Diving Diseases Research Center

Plymouth, United Kingdom

Diving Diseases Research Center

Plymouth, United Kingdom
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Dowse M.S.L.,Diving Diseases Research Center | Cridge C.,Hyperbaric Medical Center | Smerdon G.,Hyperbaric Medical Center
Diving and Hyperbaric Medicine | Year: 2011

Introduction: Various prescribed and over-the-counter medications may theoretically be incompatible with the diving environment. Anecdotally, it is known divers regularly take medications around the time of their diving activities for different health conditions, possibly ignoring the recommendations not to do so. As part of a diversion in a study of illicit drug use in sport divers, secondary data regarding the use of prescribed and over-the-counter medications were gathered. Aims: The aim of presenting these data is to attempt to evaluate and promote debate surrounding the fitness of some divers to participate in the sport and the potential problems medication may cause whilst diving. Methods: Anonymous questionnaires addressing diving demographics, general health, alcohol, smoking, illicit drugs, prescribed and over-the-counter medications were circulated via United Kingdom dive clubs, schools, dive shows and conferences. Divers were asked if they were currently taking medication prescribed by a physician, if they had ever taken any over-the-counter drugs within six hours before a dive, and to give details. Questions were fixed-option and free-format. Results: A response rate of 26% provided 531 records (68% male, 32% female) for analysis. Over-the-counter medication was used by 303 (57%) of the respondents 6 hours or less before diving. Analgesics were the most commonly reported (180/303), with the use of decongestants (132/303) the next most regularly reported. Prescribed medications were used by 23% of respondents, with 10% reporting the use of cardiovascular drugs. The majority of the cardiovascular medication was for primary disease prevention; however, drugs only used in the treatment of symptomatic cardiovascular disease were reported, indicating individuals were diving with medical conditions recommended not compatible with diving. Other medication reported would also suggest liaison with a diving physician should have been undertaken prior to diving. Conclusion: Although these data were diversionary, secondary and therefore open to criticism, the range of prescribed medications reported in this study was broad and suggested a need for further investigation regarding medication use and fitness to dive.

Williams S.T.B.,University of Birmingham | Williams S.T.B.,Diving Diseases Research Center
Trauma | Year: 2010

This review explains the method of action of hyperbaric oxygenation (HBO) therapy and examines the evidence for its use in trauma. Methods of delivery, complications and contra-indications are discussed. It is acknowledged that there are few controlled trials which evaluate the efficacy of HBO in this indication; supporting evidence for its efficacy is mainly in the form of case reports, or by implication from laboratory and animal work. Lack of evidence may not equate to lack of efficacy, but may reflect the difficulties in coordinating clinical trials involving critically ill patients and a complex treatment modality, the availability of which is not widespread. The adjunctive use of HBO has shown promising results in the treatment of crush injury. Consideration of tissue pathophysiology suggests that such an approach may also offer improved outcomes in the broader spectrum of trauma scenarios involving marginally viable tissues with compromised perfusion.

Bishop A.J.,Diving Diseases Research Center | Mudge E.,University of Cardiff
International Wound Journal | Year: 2014

Hyperbaric oxygen therapy (HBO) has been used as an adjunct for healing diabetic foot ulcers (DFUs) for decades. However, its use remains controversial. A literature search was conducted to locate clinical studies and assess the available evidence. Ten prospective and seven retrospective studies evaluating HBO for DFUs were located. These were reviewed and the outcomes were discussed. One study reported no difference in outcomes between patients receiving hyperbaric oxygen and the control group. However, their regime differed from all other studies in that the patients received hyperbaric oxygen twice rather than once daily. Reduced amputation rates and improved healing were the most common outcomes observed. © 2012 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

Bishop A.J.,Diving Diseases Research Center | Mudge E.,University of Cardiff
International Wound Journal | Year: 2012

A retrospective review of patient medical records was conducted to assess what factors influence the outcomes of diabetic foot ulcers treated with hyperbaric oxygen (HBO) therapy. Patients referred to the Diving Diseases Research Centre for HBO therapy for the treatment of diabetic foot ulcers during a 2-year period were included in this study. Data collected from 30 sets of patient records were entered into SPSS and statistical analysis was undertaken to investigate whether any underlying pathologies or confounding factors appeared to influence patient outcome. A 73·3% of patients achieved a successful outcome of partial healing, major amputation no longer required, amputation level lower than anticipated prior to HBO or healing at the end of HBO therapy and 70% remained successful 3 months later. A 13·3% of patients were lost to follow-up at 3 months and one patient (3·3%) had a major amputation. Steroid therapy, peripheral vascular disease, previous minor amputation, type of diabetes, previous HBO therapy, larvae therapy, the use of interactive dressings and haemoglobin A1c levels were all observed to have had a significant relationship with patient outcome (P < 0·05). These results were compared with data from other published research conducted in this area on similar patient groups. A larger scale study focussing on the factors found to be significant in this study is recommended. An improvement of patient documentation would allow patient outcomes to be more consistently monitored in the future. © 2012 The Authors. © 2012 Blackwell Publishing Ltd and Medicalhelplines.com Inc.

