海拔3680m人体体力活动时氧耗量及血氧饱和度的观察

目的观察海拔3680m人体体力活动时氧耗量([AKV*O2)和氧脉搏(O2/HR)及血氧饱和度(SaO2)的变化.方法受试者坐于踏车功率计上,以60rpm连续蹬车,每3min递增25W,蹬车至极量点时停止,记录每个量极负荷最后5s的心率(HR),测定每个量极负荷最后半分钟的O2和CO2含量及SaO2,计算O2和O2/HR.结果HR在100～170*min-1时,O2随HR的增加而呈线性增加(=106.4208-0.1928x,γ=0.9936,P＜0.01);HR为100～130*min-1时,O2/HR也随HR的增加而增加;HR增加到140～170*min-1时,O2/HR不但不增加反而减少,SaO2亦随HR的增加而减少.结论高原低氧环境增加了人体生理负荷,致使人体在高原的劳动能力下降.     

一名热气球飞行员在不同海拔高度飞行前后心率和血氧饱和度的观察

目的：观察一例首次高原热气球飞行从不同海拔高度（2260m、3300m、4200m、4850m）起飞前和起飞后（限定高度1000m）飞行员心率（HR）和血氧饱和度（SaO2）的变化。方法：观察对比选用不同海拔高度起飞,飞行员起飞前后每分钟心跳次数以及用便携式血氧饱和度监测仪记录起飞前后血氧饱和度的变化。结果：在海拔2260m处起飞前后HR和SaO2分别为（80．04±14．2）次／min,（90．1±5．2）％;（85．03±1．04）次／min,（88．02±4．3）％。在海拔3300m处起飞前后HR和SaO2分别为（84．02±9．02）次／min,（87．08±4．1）％;（95．04±10．8）次／min,（86．02±5．4）％。在海拔4200m处起飞前后HR和SaO2分别为（87．04±13．67）次／min,（85．02±4．7）％;（110．08±19．01）次／min,（80．04±6．06）％。在海拔4850m处起飞前后HR和SaO2分别为（90．5±10．05）次／min,（80．0±4．0）％;（151．0±9．0）次／min,（75．0±3．0）％。结论：高原低氧环境增加了人体生理负荷,致使人体在高原的劳动能力下降。     

单兵高原增氧呼吸器在高原地区增氧效果的评价

目的:探讨单兵高原增氧呼吸器在高原现场的增氧效果。方法:5名从海拔3 700 m到5 380 m往返途中和10名在海拔5 380 m高原的受试者,佩戴单兵高原增氧呼吸器进行踏阶负荷运动试验,分别检测血氧饱和度(SaO2)、心率(HR)及台阶指数。结果:在往返海拔5 380m途中,5名在7处的不同海拔高度佩戴与不佩戴单兵高原增氧呼吸器时,SaO2分别为(82.17±8.93)%和(77.17±11.41)%,有显著性差异(P<0.05);HR分别为(86.74±17.33)次/min、(90.25±20.46)次/min,无统计学意义(P>0.05)。在海拔5 380m高原,佩戴与不佩戴单兵高原增氧呼吸器时,踏阶运动台阶指数分别为(53.83±6.10)和(49.28±3.01),有显著性差异(P<0.05)。结论:单兵高原增氧呼吸器能有效地促进高原习服过程,提高和改善低氧条件下人体的劳动能力。     

富氧室在高原对人体PWC170时心率及血氧饱和度的影响

目的 :探讨在高原建立富氧室对人体PWC1 70时心率及血氧饱和度的影响 ,为提高高原作功效率探讨有效途径 ;方法 :1 0名受试者在进入富氧室前、后分别坐于踏车功量机上 ,以 60rpm连续蹬车 ,0W为静息时对照值 ,从 2 5W开始 ,每 3分钟递增 2 5W ,蹬车至力竭时停止 ,用心电图机及掌式血氧仪记录每个负荷末期 5秒的心率 (HR)及血氧饱和度(SaO2 ) ;结果 :HR的富氧室后较富氧前 3分钟及 5分钟恢复速度明显加快 ,差别有显著性(P <0 .0 5) ;血氧饱和度的 0W至 1 2 5W升高 ,差别有显著性 (P <0 .0 5) ;血氧饱和度在1 75W至 2 2 5W时明显升高 ,差别有非常显著性 (P <0 .0 0 1 ) ;结论 :高原富氧室能增强心脏功能和肺功能及提高动脉SaO2 ,是一种有效的高原供氧途径     

