Hyperbaric Oxygen Chamber Research Articles

Hyperbaric oxygen therapy for Bell's palsy.

Bell's palsy is an idiopathic, acute unilateral facial weakness that evolves rapidly and is maximal within two days. Moderate ear discomfort, sensitivity to sound and reduced tearing may occur. To assess the effects of hyperbaric oxygen therapy on recovery of facial function in adults with moderate to severe Bell's palsy. We searched the Cochrane Neuromuscular Disease Group Specialized Register (January 2012), CENTRAL (2011, Issue 4), MEDLINE (January 1966 to January 2012), EMBASE (January 1980 to January 2012), CINAHL (1937 to January 2012), AMED (1985 to January 2012), LILACS (January 1982 to January 2012). In addition we made a systematic search for relevant controlled trials in specific hyperbaric literature sources. Randomised controlled trials or quasi-randomised controlled trials of adults (over 16 years of age) undergoing hyperbaric oxygen therapy for moderate to severe Bell's palsy. We considered studies to be of sufficient quality for inclusion in the review only if there was blinding in the assessment of the facial palsy grade. We planned to include studies of HBOT used as adjuvant therapy, or in addition to routine medical therapy (including corticosteroids or antivirals, or both). Both treatment and control groups were to receive the same baseline therapy. HBOT had to be delivered at concentrations greater than or equal to 1.2 ATA in a hyperbaric oxygen chamber as a series of dives of 30 to 120 minutes. Two reviewers independently assessed eligibility and study quality and extracted data. We contacted study authors for additional information. Our searches found no randomised controlled trials or quasi-randomised controlled trials that met the eligibility criteria for this review.There is very low quality evidence from one randomised trial involving 79 participants with acute Bell's palsy, but this study was excluded as the outcome assessor was not blinded to treatment allocation and thus did not meet pre-defined eligibility criteria. The trial compared 42 people who received hyperbaric oxygen therapy (2.8 atmospheres for 60 minutes twice daily, five days per week until the facial palsy resolved; maximum 30 'dives') and placebo tablets with 37 people who received placebo hyperbaric oxygen therapy (achieving only a normal partial pressure of oxygen) and prednisone (40 mg twice daily, reducing over eight days). Facial function recovered in more participants treated with hyperbaric oxygen therapy than with prednisone (hyperbaric oxygen therapy, 40/42 (95%); prednisone, 28/37 (76%); risk ratio 1.26, 95% CI 1.04 to 1.53). There were no reported major complications and all participants completed the trial. Very low quality evidence from one trial suggests that hyperbaric oxygen therapy may be an effective treatment for moderate to severe Bell's palsy, but this study was excluded as the outcome assessor was not blinded to treatment allocation. Further randomised controlled trials are needed.

Effects of Hyperbaric Oxygen Therapy on Rat Nasal Mucosa

ABSTRACTThe objective of this study was to evaluate the histopathologic effects of hyperbaric oxygen (HBO) therapy on the rat nasal mucosa. Twelve adult Sprague-Dawley rats, each weighing 180–220 g, were used as experimental animals. The rats were divided into HBO (hyperbaric oxygen) and control group. The rats in the HBO group (n = 6) were placed into a 20-liter HBO chamber (2.5 atmospheres absolute [ATA], 25–26°C with 100 % oxygen) for 90 min per day. The rats received hyperbaric oxygen over a period of 7 days. The rats in the control group (n = 6) were not given HBO. All animals were sacrificed at the end of the study, and nasal tissue samples were prepared. The sections were stained with Haematoxylin and Eosin (H-E), Periodic acid-Schiff (PAS) and Trichrome-Masson to observe the under a light microscope. Immunoreactivity of pseudostratified epithelial cells of the nasal mucosa was assessed with E-cadherin expression by immunohistochemical staining. There were significant differences in the average histopathological score between the groups exposed and non-exposed to HBO. In the HBO group, degenerative changes in epithelial cells were observed. The goblet cells showed expansion of their structure. Mononuclear lymphocyte infiltration, dilation of blood vessels, and hemorrhage were observed in considerable areas of connective tissue. In the immunohistochemical evaluation of E-cadherin expression, there were no significant differences between the two groups.

