditions tested at 23 °C and 36.5 °C. Subsequent tests with wild strains of pseudomonads, burkholderias, and stenotrophomonads not only confirmed the fact that these bacteria stop growing under hyperbaric conditions at a pressure of 2.8 ATA of 100% oxygen but also indicated that inhibition of growth of these bacteria under hyperbaric conditions is reversible.

Challenges in the management of high-altitude illnesses and emergencies in Bhutan and Nepal

Many popular tourist attractions and trekking routes in Bhutan and Nepal are situated between 3000 and 6000 m in elevation. High-altitude emergencies are becoming more common and medical providers must be aware of the practical and medical issues in managing these disorders. We reflect on the challenges in providing high-altitude emergency medical services in Bhutan and Nepal.

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.

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 .

Addition of hyperbaric oxygen therapy versus usual care alone for inflammatory bowel disease: A systematic review and meta-analysis

Objective

Inflammatory bowel disease (IBD) is a chronic idiopathic inflammatory disease that includes ulcerative colitis (UC) and Crohn's disease (CD). Hyperbaric oxygen therapy (HBOT) involves breathing pure oxygen in a pressurized environment. Existing literature suggests that HBOT may be an effective therapy for IBD, but a quantitative analysis is lacking. This study aims to estimate the adjunctive role of HBOT in treating IBD and lowering its recurrence rate.

Design

Systematic review and meta-analysis.

Methods

The Cochrane Library, EMBASE, PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), China Science and Technology Journal Database (VIP), and Wanfang databases were systematically searched by two reviewers independently. Meta-analyses were performed using Review Manager (RevMan, version 5.3). A random-effects model was applied due to the heterogeneity between studies.

Results

Twenty-nine out of the initially identified 606 articles were covered in this review, with a total of 2151 patients (2071 for UC and 80 for CD). No randomized data of HBOT for CD were included. Among UC patients, usual care plus HBOT were more likely to achieve a clinical response than usual care alone (risk ratio [RR], 1.24; 95% confidence interval (CI), 1.17 to 1.31; P < 0.001). Subgroup analysis showed that the number of HBOT sessions had no statistically significant effect on overall efficacy (P > 0.05). The pooled data showed a lower recurrence rate in the usual care plus HBOT group (RR, 0.35; 95% CI, 0.24 to 0.53; P < 0.001). The standardized mean difference in the serum tumor necrosis factor level between HBOT and non-HBOT groups was -2.13 (95% CI, -3.09 to -1.18; P < 0.001). No severe adverse events of HBOT were observed.

Conclusions

HBOT might be an effective and safe adjunctive treatment for IBD. Further studies are required to investigate the optimal protocol of HBOT in IBD treatment.

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.

[Effects of short-segment pedicle screw internal fixation surgery combined with hyperbaric oxygen treatment for acute spinal injury on the morphology and function of the spine]

OBJECTIVE

To explore effect of short-segment pedicle screw internal fixation combined with hyperbaric oxygen in treating acute spinal fractures and its influence on recovery of spinal nerve function.

METHODS

A total of 96 patients with acute spinal fracture admitted from February 2017 to March 2020 were divided into combined group and control group, with 48 cases in each group. Both groups were treated with short-segment pedicle screw internal fixation. The combined group was given hyperbaric oxygen after surgery. The operation time, surgical blood loss, incision length and other general operation conditions between two groups were recorded. The differences in spinal morphology and function, Ameraican Spinal Injury Assiciation(ASIA) neurological function grade, serum inflammatory factors and ability of daily living activities were observed before and after surgery.

RESULTS

There was no significant difference in operation time, surgical blood loss, and incision length between combined group and control group(P>0.05). There were no significant differences in anterior height ratio and Cobb angle between two groups before surgery, 1 week and 6 months after surgery(P>0.05). The height ratio of anterior margin of the injured spine was significantly improved in both groups at 1 week and 6 months after surgery compared with preoperative period (P<0.05), and Cobb angle was significantly reduced in both groups compared with preoperative period (P<0.05). There was no statistically significant difference in serum interleukin-6(IL-6), interleukin-8(IL-8), and tumor necrosis factor-α(TNF-α) levels between two groups at 1 d after surgery(P>0.05);the serum IL-6, IL-8, and TNF-α levels of combined group were lower than those of control group at 1 week after surgery (P<0.05). At 6 months after surgery, ASIA neurological function grade of combined group was C grade in 2 cases, D grade in 23 cases, E grade in 22 cases. In control group, 7 cases was grade C, 26 cases was grade D, 13 cases was grade E, and the difference between two groups was statistically significant(P<0.05). The Barthel score of combined group was higher than that of control group at 1 month and 3 months after surgery, and the difference was statistically significant (P<0.05);at 6 months after surgery, there was no significant difference in Barthel score between two groups(P>0.05).

CONCLUSION

Short-segment pedicle screw internal fixation combined with hyperbaric oxygen for the treatment of acute spinal fractures is beneficial to the recovery of spinal nerve function after surgery, and has a certain effect on the early improvement of the patients' activities of daily living.

Hyperbaric oxygen therapy mitigates left ventricular remodeling, upregulates MMP-2 and VEGF, and inhibits the induction of MMP-9, TGF-β1, and TNF-α in streptozotocin-induced diabetic rat heart

AIMS

Hyperbaric oxygen (HBO) therapy has been widely used for the adjunctive treatment of diabetic wounds, and is currently known to influence left ventricular (LV) function. However, morphological and molecular repercussions of the HBO in the diabetic myocardium remain to be described. We aimed to investigate whether HBO therapy would mitigate adverse LV remodeling caused by streptozotocin (STZ)-induced diabetes.

MAIN METHODS

Sixty-day-old Male Wistar rats were divided into four groups: Control (n = 8), HBO (n = 7), STZ (n = 10), and STZ + HBO (n = 8). Diabetes was induced by a single STZ injection (60 mg/kg, i.p.). HBO treatment (100% oxygen at 2.5 atmospheres absolute, 60 min/day, 5 days/week) lasted for 5 weeks. LV morphology was evaluated using histomorphometry. Gene expression analyzes were performed for LV collagens I (Col1a1) and III (Col3a1), matrix metalloproteinases 2 (Mmp2) and 9 (Mmp9), and transforming growth factor-β1 (Tgfb1). The Immunoexpression of cardiac tumor necrosis factor-α (TNF-α) and vascular endothelial growth factor (VEGF) were also quantified.