高原条件下使用增氧呼吸器对血氧饱和度和心率的影响

目的 探讨高原低氧条件下增氧呼吸器对人体血氧饱和度和心率的影响。方法 9名被试者初到高原（海拔3700m）2h后，进行4次试验，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。然后使用仪器，重复检测。其次进行负荷运动，检测数据。恢复1h后。使用呼吸器进行负荷运动，重复检测。结果 静息状态下，与不使用增氧呼吸器试验结果相比较，使用增氧呼吸器后机体SaO2明显增加（P〈0．05），心率明显降低（P〈0．05）。运动负荷中，与不使用增氧呼吸器试验结果相比较，使用增氧呼吸器后SaO2值明显增加（P〈0．05），心率的变化则不显著（P〉0．05）。运动负荷实验结束后，恢复期3min及5min心率恢复速度使用仪器后明显加快（P〈0．05）。结论 增氧呼吸器能改善低氧务件下人体的劳动能力，促进高原习服。     

富氧室在海拔3700m对人体体力活动时氧耗量的影响

目的观察在海拔3700m建立富氧室对人体体力活动时氧耗量的影响。方法:10名受试者在进入富氧室前后分别观察氧耗量(VO2)及氧脉搏(VO2/HR)。结果:心率在100b-170b/min时,富氧室随HR增加而呈线性增加[分别为Y=(0.0165+0.0073)x,r=0.9877,P<0.001;Y=(-0.1629+0.0087)x,r=0.9902,P<0.001]。结论:富氧室在高原能提高心脏作功效率和改善肺功能。     

西地那非对高原移居青年心肺功能的影响

目的探讨西地那非对高原移居青年心肺功能及体力作业效率的影响。方法把进驻海拔3 700 m半年的20名青年随机分为两组,一组为服药组,另一组为对照组,两组在服药前后分别用EGM-Ⅱ型踏车功量计做坐位踏车运动,初始负荷功率为50 W,每3 min递增50 W,以60r/mim连续踏车至200 W 3 min后终止。用直线回归法计算每位受试者功率200 W时的心率(HR)及血氧饱和度(SaO2),记录运动终止后5 min时HR。结果与对照组相比,服药组踏车功率达200 W时的SaO2增高;而运动时HR和运动终止后5 min时HR低(P<0.05)。结论在高原服用西地那非能明显提高高原移居青年的心肺功能及体力作业效率。     

吸一氧化氮或氧对高原健康人和高原肺水肿患者血氧饱和度及心率的影响

目的　研究吸一氧化氮(NO)或氧(O2)对高原健康人和高原肺水肿患者血氧饱和度(SaO2)及心率(HR)的影响。方法　高原健康士兵20名及高原肺水肿患者24名,随机各分为两组,每组10人和12人。一组分别吸入0.001％(10PPm)NO,另一组分别吸O2,吸入气O2含量均为80％,结果　高原健康人吸NO或O2后及高原肺水肿患者吸NO后SaO2明显增高(P<0.01);高原健康人吸NO10-30min及吸后3-5min和高原肺水肿患者吸NO20-30min及吸后3-5min HR明显降低(P<0.01),吸氧后改变不明显(P>0.05)。结论　吸入低浓度NO可明显提高高原健康人和高原肺水肿患者的SaO2及降低HR,改善其心肺功能。     

可可西里地区进驻人员的血氧与心率调查与分析

目的:调查与分析可可西里地区(平均海拔4 550m)进驻人员的血氧饱和度(SaO2)、血氧分压(PaO2)及心率(HR)。方法:运用便携式氧饱和度检测仪及海拔表,检测32名分别来自平原(北京)、中度高原(西宁)地区的健康急进人群和当地(可可西里)长期居住人群的血氧饱和度(SaO2)、血氧分压(PaO2)及心率(HR)。结果:可可西里地区进驻人员的血氧饱和度(SaO2)、血氧分压(PaO2)及心率(HR)分别为:(83±4)%、(48.69±4.46)mmHg、(105±11)次/分。三组间平均血氧饱和度(SaO2)、平均血氧分压(PaO2)及平均心率(HR)均有显著性差别。结论:可可西里地区(平均海拔4 550m)人体的血氧饱和度(SaO2)、血氧分压(PaO2)及心率(HR)明显不同于平原及中度高原地区。平原地区人员尤其应该遵循缓慢进驻高海拔地区的原则。     

