高原供氧研究进展

氧气是人类赖以生存的物质,高原低氧影响人们的生命活动,严重者可引发高原病甚至死亡,随着海拔升高,空气愈加稀薄,这种影响愈趋明显,为此,人们以增加氧气供给的方法来缓解这种困境。本文综述了近年来国内外学者在高原供氧方面的实验研究,列举几种吸氧方法的比较;缺氧条件下的吸氧反应;富氧室和液态氧在高原的应用;高压氧和压缩空气供氧;化学制氧;制氧机供氧;以及海拔5000m以上的氧疗等。     

小型医用制氧机高原性能定量评价方法

在工作中时常遇见同一类产品不同品牌的质量比较 ,如何达到公正定量评价是一大难题。为此 ,我们应用统计学和名次累加方法 ,对 5种小型医用制氧机高原性能进行了公正定量评价 ,综合评出了制氧机高原性能的名次 ,为上级机关产品招标工作提供了产品质量定量评价依据。这里主要论述评价方法。一、材料与方法上级机关组成四个实验小组 ,选择5种制氧机进行其高原性能实验 ,确定其制氧机在 40 0 0 m± 10 0 0 m的高原恶劣环境下能否稳定正常工作。目的是 :在实际高度和环境下测试制氧机高原性能 ,根据实验数据对 5种制氧机进行客观分析评价 ,综合…     

运动员的仿高原训练

该文提出,用人工降低环境的大气压和吸入气中氧浓度的办法进行仿高原训练,能有效地提高运动员的耐力与速度,减少体力消耗,提高运动员的耐缺氧能力。但便携式器材有一定呼吸阻力,CO_2的滤除性能尚不够满意。     

高原救生固体化学氧气发生器的研制

目的 研制可用于高原环境、便于携带和使用的固体化学氧气发生器（简称固氧）,供氧量为120 L,供氧流量＞1.5 L/min,供氧时间30 min,使用环境温度为-40～50℃. 方法 根据氯酸盐燃烧分解产氧原理设计高原救生固氧的结构,设计4种不同配方的固氧药柱.配方1：91％产氧剂＋3％金属粉＋2％催化剂＋4％抑氯剂;配方2：91％产氧剂＋5％金属粉＋4％抑氯剂;配方3：前部91％产氧剂＋5％金属粉＋4％抑氯剂,后部91.5％产氧剂＋4.5％金属粉＋4％抑氯剂;配方4：前部88％产氧剂＋5％金属粉＋4％抑氯剂＋3％稳定剂,后部88.5％产氧剂＋4.5％金属粉＋4％抑氯剂＋3％稳定剂.在高、低、常温3种不同状态下对4种配方的供氧时间、流量等性能进行测试,并对固氧所产氧气质量进行净化研究.选取2名健康志愿者作为高原环境实际应用试验对象,观察其在不同高度使用固氧后血氧饱和度的变化. 结果 配方3和配方4的产氧性能均能满足指标要求,配方4供氧性能更稳定,温度敏感系数更低.固氧所产气体成分均能满足标准和规范.2名受试者在4 939m高原使用固氧产品后血氧饱和度均达到了90％以上. 结论-40～50℃环境条件下能正常工作30 min的固氧,可满足高原救生供氧使用要求.降低催化剂含量,提高金属粉用量,药柱中加入稳定剂有助于稳定固氧的产氧速度.1支30 min固氧可同时满足2人吸氧并保证吸氧效果,达到了高原缺氧防护的目的.     

两种不同方式供氧对新入高原某部官兵血气的影响

目的：观察医用氧气瓶和高原移动式制氧站两种不同方式供氧对新入高原官兵血气的影响。方法按随机抽取原则将40名新入高原1周内的官兵分为A组（医用氧气瓶供氧,氧浓度≧99.5%）和B组（制氧站供氧,氧浓度≧90%）,每组20人,各吸氧40min。在吸氧前和吸氧后30min内抽取动脉血进行血气分析比较。结果（1）A、B两组人员在吸氧前血气指标不具有统计学差异（P＞0.05）,吸氧后两组人员的氧分压（PO2）和氧饱和度（SO2%）均高于吸氧前（P＜0.05）。（2）A、B两组人员吸氧后血气差异无统计学意义（P＞0.05）。结论高原移动式制氧站和医用氧气瓶供氧一样,都能明显提高新入高原人员的氧分压和氧饱和度,提高部队战斗力。     