KEY FINDINGS

HBO therapy prevented LV concentric remodeling, heterogeneous myocyte hypertrophy, and fibrosis in diabetic rats associated with attenuation of leukocyte infiltration. HBO therapy also increased Mmp2 gene expression, and inhibited the induction of Tgfb1 and Mmp9 mRNAs caused by diabetes, and normalized TNF-α and VEGF protein expression.

SIGNIFICANCE

HBO therapy had protective effects for the LV structure in STZ-diabetic rats and ameliorated expression levels of genes involved in cardiac collagen turnover, as well as pro-inflammatory and pro-angiogenic signaling.

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 effects of hyperbaric oxygen therapy (HBOT) on coronavirus disease-2019 (COVID-19): a systematic review

Background

Oxygenation serves as a cornerstone in the treatment of COVID-19, and several methods have been extensively studied so far. Herein, we aimed to systematically review the studies discussing hyperbaric oxygen therapy (HBOT) to examine its reported efficacy and adverse events in patients with COVID-19.

Methods

We systematically searched and retrieved the relevant articles using keywords on the online databases, including PubMed, Scopus, Embase, Web of Science, and Cochrane databases up to April 11th, 2021. The retrieved records underwent a two-step title/abstract and full-text screening process, and the eligible papers were identified. National Institutes of health (NIH) quality assessment tool was used for this study. This study was registered in the International Prospective Register of Systematic Reviews (PROSPERO) with ID CRD42021269821.

Results

Eight articles from three countries were included. All the included studies had good and fair quality scores, with no poor studies included in this systematic review (Good: n = 5, Fair: n = 3). Studies were divided into clinical trials and case reports/series. Most of the studies used HBOT less than 1.5–2 absolute atmospheres (ATA) for 90 min sessions and thereafter sessions were decreased to 60 min. Trials demonstrated most of the patients recovered after receiving HBOT, and blood oxygen saturation increased after several sessions of HBOT.

Conclusion

Overall, HBOT seems to be a safe and effective oxygenation method in patients with COVID-19. However, there is limited knowledge and evidence regarding the effects and mechanism of HBOT in COVID-19 treatment, and further evaluations require extensive well-designed studies.

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.

Hyperbaric oxygen therapy in the prevention and management of tracheal and oesophageal anastomotic complications

OBJECTIVES

Failure of anastomotic healing is a morbid complication after airway or oesophageal surgery. Hyperbaric oxygen therapy (HBOT) has been used extensively in the management of complex wound-healing problems. We demonstrate the use of HBOT to rescue at-risk anastomoses or manage anastomotic failures in thoracic surgery.

METHODS

Retrospective review of 25 patients who received HBOT as part of the management of tracheal or oesophageal anastomotic problems during 2007-2018. HBOT was delivered at 2 atm with 100% oxygen in 90-min sessions.

RESULTS

Twenty-three patients underwent airway resection and reconstruction while 2 patients underwent oesophagectomy. There were 16 (70%) laryngotracheal and 7 (30%) tracheal resections. Necrosis at the airway anastomosis was found in 13 (57%) patients, partial dehiscence in 2 (9%) patients and both in 6 (26%) patients. HBOT was prophylactic in 2 (9%) patients. Patients received a median of 9.5 HBOT sessions (interquartile range 5-19 sessions) over a median course of 8 days. The airway anastomosis healed in 20 of 23 (87%) patients. Overall, a satisfactory long-term airway outcome was achieved in 19 (83%) patients; 4 patients failed and required reoperation (2 tracheostomies and 1 T-tube). HBOT was used in 2 patients after oesophagectomy to manage focal necrosis or ischaemia at the anastomosis, with success in 1 patient. Complications from HBOT were infrequent and mild (e.g. ear discomfort).

CONCLUSIONS

HBOT should be considered as an adjunct in the management of anastomotic problems after airway surgery. It may also play a role after oesophagectomy. Possible mechanisms of action are rapid granulation, early re-epithelialization and angiogenesis.

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.

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.

Efficacy of Hyperbaric Oxygen Therapy on Central Corneal Thickness, Intraocular Pressure, and Nerve Fiber Layer in Patients with Type 2 Diabetes: A Prospective Cohort Study

PURPOSE

To evaluate the effect of hyperbaric oxygen therapy (HBOT) on central corneal thickness (CCT), intraocular pressure (IOP), and the retinal nerve fiber layer (RNFL) thickness in patients with type 2 diabetes mellitus.

METHODS

This prospective non-randomized cohort study consisted of type 2 diabetes mellitus patients who received 30 sessions of HBOT for diabetic foot ulcer. The CCT, IOP, and RNFL measured at baseline, after the 10th session of HBOT, after the 20th session of HBOT, after the 30th session of HBOT, and after the 3 months of the last session of HBOT. We gained the superior-nasal, superior-temporal, inferior-nasal, inferior-temporal, nasal and temporal quadrant RNFL values with a spectral-domain optical coharence tomography.

RESULTS

Forty-six eyes of 46 patients included in the study. During the study period, a statistically significant increase in mean IOP values compared to baseline was observed (p < 0.001). We found no significant changes at CCT and all quadrants of RNFL values during HBOT and after 3 months of the treatment (p > 0.05). During the study period, the IOP levels increased over 21 mmHg (between 22 and 28 mmHg) in seven eyes (15.2%). The mean hemoglobin A1c values of these patients with IOP >21 mmHg were 8.2 ± 0.9 mg/dL, and there was significant differences compared with those of patients with IOP values ≤21 mmHg (7.4 ± 2.8 mg/dL) (p = 0.001).

CONCLUSIONS

HBOT increase IOP in type 2 diabetic patients especially in ones with impaired blood glucose regulation. However, it does not cause any changes in CCT and RNFL. As diabetic retinopathy and diabetic foot ulcer are in common pathologies, thus this brief report concludes a need for further studies with longer follow-up periods to explore the potential interaction of HBOT on CCT, IOP, and RNFL.

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.

Randomized controlled clinical trial evaluating the efficacy of hyperbaric oxygen therapy in facilitating the healing of chronic foot ulcers in diabetic patients: the study protocol

Background

Diabetic limb ulcers are highly prevalent and contribute to a significant increase in cost for the treatment of these patients in health services. However, healing of these wounds is a major health problem and may even lead to amputation. The primary aim of the current study is to evaluate the efficacy of hyperbaric oxygen therapy (HBOT) in facilitating the healing of diabetic foot ulcers, in addition to secondarily evaluating whether it reduces the number of amputations and improves the quality of life in these patients.