高压氧对高原移居青年体力作业效率的影响

目的探讨高压氧对高原移居青年体力作业效率的影响。方法将进驻海拔3 700 m半年的20名健康青年随机分为两组,每组10人。分别采用高压氧前(对照组)和高压氧2次(A组)及5次(B组)后第2天和第8天进行自身对比运动负荷实验。受试者用EGM型踏车功量计做坐位踏车运动。初始负荷功率50W,每3 min递增50W,以60 r/min连续踏车至200 W3 min后终止。用直线回归法计算每位受试者运动心率达170次/min时机体所做的功(PWC170)和运动功率90 W时的心率(HR90W),记录功率200W时的肺通气量及血氧饱和度(SaO2),计算心功能指数。结果两组高压氧组较对照组PWC170、SaO2及心功能指数均增高(P<0.01);HR90W、肺通气量降低(P<0.01),且其效率能保持1周。结论高压氧能明显提高高原移居青年的体力作业效率。     

吸液态氧对高原移居青年氧耗量的影响

目的 :探讨在高原吸入液态氧对移居青年氧耗量的影响。方法 :将进驻海拔 370 0m半年的 4 0名健康青年随机分为两组 ,每组 2 0人。对照组用EGM型踏车功量计做坐位踏车运动 ,初始负荷功率 2 5W ,每 3min递增 5 0W ,以 6 0r/min连续踏车直至力竭。实验组在运动前 10min开始用面罩吸液态氧 ,每分钟吸入量为 4L ,在踏车运动中全程吸氧 ,踏车方式同对照组。结果 :心率在 10 0～ 170 /min时 ,两组氧耗量随心率增加而呈线性增加 (P <0 .0 1)。结论 :在高原运动时吸液态氧能提高移居青年心脏作功效率和改善肺功能。     

氧烛对缺氧性肺动脉高压青年血氧饱和度与心率的影响

目的在高海拔地区(5 200 m)利用氧烛建立富氧室观察对缺氧性肺动脉高压移居青年血氧饱和度(SaO2)及心率(HR)的影响。为防治高原缺氧性肺动脉高压,减少高原移居者急慢性高原病的发生,寻觅新的方法和途径。方法选择驻守在海拔5 200 m以上地区1年、经超声心动图和心电图检测拟诊为肺动脉高压的8名受试者在该海拔夜间睡眠时,分别监测常氧和富氧(氧浓度为24%～25%)条件下的SaO2和HR。结果富氧较常氧条件下SaO2增高,有统计学差异(P<0.01);富氧较常氧下HR降低,有统计学差异(P<0.01)。结论用氧烛制作富氧室可显著改善低氧环境条件下肺的氧合效率、提高动脉血氧饱和度,降低心率,从而使人体缺氧状态得以充分改善。     

富氧室对海拔5380m高原人体运动血气及心率的影响

目的　探讨富氧室对高原人体运动血气及心率的影响。方法　在海拔 5 380m高原建立富氧室 ,对 10名健康青年在进入富氧室前后分别进行踏阶运动 ,检测血气指标、运动后即刻心率和 5min恢复心率。结果　富氧运动后较未富氧运动后PCO2 ,PO2 和SaO2 均增高 ,AaDO2 、5min恢复心率降低 ,有非常显著差异 (P <0 .0 1) ,pH、运动后即刻心率无统计学意义 (P >0 .0 5 )。结论　富氧室能改善高原缺氧人体气体交换和心肌功能效应 ,增强氧合功能。     

β-胡萝卜素大豆肽和蚕蛹蛋白提升高海拔人群作业能力的研究

目的探讨β-胡萝卜素、大豆肽和蚕蛹蛋白对提升高海拔地区移居人群体力作业能力的影响。方法在海拔5100 m将40名青年随机分为4组,分别为β-胡萝卜素组、大豆肽组、蚕蛹蛋白组、对照组（口服安慰剂）。于服用前运动前、服用前运动后、服用后运动后分别检测血液生化指标。结果⑴服用后与服用前比较,β-胡萝卜素组VO2max、静息SaO2增高,蚕蛹蛋白组和大豆肽组VO2max、PWC170、台阶指数、静息和运动后SaO2均增高,有显著性差异（P〈0.05或0.01）。与对照组比较,服用后运动后3组SaO2均增高,蚕蛹蛋白组和大豆肽组台阶指数增高,大豆肽组VO2max增高,有显著性差异（P〈0.05,P〈0.01）。⑵服用后运动后与服用前运动后比较、与对照组服用后运动后比较,ALT、AST、TB、DB均降低,有显著性差异（P〈0.05,P〈0.01）;NOS、NO、SOD均增高,MDA降低,有显著性差异（P〈0.05,P〈0.01）;Glu均增高,BUN、BLA降低,有显著性差异（P〈0.05,P〈0.01）。结论β-胡萝卜素、大豆肽和蚕蛹蛋白均可提高高原机体作业能力,增强机体抗氧化作用,延缓运动性疲劳发生。     