安静和运动条件下富氧气体排氮效果的观察

目的探讨人体呼吸不同富氧气体的排氮规律,为促进吸氧排氮效果提供依据。方法7名男性青年采用自身对照,在静坐和运动状态下呼吸60％至纯氧的氧氮混合气。采用开放式排氮测量方法,用氧浓度计测量储气袋中氧气浓度,同步实时测量肺通气量和心输出量,功率脚踏车提供40w运动负荷。结果呼吸60％、70％、80％和90％富氧气体的排氮效果分别相当于呼吸纯氧排氮效果的59．31％、72．81％、76．45％和84．18％。运动对呼吸不同富氧气体排氮作用的影响不同。40w的运动负荷能使呼吸60％、70％富氧气体的排氮作用分别增加45％和12％;但呼吸80％和90％富氧气体时排氮作用增加的很少。结论体力活动所致的呼吸和循环功能增加能促进吸氧排氮的作用,吸氧浓度越低时,运动促进排氮的作用越明显。     

高原护唇膏预防高原性唇炎的疗效分析

目的观察高原护唇膏预防高原高发唇炎的临床效果。方法在西藏不同海拔驻军中采用随机、平行对照试验方法,设立受试药物组和空白对照组,观察两组在试验期内唇炎的发生率和不良反应发生率。结果经统计处理,试验组与对照组各366例,人口基线无显著性差异,试验组与对照组的唇炎发生率分别为0.27%和51.37%,有显著性差异,使用高原护唇膏的保护率为99%;试验期间未发生不良反应。结论高原护唇膏预防高原唇炎效果确切,安全性好,是值得推广而行之有效的预防高原性唇炎的方法。     

标准与简易便携式CO_2培养箱对牛体细胞核移植重构胚的体外发育能力影响的比较(英文)

尽管利用克隆技术来扩大优良品种家畜的数量 ,以及生产以农业和生物医学为目的的转基因动物和拯救濒危动物品种的需求不断增加 ,克隆技术对于大规模应用仍然成功率太低 ,而且成本昂贵。为了探索培养因素对改进克隆效率的作用 ,我们比较了标准与简易便携式CO2 培养箱对通过融合胎儿成纤维细胞核与去核的体外成熟卵母细胞生产的牛重构胚。在这两种培养系统中 ,温度 ( 38.5℃ )和CO2 浓度( 5% )相同 ,便携式培养箱的CO2 浓度较低 ( 8%到 1 0 % ) ,该培养系统同时在负压影响下进行了操作。虽然两种培养系统对卵母细胞体外成熟 (MII)、融合率和第 7d发育囊胚的细胞数无显著差异 ,但便携式培养箱的卵裂率 (P <0 .0 5)和囊胚率 (P <0 .0 1 ) ( 70 .5%±0 .6 %和 36 .1 %± 1 .4% )显著高于标准培养箱 ( 6 4.1 %± 3.2 %和 2 3.5%± 1 .4% )。将 6枚在便携式培养箱培养的重构胚移入 3只受体牛 ,在 6 0、90和 1 2 0d的存活率分别为 1 0 0 %、6 6 .7%和 33.3%。这种相对较高的早期胚胎死亡可能与多因素影响怀孕的复杂性和在克隆胚上经常观察到的胎盘形成异常有关。使用便携式培养系统还需对CO2 、O2 和气压的最佳水平进行深入研究     

袖珍呼吸机的研制与应用

为解决麻醉师在抢救插管后手捏皮球辅助呼吸的麻烦,笔者分析国内外各型急救呼吸机的特点,研制成便携袖珍式气控呼吸机,经临床应用,效果满意。1　结构与组成机壳由不锈钢模具成形为13cm×6cm×4cm;机芯65mm×60mm×40mm,由气道压力表、气控低压报警器、呼吸活瓣及管道等组成。参照气动呼吸机-中华人民共和国专业标准和人用麻醉机-国际标准制作。循环发生器设定自动、间断、定时、放氧气,并可受潮气量调节控制,氧气通过呼吸活瓣可混合空气,吸氧浓度45%～100%,可调。附图　便携式袖珍呼吸机2　使用方法把快速插头插入任何房间有中心供氧插座的…     

