Increased Tissue Oxygen Research Articles

A Prospective Clinical Trial to find the Efficiency of the Therapeutic use of a Combination of Transdermal gels Producing CO2 in Treating Varicose Ulcers that do not Respond to Primary Treatment

In this study, we evaluated 40 patients, all carriers of severe varicose ulcers. After four weeks of undergoing the same primary treatment, the progress was not as expected. We added two weekly applications, eight sessions in total, of transdermal carboxytherapy CO2-producing gels to their treatment primary regimen. We assessed the patients through photos taken before applying the gels and after 4 and 6 weeks of the starting date. We evaluated clinical manifestations, including the varicose ulcer's diameter and length, granulation, exudates, and pain. The patients underwent an arterial and venous Echo Doppler before and immediately after the first application to rule out arterial involvement and to observe any changes in stroke flow at the microcirculatory level. We measured the transcutaneous oxygen pressure (TcPO2) at a specific point for reference using a sensor before and after the first application and after the eighth application (one month later) of the gels (CO2PRO®) to see if transdermal carboxytherapy increased tissue oxygenation. Purpose This prospective study aims to evaluate the efficacy of a transdermal product (CO2PRO®) that, through a combination of gels, provides carbon dioxide to increase microcirculation and promote tissue oxygenation through the Bohr effect, helping to regenerate varicose ulcers. Patients selected to enter the study were under primary ulcer treatment and were not responding as expected. The patients continued to use their primary treatment and added the combination of gels that produce transdermal CO2.

Analyzing Uttarakhand's COVID-19 Outbreak: Demographic Insights and Strategies for Future Pandemic Prevention

Background:: The Indian state of Uttarakhand, also known as "Dev Bhoomi" or the Abode of Gods, is snuggled in the lap of the Himalayas. It is endowed with an abundant natural hilly environment and occupies more people in total than Israel, Switzerland, Hong Kong, etc. In this report, we look closely at the impact of COVID-19 on both high land/ hilly and low land/ plain bhabar zones across the state. Methods:: The data was retrieved from the Uttarakhand Government Covid-19 health bulletin for 12 months using the Python command line. The data analysis covers percentage positivity/COVID-19 positivity rate, recovery, deceased and doubling rate, along with a detailed statistical analysis. Results:: In the first wave, low-land- inhabitants residing in 4 districts, Dehradun, Haridwar, U. S. Nagar and Nainital, were found more vulnerable, with a peak positive case during the 21st – 26th week. On the other hand, the districts with exclusive hilly terrains, including Chamoli, Pauri Garhwal, and Rudraprayag, were found to be the least susceptible and reported a high number of positive cases between the 30th and 31st week. The highest recovery rate was found to be in the hilly district of Rudraprayag. The multiple regression with confirmed cases was explained in relation to deceased, recovered, other, and tested variables (R2 adj= 0.99). The analysis also revealed a very high doubling rate from the last week of May to the first week of Jun 2020. Conclusion:: The reduced number of COVID-19 cases in high-altitude hilly districts may be associated with factors such as enhanced ventilation, improved arterial oxygen transport, and increased tissue oxygenation. The findings from this study offer insights that can contribute to future pandemic prevention efforts. Summarising the current study, we have suggested 5-point solutions for preventing the next pandemic. It's important to note that while this study suggests a potential link between these factors and lower COVID-19 cases, further research is needed to establish a conclusive connection.

Effects of blood donor characteristics and storage on red blood cell haemoglobin β S-nitrosylation.

