Hyperbaric Chamber Research Articles

A New Proposal for Management of Severe Frostbite in the Austere Environment

Despite advances in outdoor clothing and medical management of frostbite, individuals still experience catastrophic amputations. This is a particular risk for those in austere environments, due to resource limitations and delayed definitive treatment. The emerging best therapies for severe frostbite are thrombolytics and iloprost. However, they must be started within 24 hours after rewarming for recombinant tissue plasminogen activator (rt-PA) and within 48 hours for iloprost. Evacuation of individuals experiencing frostbite from remote environments within 24 to 48 hours is often impossible. To date, use of these agents has been confined to hospitals, thus depriving most individuals in the austere environment of the best treatment. We propose that thrombolytics and iloprost be considered for field treatment to maximize chances for recovery and reduce amputations. Given the small but potentially serious risk of complications, rt-PA should only be used for grade 4 frostbite where amputation is inevitable, and within 24 hours of rewarming. Prostacyclin has less risk and can be used for grades 2 to 4 frostbite within 48 hours of rewarming. Until more field experience is reported with these agents, their use should probably be restricted to experienced physicians. Other modalities, such as local nerve blocks and improving oxygenation at high altitude may also be considered. We submit that it remains possible to improve frostbite outcomes despite delayed evacuation using resource-limited treatment strategies. We present 2 cases of frostbite treated with rt-PA at K2 basecamp to illustrate feasibility and important considerations.

Acute and long-term effects of hyperbaric oxygen therapy on hemorheological parameters in patients with various disorders.

Inhalation of 100% oxygen in a hyperbaric chamber has been accepted as a useful treatment for patients with various pathologies who suffer from hypoxia. The oxidative effects of hyperbaric oxygen (HBO) on RBCs have been investigated in animals but there is not enough data on hemorheological parameters in patients following HBO treatment (HBOT).In this study, we investigated the effect of HBO on hemorheological and haematological parameters during treatment. Red blood cell (RBC) deformability and aggregation, blood and plasma viscosity and superoxide dismutase activity were investigated in patients who underwent HBOT. Hematological parameters were determined by an electronic hematology analyzer. A Laser-assisted Optical Rotational Cell Analyzer (LORCA) was used to measure RBC deformability. RBC aggregation was measured for cells in autologous plasma and for cells resuspended in PBS containing Dextran70 (3% ) by using a Myrenne Aggregometer. A Wells-Brookfield cone/plate rotational viscometer was used for viscosity measurements. According to our results, a significant decrement of the hematocrit and the RBC count was observed after the 20th session of HBOT compared to the baseline, but none of the hemorheological parameters changed significantly. Our results showed that HBOT did not cause any significant changes in hemorheological parameters, thereby not representing any problems for the patients.

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

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. 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. 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. 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.

Buoyancy engine developed for underwater gliders

A buoyancy engine with a swashplate-type axial piston pump was developed. Its oil extrusion and drawing properties under high hydraulic pressure were evaluated. This buoyancy engine is now installed in an underwater glider that will achieve long-term monitoring of ocean environments up to 2100 m depth in a designated area with lower operational costs. This bidirectionally functioning pump can control the amount of oil in extrusion and draw operations. When drawing oil under high pressure, the hydraulic pump and the electric motor, respectively, act as a hydraulic motor and an electric generator. The generated electric power is absorbed by a damping resistor. The oil-drawing and extrusion properties were measured using a large hyperbaric chamber that is able to produce an almost identical environment to that of actual operations. Results confirmed stable oil extrusion operations up to 21 MPa. Regarding oil-drawing properties, although it was measured only up to 10 MPa in the hyperbaric chamber, it can be inferred that the system can draw the oil and can control the buoyancy precisely up to 21 MPa by replacing the two-way ball valve with an electromagnetic latching solenoid valve.