Methods

A non-blind randomized clinical study will be conducted in the city of Imperatriz, Maranhão state, Brazil, from 2019 to 2020, in diabetic patients with chronic foot ulcers (classified as Wagner grades 2, 3 and 4, persisting for more than 1 month). The outpatient follow-up for diabetic foot patients will be done at the Unified Health System, with a sample size of 120 patients (the randomization allocation will be 1:1, being 60 patients for each arm). Half of the patients will receive standard treatment, i.e. dressings, debridement, antibiotics and load relief, along with HBOT (HBOT group), and the other half will receive only standard treatment (control group). The patients of the HBOT group will be evaluated upon admission, after 10, 20, 30 and 35 HBOT sessions, and after 6 months and 1 year. The patients of the control group will also be evaluated at equivalent periods (upon admission, after 2, 4, 6 and 7 weeks, 6 months and 1 year). The SF-36 quality of life questionnaire will be filled upon admission and after 3 months of follow-up in both groups. The primary and secondary endpoints will be assessed with 1 year of follow-up.

Discussion

Diabetic foot ulcers are a highly prevalent complication of diabetes with serious consequences. A study to assess the efficacy of HBOT in healing the ulcers and reducing the rate of amputations in diabetic patients is justified, which will eventually aid in the development of guidelines for treating these ulcers.

Trial registration

Registration number RBR-7bd3xy. Registered on 17 July 2019—Retrospectively registered.

Necrotizing fasciitis caused by the treatment of chronic non-specific back pain

Background

Chronic back pain is a multifactorial disease that occurs particularly in adults and has many negative effects on the quality of daily life. Therapeutic strategies are often multimodal and designed for a long-term therapy period. In some cases, one option is joint infiltration or intrathecal injection with local anaesthetics. An adverse effect of this intervention may be necrotic fasciitis, a disease with high mortality and few therapeutic options.

Case presentation

This case shows a 53-year-old female patient who developed necrotic fasciitis after infiltrations of the sacroiliac joint and after epidural-sacral and intrathecal injections.

Conclusion

Thanks to early and aggressive surgical intervention, antibiotic treatment and hyperbaric oxygenation, she survived this serious complication and was able to return to life.

Hyperbaric oxygen therapy for the placement of dental implants in irradiated patients: systematic review and meta-analysis

This study was a systematic review with meta-analysis to evaluate the influence of hyperbaric oxygen therapy (HBOT) on the survival of dental implants placed in patients who had had radiotherapy for cancer of the head and neck. A systematic literature search was conducted using the PubMed/Medline, Science Direct, Embase and the Cochrane Library, between January 1985 and July 2018. The study observed the PRISMA (Preferred Reporting Items for Systematic review and Meta-Analysis) declaration and norms, and the systematic review was duly recorded in the PROSPERO (International prospective register of systematic reviews) database. Inclusion and exclusion criteria were applied, and all articles were selected on the basis of PICO questions. The process of eligibility and quality evaluation yielded three studies for statistical analysis. Based on the survival rates, there was no evidence that the risk of an implant failing was different between the patients who received HBOT and those who did not. Moreover, the risk of an implant failing did not depend on the anatomical site. HBOT exerted no beneficial influence on the survival rates of implants placed in irradiated patients, and the risk of an implant failing did not depend on its location.

The effect of hyperbaric oxygen therapy on bone macroscopy, composition and biomechanical properties after ionizing radiation injury

Background

Radiotherapy used in tumor treatment compromises vascularization of bone tissue. Hyperbaric oxygenation (HBO) increases oxygen availability and improves vascularization, minimizing the deleterious effects of ionizing radiation (IR). Therefore, the aim of this study was to evaluate HBO therapy effect on bone macroscopy, composition and biomechanical properties after IR damage.

Methods

Twenty male Wistar rats weighing 300 ± 20 g (10 weeks of age) were submitted to IR (30 Gy) to the left leg, where the right leg was not irradiated. After 30 days, ten animals were submitted to HBO therapy, which was performed daily for 1 week at 250 kPa for 90-min sessions. All animals were euthanized 37 days after irradiation and the tibia were separated into four groups (n = 10): from animals without HBO - right tibia Non-irradiated (noIRnoHBO) and left tibia Irradiated (IRnoHBO); and from animals with HBO - right tibiae Non-irradiated (noIRHBO) and left tibia Irradiated (IRHBO). The length (proximal-distal) and thickness (anteroposterior and mediolateral) of the tibiae were measured. Biomechanical analysis evaluated flexural strength and stiffness. Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) was used to calculate the amide I ratio, crystallinity index, and matrix to mineral ratios.

Results

In the macroscopic and ATR-FTIR analysis, the IRnoHBO showed lower values of length, thickness and amide I ratio, crystallinity index and matrix to mineral ratios compared to noIRnoHBO (p < 0.03). IRnoHBO showed no statistical difference compared to IRHBO for these analyses (p > 0.05). Biomechanics analysis showed that the IRnoHBO group had lower values of flexural strength and stiffness compared to noIRnoHBO and IRHBO groups (p < 0.04). In addition, the noIRHBO group showed higher value of flexural strength when compared to noIRnoHBO and IRHBO groups (p < 0.02).

Conclusions

The present study concluded that IR arrests bone development, decreases the collagen maturation and mineral deposition process, thus reducing the flexural strength and stiffness bone mechanical parameters. Moreover, HBO therapy minimizes deleterious effects of irradiation on flexural strength and the bone stiffness analysis.

