Millerallison1032

INTRODUCTION Divers with suspected decompression illness require high concentration oxygen (O₂). There are many different O₂ delivery devices, with few data comparing their performance. This study evaluated O₂ delivery, using tissue O₂ partial pressure (PtcO₂), in healthy divers breathing O₂ via three different delivery devices. METHODS Twelve divers had PtcO₂ measured at six limb sites. https://www.selleckchem.com/products/lee011.html Participants breathed O₂ from a demand valve using an intraoral mask with a nose clip (NC); a medical O₂ rebreathing system (MORS) with an oronasal mask and with an intraoral mask; and a non-rebreather mask (NRB) at 15 or 10 L·min⁻¹ O₂ flow. In-line inspired O₂ FIO₂) and nasopharyngeal FIO₂ were measured. Participants provided subjective ratings of device comfort, ease of breathing, and overall ease of use. RESULTS PtcO₂ values and nasopharyngeal FIO₂ were similar with the demand valve with intraoral mask, MORS with both masks and the NRB at 15 L·min⁻¹. PtcO₂ and nasopharyngeal FIO₂ values were significantly lower with the NRB at 10 L·min⁻¹. The NRB was rated as the most comfortable to wear, easiest to breathe with, and overall the easiest to use. CONCLUSION Of the commonly available devices promoted for O₂ delivery to injured divers, similar PtcO₂ and nasopharyngeal FIO₂ values were obtained with the three devices tested MORS with an oronasal or intraoral mask, demand valve with an intraoral mask and NRB at a flow rate of 15 L·min⁻¹. PtcO₂ and nasopharyngeal FIO₂ values were significantly lower when the flow rate using the NRB was decreased to 10 L·min⁻¹. Copyright This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.INTRODUCTION Professional divers, like many other specialised occupational groups, are subject to regulatory constraints that include mandatory initial medical certification and routine recertification. The New Zealand system of diver certification and health surveillance has undergone modifications in recent years, but its acceptance among end-users has never been formally assessed. Because of the wide variety of tasks, circumstances and personalities encountered in the diving industry, unanimous satisfaction is an unrealistic expectation, but establishing the current mood of divers in this regard and canvassing opinions on possible improvements is an important step towards optimising the certification process. METHOD A multi-choice satisfaction questionnaire was added, as a quality assurance measure, to the on-line health questionnaire completed annually by all New Zealand professional divers. A complete 12-month dataset was analysed to determine levels of satisfaction, areas of dissatisfaction and suggestions for improvement. link2 Comparison of the opinions of various diver groups was achieved by stratification into employment-type sub-groups and those working locally, overseas or both. RESULTS The responses of 914 divers who completed the survey established an 85% satisfaction rate with the existing diver certification system. Dissatisfaction was independent of diving locality. Compliance cost was the most common area of dissatisfaction, particularly among recreational diving instructors. CONCLUSIONS Most New Zealand professional divers consider the current certification system satisfactory. Effective communication between the regulating authority and divers was identified as an important area for further development. Copyright This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.INTRODUCTION Prolonged cold-water immersion (CWI) has the potential to cause significant hypothermia and haemoconcentration; both of which have previously been shown to independently increase blood viscosity in vitro. The purpose of this study was to determine the effect of CWI on blood viscosity and examine the relative contribution of decreased blood temperature and haemoconcentration. METHODS Ten healthy volunteers were immersed to mid-sternum in 10°C water for 90 minutes. Gastrointestinal (GI) temperature, haematocrit (Hct), and blood viscosity were measured pre- and post-CWI. RESULTS CWI caused mean (SD) GI temperature to decrease from 37.5 (0.3)°C to 36.2 (0.7)°C (P less then 0.05). CWI also caused mean Hct to increase from 40.0 (3.5)% to 45.0 (2.9)% (P less then 0.05). As a result of the haemoconcentration and decreased GI temperature during CWI the mean blood viscosity increased by 19% from 2.80 (0.28) mPa·s⁻¹ to 3.33 (0.42) mPa·s⁻¹ (P less then 0.05). However, when the pre-CWI blood sample was measured at the post-CWI GI temperature (36.2°C) there was no significant difference in the blood viscosity when compared to the pre-CWI (37.5°C) blood sample (2.82 (0.20) mPa·s-1 and 2.80 (0.28) mPa·s-1 respectively). Furthermore, the changes in Hct and blood viscosity during CWI were significantly correlated with an r = 0.84. CONCLUSION The results of the current study show that prolonged, severe CWI causes a significant 19% increase in blood viscosity. In addition, the results strongly suggest that almost all of the increased blood viscosity seen following CWI is the result of haemoconcentration, not decreased blood temperature. Copyright This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.INTRODUCTION Treatment of diabetic foot ulcers is complex and often protracted. Hyperbaric oxygen treatment (HBOT) improves