In the setting of tissue hypoxia, S-nitrosylated haemoglobin (SNO-Hb) plays crucial roles in the control of blood flow. This is associated with decreased oxygen affinity to haemoglobin and increase in tissue oxygenation. Red blood cell (RBC) transfusion is primarily performed to improve tissue oxygenation in anaemic patients. RBCs after storage undergo a variety of biochemical and functional alterations, including deficiency of nitric oxide (NO) bioactivity. However, how donor characteristics affect NO levels during RBC storage is unclear. We sought to investigate the association of blood donor age, gender and storage duration with NO and SNO-Hb levels in blood units. Blood samples from 42 healthy younger (≤30 years) and older (≥45 years) donors were collected and stored for up to 42 days. Total NO kits were used to detect total nitrite and nitrate levels in blood storage solution. SNO-Hb levels in RBCs were detected and analysed by quantitative mass spectrometry. Total NO levels in the blood storage solution significantly increased with donor age and storage duration. Proteomic analysis revealed that RBCs from older donors, particularly older females, significantly lost SNO-Hb during storage. Our findings indicate that RBCs from older donors are associated with reduced SNO-Hb levels and increased NO metabolites in storage solution after ≥35 days storage. The findings suggest stored RBCs from older donors may have reduced capacity to deliver oxygen to tissues under hypoxia. A shorter shelf life may be required for storing RBCs from older donors, particularly older females.

Hyperbaric oxygen therapy: future prospects in regenerative therapy and anti-aging.

Hyperbaric Oxygen Therapy (HBOT) utilizes 100% oxygen at high atmospheric pressure for clinical applications. HBOT has proven to be an effective supplementary treatment for a variety of clinical and pathological disorders. HBOT's therapeutic results are based on the physiological effects of increased tissue oxygenation, or improved oxygen bioavailability. HBOT's current indications in illnesses like as wound healing, thermal or radiation burns, and tissue necrosis point to its function in facilitating the regeneration process. Various research has revealed that HBOT plays a function in vascularization, angiogenesis, and collagen production augmentation. Individual regeneration capacity is influenced by both environmental and genetic factors. Furthermore, the regenerating ability of different types of tissues varies, and this ability declines with age. HBOT affects physiological processes at the genetic level by altering gene expression, delaying cell senescence, and assisting in telomere length enhancement. The positive results in a variety of indications, ranging from tissue regeneration to better cognitive function, indicate that it has enormous potential in regenerative and anti-aging therapy.

(108) Evaluation the Efficacy and Safety of Hyperbaric Oxygen Therapy in Sildenafil Citrate Non Responder Organic Erectile Dysfunction Patients: a Randomized Double Blinded Controlled Clinical Trial

Abstract Introduction Although the phosphodiesterase 5 inhibitors (PDE5i) are the first-line oral agents for erectile dysfunction (ED) treatment, there is growing number of PDE5i- non responder patients. Management of those patients is challenging and one of the new suggested regenerative therapies is the hyperbaric oxygen therapy (HBOT). HBOT is the application of oxygen under pressure to increase tissue oxygen levels. Few clinical reports were published about HBOT and ED. Objective To evaluate the efficacy and safety of HBOT in sildenafil citrate non- responder organic ED patients. Methods The current study included 30 sildenafil citrate non-responder ED patients. Patients were divided into two groups (randomly assigned and comparably cross-matched for age). Both patients and the investigators were blinded as regards the treatment until the end of the study. Group 1: Patients assigned to the HBOT group (20 patients) were treated with (30) sessions in 5 days/week (90 minutes of 100% oxygen at 2.2 ATA); Group 2: Patients assigned to the control group (10 patients) were exposed to (30) sessions of air oxygen tension at 1 ATA with room oxygen. Baseline laboratory investigations were done (random blood sugar, lipid profile, total & free testosterone). All patients were evaluated with the sexual health inventory for men (SHIM), erection hardness score (EHS), the sexual health encounter profile (SEP), and penile color Doppler initially, at 1 & 3 months after the end of treatment. Results The age mean ± SD in the HBOT group was 56.35±7.43 years and in the control group was 61.7±7.14 years. The current study showed that sildenafil citrate non-responders ED patients with 30 sessions of HBOT in 5 days/week, demonstrated a significant improvement of the total SHIM score, EHS, and SEP after 1 month of stoppage of treatment as compared to the control group. Also, penile color Doppler evaluation showed a significant improvement of 10 &20 minutes peak systolic velocity (PSV) between patients receiving HBOT compared to the control after 1 month of stoppage of treatment. More interestingly, the improvement of the total SHIM score, EHS, and SEP continued after 3 months of stoppage of the HBOT treatment as compared to the baseline evaluation. In addition, 10 &20 minutes PSV with penile color Doppler evaluation demonstrated maintained improvement after 3 months of stoppage of the HBOT treatment as compared to the baseline evaluation. In addition, the linear regression analysis was done for factors affecting SHIM score improvement (1 month/baseline) in the HBOT treatment group, revealing that hypertension was an independent predictor for SHIM score improvement. Hypertensive patients showed 4.6 times more SHIM score improvement as compared to non-hypertensive patients. As regards HBOT safety, there was no significant difference in adverse effects between the HBOT treatment group and the control group. Conclusions HBOT might be a potential therapeutic modality for sildenafil citrate non-responder ED patients especially in hypertensive patients with good safety profile. Further a multi-centric trial with a larger sample size and a longer follow-up period is recommended. Disclosure No.