Diving Bubble Model Data Correlations

This short article deals with useful and modern bubble models used to stage divers to the surface and correlations, if and when they exist, with actual data, usually decompression sickness (DCS) outcomes across a limited spectrum of exposures. Many of the early (wet) tests were carried out by world Navies, later by hyperbaric chamber testing and today also by statistical inference from downloaded computer profiles. All have contributed to correlation of models and data but in varying degrees as the scope of mixed gas, open circuit (OC) and rebreather (RB), nonstop to saturation and sea level to altitude diving is immense. No amount of wet or chamber testing will ever cover the ground here, but there is considerable hope and potential for downloaded computer profile data coupled to DCS outcomes to provide necessary correlations across the varied activities of modern diving.

Adjunctive Hyperbaric Oxygen Therapy promotes successful healing in patients with refractory Crohn's disease.

To investigate de adjunctive effect of Hyperbaric Oxygen Therapy in a group of patients with refractory Crohn's disease. A total of 29 subjects with refractory Crohn's disease were submitted to daily sessions of Hyperbaric Oxygen Therapy, in a 2800 Sechrist Monoplace Hyperbaric Chamber (Sechrist, USA) pressurized to 2.4 ATA. Each session lasted 2 hours. The endpoint was closure of enterocutaneous fistulas and complete healing of Pyoderma Gangrenosum and perineal Crohn's disease. A total of 829 HBOT sessions were performed and no complications were noted. Overall success rate was 76% (22 cases). Pyoderma Gangrenosum and enterocutaneous fistulas had the highest successful healing rates (100% and 91%, respectively). Perineal Crohn's disease healing rate was 65%. Adjunctive Hyperbaric Oxygen Therapy promoted satisfactory healing in a group of patients with refractory Crohn's disease.

EPR Oximetry for Investigation of Hyperbaric O2 Pre-treatment for Tumor Radiosensitization.

A number of studies have reported benefits associated with the application of hyperbaric oxygen treatment (HBO) delivered immediately prior to radiation therapy. While these studies provide evidence that pre-treatment with HBO may be beneficial, no measurements of intratumoral pO2 were carried out and they do not directly link the apparent benefits to decreased hypoxic fractions at the time of radiation therapy. While there is empirical evidence and some theoretical basis for HBO to enhance radiation therapy, without direct and repeated measurements of its effects on pO2, it is unlikely that the use of HBO can be understood and optimized for clinical applications. In vivo EPR oximetry is a technique uniquely capable of providing repeated direct measurements of pO2 through a non-invasive procedure in both animal models and human patients. In order to evaluate the ability of pretreatment with HBO to elevate tumor pO2, a novel small animal hyperbaric chamber system was constructed that allows simultaneous in vivo EPR oximetry. This chamber can be placed within the EPR magnet and is equipped with a variety of ports for multiplace gas delivery, thermoregulation, delivery of anesthesia, physiologic monitoring, and EPR detection. Initial measurements were performed in a subcutaneous RIF-1 tumor model in C3H/HeJ mice. The mean baseline pO2 value was 6.0 ± 1.2 mmHg (N = 7) and responses to two atmospheres absolute pressure HBO varied considerably across subjects, within tumors, and over time. When an increase in pO2 was observed, the effect was transient in all but one case, with durations lasting from 5 min to over 20 min, and returned to baseline levels during HBO administration. These results indicate that without direct measurements of pO2 in the tissue of interest, it is likely to be difficult to know the effects of HBO on actual tissue pO2.

Morphology of First Zoeal Stage of Four Genera of Alvinocaridid Shrimps from Hydrothermal Vents and Cold Seeps: Implications for Ecology, Larval Biology and Phylogeny.