A hyperbaric oxygen chamber for animal experimental purposes

Facilities for hyperbaric oxygen therapy that are suitable for animal experimental research are scarce. In this paper, the authors introduce a hyperbaric oxygen chamber that was developed specifically for animal experimental purposes. The hyperbaric oxygen chamber was designed to meet a number of criteria regarding safety and ease of use. The hyperbaric oxygen chamber conforms to 97/23/EC (Pressure Equipment Directive), Conformity Assessment Module G Product Group 1. It provides easy access, and can be run in manual mode, semi-automatic mode and full-automatic mode. Sensors for pressure level, oxygen level, temperature, humidity and carbon dioxide level allow full control. This state-of-the-art hyperbaric oxygen chamber for animal experimental purposes permits the investigation of the biological mechanisms through which hyperbaric oxygen therapy acts at a fundamental level.

Reduction of Apoptosis in Ischemic Retinas of Two Mouse Models Using Hyperbaric Oxygen Treatment

To investigate the effect of hyperbaric oxygen (HBO) chamber treatment in mouse models of retinal ischemia. Unilateral central retinal artery occlusion (CRAO) or optic nerve crush (ONC) was induced in 50 mice each, of which 30 were treated with 100% oxygen at 2 atm for 90 minutes immediately after injury and then daily for up to 14 days. Mice were euthanatized on days 1, 3, and 21 for histologic analysis, apoptosis assay, and quantitative real-time polymerase chain reaction test. Findings were analyzed by injury and by treatment. HBO treatment reduced cell loss from 58% to 30% in the CRAO model and from 52% to 32% in the ONC model. In both models, it was associated with significantly increased cell survival in the retinal ganglion cell layer. Expression levels of the proapoptosis genes (bax, caspase-3) decreased minimally in the HBO-treated CRAO mice on day 1, but this trend was reversed on day 3. In the ONC group, levels of caspase-3, bax, and bcl-x increased on day 1 and dropped below baseline on day 3. The pattern of changes in the expression levels of the ischemia- and oxidative-stress-related genes (HO-1, SOD-1, GPX-1, NOX-2) and the effectiveness of HBO treatment varied by model. Overall, however, gene expression levels that increased in the untreated mice increased further with HBO treatment and levels that decreased, decreased further with treatment. HBO treatment protects injured neuronal cells from apoptosis. Response to treatment differs molecularly after ONC or CRAO. These results should prompt clinical trials of acute ischemic retinal damage.

Mass Sociogenic Illness Initially Reported as Carbon Monoxide Poisoning

BackgroundMass sociogenic illness (MSI) is a rare occurrence involving a constellation of physical signs and symptoms in a group of individuals that are exhibited subconsciously and have no corresponding organic etiology. ObjectivesTo describe an outbreak of MSI initially attributed to carbon monoxide (CO) poisoning. Case ReportsWhile attending a church service, one child fainted, followed by another. This led to multiple individuals reporting a constellation of symptoms. A total of 22 individuals presented to emergency departments (EDs) with neurologic, gastrointestinal, and respiratory complaints. The onset of symptoms followed evacuation in most of these patients. Prehospital personnel obtained carboxyhemoglobin (COHb) levels with a portable oximeter device, identifying levels up to 19% in 6 patients; 17 were taken to a tertiary hospital with a hyperbaric oxygen chamber, and the other 5 to a local ED. All other attendees were asymptomatic. Within the 15-min transport time, all patients were asymptomatic and had normal physical examinations. The mean age of patients was 13 years; 7 were male and 10 were female. Venous blood gas identified normal COHb levels in all patients. Pulse oximetry in the ED was normal. Another handheld oximeter device in the ED found normal COHb and methemoglobin levels. ConclusionVarying complaints with onset after removal from the church suggest MSI. The hazardous materials team reproduced the scenario and no toxic gases were detected. Escalation of symptoms and an increased number of persons being affected along with increasing ambulance presence are common in MSI. We suspect that field oximeter readings were either aberrant from an inexperienced operator or were false-positive COHb readings. Clinicians should consider MSI after mass outbreaks of illness, particularly with rapid onset, rapid resolution of symptoms, and normal physical examinations and laboratory analyses. However, the diagnosis of MSI should be entertained only after potential toxicologic etiologies have been excluded.