wound healing in diabetic ulcers and serves as an important adjunct to regular diabetic wound care. Endothelial dysfunction plays a central role in diabetes-related vascular complications and may be evaluated by a non-invasive technique called peripheral arterial tonometry which measures a reactive hyperaemia index (RHI). We hypothesized that endothelial function measured by peripheral arterial tonometry is impaired in diabetic foot ulcer patients and that HBOT might improve endothelial function. METHODS Endothelial function was prospectively assessed by peripheral arterial tonometry in 22 subjects with diabetic foot ulcers and 17 subjects without diabetes during courses of HBOT. Endothelial function was evaluated before first (baseline) and 30th treatments, and at 90-day follow-up. Serum insulin growth factor-I (IGF-I) concentrations were determined by immunoassay. Results were compared to 23 healthy subjects. RESULTS No baseline differences were found in endothelial function between subjects with diabetes, HBOT patients without-diabetes and healthy control subjects (RHI; 1.26, 1.61 and 1.81, respectively). No significant changes in RHI were found in patients with (P = 0.17) or without (P = 0.30) diabetes during courses of HBOT. At 90-day follow-up IGF-I was significantly reduced in the subjects with diabetes (P = 0.001) and unchanged in the group without diabetes (P = 0.99). CONCLUSIONS We found no significant differences in RHI between subjects with diabetic foot ulcers and patients without diabetes, nor improvement in endothelial function assessed by peripheral arterial tonometry during courses of HBOT. Copyright This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.INTRODUCTION Numerous studies have been conducted to identify the factors influencing the short-term prognosis for neurological decompression sickness (DCS). However, the long-term sequelae are rarely assessed. The purpose of this study to investigate the factors likely to influence the long-term prognosis. METHODS Twenty-seven Vietnamese fishermen-divers who on average 9 (SD 6) years beforehand had presented with neurological DCS and ongoing sequelae, were questioned and examined. The severity of the initial clinical profile was quantified using a severity score. The long-term sequelae were clinically evaluated by looking for a motor or sensory deficit or muscular spasticity, and by applying a severity score for the sequelae which focussed on gait and sphincter disorders. RESULTS An initial severity score of ≥ 15 is significantly associated with a risk of serious long-term sequelae [OR = 13.7 (95% CI 2.4 to 79.5)]. Furthermore, certain treatment practices such as in-water recompression to depths > 17 metres' seawater breathing air are significantly associated with more serious sequelae. The practice of intensive non-standardised hyperbaric oxygen sessions over prolonged durations (median 30 days [IQR 19.5]) delayed after the initial accident (median 4 days [IQR 6]) also seems unfavourable. CONCLUSION This study establishes a link between the initial DCS severity and the long-term sequelae causing severe gait disorders and sphincter incontinence. Furthermore, this work suggests that certain detrimental treatment practices should be modified. During this field study, we also found that it was possible to reduce sequelae of these divers by offering them an individual programme of self-rehabilitation. Copyright This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.INTRODUCTION The Netherlands Maritime Special Operations Forces use closed circuit oxygen rebreathers (O₂-CCR), which can cause pulmonary oxygen toxicity (POT). Recent studies demonstrated that volatile organic compounds (VOCs) can be used to detect POT in laboratory conditions. link3 It is unclear if similar VOCs can be identified outside the laboratory. This study hypothesised that similar VOCs can be identified after O₂-CCR diving in operational settings. METHODS Scenario one 4 h O₂-CCR dive to 3 metres' seawater (msw) with rested divers. Scenario two 3 h O₂-CCR dive to 3 msw following a 5 day physically straining operational scenario. Exhaled breath samples were collected 30 min before and 30 min and 2 h after diving under field conditions and analysed using gas chromatography-mass spectrometry (GC-MS) to reconstruct VOCs, whose levels were tested longitudinally using a Kruskal-Wallis test. RESULTS Eleven divers were included four in scenario one and seven in scenario two. The 2 h post-dive sample could not be obtained in scenario two; therefore, 26 samples were collected. GC-MS analysis identified three relevant VOCs cyclohexane, 2,4-dimethylhexane and 3-methylnonane. The intensities of 2,4-dimethylhexane and 3-methylnonane were significantly (P = 0.048 and P = 0.016, respectively) increased post-dive relative to baseline (range 212-461%) in both scenarios. Cyclohexane was increased not significantly (P = 0.178) post-dive (range 87-433%). CONCLUSIONS VOCs similar to those associated with POT in laboratory conditions were identified after operational O₂-CCR dives using GC-MS. Post-dive intensities were higher than in previous studies, and it remains to be determined if this is attributable to different dive profiles, diving equipment or other environmental factors. Copyright This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.