高原缺氧复合光气中毒动物模型的建立

目的 探索高原缺氧复合光气中毒动物模型的制作方法。方法 将24只新西兰大白兔随机分为4组,每组6只,正常对照组、高原低压缺氧组（在模拟高原低压舱内2h）、光气中毒组（将动物放入动式染毒柜内3 min）、高原复合光气中毒模型组（将动物放人动式染毒柜内,固定染毒3 min后放入模拟高原低压舱内2h）,在动物出舱后即刻及1、3h时观察动物呼吸频率及口唇颜色,并在不同时间点抽血,测定动脉血气,3h后颈动脉放血处死动物,开胸取肺,测定肺水含量、肺系数。结果 动物光气中毒后逐渐出现呼吸频率加快、口唇发绀,并随着时间的推移呈渐进性发展,高原复合光气中毒模型组动物光气中毒后进入模拟高原低压舱内,呼吸频率进一步加快,发绀更为严重,3个时间点的动脉血氧分压均明显低于高原低压缺氧组和光气中毒组,差异有统计学意义（P＜0.05或P＜0.01）,肺水含量、肺系数均明显增加,差异亦有统计学意义（P＜0.05或P＜0.01）。结论 成功建立了高原缺氧复合光气中毒急性肺损伤动物模型,该模型显示高原低压缺氧复合光气中毒造成中毒症状加重,低氧血症进一步加重,肺损伤程度更加严重,该模型的建立为进一步研究高原环境下光气中毒的分子学机制及其救治奠定了基础,具有一定的理论和实践意义。     

高原急性低氧对大鼠食欲及食欲肽mRNA表达的影响

目的:探讨模拟不同海拔高度急性高原低氧对大鼠的食欲及其下丘脑食欲肽表达的影响.方法:利用低压舱模拟海拔高度为3 000、4 000、5 000和6 000 m;各海拔高度缺氧时间包括1、3和7天,每天缺氧时间为8 h.并根据不同海拔高度和时间将动物随机分组.观察大鼠在低氧环境下食欲及其体重增长的变化;应用RT-PCR法研究大鼠下丘脑食欲肽的表达.结果:与对照组比较,随着低氧时间的延长和海拔高度的升高,动物每天总的摄食量逐渐降低;间断性低氧7天后,各海拔高度组大鼠体重增加与对照组比较有显著性差异(P＜0.05);随着海拔高度的升高和低氧时间的延长,食欲肽A和B的mRNA表达均减弱.结论:高原急性低氧对大鼠的食欲有抑制作用,同时其下丘脑组织中食欲肽的表达降低.     

腹式呼吸放松训练缓解高原缺氧环境心血管应激反应的效应观察

目的观察腹式呼吸放松训练缓解高原缺氧环境心血管应激反应的效应,为制定部队官兵急进高原的卫生保障技术方案提供试验依据。方法模拟3 700 m及4 100 m高原环境,在模拟高原环境下由专业医师指导20名青年志愿者分别进行腹式呼吸放松训练法5～10 min。使用腹式呼吸放松法前后应用PHILIPS指夹式脉搏血氧仪(DB12型)测量受试者血氧饱和度与心率。在海拔3 700 m随机抽取武警某部急进高原的27名武警部队新兵,从受试者第1天进驻高原环境开始,在专业医师指导下每天定时进行腹式呼吸放松法训练,连续2 d每天应用脉氧仪测量受试者使用腹式呼吸放松法前后的血氧饱和度与心率。数据统计采用重复测量的方差分析。结果不同模拟海拔高度(3 700 m及4 100 m)对于心率的改变有显著主效应(F=10.553,P=0.004),对于血氧饱和度未见明显差异。低氧舱试验中腹式呼吸放松法对于心率、血氧饱和度的改变有显著主效应(F=10.187,5.583,P 0.05)。海拔3 700 m高原实场环境中,腹式呼吸放松法对于心率、血氧饱和度的改变有显著主效应(F=363.138,122.197,P 0.05)。结论腹式呼吸放松训练可以有效地缓解高原缺氧环境的心血管应激反应,有利于促进高原习服,值得进一步在部队推广应用。     