Evaluating the effects of different oxygen therapies on the rats with acute nitrogen asphyxia

To Evaluate the effects of different oxygen therapies on the rats with acute nitrogen asphyxia and to study the best oxygen therapic protocol for patients with acute nitrogen asphyxia on the spot. Sixty healthy male Wistar rats were divided into 5 groups: control, exposure to nitrogen, 33% oxygen treatment, 50% oxygen treatment and hyperbaric oxygen treatment groups. The behavioral performance, arterial oxygen pressure (PO2), carbon dioxide partial pressure (PCO2) and oxygen saturation (SPO2), biochemical changes in liver and kidney function and myocardial enzymes in 5 groups were measured. The rats exposed to nitrogen firstly were excited then inactive symptoms, but consciousness was recovered after oxygen therapy. The PO2 and SPO2 in nitrogen exposure group were (79.67 +/- 9.12) and (94.92 +/- 2.78) mm Hg, respectively, which were significantly lower than those in control group (P<0.01). The PO2 and SPO2 of 3 oxygen treatment groups were (94.75 +/- 7.24), (94.92 +/- 8.98), (104.58 +/- 7.12)mm Hg and (97.17 +/- 0.83), (96.92 +/- 1.16), (97.42 +/- 0.67)mm Hg, respectively, which were significantly higher than those in nitrogen exposure group (P<0.05). The PO2 in hyperbaric oxygen treatment group was significantly higher than those in other 2 oxygen treatment groups (P<0.05). The SPO2 in hyperbaric oxygen treatment group was (51.42 +/- 6.60) mm Hg which was significantly higher than that [(44.58 +/- 3.42)mm Hg] in 50% oxygen treatment groups (P< 0.05). AST [(270.50 +/- 49.05 )U/L], ALT [(122.67 +/- 55.44 )U/L], BUN [(7.31 +/- 0.93 )mmol/L], Cr[(28.32 +/- 4.35) micromol/L], CK [(1808.42 +/- 582.05)U/L] and CtnI [(22.52 +/- 14.29 )ng/ml] in nitrogen exposure group were significantly higher than those in control group (P<0.05). AST [(165.25 +/- 30.87) U/L], HBDH [(350.83 +/- 103.00)U/L] and CtnI [(11.23 +/- 5.38) ng/ml] in hyperbaric oxygen treatment group were significantly lower than those in other 2 oxygen treatment groups (P<0.05). Timely and effective oxygen therapy can significantly increase arterial pressure of oxygen and oxygen saturation in the rats with acute nitrogen asphyxia, and can improve liver function and cardiac damage. The hyperbaric oxygen chamber can significantly increase the therapeutic effects on rats with acute nitrogen asphyxiation.

Root and canal morphology of Indian maxillary premolars by a modified root canal staining technique

The aim of this study was to investigate the root and canal morphology of maxillary first and second premolars in Indians by a modified canal staining and tooth clearing technique. Maxillary first (350) and second (350) premolars were collected, and the morphology and number of roots analyzed. After cleaning, the teeth were immersed in India ink and placed in a hyperbaric oxygen chamber at 0.6 MPa for 2 h. The teeth were then demineralized and cleared. Digital images of the teeth were examined under magnification to evaluate the number of root canals, root canal system configurations, number of apical foramina, and intercanal communications. Root canal configurations were identified based on Vertucci's classification and Gulabivala's additional classes. The most common root morphology of the first premolars was the classical two separate root morphology (a Caucasian trait) and that of the second premolars was a single-root morphology (a Mongoloid trait), though other morphologies such as singlerooted first premolars and three-rooted first and second premolars were also identified. A "radiculous" first premolar was identified in two samples. The buccal roots of the first premolar showed the maximum variation, the most common being type I (Vertucci's classification), followed by type IV. The highest incidence of intercanal communications was found in the single-rooted first premolars. All roots exhibiting type IV and V canal configurations showed two separate apical foramina, while additional type 2-3 canal configurations showed three separate apical foramina. The root number and morphology as well as the canal morphology of Indian maxillary premolars showed both Mongolian and Caucasian traits.