The effect of hyperbaric oxygenation therapy on myocardial function

Hyperbaric oxygenation therapy is successfully implemented for the treatment of several disorders. Data on the effect of hyperbaric oxygenation on echocardiographic parameters in asymptomatic patients is limited. The current study sought to evaluate the effect of hyperbaric oxygenation therapy on echocardiographic parameters in asymptomatic patients. Thirty-one consecutive patients underwent a 60-sessions course of hyperbaric oxygenation therapy in an attempt to improve cognitive impairment. In all subjects, echocardiography examination was performed before and after a course of hyperbaric oxygenation therapy. Conventional and speckle tracking imaging parameters were calculated and analyzed. The mean age was 70 ± 9.5 years, 28 [90%] were males. History of coronary artery disease was present in 12 [39%]. 94% suffered from hypertension, 42% had diabetes mellitus. Baseline wall motion abnormalities were found in eight patients, however, global ejection fraction was within normal limits. During the study, ejection fraction [EF], increased from 60.71 ± 6.02 to 62.29 ± 5.19%, p = 0.02. Left ventricular end systolic volume [LVESV], decreased from 38.08 ± 13.30 to 35.39 ± 13.32 ml, p = 0.01. Myocardial performance index [MPi] improved, from 0.29 ± 0.07 to 0.26 ± 0.08, p = 0.03. Left ventricular [LV] global longitudinal strain increased from - 19.31 ± 3.17% to - 20.16 ± 3.34%, p = 0.036 due to improvement in regional strain in the apical and antero-septal segments. Twist increased from 18.32 ± 6.61° to 23.12 ± 6.35° p = 0.01, due to improvement in the apical rotation, from 11.76 ± 4.40° to 16.10 ± 5.56°, p = 0.004. Hyperbaric oxygen therapy appears to improve left ventricular function, especially in the apical segments, and is associated with better cardiac performance. If our results are confirmed in further studies, HBOT can be used in many patients with heart failure and systolic dysfunction.

Hyperbaric Oxygen for Radiation Necrosis of the Brain

INTRODUCTION

Hyperbaric oxygen therapy (HBOT) shows promising results in treating radionecrosis (RN) but there is limited evidence for its use in brain RN. The purpose of this study is to report the outcomes of using HBOT for symptomatic brain RN at a single institution.

METHODS

This was a retrospective review of patients with symptomatic brain RN between 2008 and 2018 and was treated with HBOT. Demographic data, steroid use, clinical response, radiologic response and toxicities were collected. The index time for analysis was the first day of HBOT. The primary endpoint was clinical improvement of a presenting symptom, including steroid dose reduction.

RESULTS

Thirteen patients who received HBOT for symptomatic RN were included. The median time from last brain radiation therapy to presenting symptoms of brain RN was 6 months. Twelve patients (92%) had clinical improvement with median time to symptom improvement of 33 days (range 1-109 days). One patient had transient improvement after HBOT but had recurrent symptomatic RN at 12 months. Of the eight patients with evaluable follow-up MRI, four patients had radiological improvement while four had stable necrosis appearance. Two patients had subsequent deterioration in MRI appearances, one each in the background of initial radiologic improvement and stability. Median survival was 15 months with median follow-up of 10 months. Seven patients reported side effects attributable to HBOT (54%), four of which were otologic in origin.

CONCLUSIONS

HBOT is a safe and effective treatment for brain RN. HBOT showed clinical and radiologic improvement or stability in most patients. Prospective studies to further evaluate the effectiveness and side effects of HBOT are needed.

Minimizing tissue damage due to filler injection with systemic hyperbaric oxygen therapy

Recently, there is a growing interest of hyperbaric oxygen therapy in many fields of medicine. We had a 43-year-old female patient presented with severe necrosis of the nose, philtrum, and upper lip due to retrograde arterial occlusion after nasolabial fold hyaluronic acid filler injection. Our patient went through 43 sessions of systemic hyperbaric oxygen therapy from December 2, 2017 to January 18, 2018. We administered 2.8 atmosphere absolute (ATA) for 135 minutes in the first session and the remaining sessions consisted of 2.0 ATA for 110 minutes. In reporting this case, we wish to provide a warning regarding the latent risk of filler injections and share our experience about minimizing soft tissue damage in the early stages with systemic hyperbaric oxygen therapy.

[Complex treatment of pyoderma gangrenosum after minor trauma and primary surgical intervention with suspected necrotizing fasciitis]

This article presents the case of a rapidly progressing pyoderma gangrenosum (PG) following a minor trauma and surgical intervention. A 46-year-old patient was admitted to hospital after a minor trauma of the right lower leg with a suspected diagnosis of erysipelas bullosum. A magnetic resonance imaging (MRI) scan showed the suspicion of necrotizing fasciitis (NF) with indications for immediate incision and fascia resection. According to the results of the histopathological analysis and microbiological assessment without signs for a bacterial infection, high-dose steroid treatment and immunosuppressive treatment with cyclosporin A were initiated under the assumption of PG. Additionally, the patient was treated with hyperbaric oxygenation (HBO). The 2‑year follow-up showed a gradual restitution of the soft tissues.

Atypical Wounds; Hyperbaric Oxygen Therapy

Patients with severe diabetic foot ulcerations that fail to heal with standard conventional therapies may be candidates for hyperbaric oxygen therapy; these patients also should be evaluated for atypical wound etiologies. Medical evaluation includes thorough history, physical examination, screening laboratory tests, and ulcer biopsy. During hyperbaric oxygen therapy, patients breathe 100% oxygen at 2 times to 3 times atmospheric pressure while enclosed in a hyperbaric chamber. Over time, administration of hyperbaric oxygen therapy can result in wound neovascularization and enhanced limb salvage. In patients with suspected atypical ulceration, referral to a multidisciplinary wound healing center is considered standard of care.

350 años de la medicina hiperbárica: aspectos históricos, fisiopatogénicos y terapéuticos

The early use of hyperbaric therapy started with the quest to relieve respiratory problems among inhabitants of large cities during the industrial revolution, and from this, we have explored the benefits of treatment with hyperbaric oxygen in different areas of medicine. With the advances of the medical sciences, our knowledge concerning the therapies with hyperbaric oxygenation certainly has broadened and hyperbaric medicine still intrigues the contemporary medical researchers that are in seek of improve the quality of life of their patients.

Effects of hyperbaric oxygen and iloprost on intestinal ischemia-reperfusion induced acute lung injury

Purpose

To research the effects of iloprost (IL) and hyperbaric oxygen (HBO) combination treatment on lung injury and on tumor necrosis factor alpha (TNF-α), myeloperoxidase (MPO), malondialdehyde (MDA), and soluble intercellular adhesion molecule-1 (sICAM-1) levels after tissue or organ ischemia-reperfusion, and on ischemia-reperfusion induced lung neutrophil sequestration.