Pontier J.-M.,British Petroleum | Gempp E.,St Annes Military Hospital | Ignatescu M.,Diving Diseases Research Center
Applied Physiology, Nutrition and Metabolism | Year: 2012

Bubble-induced platelet aggregation offers an index for evaluating decompression severity in humans and in a rat model of decompression sickness. Endothelial cells, blood platelets, or leukocytes shed microparticles (MP) upon activation and during cell apoptosis. The aim was to study blood platelet MP (PMP) release and bubble formation after a scuba-air dive in field conditions. Healthy, experienced divers were assigned to 1 experimental group (n = 10) with an open-sea air dive to 30 msw for 30 min and 1 control group (n = 5) during head-out water immersion for the same period. Bubble grades were monitored with a pulsed doppler according to Kissman Integrated Severity Score (KISS). Blood samples for platelet count (PC) and PMP (annexin V and CD41) were taken 1 h before and after exposure in both groups. The result showed a decrease in post-dive PC compared with pre-dive values in experimental group with no significant change in the control group. We observed a significant increase in PMP values after the dive while no change was revealed in the control group. There was a significant positive correlation between the PMP values after the dive and the KISS bubble score. The present study highlighted a relationship between the post-dive decrease in PC, platelet MP release, and bubble formation. Release of platelet MPs could reflect bubble-induced platelet aggregation and could play a key role in alteration of the coagulation. Further studies must investigate endothelial and leukocyte MP release in the same field conditions.

Golden F.S.C.,University of Portsmouth | Francis T.J.R.,Diving Diseases Research Center | Gallimore D.,Institute of Naval Medicine | Pethybridge R.,Institute of Naval Medicine
Extreme Physiology and Medicine | Year: 2013

Background: Environmental conditions in the Falklands Conflict of 1982 favoured the genesis of cold injuries. Immediately, post-war, cold injury morbidity and its contributory factors were assessed, in the personnel of UK 3 Commando Brigade (3 Cdo Bde). Methods: A questionnaire survey of the 3,006 members of 3 Cdo Bde who landed on the islands was conducted within 6-10 weeks of the end of hostilities. Questions included those relating to features of cold injury, body morphology, age, symptoms experienced, past medical history and other possible contributory causes. Additionally, the unit medical team conducted a cursory examination. Data were sent to the Royal Navy Institute of Naval Medicine (INM), where the degree of likely cold injury was broadly classified ('asymptomatic' 'mild', 'moderate' or 'severe'). A sample (total 109) was then selected at random from each category and subsequently examined and tested at the INM (nerve conduction, photoplethysmography and thermography testing). Forty-seven non-cold exposed sailors acted as a control group. These contemporaneous records have now been identified and interrogated. Results: Some 2,354 (78%) completed questionnaires were returned, revealing that 1,505 (64%) had experienced symptoms of non-freezing cold injury. The morbidity in the infantry units was significantly greater than that in the support troops (1,051 (76%) vs 454 (46%), p < 0.05). No evidence was found to support an influence of a number of factors, commonly believed to have an aetiological role in the production of cold injury. Whilst there was no significant relationship between past history and cold injury morbidity in the brigade as a whole, or within the infantry units alone, an association was identified in the collective infantry units (73%) and the support/headquarter units (59%) (p < 0.05). In comparison with uninjured sailors who acted as controls (n = 47), nerve conduction was impaired in 35% of those screened some months after returning to the UK, while the photoplethysmography and thermographic responses to a cold sensitivity test showed that most (including those classed by questionnaire as asymptomatic) had residual 'cold sensitivity'. Conclusions: Although the passage of time has made retrospective interrogation of historical documents hard, the available data do appear to offer valuable historical and clinical insights. Cold injury affected the majority of those fighting in the cold temperate climate of the Falklands. The overwhelming environmental conditions meant that, for most, a past history of cold injury did not appear to represent a risk factor for subsequent injury, as is the case for less severe conditions. Importantly, even asymptomatic individuals when tested often showed physiological evidence of cold injury-perhaps predisposing them to subsequent elevation in risk. © 2013 Golden et al.; licensee BioMed Central Ltd.