Responding to requests of families for unproven interventions in neurodevelopmental disorders: Hyperbaric oxygen “treatment” and stem cell “therapy” in cerebral palsy

Faced with the limitations of currently available mainstream medical treatments and interventions, parents of children with neurodevelopmental disorders often seek information about unproven interventions. These interventions frequently have undetermined efficacy and uncertain safety profiles. In this article, we present a general background and case vignettes that highlight the use of hyperbaric oxygen chambers and stem cells in cerebral palsy, the leading cause of pediatric physical disability. We then review the current evidence about these interventions as exemplars of unproven therapies. Building on the background and cases, we explore and review two important questions related to unproven interventions: (1) How should clinicians respond to requests for innovative and alternative interventions? (2) What should clinicians keep in mind when such requests come from online sources?

Web Alert

American Academy of Orthopaedic Surgeons Patient Handouts, Sport & Exercise: www.orthoinfo.aaos.org/menus/sports.cfm Description: This Web site offers a wealth of information on physical activity intended for the general public. The site is divided into the following sections: Common Sports Injuries and Conditions, Exercise, Prevention and Safety, Wellness, Children, Other, Patient Stories, and Resources. The Common Sports Injuries and Conditions section provides well-worded descriptions of injuries and illustrations including sprains/strains, burners/stingers, muscle cramps, and joint-specific injuries. The Exercise section addresses both the physical and mental benefits of exercise. It also includes information on starting exercise programs in both the adult and aging populations. The Prevention and Safety section discusses general safety tips (correct footwear, use of helmets), as well as sports-specific injury prevention recommendations. The section devoted specifically to children covers a wide array of topics, including common injuries, such as fractures and overuse injuries, and an extensive injury-prevention section. There also is a small section on sports supplements. Although this site is on the AAOS Web site, the AAOS does not regulate the information contained within the site. Cost: Free. Equestrian Medical Safety Association: www.emsaonline.net/index.html Description: The Equestrian Medical Safety Association (EMSA) is an organization whose mission is to promote safety for people participating in equestrian events through "education, research, and resource." This Web site contains valuable information for equestrian enthusiasts of all skill levels, including a video titled "Equestrian Safety" and newsletters on topics such as helmet use, concussion management, and injury reporting. This Web site also includes an example of contents in a first aid kit to bring to an event. There are numerous links to other equestrian sites, including the U.S. Eventing Association, U.S. Equestrian Foundation, Federation Equestrian International (FEI), and American Association for Horsemanship Safety. Cost: Navigating the Web site is free, but if interested in joining the EMSA, membership dues apply. Vanderbilt Sports Medicine: www.vanderbilthealth.com/orthopaedics/26075 Description: This Web site reviews many vital concepts in the field of sports medicine through multiple modalities, including PowerPoint presentations, PubMed links to important articles, podcasts, patient education handouts, and examples of rehabilitation guidelines. This Web site is intended for medical professionals, and contents are guided by the curriculum for both primary care sports medicine and orthopedic fellowships. In addition to expected joint sections, there also are two other sections titled "General" and "Medical Aspects Sports." These sections contain links for resources on ethics, protective equipment, sports psychology, and cardiovascular concerns in athletes. The patient handouts are particularly helpful throughout the Web site. These handouts are written in clear, concise, and easily understood language and have excellent pictures/diagrams to emphasize key concepts pertinent to a specific injury. Cost: Free. International Mountaineering and Climbing Federation: www.theuiaa.org/index.php Description: The International Mountaineering and Climbing Federation (UIAA) Web site contains a wealth of information for individuals interested in mountaineering and climbing. It offers information on equipment, access to mountains, environmental protection, youth opportunities, ethics and law, and important medical issues. Specifically, the medical section provides links to many consensus statements by the UIAA on topics such as acute mountain sickness (AMS)/high altitude pulmonary edema (HAPE)/high altitude cerebral edema(HACE), water disinfection, hyperbaric oxygen chambers, children at altitude, and women at altitude. Other formats used to share information include a brochure and personal accounts. Many of the links are available in multiple languages. Cost: Free access to Web site; membership fees apply if interested in becoming a member of the UIAA. STOP Sports Injuries: www.stopsportsinjuries.org Description: STOP Sports Injuries is a Web site devoted to preventing sports injuries, with a particular emphasis on traumatic and overuse injuries, in the pediatric athlete. This Web site contains vital information for athletes, parents, coaches, and health care providers, including team physicians. The Web site focuses on 12 sports with considerable injury rates, including baseball, basketball, football, gymnastics, and soccer. Perhaps the most helpful section for physicians is the Resources. This section contains consensus statements on topics such as tackling in football, heat injuries, sickle cell trait, sudden cardiac death, mass participation event coverage, sideline coverage, return-to-play, and psychological concerns. In addition to consensus statements, this section also contains podcasts of presentations given at the 2009 American Orthopaedic Society for Sports Medicine (AOSSM) meeting specific to overuse injuries and psychological concerns in the pediatric athlete. Cost: Free.