Cardiovascular drift is related to reduced maximal oxygen uptake during heat stress

INTRODUCTION/PURPOSE: This study investigated whether the progressive rise in heart rate (HR) and fall in stroke volume (SV) during prolonged, constant-rate, moderate-intensity exercise (cardiovascular drift, CVdrift) in a hot environment is associated with a reduction in VO(2max). METHODS: CVdrift was measured in nine male cyclists between 15 and 45 min of cycling at 60% VO(2max) in 35 degrees C that was immediately followed by measurement of VO(2max). VO(2max) also was measured after 15 min of cycling on a separate day, so that any change in VO(2max) between 15 and 45 min could be associated with the CVdrift that occurred during that time interval. This protocol was performed under one condition in which fluid was ingested and there was no significant body weight change (0.3 +/- 0.4%), and under another in which no fluid was ingested and dehydration occurred (2.5 +/- 1%, P < 0.05). RESULTS: Fluid ingestion did not affect CVdrift or change in VO(2max). A 12% increase in HR (151 +/- 9 vs 169 +/- 10 bpm, P < 0.05) and 16% decrease in SV (120 +/- 12 vs 101 +/- 10 mL.beat(-1), P < 0.05) between 15 and 45 min was accompanied by a 19% decrease in VO(2max) (4.4 +/- 0.6 vs 3.6 +/- 0.4 L.min(-1), P < 0.05) despite attainment of a higher maximal HR (P < 0.05) at 45 min (194 +/- 5 bpm) vs 15 min (191 +/- 5 bpm). Submaximal VO(2) increased only slightly over time, but VO(2max) increased from 63 +/- 5% at 15 min to 78 +/- 8% at 45 min (P < 0.05). CONCLUSION: We conclude CVdrift during 45 min of exercise in the heat is associated with decreased VO(2max) and increased relative metabolic intensity. The results support the validity of using changes in HR to reflect changes in relative metabolic intensity during prolonged exercise in a hot environment in which CVdrift occurs.     

Effect of blood donation on maximal oxygen consumption

AIM: This study determined the effect of donating one unit of blood on various physiological parameters associated with a VO2(max) test. METHODS: Ten healthy, male subjects (23+/-4 years, 178+/-7.6 cm, 74.4+/-12.3 kg) completed a VO2(max) test 24 h before donating one unit of blood (~500 mL) and 24 h after donating blood. The Bruce protocol was used to determine the subjects' VO2(max). Physiological responses were measured at the end of the VO2(max) test. A repeated measures ANOVA was used to determine if there were significant (P<0.05) differences in the subjects' physiological responses between the VO2(max) before and after blood donation. RESULTS: Significant differences were found in VO2(max) (mean+/-SD, 3.18+/-0.74 vs 2.87+/-0.53 L.min(-1)), cardiac output (Q, 25+/-5 vs 22.5+/-3.3 L.min(-1)), stroke volume (SV, 134+/-37 vs 121+/-22 mL.beat(-1)), delivery of oxygen (DO(2), 5+/-.87 vs 3.97+/-.68 L.min(-1)), and hemoglobin concentration (Hb, 153+/-12 vs 135+/-16 gm.L(-1)). No significant changes were observed for heart rate (HR); arteriovenous oxygen difference (a-vO(2) diff), systolic blood pressure (SBP), and diastolic blood pressure (DBP). CONCLUSIONS: These findings indicate that donating one unit of blood decreased VO2(max) due to the decrease in Q, which resulted from the decrease in SV since HR was unchanged. The lower VO2(max) along with the decrease in DO(2) would be expected to have a negative effect on athletic performance.     

Maximal oxygen uptake after attenuation of cardiovascular drift during heat stress

INTRODUCTION: Exercise intensity is often regulated in hot conditions by maintaining a constant target heart rate (HR) to counteract increased physiological strain and thereby avoid premature fatigue. It is unknown, however, whether the HR-percent maximal oxygen uptake (%VO2max) relationship is maintained during prolonged exercise in the heat when the rise in HR concomitant with cardiovascular drift (CV drift) is eliminated by lowering exercise intensity. The purpose of this study was to determine if VO2max is reduced when exercise intensity and absolute VO2 are lowered by a magnitude sufficient to reduce CV drift and maintain constant HR during prolonged exercise in the heat, and thereby examine if the HR-%VO2max relationship is preserved. METHODS: Seven men cycled at 60% VO2max in 35 degrees C for 15 min (one trial) and 45 min (two trials) while HR rose over time (HRvar) or remained constant (HRcon). VO2max was measured immediately after the 15 and 45 min trials to correspond with the same time interval in which CV drift occurred. RESULTS: Power output decreased 37%, VO2 decreased 24%, and VO2max decreased 7.5% from 15 to 45 min in HRcon, while HR remained the same. In HRvar, HR increased 13%, SV decreased 10%, and VO2max decreased 15%. DISCUSSION: %VO2max was decreased from approximately 60% to 50% to hold HR constant in these conditions, so the HR-%VO2max relationship was not preserved in the absence of CV drift. Attenuating CV drift by lowering exercise intensity only partially eliminated the reduction in VO2max after prolonged exercise in the heat.     