Kendall A.C.,University of Exeter | Kendall A.C.,Diving Diseases Research Center | Whatmore J.L.,University of Exeter | Harries L.,University of Exeter | And 3 more authors.
Experimental Cell Research | Year: 2012

Hyperbaric oxygen (HBO) therapy involves the inhalation of 100% oxygen, whilst inside a chamber at greater than atmospheric pressure. It is an effective treatment for chronic diabetic wounds, although the molecular mechanisms involved remain unclear. We hypothesised that HBO could alter inflammatory gene expression in human endothelial cells via a reactive oxygen/nitrogen species-mediated pathway. Endothelial cells were exposed to a chronic wound model comprising hypoxia (2% O 2 at 1 atmosphere absolute (ATA); PO 2 ~2kPa) in the presence of lipopolysaccharide and TNF-α for 24h, then treated with HBO for 90min (97.5% O 2 at 2.4 ATA; PO 2 ~237kPa). 5h post-HBO, 19 genes involved in adhesion, angiogenesis, inflammation and oxidative stress were downregulated. Notably, only angiogenin gene expression, which promotes both angiogenesis and nitric oxide production (reflected by increased eNOS protein expression in this study), was upregulated. This led to a decrease in endothelial IL-8 mRNA and protein, which could help alleviate inflammatory processes during chronic wound healing. This was no longer evident 22.5h post-HBO, demonstrating the importance of daily exposures in HBO treatment protocols. These studies indicate that elevated oxygen transiently regulates inflammatory gene expression in endothelial cells, which may enhance chronic wound healing. © 2011 Elsevier Inc..

Bishop A.,Diving Diseases Research Center
Wounds UK | Year: 2013

Hyperbaric oxygen therapy (HBO) may be a useful adjunct for chronic nonhealing wounds when the aetiology includes a hypoxic component. Occasionally, HBO is administered in unusual cases that have no obvious hypoxic involvement. The aim of this case series was to assess whether HBO would be beneficial in the management of chronic wounds with no obvious hypoxic component. Three chronic wounds with no apparent hypoxic complications were treated with HBO and the outcomes reviewed. All three cases demonstrated improved wound healing during the course of HBO, suggesting it may be a beneficial adjunct in the management of chronic wounds with no obvious hypoxic component.

Almzaiel A.J.,University of Plymouth | Billington R.,University of Plymouth | Smerdon G.,Diving Diseases Research Center | Moody A.J.,University of Plymouth
Life Sciences | Year: 2013

Aims Neutrophil apoptosis is important in the resolution of inflammation in chronic wounds. Hyperbaric oxygen (HBO) therapy, an intermittent inhalation of 100% oxygen at greater than atmospheric pressure, appears to be an effective treatment for chronic wounds. The aim was to use HL-60 cells differentiated using all-trans retinoic acid (ATRA) (neutrophil-like cells) to test the hypothesis that an HBO-induced increase in antimicrobial activity might lead to an increase in apoptosis, thereby contributing to neutrophil clearance from chronic wounds. Main methods ATRA differentiated HL-60 cells, an in vitro neutrophil model, were used to test the effects of normoxia, hypoxia (5% O 2), hyperoxia (95% O2), hyperbaric normoxia (pressure) (8.8% O2 at 2.4 ATA) and HBO (97.9% O2 at 2.4 ATA) on antimicrobial function [NBT staining, superoxide and H2O2 production, and phagocytosis activity] and apoptosis (caspase 3/7 activity and morphological changes observed using SYBR Safe staining). Key findings A single 90 min HBO exposure caused an increase in the respiratory burst activity of neutrophil-like cells post exposure. Phagocytosis of Staphylococcus aureus was also increased. HBO pre-treatment had a pro-apoptotic effect, increasing caspase 3/7 activity and causing morphological changes associated with apoptosis. Significance The potential detrimental effect of enhanced antimicrobial activity induced by HBO may be offset by enhanced apoptosis. Both hyperoxia and pressure alone seemed to contribute to the HBO-induced increases in antimicrobial activity and apoptosis, although there was no consistent pattern. These data contribute to explaining the effectiveness of HBO in the treatment of chronic wounds. © 2013 Elsevier Inc.

Hadi H.A.,University of Plymouth | Smerdon G.R.,Diving Diseases Research Center | Fox S.W.,University of Plymouth
Journal of Orthopaedic Research | Year: 2013

The cellular and molecular mechanism through which hyperbaric oxygen therapy (HBO) improves osteonecrosis (ON) is unclear. The present study therefore examined the effect of HBO, pressure and hyperoxia on RANKL-induced osteoclast formation in RAW 264.7 cells and human peripheral blood monocytes (PBMC). Daily exposure to HBO (2.4 ATA, 97% O2, 90 min), hyperbaric pressure (2.4 ATA, 8.8% O2, 90 min) or normobaric hyperoxia (1 ATA, 95% O2, 90 min) significantly decreased RANKL-induced osteoclast formation and bone resorption in normoxic conditions. HBO had a more pronounced anti-osteoclastic effect than hyperoxia or pressure alone and also directly inhibited osteoclast formation and resorption in hypoxic conditions a hallmark of many osteolytic skeletal disorders. The suppressive action of HBO was at least in part mediated through a reduction in RANK, NFATc1, and Dc-STAMP expression and inhibition of hypoxia-induced HIF-1α mRNA and protein expression. This data provides mechanistic evidence supporting the use of HBO as an adjunctive therapy to prevent osteoclast formation and bone loss associated with low oxygen partial pressure. © 2013 Orthopaedic Research Society.

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