高原富氧室供氧方法研究

目的 研究高原富氧室的供氧方法,为指导富氧室的建设和合理使用提供依据. 方法 根据飞行员宿舍和体能训练室氧气浓度变化规律,建立富氧室数学模型,并通过试验进行验证.8名志愿者乘飞机进入高原(海拔3780m),按数字表法将其分为供氧组和对照组,每组各4人.供氧组晚上22:00至次日8:00在富氧室休息(氧气浓度为24％～27％,连续供氧8 d),对照组22:00至次日22:00在普通宿舍休息(不供氧);观察2组志愿者晨起心率和血氧饱和度差异. 结果 飞行员宿舍和体能训练室内实际测量的氧气浓度与数学模型计算结果呈正相关(r=0.986、0.998,P=0.000).供氧组晨起心率与对照组比较显著降低(F=13.067,P=0.011);供氧组晨起血氧饱和度与对照组比较显著升高(F=102.885,P=0.000). 结论 建立O2浓度随时间变化的数学模型可指导高原富氧室建设.飞行员宿舍和体能训练室应采用不同的供氧方式.维持宿舍供氧生理等效高度3000 m以下.     

Soccer specific aerobic endurance training

BACKGROUND: In professional soccer, a significant amount of training time is used to improve players' aerobic capacity. However, it is not known whether soccer specific training fulfils the criterion of effective endurance training to improve maximal oxygen uptake, namely an exercise intensity of 90-95% of maximal heart rate in periods of three to eight minutes. OBJECTIVE: To determine whether ball dribbling and small group play are appropriate activities for interval training, and whether heart rate in soccer specific training is a valid measure of actual work intensity. METHODS: Six well trained first division soccer players took part in the study. To test whether soccer specific training was effective interval training, players ran in a specially designed dribbling track, as well as participating in small group play (five a side). Laboratory tests were carried out to establish the relation between heart rate and oxygen uptake while running on a treadmill. Corresponding measurements were made on the soccer field using a portable system for measuring oxygen uptake. RESULTS: Exercise intensity during small group play was 91.3% of maximal heart rate or 84.5% of maximal oxygen uptake. Corresponding values using a dribbling track were 93.5% and 91.7%. No higher heart rate was observed during soccer training. CONCLUSIONS: Soccer specific exercise using ball dribbling or small group play may be performed as aerobic interval training. Heart rate monitoring during soccer specific exercise is a valid indicator of actual exercise intensity.     

Description of the oxygen concentration delivered using different combinations of oxygen reservoir volumes and supplemental oxygen flow rates with the Ohmeda Universal Portable Anesthesia Complete draw-over vaporizer system

The Ohmeda Universal Portable Anesthesia Complete system is used in austere conditions where oxygen resources are limited and must be conserved. The purpose of this study was to describe the concentration of oxygen delivered with different combinations of seven oxygen reservoir volumes and four oxygen flow rates. The Medical Education Technologies Incorporated Human Patient Simulator reproduced human physiological tidal volumes of four simulated patients of different weights based upon a typical soldier's weight. Using least squares multiple nonlinear regression, a formula for the curves of the oxygen concentrations was developed. The analysis, across the different patient weights, showed no appreciable increase in oxygen concentration beyond a reservoir volume of 260 mL. Our findings suggest the current standard universal portable anesthesia complete reservoir may not provide optimal oxygen delivery, therefore, we recommend the current reservoir volume be increased from 130 to 260 mL.     

VO2 slow component correlates with vastus lateralis de-oxygenation and blood lactate accumulation during running.

BACKGROUND: In the present study, vastus lateralis de-oxygenation was monitored contemporarily with VO2 changes along a severe constant intensity running exercise, after the 3rd min up to volitional exhaustion. Blood lactate accumulation was also measured before, during and after running. METHODS: Eleven male amateur soccer players volunteered for the study. Subjects mean age, height, and body weight were 22.9+/-2 yrs, 177.5+/-6.2 cm, 71.7+/-4 kg, respectively. Measurements were carried out during running on a treadmill. Ventilatory and gas exchange parameters were measured at the mouth on a breath-by-breath basis. For blood lactate concentration accumulation measurement, capillary blood samples were taken from the fingertip. The oxygenation of the vastus lateralis muscle were measured by a continuous wave NIRS portable instrument. By means of two pretests the onset of [La]b accumulation and its associated velocity (vOBLA), and the peak of oxygen uptake and its associated velocity (vVO2,peak) were assessed. The test consisted of running on the treadmill up to volitional exhaustion at a constant velocity corresponding to vOBLA plus 50% of the difference between vVO2,peak and vOBLA (v50%Delta). RESULTS: The principal finding of this study was that vastus lateralis de-oxygenation changes measured during running correlate with a) oxygen uptake changes between the 3rd min of exercise and the time corresponding to the subject's volitional exhaustion; b) blood lactate concentration increments measured at the 3rd and the 6th min of exercise and at the time corresponding to the subject's volitional exhaustion. CONCLUSIONS: In conclusion, the results of the present study support our hypothesis that the vastus lateralis de-oxygenation contributes consistently to the VO2 slow component development in running.     