Methods

Forty white New Zealand rabbits were assigned randomly into 5 groups: HBO, IL, HBO+IL, control, and sham groups. TNF-α values were checked before ischemia, in the 1st hour of ischemia and in the 1st and 4th hours of reperfusion, also at the end of reperfusion period, plasma and tissue MPO values, MDA values, and sICAM-1 levels were detected. After sacrifice, the degree of lung injury was determined by histopathological examination.

Results

Compared to the control group all therapy groups showed a drastically meaningful reduction in TNF-α increase in 1, 2, and 4 hours. Plasma and lung MDA, MPO, and sICAM-1 levels were significantly lower in IL, HBO, HBO+IL, and sham groups compared with the control group. IL and/or HBO suppressed MDA and MPO increase in the lung tissue and in plasma. Additionally, histopathological score was significantly lower in HBO, IL, HBO+IL, and sham groups than that of the control group.

Conclusion

Both HBO and IL therapy have a beneficial effect by causing a meaningful reduction in TNF-α production, MPO, MDA, sICAM-1 levels and pulmonary neutrophil sequestration; which play a role, especially, in ischemia reperfusion induced lung damage.

Carbon Monoxide Poisoning Presenting as Non-Convulsive Status Epilepticus Treated with Hyperbaric Oxygen Therapy

Carbon monoxide (CO) poisoning is one of the most serious medical emergencies causing life-threatening conditions, including cardiovascular and neurological sequelae. Acute CO poisoning can lead to myocardial ischemia, ventricular arrhythmia, syncope, seizures, and coma. Seizures and other neurological complications in the early stages of presentation are related to severe intoxication in CO poisoning. In such situations, aggressive hyperbaric oxygen therapy is recommended. In CO poisoning, non-convulsive status epilepticus has rarely been observed following hyperbaric oxygen therapy (HBO₂). We report a case of CO poisoning presenting as non-convulsive status epilepticus treated with HBO₂. Mechanisms and implications for non-convulsive status epilepticus provocation during HBO₂ treatment are discussed.

Successful treatment of central retinal artery occlusion using hyperbaric oxygen therapy

Central retinal artery occlusion (CRAO) is considered an ophthalmologic emergency. The prognosis of this disease is very poor. Currently, there is no generally effective therapy available to treat CRAO. Hyperbaric oxygen therapy (HBOT) can increase the volume of oxygen delivered to the ischemic retinal tissue until spontaneous or assisted reperfusion occurs. We report the case of a patient who experienced sudden visual loss due to CRAO that was treated with HBOT. The patient was an 81-year-old woman who presented with CRAO in her right eye (OD). She exhibited "hand motion" visual acuity before treatment. She underwent three sessions of HBOT at a pressure of 2.8 atmospheres absolute, performed over 3 days. After 4 days in hospital, her visual acuity improved to 0.4 (OD) for far vision and 0.5 (OD) for near vision. Her vision was stable without the supply of oxygen; therefore, she was discharged.

Hyperbaric oxygen therapy: its use in medical emergencies and its development in Hong Kong

Hyperbaric oxygen therapy is widely accepted as life-saving treatment for decompression illness. Yet its use in acute carbon monoxide poisoning has remained controversial because of inconsistent findings in clinical trials. Hyperbaric oxygen therapy has an adjunctive role in managing gas gangrene, necrotising soft-tissue infection, and crush injury, as supported by case series. Several cases have been reported in the literature detailing the use of hyperbaric oxygen therapy in patients with severe anaemia in whom blood transfusion is not possible. Today, use of hyperbaric oxygen therapy in Hong Kong is limited by low awareness among physicians and patients, a lack of service access, and inadequate hospital and critical care support for the existing non-hospital facility. The recent introduction of a hospital-based facility is expected to benefit more patients for whom hyperbaric oxygen therapy is appropriate. This article reviews the mechanistic basis of and emerging scientific evidence to support the use of hyperbaric oxygen therapy in a number of acute medical emergencies, as well as the past and future development of hyperbaric oxygen therapy in Hong Kong.

ECMO improves survival following cardiogenic shock due to carbon monoxide poisoning - an experimental porcine model

Background

Severe intoxication with carbon monoxide (CO) is extremely lethal and causes numerous deaths due to cardiac or respiratory failure. Conventional intensive treatment may not be sufficient. The aim of this study was to investigate the treatment effect of extracorporeal veno-arterial extracorporeal membrane oxygenation (ECMO) following severe CO poisoning in an experimental porcine model.

Methods

A total of twelve pigs were anaesthetized, routinely monitored and intoxicated by inhalation of CO until the beginning of cardiac failure and randomized to a treatment (ventilator using an FiO₂ of 100% or ECMO). In the case of cardiac arrest, advanced resuscitation using standard guidelines was performed for at least 10 min. ECMO was also initiated in the ventilation group if the return of spontaneous circulation did not occur within 10 min. Lung tissue biopsies were obtained before and after CO intoxication.

Results

All animals in the ECMO group survived; however, one had to be resuscitated due to cardiac arrest. A single animal survived in the ventilator group, but five animals suffered from cardiac arrest at an average of 11.8 min after initiation of treatment. Conventional resuscitation failed in these animals, but four animals were successfully resuscitated after the establishment of ECMO.

A significant decrease was noticed in PO₂ with increasing HbCO, but there was no increase in pulmonary vascular resistance. No differences in H&E-stained lung tissue biopsies were observed.

Conclusions

The use of ECMO following severe CO poisoning greatly improved survival compared with conventional resuscitation in an experimental porcine model. This study forms the basis for further research among patients.

[Clinical effect of high pressure oxygen and Butylphthalide in the recovery of cerebral metabolism after carbon monoxide poisoning]

Objective: To study the clinical effect of high pressure oxygen and Butylphthalide in the recovery of cerebral metabolism after carbon monoxide poisoning. Methods: 84 patients treated from May 2014 to May 2016 in our hospital were selected. The subjects were randomly and equally divided into two groups. The control group adopted the conventional therapy and high pressure oxygen; on the basis, the observation group also took Butylphthalide. The clinical effect, duration of coma, recovery of consciousness, incidence rate of delayed encephalopathy was observed. After 1m of treatment, the HDS point was evaluated. Results: The total effective rate of control group (76.19%, 32/42) was lower than that of observation group (95.24%, 40/42) (P<0.05) . The duration of coma for observation group was shorter than that of control group. The percentage for patients with recovery of consciousness and incidence rate of delayed encephalopathy for observation group was better than that of control group (P<0.05) . The HDS point for observation group was even higher than that of control group (P<0.05) . Conclusion: The high pressure oxygen and butylphthalide can improve the clinical effective rate, shorten the duration of coma and promote the patient's recovery of consciousness. It is worthy of clinical promotion.