Abstract WP303: Hypertension Disrupts the Relationship Between Pial Collateral Flow and Tissue Oxygenation During Ischemic Stroke

Introduction: Chronic hypertension decreases collateral blood flow through leptomeningeal anastomoses (LMAs) during ischemic stroke, which has been linked to worsened stroke outcome. Given the important relationship between LMA flow, tissue oxygenation and cortical cerebral blood flow (CBF), we characterized the interplay between CBF and tissue oxygenation during the sub-acute progression of ischemia in normotensive Wistar (n=6) and spontaneously hypertensive rats (SHR, n=5). Methods: Transient middle cerebral artery occlusion was used to induce ischemia for 2 hours. Relative change in LMA flow, normalized to initial drop after occlusion, was measured via surface laser Doppler; tissue oxygenation and change in parenchymal CBF were measured using a combined laser Doppler-oxygen sensor placed in the expected cortical peri-infarct region. Recording was done at 400Hz, and data analyzed in 20 second blocks over the first hour of ischemia. Data reported as mean ± SEM, statistical comparisons done via Mann-Whitney tests. Results: CBF through LMAs was significantly higher in Wistars compared to SHR at 60 min of occlusion (156±18% vs 80±4% p<0.05). Pial LMA flow strongly correlated with tissue CBF (Wistar: r=0.91, SHR: r=0.75), which was also greater in Wistars at 60 min compared to SHR (80±14% vs.19±3%, p<0.05). Tissue oxygenation initially dropped below 10mmHg in all animals, increasing in Wistars over the course of ischemia to 22.8±0.34 mmHg at 60 min. However, oxygenation did not recover in SHR (5.9±0.23 mmHg). The relationship between CBF and oxygenation was strongly correlated in Wistar rats with both LMA (r=0.88) and tissue CBF (r=0.88). However, in SHR, oxygenation had an inverse relationship with CBF (LMA: r= - 0.56, tissue CBF r= - 0.37). Conclusion: Under normotensive conditions the relationship between CBF and oxygenation had a strong, linear relationship. However, this relationship was disrupted by chronic hypertension, with LMA and tissue CBF increasing without an increase in tissue oxygenation. This uncoupling was potentially due to cerebrovascular dysfunction and metabolic dysregulation due to chronic hypertension. These findings could be an important consideration for the development of stroke therapeutics in hypertensive patients.

Efficacy and Safety of Hyperbaric Oxygen Therapy in Fistulizing Crohn's Disease: A Systematic Review and Meta-analysis.