Comparative analysis of the Cosmed Quark b2 and K4b2 gas analysis systems during submaximal exercise

AIM: The purpose of this study was to compare the Cosmed K4b2 portable gas analysis system with the Cosmed Quark b2 metabolic cart. METHODS: Twenty-one subjects attended one testing session that consisted of duplicate measurements of gas volumes and concentrations using both Cosmed gas analysis systems at 3 treadmill work rates; 1) 80m x min(-1), 0% grade, 2) 80m x min(-1), 5% grade, and 3) 80m x min(-1), 10% grade. Subjects walked for 3 min at each rate with one of the gas analysis systems attached to the facemask. The order of the procedures was randomized so that one system was used during both phases (1st or 2nd) of each work rate. RESULTS: The results indicated that oxygen consumption (VO2) was significantly higher in the K4b2 compared to the Quark at 80m x min(-1), 0% grade (14.3+/-1.2 vs 13.6+/-1.2ml x kg(-1) x min(-1), respectively), (p<0.01). The fractional concentration of oxygen in expired air was also significantly lower in the K4b2 at 80 m x min(-1), 0% grade and 80 m x min(-1), 10% grade (p<0.05). There were no significant differences between systems for minute ventilation or carbon dioxide production. Despite the small mean bias in mean VO2 values (0.5-1.0ml x kg-1 x min(-1) higher) in the K4b2, all individual values were within the limits of agreement (mean difference+/-2 SD) as determined by the Bland-Altman technique. CONCLUSION: The findings show a minimal bias in respiratory and metabolic parameters during bi-pedal locomotor activities at low to moderate exercise intensities in the two gas analysis systems.     

Effect of free versus constant pace on performance and oxygen kinetics in running.

PURPOSE: This study tested the hypothesis that free versus constant pace enhanced the performance (i.e., distance run) in suprathreshold runs between 90 and 105% of the velocity associated with the maximal oxygen consumption determined in an incremental test (v.VO(2max)). Moreover, we hypothesized that variable pace could decrease the slow phase of oxygen kinetics by small spontaneous recoveries during the same distance run at an average velocity. METHOD: Eleven long-distance runners performed nine track runs performed until exhaustion. Following an incremental test to determine v.VO(2max), the runners performed, in a random order, four constant-velocity runs at 90, 95, 100, and 105% of v.VO(2max) to determine the time to exhaustion (tlim90, tlim95, tlim100, and tlim105) and the distance limit at 90, 95, 100 and 105% of v.VO(2max) (dlim90, dlim95, dlim100, and dlim105). Finally, they performed the distance limit determined in the constant velocity runs but at variable velocity according to their spontaneous choice. RESULTS: The coefficient of variation of velocity (in percent of the average velocity) was small and not significantly different between the four free pace dlim (4.2 +/- 1.3%, 4.8 +/- 2.4%, 3.6 +/- 1.1%, and 4.6 +/- 1.9% for dlim90, dlim95, dlim100, and dlim105, respectively; P = 0.40). Performances were not improved by a variable pace excepted for the dlim at 105% v.VO(2max) (4.96 +/- 0.6 m.s-1 vs 4.86 +/- 0.5 m.s-1, P = 0.04). Oxygen kinetics and the volume of oxygen consumed were not modified by this (low) variation in velocity. CONCLUSION: These results indicate that for long-distance runners, variable pace modifies neither performance nor the oxygen kinetics in all-out suprathreshold runs.     