飞行员低高度迅速减压训练方法的效果和安全性研究

目的 研究低高度迅速减压训练方法 的训练效果和安全性. 方法 以187名男性高性能战斗机飞行员为对象,采用序贯试验设计,随机分为减压供氧组(A组,93人)和减压不供氧组(B组,94人).每批次试验A组和B组各1人参加,首先低压舱以30～40 m/s速度上升至起爆高度2500 m,并停留1～3 min,待心率稳定后,进行减压准备.各项准备就绪后,开始减压,低压舱在0.48 s内迅速减压至5500 m高度.在此高度停留1～2 min后,低压舱以10～20 m/s速度下降至地面.下降过程中高度低于4000 m后停止供氧.试验过程中记录飞行员不同时期的血氧饱和度、ECG(标准肢体Ⅱ导联)和减压瞬间的肺内减压峰值.低压舱试验完成后进行胸部X线透视检查并填写调查问卷,问卷内容包括试验过程中的主观体验和对迅速减压训练效果的评价. 结果 A组血氧饱和度在供氧期间始终维持在99%左右,停止供氧后出现明显下降,然后,随着高度降低逐渐回升;B组血氧饱和度则与高度呈现明显负相关的变化.ECG分析显示:两组飞行员心率在减压前均持续上升,在减压即刻达到最大值,A组(87.87士15.97)次/min,B组(91.29±2.78)次/min,减压后则明显降低;肢体Ⅱ导联T波振幅在减压即刻,即心率最大时显著降低,A组(0.19±0.11)mV,B组(0.20士0.12)mV.肺内减压峰值为(139士11)mm H2O(1 mm H2O=9.8 Pa).全部飞行员减压试验后胸部X线透视检查未见异常.调查问卷结果 显示100%被调查人员认为该方法 能较真实模拟飞机增压座舱发生迅速减压的情景,并有效提高飞行员迅速判断是否发生迅速减压的能力. 结论 飞行员低高度迅速减压训练方法 具有明确的训练效果和肯定的安全性. Abstract： Objective To study the effectiveness and safety of pilot's rapid decompression (RD)training at low altitude. Methods According to sequential design methods, 187 male high performance fighter pilots were selected for RD and divided as Group A (93 pilots) and B (94 pilots),that with and without oxygen supply respectively. Each traning was for 2 pilots who were respectively from Group A and B. Training started from the climb to 2500 m with the rate of 30-40 m/s and stayed there 1-3 minutes for stabilizing heart rate (HR). RD was executed to 5500 m within 0. 48 s and returned to ground level by the rate of 10-20 m/s after plateau maintained for 1-2 min. Oxygen had no longer supplied while the altitude was lower than 4000 m in descend. The saturation of blood oxygen (SaO2), electrocardiogram (ECG) and peak value of pressure in lung were recorded during training.Pilots were examined by thoracic roentgenoscopy when training finished and completed a questionnaire that concerned about subjective experience and the evaluation of the effect of rapid decompression training. Results Observed SaO2 in Group A was about 99% when oxygen applied but significantly dropped as the supply stopped and finally gradually recovered. In Group B, SaO2 was decreased with the altitude. ECG analysis showed that pilots in both groups appeared growing HR before RD applied and respectively reached peak value at RD started (87. 87 ±15. 97) beats/min in Group A and (91. 29±2.78) beats/min in Group B. Then HR was significantly dropped in descend. The amplitude of lead Ⅱ T wave was significantly reduced as maximum HR appeared (0.19±0.11) mV in Group A and (0. 20±0.12) mV in Group B. During decompression the peak value of the pressure in lung was (139±11) mm H2O (1 mm H2O=9.8 Pa). No abnormity was observed by thoracic roentgenoscopy for both groups. Questionnaire analysis showed that all pilots admitted the reality of simulated RD and the effectiveness of judging the happening of RD in time. Conclusions The RD training program for pilots at low altitude is categorically safe and effective.