Hyperbaric oxygen therapy (HBOT) delivers 100% oxygen in a pressurized chamber, increasing tissue oxygen levels and regulating inflammatory pathways. Mounting evidence suggests that HBOT may be effective for inflammatory bowel disease. Our systematic review and meta-analysis aimed to quantify the efficacy and safety of HBOT in fistulizing Crohn's disease (CD). A systematic review was conducted using the EMBASE, Web of Science, Pubmed, and Cochrane Library databases according to the "Preferred Reporting Items for Systematic Reviews and Meta-analyses" criteria. Study bias was assessed using the Cochrane Handbook guidelines. Sixteen studies with 164 patients were included in the analysis. For all fistula subtypes, the pooled overall clinical response was 87% (95% CI: 0.70-0.95, I2 = 0) and the pooled clinical remission was 59% (95% CI: 0.35-0.80, I2 = 0). The overall clinical response was 89%, 84%, and 29% for perianal, enterocutaneous, and rectovaginal fistulas, respectively. On meta-regression, hours in the chamber and the number of HBOT sessions were not found to correlate with clinical response. The pooled number of adverse events was low at 51.7 per 10,000 HBOT sessions for all fistula types (95% CI: 16.8-159.3, I2 = 0). The risk of bias was observed across all studies. HBOT is a safe and potentially effective treatment option for fistulizing CD. Randomized control trials are needed to substantiate the benefit of HBOT in fistulizing CD.

The role of continuous moderate-intensity exercise on increasing collagen density after tooth extraction

Background: The wound healing process post-extraction is expected to be quick, which can reduce the risk of complications and restore normal tissue function. A minimum oxygen supply needs to be met so that acceleration of the wound healing process can occur. Wound healing can be accelerated by continuous moderate-intensity exercise with increasing tissue oxygenation. Collagen requires oxygen in the procollagen formation process to support wound healing. Purpose: This study aimed to prove the role of continuous moderate-intensity exercise in increasing collagen density in the dental sockets of Wistar rats (Rattus norvegicus) after tooth extraction. Methods: Four groups of Wistar rats were created: control groups K1 (on day 3) and K2 (on day 7), and treatment groups K3 (on day 3) and K4 (on day 7). K1 and K2 were submerged in a bucket of water, and K3 and K4 received daily moderate-intensity exercise for a duration of two weeks. The rats’ incisors were extracted on the day 15. Post-extraction collagen density was measured on day 3 (K1 and K3) and on day 7 (K2 and K4). The one-way ANOVA test and post-hoc Tukey test were used in the statistical analysis of the data. Results: There was a significant difference between all groups (p: 0.0001; p<0.05). Group K4 had a higher collagen density than the other groups. Conclusion: Continuous moderate-intensity exercise played a role in increasing the density of collagen in the rat tooth socket after tooth extraction.

Effects of endoluminal vacuum sponge therapy on the perfusion of gastric conduit in a porcine model for esophagectomy.

After esophagectomy, the postoperative rate of anastomotic leakage is up to 30% and is the main driver of postoperative morbidity. Contemporary management includes endoluminal vacuum sponge therapy (EndoVAC) with good success rates. Vacuum therapy improves tissue perfusion in superficial wounds, but this has not been shown for gastric conduits. This study aimed to assess gastric conduit perfusion with EndoVAC in a porcine model for esophagectomy. A porcine model (n = 18) was used with gastric conduit formation and induction of ischemia at the cranial end of the gastric conduit with measurement of tissue perfusion over time. In three experimental groups EndoVAC therapy was then used in the gastric conduit (- 40, - 125, and - 200 mmHg). Changes in tissue perfusion and tissue edema were assessed using hyperspectral imaging. The study was approved by local authorities (Project License G-333/19, G-67/22). Induction of ischemia led to significant reduction of tissue oxygenation from 65.1 ± 2.5% to 44.7 ± 5.5% (p < 0.01). After EndoVAC therapy with - 125 mmHg a significant increase in tissue oxygenation to 61.9 ± 5.5% was seen after 60 min and stayed stable after 120 min (62.9 ± 9.4%, p < 0.01 vs tissue ischemia). A similar improvement was seen with EndoVAC therapy at - 200 mmHg. A nonsignificant increase in oxygenation levels was also seen after therapy with - 40 mmHg, from 46.3 ± 3.4% to 52.5 ± 4.3% and 53.9 ± 8.1% after 60 and 120 min respectively (p > 0.05). An increase in tissue edema was observed after 60 and 120 min of EndoVAC therapy with - 200 mmHg but not with - 40 and - 125 mmHg. EndoVAC therapy with a pressure of - 125 mmHg significantly increased tissue perfusion of ischemic gastric conduit. With better understanding of underlying physiology the optimal use of EndoVAC therapy can be determined including a possible preemptive use for gastric conduits with impaired arterial perfusion or venous congestion.