Alvinocaridid shrimps are endemic species inhabiting hydrothermal vents and/or cold seeps. Although indirect evidences (genetic and lipid markers) suggest that their larval stages disperse widely and support large scale connectivity, larval life and mechanisms underlying dispersal are unknown in alvinocaridids. Here we provide for the first time detailed descriptions of the first larval stage (zoea I) of four alvinocaridid species: Rimicaris exoculata and Mirocaris fortunata from the Mid-Atlantic Ridge, Alvinocaris muricola from the Congo Basin and Nautilocaris saintlaurentae from the Western Pacific. The larvae were obtained from onboard hatching of brooding females (either at atmospheric pressure or at habitat pressure in hyperbaric chambers) and from the water column near adult habitats, sampled with plankton pumps or sediment traps. Major characteristics of the alvinocaridid larvae include undeveloped mandible and almost complete absence of setation in the inner margin of the mouth parts and maxillipeds. Although the larvae are very similar between the four species studied, some morphological features could be used for species identification. In addition, undeveloped mouthparts and the large amount of lipid reserves strongly support the occurrence of primary lecithotrophy in the early stage of alvinocaridids. Although lecithotrophy in decapod crustaceans is usually associated with abbreviated larval development, as a mechanism of larval retention, morphological and physiological evidences suggest the occurrence of an extended and lecithotrophic larval stage in the Alvinocarididae. These traits permit the colonization of widely dispersed and fragmented environments of hydrothermal vents and cold seeps. Distribution of larval traits along the phylogenetic reconstruction of the Alvinocarididae and related families suggest that lecithotrophy/planktotrophy and extended/abbreviated development have evolved independently along related families in all potential combinations. However, the Alvinocarididae is the only taxa with a combination of lecithotrophy and extended larval development.

Severe skin radiodermatitis fully healed with the use of platelet gel and a hyperbaric chamber.

Severe skin radiodermatitis fully healed with the use of platelet gel and a hyperbaric chamber.

Повышенное давление азотно-кислородной смеси и температура животных

The work is devoted to the study of thermoregulation of rats under high pressure in the respiratory-&#x0D; gas medium, both experimentally and in mathematical models. Experiments conducted on rats in a hyperbaric&#x0D; chamber, where the pressure of the gas medium was raised to 4,1 MPa. The pressure increase in the hyperbaric&#x0D; chamber up to 2,1 MPa leds to augmentation of oxygen consumption by 1.7 times and at a pressure of 4.1&#x0D; MPa – to oxygen consumption by 2,3 times. Thermo-neutral zone in animals, on the contrary, is progressively&#x0D; decreased with increasing pressure in the hyperbaric chamber. Using a mathematical model, it has been shown&#x0D; that the augmentation of pressure in the hyperbaric chamber to 2,1 MPa leads to increase the heat transfer in 1,9&#x0D; times. The augmentation of pressure in the hyperbaric chamber to 4,1 MPa increases the heat transfer from the&#x0D; organism body in the medium in 2,6 times.

Final Results of the First-in-Human Clinical Study Incorporating Hyperbaric Oxygen into Umbilical Cord Blood Transplantation