The Comparison of the Effectiveness of Hyperbaric Oxygen and Medical Ozone Therapy Against Acute Distal Colitis in a Rat Model

Purpose: Previous studies have shown that hiperbaric oxygen (HBO) is effective in reducing severity of acute distal colitis (ADC). On the other hand, ozone therapy (OT) is shown to reduce inflammation in several pathological entities. Thus, we designed a study to evaluate the efficacy of OT in an experimental rat model of ADC and to compare effects of both HBO and OT in this entity. Methods: Forty Sprague-Dawley rats were divided into four groups: sham, ADC, ADC+HBO, ADC+OT groups. All groups except sham group were subjected to ADC procedure, which was induced by intracolonic installation of %4 acetic acid to investigate acute phase of inflamation. ADC+HBO group underwent to hyperbaric oxygen chamber at 2.8 atmosphere absolute pressure with 100 % O2 inhalation for 90 minutes twice in a day and ADC+OT group received 0.7 mg/kg/day ozone/oxygen mixture intraperitoneally for a total of 4 days after induction of colitis. The surviving animals were killed at the 5th day and their distal colons were harvested for biochemical and histopathologic analysis. Results: The Malondialdehyde (MDA) levels in the ADC group were significantly higher when comparing with the other groups indicating increased damage in tissue with colitis (p<0.05, ADC vs. the other groups). Althougt the MDA levels were decreased in the ADC+HBO and the ADC+OT groups, only that of ADC+OT group was statistically significant (p<0.005, ADC+OT vs. AP). The tissue Superoxydedismutase (SOD) activity in ADC group were significantly lower than the sham-operated group (p<0.05, ADC vs. sham-operated). There is no significantly difference for the tissue SOD activities between the treatment groups and the sham-operated group. The difference between all groups in terms of the values of the Gluthatione dismutase (GSH-Px) activity were not statistically significant. At the histopathological evaluation, there is a significant improvement in the ADC+OT group. Conclusion: Our data showed that OT reduced severity in the experimental ADC compared with HBO in term of oxidative stress, histopathologic damage score. These findings suggest that it is possible to improve the outcome of ADC by using ozone therapy as an adjuvant therapy.FigureTable: [1215] Histopathological score of the each group

Diabetic persons with foot ulcers and their perceptions of hyperbaric oxygen chamber therapy

To elucidate how diabetic patients with limb-threatening foot lesions perceive and evaluate content and organisation of treatment in a multi-place hyperbaric oxygen chamber. To our knowledge there are no patients' evaluations of diabetes care in a high-technology area like the hyperbaric oxygen chamber. The burden on persons with diabetic foot complications might be increased if adjuvant therapy with hyperbaric oxygen therapy (HBOT) within a locked airtight vessel is given. Explorative study. Participants were included in the HODFU study, a prospective randomised double-blind study, designed to evaluate whether HBOT heals more chronic foot ulcers than placebo treatment with hyperbaric air. Six females and 13 males, aged 44-83 years (median 70), with diabetic foot ulcers, participated. Focus-group interviews by an external evaluator. Management was perceived as well-functioning with competent staff delivering quick treatment in a positive manner and in good co-operation. HBOT sessions, in groups, were described as unproblematic and pleasant, through sharing experiences with others, although time-consuming and tiring. Recognising the responsible physician and communication with other physicians in the health-care chain was perceived as problematic. Placebo treatment, when given, did not reveal any problems; many perceived HBOT as the last resort and respondents had a negative view of future health and expressed fears of new wounds and amputation. From patients' perspective HBOT in the delivered health-care model was perceived as well-functioning, taking into consideration both technical and relational aspects of care in this high-technology environment. Communication with the patient and between different care givers, with a consistent message given and information about who is responsible and to whom one should turn, wherever treated, is the most crucial aspect of the model. Future fears need to be recognised and group interaction can be encouraged to share the burden of disease.