Effects of phenylephrine on systemic and cerebral circulations in humans: a systematic review with mechanistic explanations.

We conducted a systematic review of the literature reporting phenylephrine-induced changes in blood pressure, cardiac output, cerebral blood flow and cerebral tissue oxygen saturation as measured by near-infrared spectroscopy in humans. We used the proportion change of the group mean values reported by the original studies in our analysis. Phenylephrine elevates blood pressure whilst concurrently inducing a reduction in cardiac output. Furthermore, despite increasing cerebral blood flow, it decreases cerebral tissue oxygen saturation. The extent of phenylephrine's influence on cardiac output (r = -0.54 and p = 0.09 in awake humans; r = -0.55 and p = 0.007 in anaesthetised humans), cerebral blood flow (r = 0.65 and p = 0.002 in awake humans; r = 0.80 and p = 0.003 in anaesthetised humans) and cerebral tissue oxygen saturation (r = -0.72 and p = 0.03 in awake humans; r = -0.24 and p = 0.48 in anaesthetised humans) appears closely linked to the magnitude of phenylephrine-induced blood pressure changes. When comparing the effects of phenylephrine in awake and anaesthetised humans, we found no evidence of a significant difference in cardiac output, cerebral blood flow or cerebral tissue oxygen saturation. There was also no evidence of a significant difference in effect on systemic and cerebral circulations whether phenylephrine was given by bolus or infusion. We explore the underlying mechanisms driving the phenylephrine-induced cardiac output reduction, cerebral blood flow increase and cerebral tissue oxygen saturation decrease. Individualised treatment approaches, close monitoring and consideration of potential risks and benefits remain vital to the safe and effective use of phenylephrine in acute care.

The Effect of Brisk Walking Exercise on Changes in ESR Levels and CRP in Old Women with Symptoms of Rheumatoid Arthritis

Examination of the sedimentation rate (ESR) and C-reactive protein (CRP) is recommended as an initial examination in patients suspected of having symptoms of rheumatoid arthritis. Brisk walking is a form of moderate activity aerobic exercise using fast walking techniques for 20-30 minutes with an average speed of 4-6 km/hour. This training model is effective enough to increase the maximum capacity of the heart rate, stimulate muscle contraction, breakdown of glycogen and increase tissue oxygen. The method in this study was a quasi-experimental design with a pre-test – post-test group design without a control group. The sample in this research is 10 respondents. The data collection used was in the form of pre-test and post-test data using data analysis techniques using the independent sample t test and processed using the SPSS application version 20. The results showed 1) There was a significant effect between giving brisk walking exercise to ESR levels (mm/h) in elderly women with rheumatoid arthritis symptoms from the t-test results that the value of P &lt;0.05. 2) There is a significant effect between giving brisk walking exercises on CRP (mg/L) levels in elderly women with rheumatoid arthritis symptoms, this can be seen from the results of the t-test that the value of P &lt;0.05. 3) There is a significant effect between giving brisk walking exercise to ESR levels (mm/h) and CRP levels in elderly women with rheumatoid arthritis symptoms, this can be seen from the results of the t-test that both P &lt;0.05.

