gammadelta T cells increased earlier at 24 hours, whereas CD4CD25 regulatory T cells increased later at 48 hours in spleen of wild type. Hypertonic saline was effective without the presence of iNOS, i.e., decreased gammadelta T cells at 24 hours and increased apoptosis of CD4CD25 regulatory T cells at 48 hours. CD4CD25 regulatory T cells at 48 hours without iNOS decreased compared with those of wild type. gammadelta T cells at 48 hours induced apoptosis under the condition without iNOS in spleen and thymus. iNOS worked as an accelerating factor for immunosuppressive condition, affected apoptosis, and immunoenhancing effect by hypertonic saline.

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IntroductionIt is important to have a venous line in cardiopulmonary arrest (CPA) patients as an emergency treatment measure in prehospital settings, but establishment of a peripheral venous line is difficult in such patients. This study aimed to investigate the current status of intravenous infusion (IVI) in CPA patients by Emergency Life-Saving Technicians (ELSTs) in Japan. We also considered alternative measures in case IVI was difficult or impossible.MethodsWe investigated a nationwide database between 1 January 2005 and 31 December 2008. From a total of 431,968 CPA cases, we calculated the IVI success rate and related parameters.The Bone Injection Gun (BIG) and simulator legs (adult, pediatric, and infant) were used by 100 ELSTs selected for the study to measure the time required and the success rate for intraosseous infusion (IOI).ResultsThe number of CPA patients, IVI, adrenaline administration, and the IVI success rate in adult CPA patients increased every year. However, the IVI success rate in pediatric CPA patients did not increase. Although adrenaline administration elevated the ROSC rate, there was no improvement in the 1-month survival rate. The time required for IOI with BIG was not different among the leg models. The success rates of IOI with BIG were 93%, 94%, and 84% (p < 0.05 vs. adult and pediatric) in adult, pediatric, and infant models, respectively.ConclusionsThe rate of success of IVI in adult CPA patients has been increased yearly in Japan. However, as establishing a peripheral venous line in pediatric patients (1-7 years old) by ELSTs is extremely difficult in prehospital settings, there was no increase in the IVI success rate in such patients. As the study findings indicated IOI with BIG was easy and rapid, it may be necessary to consider IOI with BIG as an alternative option in case IVI is difficult or impossible in adult and pediatric patients.

Introduction:It is important to have a venous line for infusion as an emergency treatment for patients suffering from crush syndrome or bleeding under confined space (CS) conditions in disaster medicine. However, it is not easy to for Emergency Life-Saving Technicians (ELSTs) to establish a venous line in such settings. Although previous studies have described the use of mechanical intraosseous (IO) devices and IO access while wearing chemical protection gears, problems for the use of IO devices under CS conditions have not been considered. This study aimed to investigate usefulness and problems of using a Bone Injection Gun TM (BIG) for IO infusion by ELSTs and rescue workers in CS conditions. Methods: The time required and success rate for IO infusion using a BIG in a manikin leg were measured, and for administering intravenous infusion in a manikin arm using either rescue gloves or plastic gloves by ELSTs or rescue workers under CS conditions. Results: Wearing rescue gloves, ELSTs were significantly faster in placing intraosseous infusion (IOI) compared with rescue workers. The success rate of the placement was not significantly different between ELSTs and rescue workers whether or not they wore rescue or plastic gloves. Conclusions: Although the finite usefulness of IOI with BIG under CS conditions is indicated, some problems such as the timing of removal of the IOI and difficulty in finding the location of the trocar needle after activating BIG are pointed out. Therefore, there are rooms to consider using IOI with BIG under CS condition. (Hong Kong j.emerg. med. 2014;21:23-30) 簡介：在密閉空間（ CS ）的條件下，有一條靜脈輸液管路作為緊急治療患有擠壓綜合徵或出血的患 者，在災難醫學是很重要的。然而，在這樣的環境，應急救生技術人員（ ELSTs ）要建立靜脈管路並 不容易。儘管以前的研究已經描述了穿化學防護裝備使用機械骨內（ IO ）設備和 IO 輸液，但在 CS 條 件下使用 IO 設備的問題還沒有得到考慮。本研究旨在探討在 CS 條件下， ELSTs 和救援人員使用骨注射 槍 TM （ BIG ）作 IO 輸注的效用和問題。方法：量度在 CS 條件下， ELSTs 或救援人員穿上救援手套或 塑料手套，在假人腿用 BIG 作骨內輸液（ IOI ），所需的時間和成功率。結果：與救援人員相比，戴 救援手套的 ELSTs 顯著更快地把 IOI 放置好。不論他們是穿著救援或塑料手套， ELSTs 和救援人員之間 放置的成功率並無任何顯著不同。結論：儘管在 CS 的條件下使用 BIG 作 IOI 有一定的效用，但也有一

We present a rare case of a 47-year-old man who developed pneumomediastinum and subcutaneous emphysema after a high pressure hose accidentally injected air and sand particles into his right upper arm. On presentation, he complained of dyspnoea and chest pain. He had palpable subcutaneous emphysema extending from the upper arm to his neck, face, and trunk. Plain X-ray films and computed tomography showed pneumomediastinum and subcutaneous emphysema, but no sand particles. Conservative treatment was done with close observation, and serial radiographs were obtained. There was complete resolution of the mediastinal and subcutaneous air after about two weeks with no evidence of infection. This was an extremely rare case of pneumomediastinum and severe subcutaneous emphysema occurring after accidental air injection injury to the upper arm. With regard to how air entered the mediastinal cavity, possible pathways are discussed. (Hong Kong j.emerg.med. 2014;21:51-54)