大型复合低压舱模拟海拔高度稳定性和准确性验证研究

目的：验证大型复合低压舱模拟海拔高度的稳定性和准确性。方法：（1）验证稳定性：将153名健康人员分为15组,每次进入舱内一组。使用指式脉冲便携式血氧饱和度检测仪分别在9个不同海拔高度上记录个人的血氧饱和度值,对同一海拔高度的15组数据进行单因素方差分析。（2）验证准确性：实验组、文献对照组Ⅰ、文献对照组Ⅱ、文献对照组Ⅲ中,每组包含6个海拔高度的血氧饱和度值。对4个组分别作回归分析,应用回归方程计算出每组对应海拔高度缺失的理论血氧饱和度值,在此基础上作组间的相关分析。结果：（1）在舱内每一模拟高度上,15组健康人员的血氧饱和度值的组间差异不显著（P〉0.05）,表明该舱在模拟这9个海拔高度时运行稳定;（2）实验组与文献对照组Ⅰ、文献对照组Ⅱ、文献对照组Ⅲ在不同海拔高度血氧饱和度值的相似度分别为0.991、0.990、0.999,说明该舱模拟不同海拔高度时健康人员的血氧饱和度值与在自然环境中的相同海拔高度时是相似的,表明大型复合低压舱模拟的海拔高度是准确的。结论：在模拟高原海拔高度时,大型复合低压舱运行稳定,能够准确模拟自然海拔高度,表明该舱能够满足在基础研究、医学诊断和治疗及高原生理学、高原运动训练和高原设备试验中重复性好、误差小的要求。     

常压低氧环境中呼吸道水蒸气压对模拟高度影响的分析

阐述了呼吸道水蒸气压对常压低氧方法所模拟的海拔高度的影响,分析了在同样环境的氧分压条件下,由于呼吸道水蒸气压的影响,常压低氧模拟的海拔和高原海拔之间的差异,发现二者的差异量和高原海拔值是正相关的。为了真实地模拟高原低氧环境．常压低氧环境氧分压要低于相应的高原环境值。     

机械通气两种BIPAP的比较

本文介绍了机械通气当中有创BIPAP和无创BIPAP原理及临床应用的不同。为临床治疗时选取合适的呼吸模式提供参考。     

慢性缺氧对人体血清瘦素和激素水平的影响

目的　探讨高原慢性缺氧对人体瘦素及与能量代谢相关激素水平的影响。方法　分别测定久居3个海拔高度(<30 0 0m、30 0 0m～、4 0 0 0m～)的正常成年人血清瘦素(Leptin)、胰岛素、生长激素水平。采用酶联免疫法(ELISA)进行测定。结果　久居不同海拔高度的人群体内瘦素水平差异无统计学意义(P >0 . 0 5 )。而胰岛素、生长激素水平差异有统计学意义,但男女有差别,男性胰岛素水平(P <0 . 0 1)、女性生长激素水平(P <0 . 0 5 )在不同海拔高度组差异有统计学意义。并且随海拔高度的增加,瘦素、胰岛素、生长激素水平男女均呈现低高低的变化规律。结论　高原慢性缺氧对人体瘦素水平影响不大,但对其他与能量代谢相关激素有一定影响,与缺氧程度可能无关。     

高原地区老年患者呼吸系统疾病护理

由于高原地区空气稀薄,氧分压降低,肺泡内氧分也降低,直接影响肺泡气体交换、血液载氧和氧合血红蛋白在组织内的释放速度造成供氧不足,产生缺氧。轻度缺氧时,仅表现为呼吸深度增加;缺氧继续加重,则呼吸频率随之加快;严重缺氧时,呼吸深度和频率同时加重,节律改变出现肺通气量增加,摄氧量下降,所以高原地区是慢性呼吸系统疾病多发区,老年患者病程长,合并症多,护理不当,极易导致呼衰、心衰加重,影响预后。     

典型的缺氧病征——高山病

氧（O2）在大气中以游离状态存在于地球表面20千米范围内，海拔越高，氧分压越低。资料表明，当空气中氧分压低于129mmHg时，人体就会出现缺氧症状。海拔高度在3000米以上的高原地区，其特点是大气压低，氧分压也相对降低。所以，人们初上高原（或高山）时，由于人体肺泡气体交换及血液溶解氧和结合氧在组织内释放功能障碍，供氧、耗氧失调，而导致细胞缺氧。     