The Potential Role of Hyperbaric Oxygen Therapy in Psoriasis Treatment: A Review of PI3K/AKT/FOXO Signaling Cascade and Interleukin-1β

Psoriasis is a chronic, immune-mediated inflammatory skin disorder that affects 2-3% of the population worldwide. Current therapies, including biologic agents, often have adverse effects and incomplete efficacy. Recent studies suggest that the PI3K/AKT/FOXO signalling cascade and interleukin-1 β play a crucial role in the pathogenesis of psoriasis. Hyperbaric oxygen therapy, a safe and well-tolerated procedure, has been suggested as a potential treatment for psoriasis due to its ability to increase tissue oxygenation and reduce inflammation. This review article summarizes the current understanding of the pathophysiology of psoriasis and the potential benefits of hyperbaric oxygen therapy as a treatment modality. The authors suggest that hyperbaric oxygen therapy may modulate the PI3K/AKT/FOXO signalling cascade, reduce interleukin-1 β levels, and improve skin oxygenation, leading to the attenuation of psoriatic plaques. Further clinical studies are needed to confirm the safety and efficacy of hyperbaric oxygen therapy in psoriasis treatment.

#3816 HYPERBARIC OXYGEN TREATMENT IN CALCIFIC UREMIC ARTERIOLOPATHY PATIENTS IN ADDITION TO CONVENTIONAL MULTIDISCIPLINARY CARE

Abstract Background and Aims Calcific uremic arteriolopathy (CUA), also referred to as calciphylaxis, is a rare and serious complication in patients with advanced kidney disease. CUA has limited treatment options and poor prognosis, with one- year survival often reported to be below 50% after diagnosis [1,2]. Hyperbaric oxygen therapy (HBOT) may improve wound healing by increasing tissue oxygenation, and has been suggested as adjuvant treatment for CUA patients [3]. We added HBOT to our conventional multidisciplinary care of CUA patients in 2012 and this study aims to evaluate long- term outcomes of CUA patients after this. Method Data from all CUA patients treated at our institution from 2012 to 2022 were retrospectively retrieved from hospital records. This is a single-centre study, but patients from different Norwegian hospitals were referred for treatment at our centre. Conventional multidisciplinary care of CUA in our centre included sodium-thiosulphate, dialysis if indicated medical optimization of calcium- phosphate homeostasis, substitution of vitamin K2, withdrawal of warfarin and iron and vitamin D if used, minimization of systemic steroids, in addition to optimization of weight- and nutritional status. Our centre is restrictive with surgical revisions to CUA patients. Results 25 CUA patients received a total number of 1493 HBOT treatments in addition to conventional CUA multidisciplinary care in the study period. Median HBOT per patient was 45 (range 1–267). One year after CUA diagnosis, 20 out of 25 patients were alive (80%). Fifteen out of the 20 patients, who were alive at one year after CUA diagnosis, had completely resolved CUA lesions (75%). Five patients died within the first year after CUA diagnosis, due to acute cardiovascular disease (n = 3) and infection (n = 2). Our impression is that HBOT is well- tolerated and associated with less wound- associated pain. Conclusion Our results suggest that HBOT is well- tolerated in CUA patients. After we included HBOT in our multidisciplinary care of CUA patients, 80% of the patients were alive one- year after CUA diagnosis.

Allopurinol

Allopurinol

Hypothesis: Drainage of the peripheral tissue edema by the hyperbaric oxygen therapy because of hyperoxygenation that constricts arterioles and alters the downstream capillary fluid traffic in affected tissues.

Hyperbaric oxygen (HBO) therapy still lacks proper interpretations of its many actions. This hypothesis is based on reports of temporarily elevated peripheral vascular resistance (PVR) during HBO sessions. Besides that, during HBO sessions, hyperoxygenated tissues can reduce their perfusion so much that CO2 can accumulate in them. Tissue perfusion depends on vascular innervation and on the balance between systemic constrictors and local dilators. During an HBO session, increased tissue oxygen levels suppress dilatory mechanisms. Tissue hyperoxygenation increases PVR, suggesting that the HBO action on an edematous tissue may be caused by an oxygen-induced disbalance among Starling capillary forces. The presented hypothesis is that oxygen-caused arteriolar constriction reduces the hydrostatic pressure in downstream capillaries. Thus, more tissue fluid is absorbed in vascular capillaries, under the condition that the plasma colloid osmotic pressure remains unaltered during the HBO session. Among several known mechanisms behind the HBO actions, the vasoconstriction has been listed as a therapeutic modality for the reduction of the tissue edema, for a crush injury, for burns (in an acute phase), and for the compartment syndrome. The Bell's palsy is among often listed indications for the HBO treatment, although evidence is poor and reports of randomized trials are scarce.