Hyperbaric oxygen therapy reduces astrogliosis and helps to recovery brain damage in hydrocephalic young rats

PURPOSE

We investigated the possible beneficial effects that hyperbaric oxygen therapy could offer in different brain structures affected by ventriculomegaly in pup rats submitted to experimental hydrocephalus.

METHODS

Seven-day-old Wistar rats were submitted to hydrocephalus by intracisternal injection of 10% kaolin into the cisterna magna. The animals were divided into four groups: control (n = 5); control with HBOT (3ATA/2 h/day) (n = 5); untreated hydrocephalic (n = 10); hydrocephalic treated with HBOT (3ATA/2 h/day) (n = 10). The treatment with HBOT was performed daily for 14 days post-induction of hydrocephalus. To evaluate the response to treatment, behavioral tests (open field, Morris water maze, and activity monitor) were performed. After 14 days, the animals were euthanized, and the brain was removed for histological (hematoxylin-eosin and solochrome-cyanine) and immunohistochemical (GFAP and Ki-67) studies.

RESULTS

The hyperbaric treatment, although not causing changes in ventricular enlargement, resulted in a significant improvement in the behavioral performance (p = 0.0001), with greater agility and exploration of the environment, preservation of spatial memory, and greater learning capacity (p = 0.0001). Through the immunohistochemical study, the astrocytic activity (glial fibrillary acidic protein) in the corpus callosum (p = 0.0001) and in the germinative matrix (p = 0.0033) was significantly reduced as compared to that in the H group.

CONCLUSION

The results suggest that hyperbaric treatment bettered the behavioral performance and offered benefits to the structures affected by the ventricular increase helping to recover the brain damages. In this way, the HBOT it can be considered an adjuvant therapy for the treatment of hydrocephalus.

The potential long-term neurological improvement of early hyperbaric oxygen therapy on hemorrhagic stroke in the diabetics

AIMS

Although Hyperbaric oxygen therapy (HyperBOT) attract our attention successfully these days, it is still full of controversy on the treatment of acute stroke. The aim of this study is to assess the potential long-term neurological consequences and safety of using HyperBOT on intracerebral hemorrhage (ICH) in the diabetics.

METHODS

In this prospective, randomized controlled trial, 79 diabetes patients suffering from acute ICH were randomized to treat for 60 min in a monoplace hyperbaric chamber pressurized with pure oxygen to 2.5-atm absolute (ATA) in the HyperBOT group or 1.5 ATA in the normobaric oxygen therapy (NormBOT) group, which was performed as control. Both short-term and long-term neurological consequences were studied and compared in each group on National Institutes of Health Stroke Scale [NIHSS], Barthel Index, modified Rankin Scale [mRS] and Glasgow Outcome Scale [GOS]. The related complications or side-events of all patients were recorded as well at the final follow-up of six months after onset.

RESULTS

No distinct difference was observed between each group at one month follow-up. However, in the long-term follow-up of six months, a higher frequency of patients in the HyperBOT group resulted into good outcome with a relative high neurological consequence compared with the NormBOT group (Barthel Index: 85.1% versus 65.6%, P = 0.080; mRS: 89.4% versus 68.8%, P = 0.045; GOS: 83.0% versus 62.5%, P = 0.073; NIHSS: 80.9% versus 56.2%, P = 0.035).

CONCLUSIONS

Early HyperBOT was found to be safe and effective with regards to the long-term neurological outcome of diabetic patients suffering from ICH.

Benefits of hyperbaric oxygen pretreatment for decompression sickness in Bama pigs

Decompression sickness (DCS) occurs when ambient pressure is severely reduced during diving and aviation. Hyperbaric oxygen (HBO) pretreatment has been shown to exert beneficial effects on DCS in rats via heat-shock proteins (HSPs). We hypothesized that HBO pretreatment will also reduce DCS via HSPs in swine models. In the first part of our investigation, six swine were subjected to a session of HBO treatment. HSP32, 60, 70 and 90 were detected, before and at 6, 12, 18, 24 and 30 h following exposure in lymphocytes. In the second part of our investigation, another 10 swine were randomly assigned into two groups (five per group). All swine were subjected to two simulated air dives in a hyperbaric chamber with an interval of 7 days. Eighteen hours before each dive, the swine were pretreated with HBO or air: the first group received air pretreatment prior to the first dive and HBO pretreatment prior to the second; the second group were pretreated with HBO first and then air. Bubble loads, skin lesions, inflammation and endothelial markers were detected after each dive. In lymphocytes, all HSPs increased significantly (P<0.05), with the greatest expression appearing at 18 h for HSP32 and 70. HBO pretreatment significantly reduced all the determined changes compared with air pretreatment. The results demonstrate that a single exposure to HBO 18 h prior to diving effectively protects against DCS in the swine model, possibly via induction of HSPs.

Hyperbaric oxygen therapy for pyoderma gangrenosum associated with ulcerative colitis

Pyoderma gangrenosum (PG), an ulcerating skin condition, is rare in patients with ulcerative colitis (UC). We report a case of successful treatment of PG in a patient with UC using hyperbaric oxygen therapy (HBOT). The patient had UC that was in remission following treatment with mesalazine and azathioprine therapy. After visiting an orthopedic clinic, the patient opted for treatment with antibiotics and daily dressing of the ulcerative skin lesions, while azathioprine was discontinued. However, the lesions did not improve. Two months later, the patient visited a dermatologist who diagnosed the lesions as PG, and he was admitted to our unit. Surgical debridement and HBOT were performed by a plastic surgeon in the emergency department. After 3 months of HBOT and topical treatment, the patient's PG completely resolved. His UC was still in remission with mesalazine alone. HBOT may be an effective and safe alternative treatment for PG associated with UC, particularly in patients in whom anti-tumor necrosis factor agents are unnecessary.