高原对工人生理指标的影响分析

目的测量不同海拔高度在静息状态和运动状态下的生理指标,评价高原对工人生理指标的影响。方法在3个海拔高度测量5个青年男性工人在静息和运动状态及运动恢复过程中的肺通气量、心率、血氧饱和度(SaO_2)等生理指标,用配伍设计的方差分析法分析海拔对各生理指标的影响及运动后恢复情况。结果静息状态,随着海拔的升高,单位体表面积肺通气量和单项动作能量代谢率逐渐下降,但差异没有统计学意义;不同海拔环境的心率和SaO_2差异有统计学意义(P0.05),平原低于高原。运动状态,肺通气量、单位体表面积肺通气量、单项动作能量代谢率和SaO_2在不同海拔之间差异有显著性。不同海拔的SaO_2恢复差异有统计学意义(P0.05):500 m平原,在第3分钟仍下降,至第5分钟恢复;3500 m高原,第3分钟即大幅升高,持续至第5分钟;4 200 m在第3分钟继续下降,至第5分钟恢复并升高,但幅度小于3500 m。HR的变化不受海拔高度变化的影响,在不同海拔高度均表现为运动后快速上升,随后恢复,至3分钟时基本恢复至正常。结论高原对工人的生理指标有明显影响,且静息状态和运动状态是不一致的。运动后,心率恢复较快,基本不受海拔高度影响;SaO_2先下降再恢复并超过运动前,但海拔不同恢复过程不同。     

增氧呼吸器在不同海拔高度下对血氧饱和度和心率的影响

目的：探讨增氧呼吸器在高原不同海拔环境下对机体血氧饱和度和心率的影响;方法：140名受试者分别在高原（海拔3 700,3 750,3 950,4 700,4 900,5 300m）进行运动负荷实验,首先检测静息状态下不使用仪器的血氧饱和度（blood oxygen saturation,SaO2）和心率.而后进行运动负荷实验（不佩戴增氧呼吸器）,检测数据,并检测1,2,3min的恢复心率和血氧饱和度.24h后佩戴仪器后,重复以上检测;结果：静息状态下,与不使用单兵高原增氧呼吸器的试验结果相比较,在高原不同海拔环境下使用增氧呼吸器后,SaO2明显增加,心率明显降低,其差异具有统计学意义（P＜0.05）.运动负荷实验结束后,佩戴增氧呼吸器后在3 750,3 950,4 900m的高度下机体SaO2明显升高,差异特别显著（P＜0.01）;结论：增氧呼吸器在高原不同海拔高度下能有效地提高和改善士兵的军事作业能力,而且效果显著,对高原习服有明显的促进作用.     

呼吸机主要性能指标的质量控制技术

目前呼吸机的临床应用越来越广泛，各医院对所购进呼吸机的性能判定通常是依据设备供应商提供的技术指标，医院缺乏自己的检测和判定设备技术性能的方法和设备。采用呼吸机的质量监测技术，提出对潮气量调节范围、分钟最大通气量、输出气体最低氧浓度、呼吸频率范围、呼吸比、最大安全压力等技术参数进行检测的方法和技术性能要求，可以客观评价呼吸机的主要技术指标，保证临床安全、准确地使用呼吸机。     

Respiration in High Flying: (United Services Section)

Atmospheric pressure falls, as height increases, to about one-ninth of its sea-level value at 50,000 feet. The intake of oxygen into the blood depends on the partial pressure of oxygen in the inspired air, which is about one-fifth of the atmospheric pressure. But since the gaseous content of the lungs is saturated with water vapour at body temperature, 47 mm. Hg. of the atmospheric pressure in the lungs is due to water vapour and is therefore not available for oxygen or other gases, while the alveolar air contains also an almost constant pressure of 40 mm. CO₂.Mental and physical output demand an adequate partial pressure of O₂; they begin to be limited as soon as this falls, and at heights above 18,000 feet are seriously reduced. Consequently in order to fly higher than about 15,000 feet it is necessary to increase the partial pressure of oxygen in the inspired air. Up to about 44,000 feet this can be done by merely raising the percentage of oxygen, usually by allowing a regulated stream of oxygen to enter a small naso-buccal mask, but preferably by a closed system in which the negative pressure of inspiration opens a valve and allows oxygen to enter a bag from which it is inspired.Beyond 44,000 feet as a limit (and a lesser height for safety) it is necessary to create a local atmospheric pressure around the pilot higher than that of the surrounding air, by enclosing him in an airtight sit or cabin in which a relatively increased pressure with a maximum value of about 2½ lb. per square inch is maintained, while he breathes pure oxygen. This device was used in the recent British world record high flight, when a height of 50,000 feet was attained. The pressure-suit used by the pilot on this occasion and the decompression chamber recently built at Farnborough are described in detail.     