Background: Umbilical cord blood (UCB) transplantation is associated with delayed blood count recovery and engraftment. We have demonstrated that pre-treatment with hyperbaric oxygen (HBO) therapy to the recipient mice improved engraftment of intravenously infused human UCB CD34+ in a murine transplant model. Further studies from our laboratory attribute HBO effects on engraftment to HBO-induced low erythropoietin (EPO) state in the host, resulting in early UCB CD34+ cell bone marrow homing and an increase in myeloid to erythroid differentiation. These results lead to the first in-human pilot clinical trial investigating the safety of HBO in the setting of UCB transplantation and secondarily evaluating time to blood count recovery. Herein, we report the final results of this study in comparison to our historic institutional data to determine the impact of HBO on blood count recovery and day +100 survival.Materials/methods: Enrolled patients had hematologic malignancies that required reduced intensity conditioning (RIC) or myeloablative conditioning (MAC) and UCB transplantation. They received HBO therapy on day 0 consisting of exposure to 2.5 atmosphere absolutes for a total of 2 hours, in a single hyperbaric chamber, breathing 100% oxygen. Six hours from the start of HBO, single or double UCB units were intravenously infused and patients were followed daily for toxicity and blood count recovery. Serum EPO levels were measured by enzyme-linked immunosorbent assay (ELISA). Mycophenolate mofetil and cyclosporine were used for GVHD prophylaxis. Charts of 48 patients who received UCB transplantation at our institution for hematologic malignancies between 2008 and 2013 were reviewed for comparison.Results: 15 patients, 9 males (60%) and 6 females (40%), with a median age of 44 years (17-70) were treated. One patient had lymphoma and 14 patients had acute leukemia; 10 in first remission and 4 in second remission. Eight patients received one UCB unit and 7 received two units. Patients received a median total nucleated cell dose of 3.02(1.67-4.51) ×107/Kg recipient body weight (BWT), a median CD34 cell dose of 1.2 (0.7-6.5) ×105/Kg recipient BWT, and 9/15 patients received RIC. 14/15 treated patients completed the planned therapy, while one patient did not finish the last 15 minutes due to nausea. None of the patients experienced an unexpected toxicity. All patients engrafted except for one patient who demonstrated prompt autologous blood count recovery. Full donor chimerism was achieved in 7/8 (88%) of engrafted RIC patients 30 days post-transplant. Eleven of the 15 (67%) patients developed acute graft versus host disease at time of engraftment; 36% developed grade I, 54% had grade II and 9% had grade III. On average, EPO levels 8-hours post HBO were 56 (27-92) % of their pre-HBO values. Median time to neutrophil count recovery, median time to platelet count recovery, day +100 survival (Figure-1), percentage of patients who achieved neutrophil recovery and platelet count recovery in the HBO and historic cohorts are summarized in table-1.Conclusions: HBO therapy prior to UCB cell infusion appears to be safe and well-tolerated in the setting of clinical UCB transplantation. Given the potential benefits of relatively fast recovery and lack of toxicity, HBO should be further evaluated as a strategy to promote engraftment in UCB transplantation.Table 1Summary of transplant outcomes in HBO and historic cohorts.AllMACRICHBO (n=15)Historic (n=48)P valueHBO (n=6)Historic (n=21)P valueHBO (n=9)Historic (n=27)P valueDay 100 survival (n/%)No- (0%)11 (24%)0.051- (0%)10 (48%)0.03- (0%)1 (4%)NSYes15 (100%)34 (76%)6 (100%)11 (52%)9 (100%)23 (96%)Neutrophil recovery (n/%)No- (0%)6 (12%)NS- (0%)4 (19%)NS- (0%)2 (7%)NSYes15 (100%)42 (88%)6 (100%)17 (81%)9 (100%)25 (93%)Platelet recovery (n/%)No- (0%)15 (31%)0.013- (0%)11 (52%)0.023- (0%)4 (15%)NSYes15 (100%)33 (69%)6 (100%)10 (48%)9 (100%)23 (85%)Median time to neutrophil recovery (Range)14 (6-45)20.5 (5-71)NS24.5 (16-45)33 (13-71)NS7 (6-17)14 (5-28)NSMedian time to platelet recovery (Range)37.5 (0-85)38 (0-161)NS54.5 (30-84)50 (29-161)NS32 (0-85)38 (0-112)NS [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Pulmonary barotrauma in divers vs procedures initiated by emergency medical personel

Abstract Introduction: Pulmonary barotrauma consists in the damage of pulmonary tissues resulting from pressure differences in the body and the surroundings. Barotrauma may occur during diver's ascent with a held breath. Objective: Presentation of symptoms in divers performing dives at shallow depths. A detailed description of pulmonary barotrauma as a direct hazard to life. Rescue procedure in the case of an occurrence of pulmonary barotrauma, methods of prevention. Abridged description of the state of knowledge: Proper equipment preparation, systematic diving training, as well as systematic medical control aimed at conducting medical examinations with regard to staying under water, all constitute primary preventive measures. At the moment of an occurrence of pulmonary barotrauma in a diver it is necessary to perform first aid activities by qualified medical personnel and arrange for a quick transportation to the nearest hyperbaric centre. Summary: Commonly, pulmonary barotrauma concerns individuals diving at depths up to 10 metres. Pulmonary barotrauma is a state of danger to one's health and life. Proper procedures at the scene of an accident as well as quick transportation to a hyperbaric chamber increase the chance of one's recovery and may constitute the necessary condition during rescue activities.