Root Canal Morphology of Permanent Maxillary Teeth in the Han Nationality in Chinese Guanzhong Area: A New Modified Root Canal Staining Technique

Introduction The purpose of this study was to investigate the canal morphology of 504 maxillary permanent teeth of subjects of Han nationality in Chinese Guanzhong area. Methods Maxillary permanent teeth were randomly collected in Guanzhong area. After regular preparation, the teeth were immersed into ink without preparing access cavities and then put into hyperbaric oxygen chamber (0.6 Mpa) for 2 hours to let the ink penetrate into root canal from apical foramen, apical deltas and foramen of lateral canals under stable positive pressure. After demineralization and clearing, the following observations were made: (1) number of root canals, (2) root canal configuration by using Vertucci's classification, (3) presence of lateral canals, and (4) frequency of apical deltas. Results All the teeth were well-stained, and the fine details were well-revealed. Apical deltas (12.2%–83.3%) and lateral canals (13.7%–68.8%) could be frequently found in all types of maxillary teeth. Most of central incisors (95.8%), lateral incisors (91.4%), and canines (75.4%) displayed type I canal configuration, whereas most of first premolars (87.3%) and second premolars (72.3%) possessed 2 canals with type II, IV, or VI canal configuration. The majority of distobuccal roots and palatal roots of first molars (88.9%, 97.8%), second molars (92.0%, 94.0%), and third molars (87.5%, 91.6%) possessed type I canal configuration. The prevalence of mesiobuccal roots with type I configuration was 66.7% in maxillary first molars, 82% in second molars, and 62.5% in third molars. Conclusions The modified technique of canal staining can effectively reveal detailed root canal system. The canal configuration of maxillary teeth in subjects of Han nationality in Chinese Guanzhong area is consistent with previous reports in other races.

Discussion of “Effects of hyperbaric oxygen on the replanted extremity subjected to prolonged warm ischemia”

The authors are to be commended for developing an animal model for evaluating the potential value of hyperbaric oxygen (HBO). However, more work must be done before we ask our hospitals to purchase HBO chambers.

Review of Equine Hyperbaric Medicine

Hyperbaric oxygen therapy appears to be a promising adjunctive treatment for a variety of equine disorders, including laminitis and other ischemic injuries. Hyperbaric oxygen (HBO) is a high-dose oxygen inhalation therapy that is achieved by having the patient breathe 100% oxygen inside a pressurized hyperbaric chamber. The delivery of oxygen to the tissues is through respiration because there is insufficient absorption of oxygen through the skin. The benefits of HBO are derived from both the physiologic and pharmacologic effects of high-dose oxygen. HBO is based on two physical factors related to the hyperbaric environment: mechanical effects of pressure and increased oxygenation of tissues. The use of HBO by veterinary medical hospitals is in its infancy. Our clinic has currently treated more than 250 patients in our HBO chamber. Patients included pregnant animals as well as neonatal foals, with no adverse effects noted. Patients have been pressurized from 1.5 to 3 ATA (ATM absolute) ranging from 60 to 90 minutes at treatment pressure (depth). Hagyard Equine Medical Institute has used HBO as adjunctive therapy for fungal disease (fungal pneumonia); thermal burns, carbon monoxide, smoke inhalation; closed head injuries; ileus; central nervous system edema/perinatal asphyxia; peripheral neuropathies; sports injuries (exertional rhabdomyolysis); cellulitis; compartment syndrome; and ischemic injuries (laminitis ). In carefully selected patients, the addition of HBO therapy to standard measures may improve clinical outcomes. Further research is needed in the field of equine HBO medicine.