Salvage of Unilateral Complete Ear Amputation with Continuous Local Hyperbaric Oxygen, Platelet-Rich Plasma and Polydeoxyribonucleotide without Micro-Revascularization

In many cases of complete ear amputation, microvascular surgery is required for tissue perfusion and organ survival. However, microvascular reconstruction is not always feasible in the absence of suitable vessels. Here, we present the case of a 76-year-old man who underwent complete amputation of the left ear after a collapse at home because of cardiogenic syncope. He was treated with primary replantation and underwent a postoperative salvage course including continuous local hyperbaric oxygen therapy (HBOT), platelet-rich plasma (PRP) injections, and polydeoxyribonucleotide (PDRN) injections. The ear was almost completely salvaged, with a tiny eschar at the mid-scapha on both the anterior and posterior aspects. This case demonstrates the efficacy of local HBOT with PRP and PDRN injections.

[Implementation of regularly performed resuscitation training at a hyperbaric treatment center]

BACKGROUND

Medical emergency situations and even cardiac arrest can occur during treatment of patients in therapeutic hyperbaric chambers just as in other clinical departments; therefore, high quality structured management should be implemented for dealing with emergencies in this special working area. To ensure this the emergency medical treatment should not only be performed according to the current state of medical knowledge but needs to take the special features of the hyperbaric environment including safety aspects into account.

METHOD

This article presents a description of the implementation and effects of routine emergency and resuscitation training at a center for hyperbaric medicine.

RESULTS

By simulation of emergencies in a hyperbaric chamber it rapidly became clear that the treatment of medical emergencies and cardiac arrest under hyperbaric conditions has some special features and due to safety aspects cannot always be performed according to current medical guidelines. At the time of this simulation in a real life working environment, previously unknown structural and logistic problems became obvious whereby the solutions contributed to a significant improvement of structural and process quality and could potentially also improve the outcome quality. Furthermore, a positive and lasting learning effect in the fields of quality of resuscitation measures, organization of the workplace, communication skills, logistics and safety aspects was detectable by analyzing participant performance over a period of 4 years. On the part of the participating staff a positive feedback and high acceptance of emergency simulator training was confirmed.

CONCLUSION

Through annual compulsory emergency training of the complete staff of the hyperbaric unit at the actual workplace, a structural and confident approach to dealing with emergencies and resuscitation situations was observed. By the use of on-site simulator training even in specialized hospital units, deficits and tentativeness regarding logistics, course of action, organization and communication in emergency situations can be minimized to provide optimum patient care in a real life emergency situation by focusing on the medical measures.

Acute carbon monoxide poisoning in a regional hospital in Hong Kong: historical cohort study

OBJECTIVES

This study aimed to describe the clinical profiles of all patients with carbon monoxide poisoning admitted to a regional hospital in order to enhance the vigilance of health care professionals for delayed neurological sequelae associated with carbon monoxide poisoning and to identify the prognostic factors associated with their development. This study also aimed to assess the impact of hyperbaric oxygen therapy on the development of delayed neurological sequelae in these patients.

METHODS

This was a historical cohort study in which all patients with a diagnosis of carbon monoxide poisoning managed in a regional hospital in Hong Kong from 12 February 2003 to 8 November 2013 were recruited. Main outcome measures included delayed neurological sequelae.

RESULTS

Of the clinical profiles of 93 patients analysed, 24 patients received hyperbaric oxygen therapy and did not develop delayed neurological sequelae. Seven patients who did not receive hyperbaric oxygen therapy developed delayed neurological sequelae. Comparison of groups with and without delayed neurological sequelae (excluding hyperbaric oxygen therapy-treated patients) revealed that loss of consciousness (P=0.038), Glasgow Coma Scale score of 3 (P=0.012), elevated troponin level (P<0.001), higher creatine kinase level (P=0.008), and intubation requirement (P=0.007) were possible prognostic factors for the development of delayed neurological sequelae.

CONCLUSION

Although not statistically significant, this study showed a 100% protective effect of hyperbaric oxygen therapy against development of severe delayed neurological sequelae in patients with severe carbon monoxide poisoning. Further study with better study design is warranted. Loss of consciousness, low Glasgow Coma Scale score, intubation requirement, elevated troponin and higher creatine kinase levels were possible prognostic factors for development of delayed neurological sequelae in patients with severe carbon monoxide poisoning. A well-defined treatment protocol, appropriate follow-up duration and neuropsychiatric tests together with a hospital-based hyperbaric chamber are recommended for management of patients with severe carbon monoxide poisoning.

Radiotherapy after hyperbaric oxygenation in malignant gliomas

OBJECTIVE

This review was to evaluate the efficacy and toxicity of radiation therapy (RT) administered immediately after hyperbaric oxygen (HBO) therapy in patients with high grade gliomas.

RESEARCH DESIGN AND METHODS

PubMed, Embase, ISI Web of Knowledge, and Cochrane databases were searched using combinations of the following search terms: radiotherapy, hyperbaric oxygenation, chemotherapy, glioma, brain tumor. Selection was limited to prospective studies involving patients given HBO followed by RT for high-grade gliomas. Data extracted from studies included the clinical research phase of the study, number of study arms, number of patients, patient age and gender, glioma type and grade, pressure and length of HBO, protocol of radiation therapy, duration of follow-up, and the outcomes.

MAIN OUTCOME MEASURES

Overall survival, time to progression, response rate, tumor regression, and toxic effects associated with HBO plus RT treatment.

RESULTS

Literature search/screening yielded eight studies for analysis. Six of the studies were single-arm in design and enrolled a total of 203 patients, of whom 142 had grade IV gliomas and 61 had grade III gliomas. In these six studies, all patients received HBO then RT. Two studies were double-arm in design, with 24 patients treated with HBO followed by RT and 26 patients treated with RT alone. The findings from both the single- and double-arm studies indicated improved outcomes (survival rate, progression free survival, time to progression, response rate) with HBO and RT therapy. Reported toxicity included leucopenia, anemia, thrombocytopenia, fever, loss of appetite, constipation, nausea, vomiting, and liver dysfunction. The addition of HBO had minimal effect on toxicity or side effects; across the eight studies, only one patient with severe middle ear barotrauma had a complication directly related to HBO exposure.

CONCLUSION

This systematic reviews suggests that the addition of HBO to RT is tolerated and may be beneficial in patients with high-grade gliomas.

Administration of a second generation perfluorochemical in combination with hyperbaric oxygenation does not provide additional benefit in a model of permanent middle cerebral artery occlusion in rats

Objective

Both, second generation perfluorochemicals (Oxycyte®) and hyperbaric oxygen (HBO) have been shown to reduce necrotic tissue volume if administered early after experimental cerebral ischemia. With the idea of exponentiation of oxygen delivery to ischemic tissue, this study was conducted to investigate the combined effect of both treatment modalities on the extent of ischemic brain damage.