Noninvasive, quantitative respirator fit testing through dynamic pressure measurement

A new method has been invented for the noninvasive and quantitative determination of fit for a respirator. The test takes a few seconds and requires less expensive instrumentation than presently used for invasive testing. In this test, the breath is held at a negative pressure for a few seconds, and the leak-induced pressure decay inside the respirator cavity is monitored. A dynamic pressure sensor is attached to a modified cartridge of an air-purifying respirator or built into the respirator body or into the air supply line of an air-supplied respirator. The method is noninvasive in that the modified cartridge can be mounted onto any air-purifying respirator. The pressure decay during testing quantifies the airflow entered through the leak site. An equation has been determined which gives the air leakage as a function of pressure decay slope, respirator volume and the pressure differential during actual wear--all of which are determined by the dynamic pressure sensor. Thus, the ratio of air inhaled through the filters or via the air supply line to the leak rate is a measure of respirator fit, independent of aerosol deposition in the lung and aerosol distribution in the respirator cavity as found for quantitative fit testing with aerosols. The new method is shown to be independent of leak and sensor locations. The concentration and distribution of aerosols entered through the leak site is dependent only on the physical dimensions of the leak site and the air velocity in it, which can be determined independently.(ABSTRACT TRUNCATED AT 250 WORDS)     

一种新型常压低氧舱的研制

目的：研制一种常压低氧舱,用于低氧试验及入驻高原前的低氧预习服训练.方法：以制氮机为氮源,采用高浓度氮气稀释舱（室）内空气的办法,使舱内空气中的氧浓度从原来的20.9％左右稀释到所需的低氧浓度,创新性地变舱体漏气缺点为优点,建立舱体气体交换模型控制舱内的CO2浓度和维持舱内的O2浓度.结果：设计了大小为5 m×3 m×2.3 m的舱体,模拟海拔高度范围可达0～8 000 m,误差为±25 m.该舱体可满足10人同时进行低氧试验,也可满足4人在低氧状况下进行睡眠试验.舱内CO2体积分数可控制在3000×10-6以内.结论：该舱体设计安全、方便,有望在以后的高原低氧试验中发挥重要的作用.     

高原病的发病机制及防治研究进展

海拔在3 000 m以上的地区,称为高原地区.其特点为气压和氧分压均低,易导致人体缺氧.如未能习服,可引起高原病.高原病的发病机制主要由于高原低氧血能导致脑和肺微循环的过分充盈,而发生高原脑水肿和高原肺水肿.治疗主要是尽速转移至低地或用轻便加压舱以及采用药物(乙酰唑胺和地塞米松),充分给氧.预防采用逐渐登高习服、锻炼、多食碳水化合物,给予高量抗氧化营养素或食用中等量抗氧化物质,如维生素C、E、硒等.     

高原车辆驾驶员医用车载PSA制氧系统的研制

根据青藏高原高海拔、低气压环境特点，针对高原车辆勤务保障的工作实际，自主开发研制了青藏线车辆驾驶员“医用车载变压吸附分体式制氧系统”。该系统通过了高原人工（低气压）环境性能模拟试验和青藏线5个不同海拔高度典型自然环境条件下实际装车试验，各项性能指标均符合国家医用氧标准。     

High altitude dives from 7000 to 14,200 feet in the Himalayas

Indian Navy divers carried out no-decompression dives at altitudes of 7000 to 14,200 ft (2134-4328 m) in the Nilgiris and Himalayas from May to July 1988. Seventy-eight dives on air and 22 dives on oxygen were carried out at various altitudes. The final dives were at Lake Pangong Tso (4328 m) in Ladakh, Himalayas, to a maximum of 140 feet of sea water (fsw) [42.6 meters of sea water (msw)] equivalent ocean depth in minimum water temperature of 2 degrees C. Oxygen diving at 14,200 ft (4328 m) was not successful. Aspects considered were altitude adaptation, diminished air pressure diving, hypothermia, and remote area survival. Depths at altitude were converted to depths at sea level and were applied to the Royal Navy air tables. Altitude-related manifestations, hypoxia, hypothermia, suspected oxygen toxicity, and equipment failure were observed. It is concluded that stress is due to effects of altitude and cold on man and equipment, as well as changes in diving procedures when diving at high altitudes. Equivalent air depths when applied to Royal Navy tables could be considered a safe method for diving at altitudes.     

Breathing simulator of workers for respirator performance test

Breathing machines are widely used to evaluate respirator performance but they are capable of generating only limited air flow patterns, such as, sine, triangular and square waves. In order to evaluate the respirator performance in practical use, it is desirable to test the respirator using the actual breathing patterns of wearers. However, it has been a difficult task for a breathing machine to generate such complicated flow patterns, since the human respiratory volume changes depending on the human activities and workload. In this study, we have developed an electromechanical breathing simulator and a respiration sampling device to record and reproduce worker’s respiration. It is capable of generating various flow patterns by inputting breathing pattern signals recorded by a computer, as well as the fixed air flow patterns. The device is equipped with a self-control program to compensate the difference in inhalation and exhalation volume and the measurement errors on the breathing flow rate. The system was successfully applied to record the breathing patterns of workers engaging in welding and reproduced the breathing patterns.