Cerebral air embolism treated with hyperbaric oxygen therapy following percutaneous transthoracic computed tomography-guided needle biopsy of the lung

A 71-year-old man presented with cough and sputum for 12 months. Chest radiography showed a homogeneous opacity in the right lower lobe. Computed tomography (CT) showed a nodular opacity, 2 cm in diameter, in the posterior segment of the right lower lobe. Mild emphysematous changes were also seen. With the patient in a prone position, a 19-gauge 7.8-cm introducer was placed in the lesion during a single inspiratory breath-hold. A coaxial 20-gauge automated needle was inserted through the introducer using a biopsy gun. Although the patient did not complain of any symptoms, postbiopsy CT showed air in the left ventricle and ascending aorta. After 5 h of bed rest, we found weakness in his left lower extremity. He was transferred to a hyperbaric oxygen chamber and recovered the next day. Air embolism is a rare, potentially fatal complication of percutaneous lung biopsy. Although the true effect of hyperbaric oxygen therapy is controversial, knowledge regarding the prompt management of such cases may help radiologists who perform this procedure.

051 Topical Oxygen Alters Angiogenesis-Related Growth Factor Expression in Chronic Diabetic Foot Ulcers

Objective: Following tissue vascular and oxygen delivery disruption, normal wound healing is a complex process requiring restoration of supplies of oxygen and other nutrients through blood vessel regeneration, or angiogenesis. Angiogenesis is stimulated by synergistic interactions of growth factors and cytokines secreted by damaged cells in wound tissues exhibiting hypoxia, high lactate levels, and inflammation. Chronic wounds, often complications of diabetes, are characterized by chronic hypoxia, inflammation, and insufficient growth factor secretion. To test growth factor sensitivity to reversed hypoxia in chronic human wounds, we administered pure oxygen topically to chronic foot ulcers in diabetic humans and used molecular probes to measure growth factors previously found to regulate angiogenesis and improve delayed healing, i.e., VEGF et al. Methods: By multiplex ELISA assays of growth factor cytokines, we quantified pg/ug levels of total proteins detectable in fluids collected from human diabetic plantar wounds after exposure to topical oxygen delivered in 0–50 mm Hg pulses during 90-minute treatments 4 days per week over a 5 week protocol. Wounds that had failed to heal for at least 4 weeks were infused with a maximum of 1.06 ATM of oxygen at 1 minute intervals in a lower limb enclosing chamber. Findings: Our initial data show increased expression in angiogenesis-related growth factors (bFGF, HB-EGF, HGF, KGF, VEGF) in wound fluid from chronic diabetic foot ulcers using the Topical Hyperbaric Oxygen Chamber (Advanced Hyperbaric Technologies, Inc., Farmingdale, NJ). Secretion of the most crucial angiogenic factor, VEGF, was increased by 8-fold to well over 10-fold using the described protocol. Conclusions: These data show evidence of a molecular mechanism for the scientific basis of topical hyperbaric oxygen-modulated growth factor expression in chronic diabetic wounds, previously unresponsive to standard wound care. We conclude that topically applied hyperbaric oxygen alters angiogenesis-related growth factor expression in wound fluids from chronic diabetic foot ulcers in a manner consistent with renewed healing. Acknowledgments: Advanced Hyperbaric Technologies, Inc., Farmingdale, NJ.

Advances in emerging nondrug therapies for acute stroke 2007.

Numerous clinical trials of thrombolytic and neuroprotective drugs for stroke have been conducted over the last 2 decades. The NINDS trial of intravenous tissue plasminogen activator remains the most notable success. Intra-arterial thrombolysis appears promising, but in the absence of phase III clinical trial data, this approach remains investigational. Numerous pharmaceutical drugs targeting 1 or more cell death pathways have failed to show efficacy. Despite failure, these prior attempts have provided insights regarding critical issues such as proper clinical trial design and the need for more rigorous preclinical drug testing in order to improve the translational leap from bench to bedside. More recently, accumulating data suggest that “non-drug” approaches toward stroke therapy might also provide new opportunities in addition to more traditional pharmaceutical therapies. As testimony to the growing importance of these alternate and sometimes complementary methods, there has been a proliferation of device trials, and the NINDS, through its key ‘Specialized Program of Translational Research in Acute Stroke’ [SPOTRIAS] initiative,1 has funded trials of therapeutic hypothermia, caffeinol, and normobaric hyperoxia, among others. Although this brief survey focuses on emerging gas and device therapies for ischemic stroke, it should be noted that several other ‘non-drug’ approaches, including physiological strategies (eg, hypothermia, glucose regulation), and natural agents (eg, albumin, magnesium), continue to be tested in ongoing trials. Increasing brain tissue oxygenation has long been considered a logical stroke treatment strategy. Although initial efforts using hyperbaric oxygen (HBO) chambers were unsuccessful, the realization that early trials had numerous methodological shortcomings has led to a resurgence of interest in hyperoxia.2 As a potential treatment, oxygen has distinct advantages over pharmaceutical drugs: it easily diffuses across the blood-brain barrier to reach target tissues, may act via multiple pathways, and high concentrations of oxygen in brain might be well tolerated. In the past …