Methods

Permanent focal cerebral ischemia was induced in rats by middle cerebral artery occlusion (MCAO). Animals were assigned randomly to one of the following treatment groups: Control (0.9% NaCl, 1 ml/100 g i.v.), Oxycyte® (1 ml/100 g i.v.), HBO (1 bar hyperbaric oxygenation for 1 h) and HBO + Oxycyte® (1 ml/100 g i.v. combined with 1 bar hyperbaric oxygenation for 1 h). Injection of NaCl or Oxycyte® was performed following MCAO. After injection, breathing was changed to 100% oxygen in Oxycyte®-, HBO- and HBO + Oxycyte®-groups. After eight hours the necrotic volume was calculated from serial coronal sections stained with silver-nitrate and corrected for the extent of swelling.

Results

Hemodynamic and metabolic parameters were not affected by infusion of Oxycyte®. Total necrosis volume was significantly reduced in HBO-treated animals (223 ± 70 mm³), when compared to control animals (335 ± 36 mm³). In animals after Oxycyte®-treatment alone (299 ± 33 mm³) or combined HBO + Oxycyte®-treatment (364 ± 50 mm³) did not show a significantly smaller necrosis volume compared to control animals (necrosis volumes are given as mean ± SD).

Discussion

These results suggest that combination of hyperbaric oxygenation and Oxycyte® administered immediately after onset of vascular occlusion does not provide an additional neuroprotective effect in the early phase of brain ischemia.

[Hyperbaric oxygen therapy and inert gases in cerebral ischemia and traumatic brain injury]

Cerebral ischemia is a common thread of acute cerebral lesions, whether vascular or traumatic origin. Hyperbaric oxygen (HBO) improves tissue oxygenation and may prevent impairment of reversible lesions. In experimental models of cerebral ischemia or traumatic brain injury, HBO has neuroprotective effects which are related to various mechanisms such as modulation of oxidative stress, neuro-inflammation or cerebral and mitochondrial metabolism. However, results of clinical trials failed to prove any neuroprotective effects for cerebral ischemia and remained to be confirmed for traumatic brain injury despite preliminary encouraging results. The addition of inert gases to HBO sessions, especially argon or xenon which show neuroprotective experimental effects, may provide an additional improvement of cerebral lesions. Further multicentric studies with a strict methodology and a better targeted definition are required before drawing definitive conclusions about the efficiency of combined therapy with HBO and inert gases in acute cerebral lesions.

Hyperbaric oxygen therapy in the battlefield

Hyperbaric oxygen therapy (HBOT) is increasingly being used in a number of areas of medical practice. It is an accepted adjunctive therapy in conditions such as burns, crush injuries, head injuries, spinal cord injuries, reconstruction surgeries, gas poisonings, radiation injuries, various anaerobic and aerobic infections that are commonly encountered in combat. It is being evaluated as a potential therapy for a variety of illnesses such as Post Traumatic Stress Disorder (PTSD) and High Altitude Cerebral Oedema (HACO) that are typically encountered in a combat scenario. The latest hyperbaric chambers are lightweight, portable and easy to operate. Provisioning of such chambers in the zonal hospitals can prove to be an invaluable resource in combat casualty care and may result in improved outcomes.

Livedoid vasculopathy managed with hyperbaric oxygen therapy

Livedoid vasculopathy is an uncommon condition resulting in painful lower extremity ulceration and scarring. This condition presents as purpuric macules and papules that progress to painful, irregular ulcers of the lower legs and dorsal feet. These ulcerations are often recurrent and chronic with spontaneous remissions and exacerbations that may be seasonal. The first case, a 22-year-old female presented with three-year history of recurrent multiple non-healing ulcers involving feet and ankles. The ulcers were associated with severe debilitating pain and paraesthesia, as a result of which she was unable to walk without support. Patient was administered HBOT at pressure of 2.5ATA for 1 h daily, six days a week. After ten sittings of HBOT, patient reported a drastic reduction in the pain along with reduction in the dose of analgesic by half and a definite improvement in her walking. The second case was a 49-year-old male who also had history of recurrent ulceration on the dorsum of feet and ankles associated with severe pain. With HBOT, the patient felt an improvement in pain and ambulation by the 8th sitting and complete relief from pain by the 17th sitting. HBOT is a recognized modality of treatment of various problem wounds and non-healing ulcers due to various etiologies. The above two cases show that it can be a useful treatment modality for livedoid vasculopathy where other treatment modalities have failed and therefore could be given to a larger number of patients in hospitals where it is available.

Hyperbaric oxygenation promotes regeneration of biliary cells and improves cholestasis in rats

AIM: To investigate the effects of hyperbaric oxygenation (HBO) on regeneration of the biliary ductal system and postoperative cholestasis in hepatectomized rats.

METHODS: HBO was performed in Wistar rats daily starting 12 h after a 70% partial hepatectomy. Regenerated liver weight, serum parameters and the proliferating cell nuclear antigen labeling index of hepatocytes and biliary ductal cells were measured. Hepatocyte growth factor (HGF), c-Met and transforming growth factor (TGF) β-1 mRNA expression levels were analyzed by quantitative reverse transcription polymerase chain reaction.

RESULTS: HBO improved the postoperative serum levels of total bile acid but not transaminase levels. HBO promoted hepatocyte and biliary ductal cell proliferation. The hematoxylin and eosin-stained specimens revealed fewer ballooned hepatocytes and higher cell densities in the HBO group compared to the control group. HBO suppressed c-Met mRNA levels at 15 h but did not modulate HGF or TGF β-1 mRNA expression levels.

CONCLUSION: HBO promoted regeneration of biliary ductal cells and improved postoperative cholestasis after a partial hepatectomy.

Quadruple H therapy for vasospasm

Triple H therapy has been enthusiastically used to increase cerebral blood flow in cases of vasospasm. Nevertheless, the oxygen-carrying capacity of the blood is lowered with this treatment. This side effect can theoretically be partially corrected using hyperbaric oxygen therapy (HBO) which appears to be the missing ring in the above therapeutic regimen. We conducted a review of of the available evidence regarding the beneficial effects of HBO in preventing postoperative ischemic complications due to vasospasm after surgery on ruptured cerebral aneurysms and the rationale for including HBO into the standards of care of these difficult patients.