Diving Injuries Presenting to the Hyperbaric Chamber in Barbados: A Review from 1995–2009

Diving Injuries Presenting to the Hyperbaric Chamber in Barbados: A Review from 1995–2009

Microvascular oxygen partial pressure during hyperbaric oxygen in diabetic rat skeletal muscle.

Hyperbaric oxygen (HBO) is a major therapeutic treatment for ischemic ulcerations that perforate skin and underlying muscle in diabetic patients. These lesions do not heal effectively, in part, because of the hypoxic microvascular O2 partial pressures (PmvO2 ) resulting from diabetes-induced cardiovascular dysfunction, which alters the dynamic balance between O2 delivery (Q̇o2) and utilization (V̇o2) rates. We tested the hypothesis that HBO in diabetic muscle would exacerbate the hyperoxic PmvO2 dynamics due, in part, to a reduction or slowing of the cardiovascular, sympathetic nervous, and respiratory system responses to acute HBO exposure. Adult male Wistar rats were divided randomly into diabetic (DIA: streptozotocin ip) and healthy (control) groups. A small animal hyperbaric chamber was pressurized with oxygen (100% O2) to 3.0 atmospheres absolute (ATA) at 0.2 ATA/min. Phosphorescence quenching techniques were used to measure PmvO2 in tibialis anterior muscle of anesthetized rats during HBO. Lumbar sympathetic nerve activity (LSNA), heart rate (HR), and respiratory rate (RR) were measured electrophysiologically. During the normobaric hyperoxia and HBO, DIA tibialis anterior PmvO2 increased faster (mean response time, CONT 78 ± 8, DIA 55 ± 8 s, P < 0.05) than CONT. Subsequently, PmvO2 remained elevated at similar levels in CONT and DIA muscles until normobaric normoxic recovery where the DIA PmvO2 retained its hyperoxic level longer than CONT. Sympathetic nervous system and cardiac and respiratory responses to HBO were slower in DIA vs. CONT. Specifically the mean response times for RR (CONT: 6 ± 1 s, DIA: 29 ± 4 s, P < 0.05), HR (CONT: 16 ± 1 s, DIA: 45 ± 5 s, P < 0.05), and LSNA (CONT: 140 ± 16 s, DIA: 247 ± 34 s, P < 0.05) were greater following HBO onset in DIA than CONT. HBO treatment increases tibialis anterior muscle PmvO2 more rapidly and for a longer duration in DIA than CONT, but not to a greater level. Whereas respiratory, cardiovascular, and LSNA responses to HBO are profoundly slowed in DIA, only the cardiovascular arm (via HR) may contribute to the muscle vascular incompetence and these faster PmvO2 kinetics.

Hyperbaric Sub-Normothermic Ex-Vivo Perfusion Delays the Onset of Acute Rejection in a Porcine VCA Model

INTRODUCTION: Vascularized composite allotransplantation (VCA) offers superior functional recovery following devastating maxillofacial and upper limb injuries compared to traditional reconstructive techniques. Here, we evaluate the efficacy of a novel sub-normothermic (SN) ex-vivo perfusion strategy using hyper-oxygenated University of Wisconsin (UW) solution to mitigate reperfusion injury (RI) and the onset of acute rejection in a porcine VCA model.1 Minimizing RI by optimizing allograft preservation strategies could improve early VCA outcomes, and reduce dose, frequency, and duration of immunosuppression. MATERIALS AND METHODS: Heterotopic gracilis myocutaneous flap transplants were performed into the necks of Yorkshire swine recipients, mismatched for one swine leucocyte antigen. Group 1 (controls, n=8) received allotransplants without additional flap treatment. Group 2 (experimental, n=8) flaps were perfused ex-vivo with hyper-oxygenated UW for five hours at 20ºC in a hyperbaric chamber at 3 atm before transplantation. Without systemic immunosuppression, flaps were monitored daily for clinical evidence of rejection and biopsied for immunohistopathological analysis. Serum was sampled for markers of immune injury secondary to RI. RESULTS: Control flaps experienced Banff2 Grade 1 rejection at a mean of 6.4 days (SD=0.52), and Grade 4 rejection at a mean of 10.5 days (SD=2.6). The experimental flaps showed a statistically significant delay in the onset of Grade 1 rejection at 13.7 days (SD=0.52, p<0.05). At the experiment’s conclusion (Day 15), 75% of the experimental flaps showed no evidence of Grade 4 rejection. CONCLUSION: Hyperbaric SN perfusion significantly delays the onset of acute rejection in the absence of systemic immunosuppression. This technology has potential utility in the field of solid organ transplantation and VCA, and could expand the donor pool dramatically. Furthermore, ex-vivo normalization of tissue physiology may reduce antigen presentation and acute rejection phenomena in allotransplantation.