Effect of hyperbaric oxygen on the blood: cerebrospinal fluid transfer of tobramycin

The blood:cerebrospinal fluid (CSF) transfer of the aminoglycoside antibiotic, tobramycin (TOB) was assessed in rabbits. The CSF:blood ratio of TOB, 90 min after a subcutaneous injection, was approximately 1:100 as measured by an agar disc diffusion bioassay. Hyperbaric oxygen therapy at a pressure of 3 ATA caused a slight, non-significant, increase in this ratio, while high dose carbon dioxide, a treatment known to damage the blood:brain barrier, more than doubled this ratio. Thus, hyperbaric oxygen has no significant effect on CSF concentration of TOB in rabbits with intact meninges.     

便携式给氧复苏呼吸器的设计

目的：设计一款具有复苏和吸氧双重功能的便携式呼吸器。方法采用正压式、气动气控的设计方案,对关键部件进行了理论计算,利用三维设计软件 Solidedge 进行了虚拟样机的构建、结构的校核,最后对样机进行了加工装配和测试。结果经过实验测试,所研制的呼吸器在3～5．5 bar 气源压力下能实现急救复苏和辅助吸氧功能,给氧流量10～12 L／min,达到预期技术指标。结论便携式给氧复苏呼吸器具有体积小、重量轻、操作简单、便于携带、无需电源等特点,具有广阔的应用前景。     

Very short (15s-15s) interval-training around the critical velocity allows middle-aged runners to maintain VO2 max for 14 minutes

The purpose of this study was to compare the effectiveness of three very short interval training sessions (15-15 s of hard and easier runs) run at an average velocity equal to the critical velocity to elicit VO2 max for more than 10 minutes. We hypothesized that the interval with the smallest amplitude (defined as the ratio between the difference in velocity between the hard and the easy run divided by the average velocity and multiplied by 100) would be the most efficient to elicit VO2 max for the longer time. The subjects were middle-aged runners (52 +/- 5 yr, VO2 max of 52.1 +/- 6 mL x min(-1) x kg(-1), vVO2 max of 15.9 +/- 1.8 km x h(-1), critical velocity of 85.6 +/- 1.2% vVO2 max) who were used to long slow distance-training rather than interval training. They performed three interval-training (IT) sessions on a synthetic track (400 m) whilst breathing through the COSMED K4b2 portable metabolic analyser. These three IT sessions were: A) 90-80% vVO2 max (for hard bouts and active recovery periods, respectively), the amplitude= (90-80/85) 100=11%, B) 100-70% vVO2 max amplitude=35%, and C) 60 x 110% vVO2 max amplitude = 59%. Interval training A and B allowed the athlete to spend twice the time at VO2 max (14 min vs. 7 min) compared to interval training C. Moreover, at the end of interval training A and B the runners had a lower blood lactate than after the procedure C (9 vs. 11 mmol x l(-1)). In conclusion, short interval-training of 15s-15s at 90-80 and 100-70% of vVO2 max proved to be the most efficient in stimulating the oxygen consumption to its highest level in healthy middle-aged long-distance runners used to doing only long slow distance-training.     

Soccer specific testing of maximal oxygen uptake

AIM: Endurance capacity in soccer players is important. A soccer specific test for direct measurement of maximal oxygen uptake does, however, not exist. The aim of this study was to evaluate maximal oxygen uptake in a soccer specific field test, compared to treadmill running. METHODS: Ten male soccer players (age 21.9+/-3.0 years, body mass 73.3+/-9.5 kg, height 179.9+/-4.7 cm) participated in the study, and 5 endurance trained men (age 24.9+/-1.8 years, body mass 81.5+/-3.7 kg, height 185.6+/-3.1 cm) took part in a comparison of the portable and the stationary metabolic test systems. The soccer players accomplished a treadmill test and a soccer specific field test containing dribbling, repetitive jumping, accelerations, decelerations, turning and backwards running. RESULTS: Maximal oxygen uptake was similar in field (5.0+/-0.5 L x min(-1)) and laboratory (5.1+/-0.7 L x min(-1)) tests, as were maximal heart rate, maximal breathing frequency, respiratory exchange ratio and oxygen pulse. Maximal ventilation was 5.4% higher at maximal oxygen uptake during treadmill running. CONCLUSION: These findings show that testing of maximal oxygen uptake during soccer specific testing gives similar results as during treadmill running, and therefore serves as a valid test of maximal oxygen uptake in soccer players.