EFFICACY AND SAFETY OF HYPERBARIC OXYGEN THERAPY IN FISTULIZING CROHN’S DISEASE: A SYSTEMATIC REVIEW AND META-ANALYSIS

Hyperbaric oxygen therapy (HBOT) delivers 100% oxygen in a pressurized chamber, increasing tissue oxygen levels and regulating inflammatory pathways. Despite significant expansion of the inflammatory bowel disease (IBD) therapeutics, there remains a significant gap in achieving fistula healing. Mounting evidence suggests that HBOT may be effective for IBD. Our systematic review and meta-analysis aimed to quantify the efficacy and safety of HBOT in fistulizing Crohn’s disease (CD).

EFFICACY AND SAFETY OF HYPERBARIC OXYGEN THERAPY IN FISTULIZING CROHN'S DISEASE: A SYSTEMATIC REVIEW AND META-ANALYSIS

Abstract BACKGROUND Hyperbaric oxygen therapy (HBOT) delivers 100% oxygen in a pressurized chamber, increasing tissue oxygen levels and regulating inflammatory pathways. Despite significant expansion of the inflammatory bowel disease (IBD) therapeutics, there remains a significant gap in achieving fistula healing. Mounting evidence suggests that HBOT may be effective for IBD. Our systematic review and meta-analysis aimed to quantify the efficacy and safety of HBOT in fistulizing Crohn’s disease (CD). METHODS A systematic review was conducted using the EMBASE, Web of Science, Pubmed, and Cochrane Library databases according to PRISMA criteria. Study bias was assessed using the Cochrane handbook guidelines. Published articles and abstracts were included for analysis if they met study design criteria, evaluated HBOT efficacy in patients with fistulizing CD, and reported sufficient outcome data. Outcome data were considered sufficient when measured clinically, radiographically, and/or endoscopically. Randomized controlled trials, case-controlled studies, and case-series were included in the analysis. Our primary outcome of interest was overall clinical response with HBOT. Overall clinical response was defined as either clinical remission or partial response. Clinical remission was defined as closure of fistula and complete cessation of drainage. Partial response was defined as improvement in fistula drainage. RESULTS Sixteen studies with 164 patients who underwent 5,125 HBOT sessions were included in the analysis. For all fistula subtypes, the pooled overall clinical response was 87% (95% CI 0.70-0.95, I2=0) (Figure) and the pooled clinical remission was 59% (95% CI 0.35-0.80, I2=0). The overall clinical response was 89%, 84%, and 29% for perianal, enterocutaneous, and rectovaginal fistulas, respectively. (Table) On meta-regression, hours in the chamber and number of HBOT sessions were not found to correlate with a clinical response. The pooled number of adverse events was low at 51.7 per 10,000 HBOT sessions for all fistula types (95% CI 16.8-159.3, I2=0). DISCUSSION With a pooled overall clinical response rate of 87% and low adverse event rate, our review emphasizes the potential clinical benefit and safety of adjunctive HBOT in refractory cases of fistulizing CD. Rectovaginal fistulas were the fistula subtype least responsive to HBOT. Data limitations include study design heterogeneity and lack of control group presence. Randomized control trials are needed to substantiate the benefit of HBOT in fistulizing CD.