Effect of hyperbaric oxygen on expression of fractalkine in nerve tissues of rats with neuropathic pain

Objective To investigate the effect of hyperbaric oxygen on the expression of fractalkine (FKN) in the nerve tissues of rats with neuropathic pain (NP). Methods Thirty-two male Sprague-Dawley rats, weighing 250-280 g, aged 10-12 weeks, were divided into 4 groups (n= 8 each) using the random number table: control group (group C), sham operation group (group S), group NP, and hyperbaric oxygen group (group H). NP was induced by chronic constriction injury (CCI) in anesthetized rats. The left sciatic nerve was exposed, and 4 loose ligatures were placed on the sciatic nerve at 1 mm intervals with 4-0 silk thread. Group H received hyperbaric oxygen therapy once a day for 5 consecutive days starting from day 1 after CCI. The rats were placed into the hyperbaric oxygen chamber, which was pressurised to 2 atmosphere absolute at a rate of 10 kPa/min, and maintained at this level for 60 min. The pressure was then decreased to the normal pressure at a rate of 10 kPa/min. The mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal latency (TWL) were measured at 1 day before CCI, and 3, 5, 7 and 14 days after CCI. After measurement of pain threshold at 3 and 7 days after CCI, 4 rats were selected and sacrificed. The sciatic nerve and lumbar segment of the spinal cord were removed for determination of the expression of FKN by Western blot. Results Compared with group C, the MWT was significantly decreased, and TWL was shortened at each time point after CCI, the expression of FKN in the sciatic nerve at 3 days after CCI, and in the sciatic nerve and spinal cord at 3 and 7 days after CCI was up-regulated in group NP (P 0.05). Compared with group NP, the MWT was significantly increased, and TWL was prolonged at each time point after CCI, and the expression of FKN in the sciatic nerve at 3 days after CCI, and in the sciatic nerve and spinal cord at 3 and 7 days after CCI was down-regulated in group H (P<0.05). Conclusion The mechanism by which hyperbaric oxygen mitigates NP is related to inhibition of over-expression of FKN in the nerve tissues of rats. Key words: Hyperbaric oxygenation; Neuralgia; Chemotactic factors

Does Hyperbaric Oxygen Therapy Have a Role in Diabetic Autonomic Neuropathy ?

Objectives: To determine if hyperbaric oxygen therapy could benefit patients with diabetic autonomic neuropathy treated at our hospital. Methods: Thirty-one consecutive patients, who were treated at Princess Haya Hospital and Prince Hahim Bin Abdullah II hospital from January 2012 to April 2014, were included. Four tests of autonomic function were carried out on all patients before and after treatment in the hyperbaric recompression chamber. Data analyzed using Statistical Package for the Social Sciences version 17 and stata version 10. Results: Twenty male and eleven female patients were included, with a mean age of 53.6 years. About 84% had Type II diabetes. Seventy-one percent of patients were found to have greater than or equal to three abnormal tests prior to treatment, and the risk of autonomic neuropathy was found to be independent of patients' sex, age, type or duration of diabetes. A statistically significant improvement was found in all tests after hyperbaric oxygen therapy. The improvement in parasympathetic function was found to be more likely affected by the number of sessions than sympathetic function (P value 0.001 and 0.07, respectively) Conclusion: Hyperbaric oxygen therapy is a promising technology in the treatment of diabetic autonomic neuropathy. Further research which includes a control group is needed.