Severe keloids caused by hydrogen cyanide injury: a case report

The purpose of this study was to report severe keloids caused by hydrogen cyanide injury. Hydrogen cyanide poisoning is still a problem as an occupational disease in China. We report a 37-year-old man with severe hydrogen cyanide poisoning. The patient fell on the floor after inhalation of hydrogen cyanide and was burned on his back by hydrocyanic acid. Sequential treatment included amyl nitrite by inhalation, intravenous sodium nitrite 3%, and intravenous sodium thiosulfate 25%. Other treatment consisted of incision of the trachea, mannitol and furosemide, antibiotics, and nutrient support measures. The patient also received hyperbaric oxygen therapy; during the first treatment, he became apneic and cardiopulmonary resuscitation was supplied in the hyperbaric oxygen chamber. He eventually recovered, but a large amount of keloids developed on his back and buttocks.

Hyperbaric Oxygen Therapy Is as Effective as Dexamethasone in the Treatment of TNBS-E-Induced Experimental Colitis

Hyperbaric oxygen (HBO) has been demonstrated to be useful as an adjunctive therapy for Crohn's disease. In the present study, HBO was tested as a treatment for trinitrobenzenesulfonic acid-ethanol (TNBS-E)-induced distal colitis, and its effects were compared with dexamethasone therapy. A total of 48 Sprague-Dawley rats were separated into six groups: the control, and those treated with vehicle, TNBS-E, HBO, dexamethasone, or combined HBO + dexamethasone. The HBO treatment group was exposed to 100% HBO at 2 ATM for 75 min twice daily at 6-h intervals in a HBO chamber, both on the day of colitis induction and 3 days thereafter. Treatment with intraperitoneal dexamethasone twice daily was started 1 h before the induction of colitis and was continued for 7 days in the dexamethasone group. The rats were decapitated 8 days after the induction of colitis, and the colonic tissue wet weight, macroscopic and microscopic lesion score, and tissue myeloperoxidase (MPO) activity were determined. HBO therapy decreased the activity of experimental colitis measured by the tissue wet weight, macroscopic score, microscopic score, and MPO activity. The dexamethasone treatment significantly reduced the colitis activity as determined by the tissue MPO activity and wet weight. There were also decreases in the macroscopic and microscopic activity scores with the dexamethasone therapy; however, these changes were not statistically significant. The combined therapy with HBO and dexamethasone provided no additional benefit over HBO therapy alone. HBO therapy can be a valuable therapeutic option in treatment of patients with inflammatory bowel disease. HBO therapy in the refractory patients deserves further, larger clinical studies.

The Roles of Hypoxia in theIn VitroEngineering of Tissues

Oxygen is a potent modulator of cell function and wound repair in vivo. The lack of oxygen (hypoxia) can create a potentially lethal environment and limit cellular respiration and growth or, alternatively, enhance the production of the specific extracellular matrix components and increase angiogenesis through the hypoxia-inducible factor-1 pathway. For the in vitro generation of clinically relevant tissue-engineered grafts, these divergent actions of hypoxia should be addressed. Diffusion through culture medium and tissue typically limits oxygen transport in vitro, leading to hypoxic regions and limiting the viable tissue thickness. Approaches to overcoming the transport limitations include culture with bioreactors, scaffolds with artificial microvasculature, oxygen carriers, and hyperbaric oxygen chambers. As an alternate approach, angiogenesis after implantation may be enhanced by incorporating endothelial cells, genetically modified cells, or specific factors (including vascular endothelial growth factor) into the scaffold or exposing the graft to a hypoxic environment just before implantation. Better understanding of the roles of hypoxia will help prevent common problems and exploit potential benefits of hypoxia in engineered tissues.