Intérêt de la Carboxythérapie Percutanée dans la ­prise en charge des douleurs et des limitations ­fonctionnelles post-traumatiques et post-opératoires du membre inférieur

Thermal waters have been known since Antiquity for their therapeutic properties in various pathologies. Since the end of the 19th century, some of them have experienced a resurgence of interest, in particular those rich in carbon dioxide. Their therapeutic properties have since been studied in rheumatic and arterial pathologies due to the increase in tissue oxygenation they induce. Trauma or surgery of a limb has the corollary of a decrease in tissue oxygenation, associated with oedema, hematomas and pain resulting in functional limitation. This article describes the basic principles of percutaneous carbon dioxide therapy (without thermal water and without injection) and reports some significant examples of its effectiveness following trauma or surgery to the lower limbs. Its use promotes the rapid reduction of analgesic treatment needs and a significant functional gain without adverse effects. Contraindications to this treatment are also reported.

Baseline oxygen consumption decreases with cortical depth.

The cerebral cortex is organized in cortical layers that differ in their cellular density, composition, and wiring. Cortical laminar architecture is also readily revealed by staining for cytochrome oxidase-the last enzyme in the respiratory electron transport chain located in the inner mitochondrial membrane. It has been hypothesized that a high-density band of cytochrome oxidase in cortical layer IV reflects higher oxygen consumption under baseline (unstimulated) conditions. Here, we tested the above hypothesis using direct measurements of the partial pressure of O2 (pO2) in cortical tissue by means of 2-photon phosphorescence lifetime microscopy (2PLM). We revisited our previously developed method for extraction of the cerebral metabolic rate of O2 (CMRO2) based on 2-photon pO2 measurements around diving arterioles and applied this method to estimate baseline CMRO2 in awake mice across cortical layers. To our surprise, our results revealed a decrease in baseline CMRO2 from layer I to layer IV. This decrease of CMRO2 with cortical depth was paralleled by an increase in tissue oxygenation. Higher baseline oxygenation and cytochrome density in layer IV may serve as an O2 reserve during surges of neuronal activity or certain metabolically active brain states rather than reflecting baseline energy needs. Our study provides to our knowledge the first quantification of microscopically resolved CMRO2 across cortical layers as a step towards better understanding of brain energy metabolism.

260. EFFECT OF ENDOLUMINAL VACUUM THERAPY ON THE PERFUSION OF GASTRIC CONDUIT IN A PORCINE MODEL FOR ESOPHAGECTOMY

Abstract After esophagectomy, the postoperative rate of anastomotic leakage is between 5 and 30% and is the main driver of morbidity and mortality. Complication management is often based on endoluminal vacuum therapy (EndoVAC) with good success rates. Vacuum therapy has been shown to improve tissue perfusion in superficial wounds but this has not been shown for gastric conduits. The present study aimed to assess changes in gastric conduit perfusion in a porcine model for esophagectomy. Porcine model (n = 18) underwent gastric conduit formation and induction of partial conduit ischemia. In three experimental groups EndoVAC therapy was used in the gastric conduit (−40 mmHg, −125 mmHg and − 200 mmHg) with continuous suction. The changes in tissue perfusion and edema were assessed using hyperspectral imaging (HSI). During EndoVAC treatment with −125 mmHg a significant and stable increase in the oxygenation index from 44.9 ± 7.6% to 61.9 ± 5.5% and 62.9 ± 9.4%. (p = 0.02) was seen after 60 minutes and 120 minutes respectively. A similar trend was seen during EndoVAC treatment with −200 mmHg. There was a non-significant increase in tissue oxygenation during treatment with −40 mmHg. A significant increase of tissue water content from 40.8 ± 7.4 to 59.5 ± 10.3 (p = 0.004) was observed after 60 minutes of EndoVAC therapy with −200 mmHg. There were no significant differences in tissue water content during EndoVAC therapy with −40 mmHg and − 125 mmHg. EndoVAC treatment with a pressure of at least −125 mmHg significantly increases perfusion of partial ischemic gastric conduit. With better understanding of underlying physiology, the optimal use of EndoVac treatment can be guided and determined including a possible preemptive use for gastric conduits with impaired arterial perfusion or venous congestion. This can potentially be translated into clinical practice.