Treatment of bladder pain syndrome and interstitial cystitis: a systematic review.

Bladder pain syndrome/interstitial cystitis (BPS/IC) has various treatments; however, no standardized treatment has been established. The aim was to analyze different types of treatment of BPS/IC and their effectiveness. A literature review with a search strategy for articles related to BPS/IC published between 1990 and 2014 was conducted on MEDLINE, PUBMED, and SCOPUS. Only randomized controlled trials in women were included in the meta-analysis, while other experimental studies were used as bases for a systematic review of the topic. Clinical trial quality was defined according to the Jadad scale. Of 356 articles, 13 were included in the analysis. The intervention methods were as follows: instillation of hyaluronic acid, botulinum toxin A, intravesical lidocaine, hyperbaric chamber, massage, physiotherapy, phosphate-buffered saline, piroxicam in combination with doxepin, and others. We did not find any treatment with at least two randomized controlled trials for meta-analysis. Among the assessment tools for symptoms of BPS/IC, the most frequently used were the visual analogue scale, voiding record, and the O'Leary-Sant questionnaire. Existing studies were not able to define the best approach for the treatment of BPS/IC. The lack of standardized treatment may be related to the diversity of interventions used; therefore, further studies with better methodological quality are needed.

Abstract 5211: In vivo fluorescence and spectral microscopy of the effects of aerobic exercise on tumor oxygenation and perfusion in breast cancer

Abstract Abnormal tumor angiogenesis leads to inefficient blood flow and inhibited delivery of oxygen, resulting in a hypoxic tumor microenvironment. In radiation therapy the presence of oxygen is necessary to impart lasting damage to cancer cells, therefore the modulation of tumor hypoxia has been an important focus to improve radiation therapy outcome. While strategies such as hyperbaric chambers and hypoxic cell radiosensitizers or cytotoxins have shown merit, their success in the clinic has been limited. A potential method to increase oxygenation and decrease hypoxia in a tumor mass that is safe and well-tolerated is aerobic exercise. For cancer patients, the benefits of exercise in a palliative setting are well known, however the effects of exercise on tumor microvasculature and blood flow have not been extensively characterized. In vivo microscopy of microvessel function in preclinical models is a useful tool for the study of tumor vascular structure and function. The combination of hyperspectral imaging of hemoglobin (Hb) saturation and first-pass fluorescence (FPF) imaging of blood transit time in the murine dorsal skinfold window chamber has been previously used to characterize tumor angiogenesis, wound healing and the response of tumor microvasculature to vascular targeting agents. Hb saturation imaging reveals the oxygenation of blood within microvessels while FPF imaging gives information regarding blood flow and network connections by recording a fluorescent contrast agent as it is injected into circulation. In the present study, this combination imaging technique is used to evaluate the impact of treadmill running on tumor blood flow and microvessel oxygenation in real time. 4T1 mammary tumors were initiated in nude mice bearing titanium window chambers. Once tumors reached a volume of ∼5mm3, mice were subjected to daily treadmill running for 5-7 consecutive days (30 min, 15-18 m/min, 10° incline). As a sedentary control, mice were placed on a stationary treadmill for equivalent periods of time. Combination imaging was performed daily to monitor microvessel oxygenation and blood flow. On the first day of exercise, imaging was performed both before and after animals were exercised. Preliminary results indicate that following one bout of exercise, tumor perfusion is increased, however there was no significant correlation between exercise and tumor microvessel oxygenation. Citation Format: Jennifer A. Lee, Jennifer M. Wiggins, Lori P. Rice, Dietmar W. Siemann. In vivo fluorescence and spectral microscopy of the effects of aerobic exercise on tumor oxygenation and perfusion in breast cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5211. doi:10.1158/1538-7445.AM2015-5211

Optimal Design of Hyperbaric Oxygen Therapy System Chamber with Separated Rooms for Multi-users

Optimal Design of Hyperbaric Oxygen Therapy System Chamber with Separated Rooms for Multi-users